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Earthquakes produce on infills In-Plane (IP) and Out-Of-Plane (OOP) actions. The recent earthquakes have proved that the OOP collapse of infills is a diffused mechanism also in buildings designed to resist to seismic events in agreement to the most modern strategies. This fact makes the question arises about the safety of infills with respect OOP actions. The strong interaction between IP and OOP behaviour of infills traduces in a progressively reduction of the OOP strength. Further, only in few cases codes suggest adequate strategies to face this issue. For what above, in the paper the reduction of OOP strength because of the IP damage is studied by an extended numerical experimental campaign based on FE models to be considered as complementary to the very few laboratory experimental tests available in the literature.

Direction selective (DS) ganglion cells (GC) in the retina maintain their tuning across a broad range of light levels. Yet very different circuits can shape their responses from bright to dim light, and their respective contributions are difficult to tease apart. In particular, the contribution of the rod bipolar cell (RBC) primary pathway, a key player in dim light, is unclear. To understand its contribution to DSGC response, we designed an all-optical approach allowing precise manipulation of single retinal neurons. Our system activates single cells in the bipolar cell (BC) layer by two-photon (2P) temporally focused holographic illumination, while recording the activity in the ganglion cell layer by 2P Ca2 imaging. By doing so, we demonstrate that RBCs provide an asymmetric input to DSGCs, suggesting they contribute to their direction selectivity. Our results suggest that every circuit providing an input to direction selective cells can generate direction selectivity by itself. This hints at a general principle to achieve robust selectivity in sensory areas.

In the last decades many strategies for seismic vulnerability mitigation of structures have been developed through analytical studies and experimental tests. Among these, energy dissipation by external devices assumes a great relevance for the relative design simplicity, even if applied to complex structures, and the effectiveness in reducing seismic demand. In particular, the use of fluid viscous dampers represents a very attractive solution because of their velocity-dependent behaviour and relatively low costs. The application on structures requires specific study under seismic excitation and a particular care of structural details. In this context the use of proper constitutive models for the dampers assumes a fundamental role. Seismic codes, as well as literature models generally provide a velocity-dependent relationship with two characteristic constants defining the shape of the force-displacement curve. In this paper an experimental campaign aimed at the determination of the damper constants in the range of low velocities is presented. A fluid viscous damper is tested with different ramp velocity functions. Results show that the assumption of velocity independence of the damper constants fails for the case of low velocity, giving rise to new issues about the limit of validity of the constitutive models generally adopted for viscous dampers.

This paper, affecting an analysis comparative of the different regional typologies, it analyzes the concept of weakness, with reference to the phenomena of degrade and disarrangement of the grounds, inside the processes of identification of functional territorial articulations to the statistical analysis and the decisions of policy, showing as despite the existence of a fed together of interpretations none of the examined typologies both indeed able to furnish a representation suitable of the phenomenon, since the different procedures of regionalization introduce not suitable discriminatory methodologies.

Marine protected areas (MPAs), when designated correctly and managed well, provide a plethora of conservation benefits for current and future generations (i.e. increased habitat heterogeneity at the seascape level, increased abundance of threatened species and habitats, and maintenance of a full range of genotypes). The distribution pattern of an important target species from the Mediterranean Sea, the parrotfish Sparisoma cretense, was determined in the Plemmirio MPA (Siracuse, Italy) during summer of 2014. Sampling was carried out by means of underwater visual census techniques at two different depth (0/10 m and 10/20 m respectively) at four sampling sites within the reserve boundaries and two sites outside the reserve. Densities and biomasses of S. cretense were significantly higher inside than outside the MPA, however no differences in depth were detected. Our findings confirm that the enforcement of the Plemmirio MPA has a strong positive effect in retaining high numbers of commercially important species, such as S. cretense.

Ecosystem resistance to species invasion is considered to be related to the abundance and diversity of native species (i.e. diversity-resistance hypothesis). In particular, the integrity of predator assemblages may enhance the control of prey populations through direct and indirect interactions (e.g.: different predation strategies by different predators, facilitative interactions among predators). Depletion of predators due to overfishing is therefore expected to enhance the abundance and ultimately the spread of alien prey species. Manipulative field experiments were performed to evaluate the effects of different abundance and diversity of predator assemblages on the invasion success of the alien crab Percnon gibbesi. The experiments were conducted in northwestern Sicily (Italy, Mediterranean Sea), in summer 2015, on bare rocky boulders, the habitat preferred by P. gibbesi. The study sites were characterized by significantly different species richness and abundance of the potential predators of P. gibbesi. Predation rate of different predator assemblages was assessed by means of tethering experiments on the alien crab. As predicted, predation rate on P. gibbesi resulted significantly higher in sites characterized by higher predator abundance and species richness than in sites with lower values. Our findings, although restricted to small spatial scales, support the diversity resistance hypothesis, revealing a negative relationship between the diversity of predator assemblages and the invasiveness (average abundance) of the alien species P. gibbesi.

