A new simulation environment to model spontaneous and evoked activity of large-scale neuronal networks coupled to micro-electrode arrays

Introduction The use of neuronal cultures coupled to Micro-Electrode Array (MEA) is becoming a widely used and recognized experimental model for studying basic properties of information processing in neuronal systems [1]. However, the electrophysiological activity of such large-scale neuronal networks is recorded only by tens/hundreds microelectrodes. This undersampling results in a lack of information. Thus the development of a new simulation environment able to reproduce the electrophysiological behavior typically found in these preparations offers a valid help to better understand the actual dynamics. In this work, we present the main features of our software showing the simulation results of the spontaneous and evoked activity of a high-connected network

Spatio-temporal analysis of SAR based time series for slope instability characterization : the Corvara in Badia landslide ( Dolomites , Italy )

The aim of this study is to estimate the influence of different forcing factors acting on instability phases of a slow alpine earthslide-earthflow, by means of the characteristics of decomposed deformations signals derived by displacement rates measured in its different sectors. In this work we analyze a slow landslide located ESE from Corvara in Badia, a famous tourist area in the Dolomites (NE Italy). Road, infrastructure, ski and other recreational facilities, isolated buildings close to the town of Corvara and finally an artificial reservoir for snow production are threatened and occasionally damaged by this mass movement. It flows from 2000m s.l. to 1500m s.l. where a paleo-landslide deposit is partially covered and re-activated. In the last 10 years the Province of Bolzano carried out discontinuous GPS surveys between 5 and 1 times per year to define the landslide’s level of hazard. The landslide volume is resulted to be 30Mm3, xtending downslope for approx. 3km, with displacement rates between few centimeters and slightly less than 10m per year. To analyze this area we used data from active radar sensors (SAR – Synthetic perture Radar). The SAR-based dataset consists in high resolution X-band SAR data from the Cosmo SkyMed (CSK) mission acquired every 8 days from August 2010 to September 2011. Part of the 38 CSK scenes contain the back-scattering signal from 17 artificial reflectors (AR) installed along the AOI and partially on existing GPS benchmarks for data validation and integration. The ARs back scattering signal has been elaborated in order to track their displacement from August 2010 to September 2011, in the lower zone of the landslide, as well as from March 2011 to September 2011 in the higher part, excluding the period when the snow was covering the surface. The signals have been analyzed with Fourier and wavelet methods to identify the different frequencies and nature of the components. T and Mann-Kendall tests have been used to assess the presence of trends. Fits with exponential functions of the de-trended and de-seasonalized signal have been performed to identify the presence of dissipating deformations. We observed that the signal of velocity and acceleration is characterized by the coexistence of different factors: first, periodic signals associated to seasonal and gravitational kinematic behavior; second, decay effects due to instability events. Moreover, using different points is possible to observe the signal propagation both in time and space. This analysis allow us to determine the spatio-temporal scale of different forcing events and their effect on the total landslide area. Finally, this study represent a new approach for identify the spatio-temporal nature of different factors in the evolution of the landslide for setting-up a system of conscious prediction of aintenance tasks of he exposed structures. The use of the SAR data demonstrated to be an innovative tool for high temporal resolution surveys with a big amount of points that in comparison with GPS surveys results to be conomically convenient in wide AOI

a simulated neuro robotic environment for bi directional closed loop experiments

AbstractWe have developed a new simulation environment, called

Approccio partecipativo per lo sviluppo integrato e la gestione delle zone marginali in Nord Africa: progetto dimostrativo di lotta alla desertificazione in Marocco e Tunisia

Nelle zone aride e semiaride, l’agricoltura e la pastorizia rappresentano fondamentali risorse per la sussistenza delle popolazioni locali. Nonostante la loro importanza strategica, in queste aree, le produzioni risultano sovente limitate e irregolari, manifestando un grosso limite allo sviluppo delle attività agropastorali. Gli ecosistemi dei territori interessati si presentano spesso fragili, a causa dell’azione combinata di fattori climatici e delle attività umane. L'aratura e la rimozione indiscriminata della vegetazione, insieme all’irregolarità e all’insufficienza delle piogge sono spesso responsabili di fenomeni di degrado dei suoli, distruzione su grande scala della copertura vegetale e desertificazione. La crescente domanda di foraggio per gli allevamenti, di gran lunga superiore alla produttività dei pascoli (Le Houerou, 1990; 2000), ha provocato un aumento della pressione sul pascolo e la messa in coltura ad orzo di terre tradizionalmente adibite esclusivamente a pascolo, causando una accelerazione dei fenomeni di degrado del suolo (Abu Zenat et al. 2004). Inoltre, si è evidenziato un impoverimento qualitativo dei pascoli, dove le specie di alto valore foraggero sono spesso sostituite da piante meno produttive, meno appetibili e meno nutrienti di quelle originali (Juneidi and Abu-Zanat, 1993). In questo contesto, l’impianto di arbusti foraggeri garantisce la copertura vegetale del suolo, offrendo protezione contro l’erosione e rappresenta una potenziale risorsa di foraggio e legna da ardere (Mulas e Mulas, 2004). Le specie Opuntia ficus indica, particolarmente tollerante all’erosione idrica ed eolica (Nefzaoui et al. 2000), e Atriplex nummularia, perfettamente adatta ai climi mediterranei aridi o semiaridi (Hyder ed Akil, 1987), sono le più impiegate nelle regioni del Nord Africa e Medio Oriente. In questo lavoro si riportano i risultati di un intervento di sviluppo integrato, basato sull’impianto di Opuntia ficus indica e Atriplex sp.pl., nell’ambito del progetto europeo SMAP II “Demonstration Project on Strategies to Combat Desertification in Arid Lands with Direct Involvement of Local Agropastoral Communities in North Africa ” coordinato da NRD-UNISS e realizzato in aree aride e semiaride degradate di Marocco e Tunisia

Genetic association study of QT interval highlights role for calcium signaling pathways in myocardial repolarization.

