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2017 Contributo in Atti di convegno open access

Design, Implementation and Test of a Flexible Tor-oriented Web Mining Toolkit

Searching and retrieving information from the Web is a primary activity needed to monitor the development and usage of Web resources. Possible benefits include improving user experience (e.g. by optimizing query results) and enforcing data/user security (e.g. by identifying harmful websites). Motivated by the lack of ready-to-use solutions, in this paper we present a flexible and accessible toolkit for structure and content mining, able to crawl, download, extract and index resources from the Web. While being easily configurable to work in the "surface" Web, our suite is specifically tailored to explore the Tor dark Web, i.e. the ensemble of Web servers composing the world's most famous darknet. Notably, the toolkit is not just a Web scraper, but it includes two mining modules, respectively able to prepare content to be fed to an (external) semantic engine, and to reconstruct the graph structure of the explored portion of the Web. Other than discussing in detail the design, features and performance of our toolkit, we report the findings of a preliminary run over Tor, that clarify the potential of our solution.

dark web tor web graph
2016 Articolo in rivista metadata only access

Autophagosome-lysosome fusion triggers a lysosomal response mediated by TLR9 and controlled by OCRL

De Leo Maria Giovanna ; Staiano Leopoldo ; Vicinanza Mariella ; Luciani Alessandro ; Carissimo Annamaria ; Mutarelli Margherita ; Di Campli Antonella ; Polishchuk Elena ; Di Tullio Giuseppe ; Morra Valentina ; Levtchenko Elena ; Oltrabella Francesca ; Starborg Tobias ; Santoro Michele ; Di Bernardo Diego ; Devuyst Olivier ; Lowe Martin ; Medina Diego L ; Ballabio Andrea ; De Matteis Maria Antonietta

Phosphoinositides (PtdIns) control fundamental cell processes, and inherited defects of PtdIns kinases or phosphatases cause severe human diseases, including Lowe syndrome due to mutations in OCRL, which encodes a PtdIns(4,5)P2 5-phosphatase. Here we unveil a lysosomal response to the arrival of autophagosomal cargo in which OCRL plays a key part. We identify mitochondrial DNA and TLR9 as the cargo and the receptor that triggers and mediates, respectively, this response. This lysosome-cargo response is required to sustain the autophagic flux and involves a local increase in PtdIns(4,5)P2 that is confined in space and time by OCRL. Depleting or inhibiting OCRL leads to an accumulation of lysosomal PtdIns(4,5)P2, an inhibitor of the calcium channel mucolipin-1 that controls autophagosome-lysosome fusion. Hence, autophagosomes accumulate in OCRL-depleted cells and in the kidneys of Lowe syndrome patients. Importantly, boosting the activity of mucolipin-1 with selective agonists restores the autophagic flux in cells from Lowe syndrome patients.

Lowe syndrome lysosome
2016 Articolo in rivista metadata only access

High-resolution analysis of the human retina miRNome reveals isomiR variations and novel microRNAs

Karali Marianthi ; Persico Maria ; Mutarelli Margherita ; Carissimo Annamaria ; Pizzo Mariateresa ; Marwah Veer Singh ; Ambrosio Concetta ; Pinelli Michele ; Carrella Diego ; Ferrari Stefano ; Ponzin Diego ; Nigro Vincenzo ; di Bernardo Diego ; Banfi Sandro

MicroRNAs play a fundamental role in retinal development and function. To characterise the miRNome of the human retina, we carried out deep sequencing analysis on sixteen individuals. We established the catalogue of retina-expressed miRNAs, determined their relative abundance and found that a small number of miRNAs accounts for almost 90% of the retina miRNome. We discovered more than 3000 miRNA variants (isomiRs), encompassing a wide range of sequence variations, which include seed modifications that are predicted to have an impact on miRNA action. We demonstrated that a seed-modifying isomiR of the retina-enriched miR-124-3p was endowed with different targeting properties with respect to the corresponding canonical form. Moreover, we identified 51 putative novel, retina-specific miRNAs and experimentally validated the expression for nine of them. Finally, a parallel analysis of the human Retinal Pigment Epithelium (RPE)/choroid, two tissues that are known to be crucial for retina homeostasis, yielded notably distinct miRNA enrichment patterns compared to the retina. The generated data are accessible through an ad hoc database. This study is the first to reveal the complexity of the human retina miRNome at nucleotide resolution and constitutes a unique resource to assess the contribution of miRNAs to the pathophysiology of the human retina.