The purple starfish Ophidiaster ophidianus is an Atlanto-Mediterranean starfish protected under the EU’s Habitats Directive. Despite the wide distribution and the current range expansion of this warm affinity species in the northern Mediterranean areas, nothing is known about its diet. Using field observations and carbon (δ13C) and nitrogen (δ15N) stable isotopes, we explored possible changes in density and diet of O. ophidianus in relation to two different Mediterranean habitats: the coralline barren and the macro algae forest. Data were collected at the Marine Protected Area of Ustica Island (Southern Tyrrhenian Sea) from June to September 2009. Starfish density was not affected by the habitat, while on the contrary the diet of O. ophidianus was significantly different between barren and macro algae forest habitat. O. ophidianus fed mainly on crustose algae and bryozoans in barren, whereas it preferred the sponge Ircinia spp. in the forested habitat. Other food sources such as small gastropods and sedimentary organic matter were selected by this starfish. In general O. ophidianus showed a short niche breadth and omnivory habits with tendency to carnivory.

Electro-Discharge machining (EDM) is a thermal process comprising a complex metal removal mechanism, which involves the formation of a plasma channel between the tool and the workpiece electrodes leading to the melting and evaporation of the material to be removed. EDM is considered especially suitable for machining complex contours with high accuracy, as well as for materials that are not amenable to conventional removal methods. However, several phenomena negatively affecting the surface integrity of EDMed workpieces need to be taken into account and studied in order to achieve the optimization of the process. Recently, artificial neural networks (ANN) have emerged as a novel modeling technique capable to provide reliable results and readily integrated into a lot of technological areas. In this paper, ANN models for the prediction of the mean surface roughness of electro-discharge machined surfaces are presented. The comparison of the derived results with experimental findings demonstrates the promising potential of using back propagation neural networks (BPNNs) for the reliable and robust approximation of the Surface Roughness of Electro-discharge Machined Components.

Simplified equations aimed at evaluating the flexural and shear capacity of corroded R.C. beams are presented and discussed in this paper, with reference to ordinary beams reinforced both longitudinally (with same-size bars) and transversely (with stirrups). A model is developed to take care of diffused and localised corrosion (pitting corrosion), concrete decay in compression and bond-strength decay at concrete-reinforcement interface. A fairly innovative contribution of this study is the introduction into the proposed equations of the main parameters governing the corrosion processes. The proposed approach is simple and effective, and may be adopted in the assessment of many damaged structures (a) on the basis of the available experimental information (e.g., carbonation depth, chloride content, pit depth and size in the bars and mass loss in the reinforcement), and (b) by utilizing analytical expressions calibrated through the knowledge of the density of the corrosion current.

L’autore principale, alla data di pubblicazione del saggio, è responsabile del Laboratorio in Pianificazione Territoriale nel corso di Laurea in Pianificazione Territoriale Urbanistica e Ambientale dell’Università di Palermo. Considerando il quadro delle modalità di insegnamento della disciplina della pianificazione territoriale, la morfologia urbana e territoriale è la prevalente tipologia di approccio alle pratiche di trasformazione caratterizza le metodologie didattiche nelle scuole di architettura, mentre le teorie, da cui tali metodologie discendono, restano ben distinte e distanti dai saperi prossimi (e indispensabili) all’urbanistica: ingegneria, scienze agrarie, geologiche, scienze della terra, scienze sociali, economiche e giuridiche. Il contributo al volume illustra i fondamenti metodologici e i risultati conseguiti dal laboratorio di pianificazione territoriale nel quadro della attualizzazione del pensiero di Giuseppe Samonà che considera centrale il principio dell'unità Urbanistica-Architettura e che con l'altro concetto di ‘città in estensione’ (1980) fornisce le basi per declinare politiche e pratiche di turismo sostenibile nella chiave relazionale da integrare alle politiche di sviluppo locale.

SUMMARY: The adoption of proper constitutive laws for confined concrete is basic for seismic assessment of new and existing reinforced concrete civil structures. The deformation capacity of reinforced concrete (RC) columns subjected to axially centred and eccentric loads depends on the effectiveness confinement action. A proper assignment of the stressstrainlaws for concrete allows obtaining an adequate definition of the ductility of the crosssections and correctly identifying mechanical nonlinearities in computational models.Several studies concerning the behaviour of confined concrete have been carried out, highlighting the role of different geometrical and mechanical parameters to the overall response of RC members in compression. In this frame, the primary aim of this paper is to discuss the reliability of the stress-strain concrete models for concrete subjected to confining stresses in the cases of normal strength concrete (NSC), and high strength concrete (HSC). A selected review of the most popular models for confined concrete available in the literature is presented and discussed together with the respective analytical formulations. Furthermore, a discussion on their reliability is carried out by comparing results coming from the implementation of each model and comparing analytical predictions with experimental data available in the literature.

