Probability hazard map for future vent opening at Etna volcano (Sicily, Italy).

We evaluate a probability hazard map for future vent opening at Etna volcano using a data set of flank vents spanning last 4.0 ka

Extension of the AMBER force field to cyclic a,a dialkylated peptides

The popular biomolecular AMBER (ff99SB) force field (FF) has been extended with new parameters for the simulations of peptides containing a,a dialkylated residues with cyclic side chains. Together with the recent set of nitroxide parameters [E. Stendardo, A. Pedone, P. Cimino, M. C. Menziani, O. Crescenzi and V. Barone, Phys. Chem. Chem. Phys., 2010, 12, 11697] this extension allows treating the TOAC residue (TOAC, 2,2,6,6-tetramethylpiperidine-1-oxyl-4- amino-4-carboxylic acid) widely used as a spin label in protein studies. All the conformational minima of the Ac–Ac6C–NMe (Ac = acetyl, Ac6C = 1-aminocyclohexaneacetic acid, NMe = methylamino) and Ac–TOAC–NMe dipeptides have been examined in terms of geometry and relative energy stability by Quantum Mechanical (QM) computations employing an hybrid density functional (PBE0) for an extended training set of conformers with various folds. A very good agreement between QM and MM (molecular mechanics) data has been obtained in most of the investigated properties, including solvent effects. Finally, the new set of parameters has been validated by comparing the conformational and dynamical behavior of TOAC-labeled polypeptides investigated by means of classical molecular dynamics (MD) simulations with QM data and experimental evidence. The new FF accurately describes the tuning of conformational and dynamical behavior of the Ac–TOAC–NMe dipeptide and double spin-labeled heptapeptide Fmoc–(Aib–Aib–TOAC)2–Aib–OMe (Fmoc, fluorenyl-9-methoxycarbonyl; Aib, a-aminoisobutyric acid; OMe, methoxy) by solvents with different polarity. In particular, we found that the 310 helical structure of heptapeptide is the most stable one in vacuo, with a geometry very similar to the X-ray crystallographic structure, whereas a conformational equilibrium between the 310- and a-helical structures is established in aqueous solution, in agreement with EPR data

Probability hazard map for future vent opening at Etna volcano (Sicily, Italy).

We evaluate a probability hazard map for future vent opening at Etna volcano using a data set of flank vents spanning last 4.0 ka.PublishedVienna, Austria4V. Vulcani e ambienteope

Extension of the AMBER force field to cyclic alpha,alpha dialkylated peptides

The popular biomolecular AMBER (ff99SB) force field (FF) has been extended with new parameters for the simulations of peptides containing alpha, alpha dialkylated residues with cyclic side chains. Together with the recent set of nitroxide parameters [E. Stendardo, A. Pedone, P. Cimino, M. C. Menziani, O. Crescenzi and V. Barone, Phys. Chem. Chem. Phys., 2010, 12, 11697] this extension allows treating the TOAC residue (TOAC, 2,2,6,6-tetramethylpiperidine-1-oxyl-4-amino-4-carboxylic acid) widely used as a spin label in protein studies. All the conformational minima of the Ac-Ac6C-NMe (Ac = acetyl, Ac6C = 1-aminocyclohexaneacetic acid, NMe = methylamino) and Ac-TOAC-NMe dipeptides have been examined in terms of geometry and relative energy stability by Quantum Mechanical (QM) computations employing an hybrid density functional (PBE0) for an extended training set of conformers with various folds. A very good agreement between QM and MM (molecular mechanics) data has been obtained in most of the investigated properties, including solvent effects. Finally, the new set of parameters has been validated by comparing the conformational and dynamical behavior of TOAC-labeled polypeptides investigated by means of classical molecular dynamics (MD) simulations with QM data and experimental evidence. The new FF accurately describes the tuning of conformational and dynamical behavior of the Ac-TOAC-NMe dipeptide and double spin-labeled heptapeptide Fmoc-(Aib-Aib-TOAC)(2)-Aib-OMe (Fmoc, fluorenyl-9-methoxycarbonyl; Aib, alpha-aminoisobutyric acid; OMe, methoxy) by solvents with different polarity. In particular, we found that the 3(10) helical structure of heptapeptide is the most stable one in vacuo, with a geometry very similar to the X-ray crystallographic structure, whereas a conformational equilibrium between the 3(10)- and alpha-helical structures is established in aqueous solution, in agreement with EPR data

Stakeholders Analysis: a Crucial Step for a Successful Volcanic Hazard Assessment, Disaster Preparedness and Mitigation Management Strategy