MOUSE RETINA; ANIMAL DEVELOPMENT; SMALL RNAS; EXPRESSION; DIFFERENTIATION; CLUSTER; IMPACT; GENES; INACTIVATION; DEGENERATION
2016 Contributo in Atti di convegno metadata only access

Non solo ornamenti. Parures e oggetti-simbolo dalle tombe dei principi indigeni dell'area apulo-lucana

The archaeological discoveries of recent years and the latest studies about the uses and customs of Italic aristocracies of the Apulian-Lucanian area have added some relevant data concerning to the class of personal adornments and symbolic objects, fundamental elements underpinning the phenomenon of the birth of aristocracies between the eighth and seventh century BC. Even more indicative, as confirmed by the latest research and depth analysis of some archaeological finds, is the bond that unites these indigenous aristocracies to those of the Tyrrhenian area, active since the ninth century BC. Testimony of such deep relationships are the ornaments found in extraordinary burials, some of which they add, to the preciousness of the material, the sophistication of the workmanship and the rare and exotic character (amber, ivory and faïence). Consider, for example, the sumptuous parures characterizing burials of Enotrian and North-Lucanian princesses (Alianello, Chiaromonte, Baragiano and Braida di Vaglio), characterized by countless amber beads, some of which depict animals whose origin sinks into religious beliefs related to earliest times and perhaps coming from foreign cultural environments, from ivory and bronze beads, as well as scarabs and faïence figurines of Egyptian deities. The parures found in the tombs of Daunian princesses are no less interesting, though less sumptuous, which are marked not only by several personal adornments but also by the presence of symbolic objects in precious metals, many of which imported by Southern Etruria (diadems, sceptres, distaffs) that emphasize royal status of the deceased with a definite reminder of the aristocracies sung by Homer in his poems. The interest and the reference to the Homeric poems are even higher at the presence of the unusual ritual of horses burial matched to the tombs of Daunian princesses. A key role is undoubtedly played by archaic figured ambers, powerful amulets able to defeat the evil eye and the fear of death, whose subjects evoke mythical figures and characters related to funerary and Dionysian world, whose task was to accompany and protect the dead during their long journey into the darkness of Underworld toward the 'everlasting salvation.'

Ornamenti personali ambre oreficerie
2016 Articolo in rivista metadata only access

Le ambre figurate in Italia meridionale tra VIII e V secolo a.C. Note sui centri di produzione e sulle botteghe

The study takes up some issues relating to the location of the workshops that produced the valuable figured ambers that marked the aristocratic burials of southern Italy from the eighth to fifth century BC. The contribution of findings and recent studies enabled us to assign some groups of artifacts to the activity of different workshops and even to identify outstanding artistic personalities, highlighting the undeniable stylistic connections between them.

Ambre preromane
2016 Articolo in rivista restricted access

Spontaneous flow in polar active fluids: the effect of a phenomenological self propulsion-like term

F Bonelli ; G Gonnella ; A Tiribocchi ; D Marenduzzo

We present hybrid lattice Boltzmann simulations of extensile and contractile active fluids where we incorporate phenomenologically the tendency of active particles such as cell and bacteria, to move, or swim, along the local orientation. Quite surprisingly, we show that the interplay between alignment and activity can lead to completely different results, according to geometry (periodic boundary conditions or confinement between flat walls) and nature of the activity (extensile or contractile). An interesting generic outcome is that the alignment interaction can transform stationary active patterns into continuously moving ones: the dynamics of these evolving patterns can be oscillatory or chaotic according to the strength of the alignment term. Our results suggest that flow-polarisation alignment can have important consequences on the collective dynamics of active fluids and active gel.

