293 research outputs found
Il silenzio e le forme. Modelli e rappresentazione nelle letterature europee moderne
No full textIl silenzio è una forma di rappresentazione e un’idea che attraversa, polisemicamente, nel corso della sua lunga storia, l’intera cultura dell’Occidente; deriva da un concetto indefinibile e pluridimensionale, che racchiude e esplicita misteriosamente la domanda sul valore del non detto, dell’inudibile, dell’ineffabile, sul silenzio della natura, su quello della scrittura e sulle sue strategie e rappresentazioni. E nell’epoca della contemporaneità, in cui ogni cosa è e può divenire rumore o frastuono, è forse utile interrogarsi sulle diverse accezioni e sulle diverse forme che esso ha acquisito nel tempo e nello spazio, le sue versioni e le sue declinazioni, in particolare nello “spazio letterario”.
L’idea del silenzio incarna, così, nella sua inafferrabilità, il senso stesso del limite dell’esprimibile e dell’inesprimibile, la tensione segreta e umanissima che unisce idea e rappresentazione. Questo libro, allora, desidera essere un’occasione per riflettere, attraverso un approccio, sia pluridisciplinare che transdisciplinare e diacronico, sulle forme e modalità in cui il silenzio è stato rappresentato nelle letterature europee moderne, su alcune loro ricorrenze e altre unicità assolute
Differential subcellular expression of P525LFUS as a putative biomarker for ALS phenoconversion
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On the determination of Jupiter's satellite-dependent Love numbers from Juno gravity data
No full textThe Juno gravity experiment, among the nine instruments onboard the spacecraft, is aimed at studying the interior structure of Jupiter to gain insight into its formation. Doppler data collected during the first two gravity-dedicated orbits completed by Juno around the gas giant have already provided a measurement of Jupiter's gravity field with outstanding accuracy, answering crucial questions about its interior composition. The large dataset that will be collected throughout the remaining phases of the mission until the end in July 2021 might allow to determine Jupiter's response to the satellite-dependent tidal perturbation raised by its moons, and even to separate the static and dynamic effects. We report on numerical simulations performed over the full science mission to assess the sensitivity of Juno gravity measurements to satellite-dependent tides on Jupiter. We assumed a realistic simulation scenario that is coherent with the result of data analysis from the first gravity passes. Furthermore, we implemented a satellite-dependent tidal model within the dynamical model used to fit the simulated Doppler data. The formal uncertainties resulting from the covariance analysis show that Juno is indeed sensitive to satellite-dependent tides on Jupiter raised by the inner Galilean satellites (the static Love numbers of degree and order 2 of Io, Europa and Ganymede can be determined respectively to 0.28%, 4.6% and 5.3% at 1 sigma). This unprecedented determination, that will be carried out towards the end of the mission, could further constrain the interior structure of the planet, allowing to discern among interior models and improving existing theories of planetary tidal response
3β,5α,6β-Trihydroxylated sterols with a saturated nucleus from two populations of the marine sponge Cliona copiosa
No full textA Deletion of the Nuclear Localization Signal Domain in the Fus Protein Induces Stable Post-stress Cytoplasmic Inclusions in SH-SY5Y Cells
No full textMutations in Fused-in-Sarcoma (FUS) gene involving the nuclear localization signal (NLS) domain lead to juvenile-onset Amyotrophic Lateral Sclerosis (ALS). The mutant protein mislocalizes to the cytoplasm, incorporating it into Stress Granules (SG). Whether SGs are the first step to the formation of stable FUS-containing aggregates is still unclear. In this work, we used acute and chronic stress paradigms to study the SG dynamics in a human SH-SY5Y neuroblastoma cell line carrying a deletion of the NLS domain of the FUS protein (homozygous: ΔNLS–/–; heterozygous: ΔNLS+/–). Wild-type (WT) cells served as controls. We evaluated the subcellular localization of the mutant protein through immunoblot and immunofluorescence, in basal conditions and after acute stress and chronic stress with sodium arsenite (NaAsO2). Cells were monitored for up to 24 h after rescue. FUS was expressed in both nucleus and cytoplasm in the ΔNLS+/– cells, whereas it was primarily cytoplasmic in the ΔNLS–/–. Acute NaAsO2 exposure induced SGs: at rescue,>90% of ΔNLS cells showed abundant FUS-containing if compared to less than 5% of the WT cells. The proportion of FUS-positive SGs remained 15–20% at 24 h in mutant cells. Cycloheximide did not abolish the long-lasting SGs in mutant cells. Chronic exposure to NaAsO2 did not induce significant SGs formation. A wealth of research has demonstrated that ALS-associated FUS mutations at the C-terminus facilitate the incorporation of the mutant protein into SGs. We have shown here that mutant FUS-containing SGs tend to fail to dissolve after stress, facilitating a liquid-to-solid phase transition. The FUS-containing inclusions seen in the dying motor neurons might therefore directly derive from SGs. This might represent an attractive target for future innovative therapies
