Cittadella Universitaria

Monserrato, Italy

Cittadella Universitaria

Monserrato, Italy
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Varrica D.,Dip. Science della Terra e del Mare DiSTeM | Tamburo E.,Dip. Science della Terra e del Mare DiSTeM | Milia N.,Cittadella Universitaria | Vallascas E.,Cittadella Universitaria | And 5 more authors.
Environmental Research | Year: 2014

The Sulcis-Iglesiente district (SW Sardinia, Italy) is one of the oldest and most important polymetallic mining areas in Italy. Large outcrops of sulfide and oxide ores, as well as the products of the long-lasting mining activity, are present throughout the district releasing significant quantities of metals and metalloids into the surrounding environment. Here are reported concentrations of 21 elements determined in scalp hair samples from children (aged 11-13 years) living in different geochemical environments of southwestern Sardinia: Iglesias, hosting several abandoned mines, and the island of Sant'Antioco, not affected by significant base metal mineralization events. Trace element determinations were performed by ICP-MS. Statistically significant differences (p<0.01) in elemental concentration levels between the two study sites were found. Hair of children from Iglesias exhibited higher concentration values for Ag, Ba, Cd, Cr, Ni, Pb, Rb, Sb, U, V, and Zn. Rubidium, V and U resulted more abundant at Sant'Antioco. Hair samples from Iglesias showed gender-related differences for a larger number of elements (Ag, Ba, Cd, Co, Cu, Ni, Sr, U and Zn) than at Sant'Antioco, where only U was significantly different. The above elemental concentrations in females were always higher than in male donors. Robust Principal Component Analysis operated on log-transformed elemental concentrations showed components indicative of a) sulfides ore minerals (PC1) reflecting the influence of the diffuse mineralization covering the entire study area, b) the presence of some bioavailable As sources (PC2) as As-rich pyrite and Fe-containing sphalerite and c) other sources of metals overlapping the diffuse mineralizations, as carbonate rocks and coal deposits (PC3). The results provided evidence of a potential risk of adverse effects on the health of the exposed population, with children living at Iglesias being greatly exposed to several metals and metalloids originated in mining tailings, enriched soils, waters and food. © 2014 Elsevier Inc.

Devoto P.,Cittadella Universitaria | Devoto P.,University of Cagliari | Flore G.,University of Cagliari | Saba P.,Cittadella Universitaria | And 3 more authors.
Addiction Biology | Year: 2014

The dopamine-beta-hydroxylase inhibitor nepicastat has been shown to reproduce disulfiram ability to suppress the reinstatement of cocaine seeking after extinction in rats. To clarify its mechanism of action, we examined the effect of nepicastat, given alone or in association with cocaine or amphetamine, on catecholamine release in the medial prefrontal cortex and the nucleus accumbens, two key regions involved in the reinforcing and motivational effects of cocaine and in the reinstatement of cocaine seeking. Nepicastat effect on catecholamines was evaluated by microdialysis in freely moving rats. Nepicastat reduced noradrenaline release both in the medial prefrontal cortex and in the nucleus accumbens, and increased dopamine release in the medial prefrontal cortex but not in the nucleus accumbens. Moreover, nepicastat markedly potentiated cocaine- and amphetamine-induced extracellular dopamine accumulation in the medial prefrontal cortex but not in the nucleus accumbens. Extracellular dopamine accumulation produced by nepicastat alone or by its combination with cocaine or amphetamine was suppressed by the α2-adrenoceptor agonist clonidine. It is suggested that nepicastat, by suppressing noradrenaline synthesis and release, eliminated the α2-adrenoceptor mediated inhibitory mechanism that constrains dopamine release and cocaine- and amphetamine-induced dopamine release from noradrenaline or dopamine terminals in the medial prefrontal cortex. © 2012 Society for the Study of Addiction.

Alaimo A.,Cittadella Universitaria | Artale V.,Cittadella Universitaria | Milazzo C.L.R.,Cittadella Universitaria | Ricciardello A.,Cittadella Universitaria
Journal of Intelligent and Robotic Systems: Theory and Applications | Year: 2014

In the last decades, the increasing interest in unmanned aerial vehicles for both military and civil applications made necessary the development of flight control theory and algorithms more and more efficient and fast. In this paper, an original trajectory controller, like a Proportional Integrative Derivative one, is taken into account and the drone structure assumes a hexacopter configuration, i.e. it consists of six rotors, located on the vertices of a regular hexagon with three pairs of counter-rotating fixed pitch blades. The motion of unmanned aerial vehicle is described by means of the Newton-Euler equations in terms of quaternions, in order to improve the numerical efficiency and stability of the controller algorithm, whose novelty lies in the quaternion error definition. Both model and algorithm have been tested and then validated through a wide experimentation, where the drone keeps going to not elementary trajectories. © Springer Science+Business Media Dordrecht 2013.

Artale V.,Cittadella Universitaria | Barbaraci G.,Cittadella Universitaria | Milazzo C.,Cittadella Universitaria | Orlando C.,Cittadella Universitaria | Ricciardello A.,Cittadella Universitaria
AIP Conference Proceedings | Year: 2013

In this paper the dynamic behaviour of a hexacopter has been studied in order to analyse the controlled dynamic via LQR with PI controller. Then, based on mathematical model a set simulation has been performed in order to carry out the results for linear and non linear model. The simulations have been performed to show how LQR and PI controller lead to zero error the position along Z earth direction and to stop the rotation of Unmanned Aerial Vehicle (UAV) around body axes. The LQR has been introduced in order to move the plant's poles of UAV in the left half plane since with out controller the systems is unstable. The reference set-point is reached by the introduction of PI controller that regulates the position when gravity force is acting on it together exogenous excitation such as applied moment leading the system to rotate around body axes. The PI controller action does not involve all 6 d.o.f. hexarotor but only the variables ze, p, q and r. Simulations, LQR and PI controllers have been designed by using Matlab/Simulink. The results show the LQR with PI controllers robustly stabilize the hexarotor. © 2013 AIP Publishing LLC.

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