Active matter Lattice Boltzmann simulations Contractile and extensile fluids
2016 Traduzione in rivista restricted access

Shear dynamics of an inverted nematic emulsion; Shear dynamics of an inverted nematic emulsion

A Tiribocchi ; M Da Re ; D Marenduzzo ; E Orlandini

Here we study theoretically the dynamics of a 2D and a 3D isotropic droplet in a nematic liquid crystal under a shear flow. We find a large repertoire of possible nonequilibrium steady states as a function of the shear rate and of the anchoring of the nematic director field at the droplet surface. We first discuss homeotropic anchoring. For weak anchoring, we recover the typical behaviour of a sheared isotropic droplet in a binary fluid, which rotates, stretches and can be broken by the applied flow. For intermediate anchoring, new possibilities arise due to elastic effects in the nematic fluid. We find that in this regime the 2D droplet can tilt and move in the flow, or tumble incessantly at the centre of the channel. For sufficiently strong anchoring, finally, one or both of the topological defects which form close to the surface of the isotropic droplet in equilibrium detach from it and get dragged deep into the nematic state by the flow. In 3D, instead, the Saturn ring associated with the normal anchoring disclination line can be deformed and shifted downstream by the flow, but remains always localized in the proximity of the droplet, at least for the parameter range we explored. Tangential anchoring in 2D leads to a different dynamic response, as the boojum defects characteristic of this situation can unbind from the droplet under a weaker shear with respect to the normal anchoring case. Our results should stimulate further experiments with inverted liquid crystal emulsions under shear, as most of the predictions can be testable in principle by monitoring the evolution of liquid crystalline orientation patterns or by tracking the position and shape of the droplet over time.

Nematic liquid crystals Shear Topological defects
2016 Contributo in Atti di convegno metadata only access

Mathematical formulation of Bioventing Optimal Design Strategies

Bioventing is a technology used to abate the presence of pollutants in the subsoil. Microorganisms biodegrade the pollutant but the biochemical reaction requires oxygen and so an airflow is induced in the subsoil by means of injection and/or extraction wells. Costs, final result and decontamination time are reliant on contaminant type, soil permeability and several other factors, but oxygen subsoil concentration plays a very important role. For this reason a rational choice of well locations and flow rates is required. The mathematical definition of the optimal design problem will be set-up starting from a simplified mathematical model describing the bioventing system. A formal definition of decontaminated subsoil will be given and the set of system control variables will be identified. Optimization strategies such as cost minimization and time optimization will be mathematically described.

Bioventing Optimal design porous media subsoil decontamination flow in unsaturated porous media
2016 Contributo in Atti di convegno metadata only access

Nonminimally coupled gravity and planetary motion

Riccardo March ; Jorge Paramos ; Orfeu Bertolami ; Simone Dell'Agnello

The effects of a nonminimally coupled curvature-matter model of gravity on planetary orbits are computed. The parameters of the model are then constrained by the observation of Mercury orbit.

modified gravity nonminimally coupled gravity perturbation theory
2016 Articolo in rivista metadata only access

Reliable and perfectly secret communication over the generalized Ozarow-Wyner's wire-tap channel

Aliberti Giulio ; Di Pietro Roberto ; Guarino Stefano

In this paper, we propose a viable encoding scheme that, to the best of our knowledge, is the first one to guarantee both perfect secrecy (i.e., no information leakage) and reliable communication over the generalized Ozarow-Wyner's wire-tap channel. To this end, we first introduce a metric called uncertainty rate that, similarly to the equivocation rate metric, captures the amount of information leaked by a coding scheme in the considered threat model, but it is simpler to apply in the context of linear codes. Based on this metric, we provide an alternative and simpler proof of the known result that no linear error correcting code alone can achieve perfect secrecy. Finally, we propose a constructive solution combining secret sharing and linear error-correcting codes, and we show that our solution provides the desired combination of reliable and perfectly secret communication. The provided solution, other than being supported by thorough analysis, is viable in practical communication systems. (C) 2016 Elsevier B.V. All rights reserved. In a typical secure communication system, messages undergo two different encodings: an error-correcting code is applied at the physical layer to ensure correct reception by the addressee (integrity), while at an upper protocol layer cryptography is leveraged to enforce secrecy with respect to eavesdroppers (confidentiality). All constructive solutions proposed so far to concurrently achieve both integrity and confidentiality at the physical layer, aim at meeting the secrecy capacity of the channel, i.e., at maximizing the rate of the code while guaranteeing an asymptotically small information leakage.