A Visibility Graph approach for path planning and real-time collision avoidance on maritime unmanned systems
No full textIn high navigation traffic areas, path planning and collision avoidance is a crucial element of safe navigation, mostly in view of possible future applications in hybrid scenarios where both manned and Autonomous Surface Vehicles (ASV) share the environment.This paper deals with a novel procedure to generate optimal paths in presence of static and moving obstacles. The proposed path planning approach deals with an optimization problem based on the so-called Essential Visibility Graph (EVG) [1], an extension of the standard Visibility Graph (VG) [2], in order to find the minimum cost piecewise linear path between two points in a scenario with several obstacles. Such approach can be used also in presence of multiple ASV or movable obstacles, by using a re-planning procedure to update the EVG over a selected prediction time interval. To make the solution compliant with the current regulation and make ASV behaviour predictable by human pilots on manned vehicles, EVG was extended by implementing a cut procedure based on Collision Regulations (COLREGS) [3]. Finally, the use of Dubins curves provides smooth paths, compliant with physics constraints such as the minimum turn radius.A campaign of numerical simulations was carried out to test the effectiveness of the proposed technique in different operational scenarios. Results show that the algorithm is always able to identify COLREGS-compliant trajectories, in order to avoid collisions and assure minimum safety distance as well. Furthermore, the low computational burden suggests that the proposed procedure can be considered a promising approach for real-time applications
Uncertainty in urban flood damage assessment due to urban drainage modeling and depth – damage curve estimation
No full textDue to the increased occurrence of flooding events in urban areas, many procedures for flood damage quantification have been defined in recent decades. The lack of large databases in most cases is overcome by combining the output of urban drainage models and damage curves linking flooding to expected damage. The application of advanced hydraulic models as diagnostic, design and decision-making support tools has become a standard practice in hydraulic research and application. Flooding damage functions are usually evaluated by a priori estimation of potential damage (based on the value of exposed goods) or by interpolating real damage data (recorded during historical flooding events). Hydraulic models have undergone continuous advancements, pushed forward by increasing computer capacity. The details of the flooding propagation process on the surface and the details of the interconnections between underground and surface drainage systems have been studied extensively in recent years, resulting in progressively more reliable models. The same level of was advancement has not been reached with regard to damage curves, for which improvements are highly connected to data availability; this remains the main bottleneck in the expected flooding damage estimation. Such functions are usually affected by significant uncertainty intrinsically related to the collected data and to the simplified structure of the adopted functional relationships. The present paper aimed to evaluate this uncertainty by comparing the intrinsic uncertainty connected to the construction of the damage-depth function to the hydraulic model uncertainty. In this way, the paper sought to evaluate the role of hydraulic model detail level in the wider context of flood damage estimation. This paper demonstrated that the use of detailed hydraulic models might not be justified because of the higher computational cost and the significant uncertainty in damage estimation curves. This uncertainty occurs mainly because a large part of the total uncertainty is dependent on depth-damage curves. Improving the estimation of these curves may provide better results in term of uncertainty reduction than the adoption of detailed hydraulic models
A particle filtering approach for fault detection and isolation of uav imu sensors: Design, implementation and sensitivity analysis
No full textSensor fault detection and isolation (SFDI) is a fundamental topic in unmanned aerial vehicle (UAV) development, where attitude estimation plays a key role in flight control systems and its accuracy is crucial for UAV reliability. In commercial drones with low maximum take-off weights, typical redundant architectures, based on triplex, can represent a strong limitation in UAV payload capabilities. This paper proposes an FDI algorithm for low-cost multi-rotor drones equipped with duplex sensor architecture. Here, attitude estimation involves two 9-DoF inertial measurement units (IMUs) including 3-axis accelerometers, gyroscopes and magnetometers. The SFDI algorithm is based on a particle filter approach to promptly detect and isolate IMU faulted sensors. The algorithm has been implemented on a low-cost embedded platform based on a Raspberry Pi board. Its effectiveness and robustness were proved through experimental tests involving realistic faults on a real tri-rotor aircraft. A sensitivity analysis was carried out on the main algorithm parameters in order to find a trade-off between performance, computational burden and reliability
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