The QT interval, an electrocardiographic measure reflecting myocardial repolarization, is a heritable trait. QT prolongation is a risk factor for ventricular arrhythmias and sudden cardiac death (SCD) and could indicate the presence of the potentially lethal mendelian long-QT syndrome (LQTS). Using a genome-wide association and replication study in up to 100,000 individuals, we identified 35 common variant loci associated with QT interval that collectively explain ∼8-10% of QT-interval variation and highlight the importance of calcium regulation in myocardial repolarization. Rare variant analysis of 6 new QT interval-associated loci in 298 unrelated probands with LQTS identified coding variants not found in controls but of uncertain causality and therefore requiring validation. Several newly identified loci encode proteins that physically interact with other recognized repolarization proteins. Our integration of common variant association, expression and orthogonal protein-protein interaction screens provides new insights into cardiac electrophysiology and identifies new candidate genes for ventricular arrhythmias, LQTS and SCD

Vortex shedding behind a blunt trailing edge turbine blade

By computational and experimental means, this-work investigates unsteady mixing processes of the wake behind a blunt trailing edge turbine blade. Numerical solutions of the Reynolds averaged Navier Stokes equations have been carried out employing state-of-the-art algorithms in a fully conservative structured multi-block approach. Predicted aerodynamic performance profile and unsteady now field features compare favorably with a set of measurements carried out on a large scale nozzle guide vane

Bursting Dynamics in Molecular Hydrogen Generation via Sodium Borohydride Hydrolysis

The hydrolysis of borohydride salts is a promising process for the generation in situ of pure molecular hydrogen that can be used as an alternative fuel. One of the obstacles toward its concrete application in the realm of green energy resides in nonlinear behaviors of H2 delivery during the reaction development. In particular, we have recently shown that this system behaves like a chemical oscillator in a wide range of experimental conditions, exhibiting nondesirable fluctuations in the production of molecular hydrogen. Despite the potential of NaBH4 hydrolysis in applicative terms, a deep understanding of the reaction mechanisms leading to these nonlinear dynamics is still left to a primary stage. Here we show how to control a typical bursting-like oscillatory scenario occurring in the gas development from NaBH4 hydrolysis. Bursting transients are isolated and stabilized by using highly concentrated solutions of dihydrogen-phosphate/hydrogen-phosphate buffers with an initial pH value around 7. The length of the bursting transients critically depends upon the initial pH, the buffering strength, and the working temperature. The stirring rate also influences this oscillatory dynamics. On the basis of the experimental evidence and NMR analysis of the reactive mixture, we hypothesize a possible kinetic scheme able to explain the onset of oscillatory instabilities. (Graph Presented).SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Prediction of landslide velocity at given cumulated rainfall values based on analysis of continuous monitoring data using ROC curves : application to the Piagneto landslide ( Northern Apennine , Italy )

A novel approach to predict landslide velocity at given cumulated rainfall values based on the analysis of continuous displacement and rainfall monitoring data by using ROC curves has been developed and tested in the Piagneto landslide (northern Apennines, Italy). It is an active rock slide for which a velocity dataset covering the period October 2009 to December 2014 is available thanks to a total station that has been monitoring tens of prisms at duty cycles of 2 hours. Over the same time frame, an hourly rainfall dataset is available from rain gauges located just a few km away from the landslide. The ROC curve (Receiver Operating Characteristic) is a well-known and widely used method to assess the efficiency of a binary classifier. In this case, it is used to assess the efficiency of different values of cumulated rainfall to determine a given value of velocity in the landslide. Operatively, the daily velocity distributions of selected monitoring prisms is plotted in order to assess upper values at given levels of occurrence probability, i.e. velocity values at the upper 1st,2nd, 3rd quartile and 2 sigma. These velocity values are then classified with respect to daily rainfall cumulated over different time windows (from 1 to 120 days), that are considered singularly or in combination one another. The area under the ROC curves, as well as the max distance from the random line, is used as indicator of performance in order to assess the cumulated rainfall (in terms of amount and duration) showing the higher performance in predicting a defined landslide velocity level. The values obtained with the retrospective analysis of monitoring data, can then be used for prediction of expected velocity levels. This has been verified by using the conventional approach of dividing the dataset in a training and a validation subsets. Results underline the added value of the analysis of long time-series of continuous landslide monitoring data by mean of operational research tools, such as in this case the ROC curves, for extracting information useful for improving the comprehension and the prediction of slope dynamics that, in specific cases, can be of great support to risk management