Phys Wire-tap channel Perfect secrecy Error-correcting codes Secret sharing
2016 Contributo in Atti di convegno open access

Extending Lifetime Through Partial Coverage And Roles Allocation in Connectivity-Constrained Sensor Networks

Carrabs Francesco ; Cerulli Raffaele ; D'Ambrosio Ciriaco ; Raiconi Andrea

We consider a scenario in which certain target locations are monitored through sensors, which are scattered all over a considered area. A quality-of-service threshold imposes that, at any given time, a predefined percentage of the overall number of targets must be monitored. Furthermore, the activated sensors must be able to transmit the sensed information to a central base station, and the different roles assumed by the sensors (sensing, relay or idle) lead to different energy consumptions. We propose an exact algorithm to solve the problem of maximizing the operational time in this scenario, and test it on a set of benchmark instances.

Column Generation Communication Networks Genetic Algorithm Maximum Lifetime Problem Partial Coverage Roles Allocation Sensors
2016 Poster in Atti di convegno metadata only access

H2020 Project ECOPOTENTIAL: making best use of remote sensing and in-situ observations to improve future ecosystem benefits

This poster has been presented at the first ILTER Open Science Meeting in Skukuza, Kruger National Park, South Africa, 9-13 October 2016 (https://na.eventscloud.com/ehome/156435), and describes the general purposes and organization of the H2020 project ECOPOTENTIAL (http://www.ecopotential-project.eu/) Questo poster è stato presentato al primo ILTER Open Science Meeting a Skukuza, Kruger National Park, Sud Africa, 9-13 ottobre 2016 (https://na.eventscloud.com/ehome/156435), e descrive gli scopi generali e l'organizzazione del progetto H2020 ECOPOTENTIAL (http://www.ecopotential-project.eu/)

Ecosistemi aree protette dati satellitari ecopotential
2016 Articolo in rivista restricted access

Minimum variation solutions for sliding vector fields on the intersection of two surfaces in R3

Dieci L. ; Difonzo F.

In this work, we consider model problems of piecewise smooth systems inR3, for which we propose minimum variation approaches to find a Filippov sliding vector field on the intersection Σ of two discontinuity surfaces. Our idea is to look at the minimum variation solution in theH1-norm, among either all admissible sets of coefficients for a Filippov vector field, or among all Filippov vector fields. We compare the resulting solutions to other possible Filippov sliding vector fields (including the bilinear and moments solutions). We further show that-in the absence of equilibria-also these other techniques select a minimum variation solution, for an appropriately weightedH1-norm, and we relate this weight to the change of time variable giving orbital equivalence among the different vector fields. Finally, we give details of how to build a minimum variation solution for a general piecewise smooth system inR3.

65P99 MSC 34A36
2016 Contributo in Atti di convegno metadata only access

Le ambre figurate in area adriatica tra l'Orientalizzante e l'età arcaica. Note sui centri di produzione e sulla diffusione di alcune tipologie di manufatti

The first carved ambers appear in the Adriatic area at the end of the eighth century BC with the beginning of the Orientalizing period. Among the most active centers, the Etruscan Verucchio is one of the main poles for the sorting of amber. At the beginning of the sixth century, a fundamental role is exercised from Piceno and the Etruscan Felsina, whose intercept part of the tra!cs previously directed on the Adriatic road. Real amber sculptures of high stylistic level appear towards the second half of the sixth century, found in the rich italic tombs (Basilicata, Apulia, Piceno), traced back to two specialized workshops, localizable in Canosa and Armento, at whose birth they certainly contributed artisans from Ionia and from Etruria.