WP6 of MED-SUV aims at showing how the improvement of the monitoring system at the Italian Supersite volcanoes may contribute to better volcanic hazard assessment and to bridge the gap between science, mitigation and preparedness of volcanic disasters. For the purposes, throughout the project scientists and decision makers are working together trying to optimise procedures for improvement their mutual information exchange. To do this effectively and efficiently a management strategy needs to be defined and implemented in order to involve the key players and make them aware of the policy, sector and institutional context within which they are undertaking their work. Stakeholders Analysis is a crucial step to achieve specific objectives related to volcanic hazard assessment, evaluation, and preparedness and mitigation. Indeed management and science are interdependent so WP1 and WP6 need to strength their efforts in setting up a proper joint strategy to identify the different stakeholders, understand their needs, and to investigate their respective roles, resources, and capacities. Stakeholders Analysis, in fact, will enable us getting an overall view of what is needed to implement actions devoted to volcanic hazards by allowing us definition of proper guidelines to clearly define the role of scientists and that of decision makers during a volcanic emergency. Guidelines will state also the kinds of information the scientists should provide to decision makers in term of both short- and long-term hazard assessment. In this prospective, we expect that findings of the analysis will ensure that the resources available in the framework of MED-SUV are appropriately targeted to meet the objectives of the project and its stakeholders. We believe that Stakeholders Analysis, in compliance with EPOS implementation plan, could significantly contribute to the “Information for Societal Benefit” part of the GEO 2012-15 work plan at which MED-SUV has subscribed

Vents Pattern Analysis at Etna volcano (Sicily, Italy).

We evaluate clustering features at Etna volcano using a dataset of flank vents spanning last 4.0 ka.PublishedVienna, Austria2V. Dinamiche di unrest e scenari pre-eruttiviope

Fine Tuning the Intermolecular Interactions of Water Clusters Using the Dispersion-Corrected Density Functional Theory

Dispersion-inclusive density functional theory (DFT) methods have unequivocally demonstrated improved performances with respect to standard DFT approximations for modeling large and extended molecular systems at the quantum mechanical level. Yet, in some cases, disagreements with highly accurate reference calculations, such as CCSD(T) and quantum Monte Carlo (MC) calculations, still remain. Furthermore, the application of general-purpose corrections, such as the popular Grimme’s semi-classical models (DFT-D), to different Kohn–Sham exchange–correlation functionals sometimes leads to variable and inconsistent results, which recommend a careful prior evaluation. In a recent study, we proposed a simple optimization protocol for enhancing the accuracy of these DFT-D methods by following an alternative and system-specific approach. Here, adopting the same computational strategy, we show how the accurate MC intermolecular interactions of a large set of water clusters of variable sizes (i.e., 300 (H2O)n structures, n = 9, 15, 27) can be reproduced remarkably well by dispersion-corrected DFT models (i.e., B3LYP-D4, PBE-D4, revPBE(0)-D4) upon re-optimization, reaching a mean absolute error per monomer of ~0.1 kcal/mol. Hence, the obtained results support the use of this procedure for fine-tuning tailored DFT-D models for the accurate description of targeted molecular systems

Probability hazard map for future vent opening at Etna volcano (Sicily, Italy).

Mount Etna is a composite stratovolcano located along the Ionian coast of eastern Sicily. The frequent occurrence of flank eruptions (at an interval of years), mostly concentrated along the NE, S and W rift zones leads to a high volcanic hazard that, linked with intense urbanization, poses a high volcanic risk. In the framework of the project PON SIGMA (Integrated Cloud-Sensor System for Advanced Multirisk Management), we develop a near real-time computer-assisted analysis and probabilistic evaluations that provides the identification of the areas prone to the highest vent opening hazard. A longterm volcanic hazard assessment, mainly based on the past flank activity of the Mt. Etna volcano, is the basic tool for the evaluation of this risk. Then, a reliable forecast of where an impending eruption will occur is needed. The use of a code such BET_EF (Bayesian Event Tree_Eruption Forecasting) delivers a long-term hazard map, that, if additional data are provided, switches into a short-term future vent opening map. The present application is based on incoming seismic and ground deformation data. Analytic inversion of high frequencies deformation data is performed to find the key parameters of a magmatic source in an elastic, isotropic and homogeneous half-space. Seismic data allow us to set the boundary of the investigated area. The inversion is performed by using the genetic algorithms (GAs) approach, a well-known search technique widely used to solve optimization problems and categorized as global search heuristics (Goldberg, 1989). Hence the magmatic source is located, a forward model is computed to evaluate the deformation field over Mt. Etna surface. Therefore, for each cell, the displacement vector modulus is estimated and the density probability function is calculated. A higher probability value matches with the cells with larger modulus, whereas lower estimate is found where the modulus is close to zero, being the sum of the probability values normalized to one over the investigated area. We modelled the final intrusion of the May 2008 – July 2009 flank eruption at Mt. Etna, whose onset was preceded by an intense seismic swarm and marked by ground deformation recorded at GPS stations. The future vent forecast highlights the area with higher probability, increasing the difference in relative values between that zone and the rest of the volcano edifice. It is worthy notice that a good accordance is evident if the highest probability area is compared with the real vent occurrence.PublishedNicolosi (Catania), Italy4V. Vulcani e ambientereserve