Ambre preromane e romane
2016 Contributo in volume (Capitolo o Saggio) metadata only access

Adaptive AMG based on Weighted Matching for Systems of Elliptic PDEs arising from Displacement and Mixed Methods

P D'Ambra ; P S Vassilevski

Adaptive Algebraic Multigrid (or Multilevel) Methods (?AMG)are introduced to improve robustness and efficiency of classical algebraic multigrid methods in dealing with problems where no a-priori knowledge or assumptions on the near null kernel of the underlined Matrix are available. Recently we proposed an adaptive (bootstrap) AMG method, ?AMG, aimed to obtain a composite solver with a desired convergence rate. Each new multigrid component relies on a current (general) smooth vector and exploits pairwise aggregation based on weighted matching in a matrix graph to define a new automatic, general-purpose coarsening process, which we refer to as "the compatible weighted matching". In this work, we present results that broaden the applicability of our method to different finite element discretizations of elliptic PDEs. In particular, we consider systems arising from displacement methods in linear elasticity problems and saddle-point systems that appear in the application of the mixed method to Darcy problems.

AMG Matching Systems of PDEs
2016 Articolo in rivista metadata only access

On the nonlinear stability of a continuous duopoly model with constant conjectural variation

The paper concerns a continuous model governed by a ODE system originated by a discrete duopoly model with bounded rationality, based on constant conjectural variation. The aim of the paper is to show (i) the existence of an absorbing set in the phase space; (ii) linear stability analysis of the critical points of the system; (iii) nonlinear, global asymptotic stability of equilibrium of constant conjectural variation.

Nonlinear duopoly game Conjectural variation model Bounded rationality Continuous models Nonlinear stability
2016 Articolo in rivista metadata only access

Bioinspired synthesis of CaCO3 superstructures through a novel hydrogel composite membranes mineralization platform: a comprehensive view

Hydrogel composite membranes (HCMs) are used as novel mineralization platforms for the bioinspired synthesis of CaCO3 superstructures. A comprehensive statistical analysis of experimental results revealed quantitative relationships between crystallization conditions and crystal texture and the strong selectivity toward complex morphologies when monomers bearing carboxyl and hydroxyl groups are used together in the hydrogel synthesis in HCMs.

advanced statistical analysis bio-inspired mineralization calcium carbonate crystallization hydrogel composite membranes membrane-assisted crystallization partial least squares regression
2016 Articolo in rivista metadata only access

Notes on RKDG methods for shallow-water equations in canal networks

PDE models for network flows are used in a number of different applications, including modeling of water channel networks. While the theory and first-order numerics are well developed, there is a lack of high-order schemes. We propose a Runge-Kutta discontinu- ous Galerkin method as an efficient, effective and compact numerical approach for numerical simulations of water flow in open canals. Our numerical tests show the advantages of RKDG over first-order schemes.

Discontinuous Galerking numerical methods canal networks
2016 Articolo in rivista metadata only access

Bridging InSAR and GPS Tomography: A New Differential Geometrical Constraint

Benevides P ; Nico G ; Catalao J ; Miranda P M A

The integration of interferometric synthetic aperture radar (InSAR) and GPS tomography techniques for the estimation of the 3-D distribution of atmosphere refractivity is discussed. A methodology to use the maps of the temporal changes of precipitable water vapor (PWV) provided by InSAR as a further constraint in the GPS tomography is described. The aim of the methodology is to increase the accuracy of the GPS tomography reconstruction of the atmosphere's refractivity. The results, which are obtained with SAR and GPS data acquired over the Lisbon area, Portugal, are presented and assessed. It has been found that the reconstruction of the atmospheric refractivity is closer to the real atmospheric state with a mitigation of the smoothing effects due to the usual geometrical constraints of the GPS tomography.

Atmosphere Global Positioning System (GPS)
2016 Articolo in rivista metadata only access

A non-local rare mutations model for quasispecies and prisoner's dilemma: Numerical assessment of qualitative behaviour

AMADORI ANNA LISA ; BRIANI MAYA ; NATALINI ROBERTO

An integro-differential model for evolutionary dynamics with mutations is investigated by improving the understanding of its behaviour using numerical simulations. The proposed numerical approach can handle also density dependent fitness, and gives new insights about the role of mutation in the preservation of cooperation.

Coevolutionary dynamics mutations numerical approximation of partial integro-differential eqxsuations prisoner's dilemma quasispecies