Già dalla seconda metà degli anni 60 del secolo scorso in Italia, alcuni urbanisti (e non solo se si pensa alla poliedrica attività di Adriano Olivetti) incoraggiavano nuove metodologie di costruzione degli spazi urbani e territoriali mediante il recepimento della domanda sociale attraverso le pratiche di partecipazione degli abitanti alle scelte di governo del territorio. Tutto ciò avveniva sulla scia dell’advocacy planning molto in voga negli states, lanciato nel decennio precedente, ma anche dalla contaminazione del “situazionismo internazionale” principalmente di derivazione francese. Così dal nord al sud del nostro Paese, dalla scala urbana a quella territoriale, alcuni pionieri del riformismo progettuale come Giancarlo De Carlo, con la progettazione di “Case Matteotti” nei pressi di Milano e Danilo Dolci (sociologo che operò con la collaborazione e il supporto della scuola urbanistica siciliana) nella Sicilia occidentale, avviavano la sperimentazione di quella che veniva definita “progettazione partecipata”, attraverso l’importante fase di ascolto degli abitanti. Lo scopo della sperimentazione era quello di coinvolgere i cittadini nel disegno degli spazi urbani e di reale assetto urbanistico nei territori da loro abitati, mediante l’esposizione delle domande sociali che provenivano dal basso in direzione di una loro soddisfazione. Nel lungo percorso della disciplina urbanistica, la sperimentazione di questa pratica si è intensificata notevolmente, dando l’avvio al consolidamento della “coscienza partecipativa e democratica” dei cittadini nelle scelte di governo del territorio

The recent large use of nonlinear seismic assessment techniques requires the definition of highly reliable computational models. The retrofitting or strengthening of RC columns by steel angles and battens is a commonly adopted technique, used to improve strength and deformation capacity of existing RC buildings. In the case of steel angles not directly loaded, the numerical definition of the cross-section model has to be handled carefully since it is affected by more uncertainties. The vertical load carried by the angles is a function of the lateral confinement pressure, the cohesion and the friction coefficient between the materials, parameters which are not always easy to predict. The paper discusses the numerical implementation in OpenSees of RC jacketed sections models, giving practical solutions to properly account for the above mentioned issues. In order to validate the predictive capacity of the model, the numerical results are compared with the outcomes of an experimental campaign carried out by the authors. Some final modelling remarks are given by the observation of the results of experimental tests and numerical simulations

Asteroids are an important group of predators in many marine ecosystems. The measure of body size is crucial in studying asteroid biology as this variable affects both prey selection and predation impact. Current field techniques for estimating asteroid size (i.e. total length TL, total weight TW) include the measure of correlated variables, such us the central disk (CD) and arm length (AL). However, these variables are often time-consuming and require a direct handling of the organism. We tested the accuracy of new asteroid body metrics, the arm height (AH) or arm width (AW), to rapidly estimate body size in asteroids. AH and AW were measured in three of the most common Mediterranean asteroids (Marthasterias glacialis, Ophidiaster ophidianus and Coscinasterias tenuispina), sampled from April to August 2008, along the coasts of Ustica Island off the northern coast of Sicily. We used both linear and exponential regression analyses to compare the performance of AH, AL, AW and CD in estimat- ing size for the three species studied. Results suggest that, in M. glacialis and C. tenuispina, AH is strongly correlated (p, peer-reviewed

La possibilità di individuare e quantificare le principali criticità legate ad eventi catastrofici naturali su un territorio, consente di pianificare strategie e interventi adeguati da parte degli organismi di Protezione Civile coinvolti in emergenze locali e internazionali. Il rischio sismico dipende soprattutto dalla vulnerabilità degli edifici appartenenti alle aree urbane. La conoscenza degli scenari di rischio è dunque fondamentale per pianificare e gestire azioni di assistenza in caso di emergenza e non può prescindere dalla quantificazione e localizzazione della vulnerabilità sismica. Il presente studio propone una procedura per la definizione di mappe di vulnerabilità sismica in termini di indici di vulnerabilità e PGA critiche con particolare riferimento ai piccoli e medi centri urbani delle aree mediterranee transfrontaliere. La procedura è stata testata sul centro urbano dell'isola di Lampedusa e si basa su una preliminare indagine storica dell'area urbana e delle principali caratteristiche formali e tecnologie degli edifici coinvolti. Gli indici di vulnerabilità sono valutati attraverso schede GNDT di secondo livello. Il modello di vulnerabilità, che consente la definizione delle curve di fragilità è infine calibrato sulla base indagini numericosperimentali condotte su un edifici prototipo significativamente rappresentativi dell'edificato urbano. Gli output forniscono, per l'area investigata, le mappe dell'indice di vulnerabilità e dei valori di PGA di primo danneggiamento e di collasso.

La riflessione che di seguito si sviluppa vuole condurre verso una più estesa considerazione delle implicazioni sociali dell’attività agricola. Il dibattito nel campo economico agrario, infatti, si concentra sui contenuti che l’attività agricola trasmette attraverso la modellazione del paesaggio, la conservazione della storia, la tutela dell’ambiente e della salute. La notorietà della Dieta mediterranea e il suo riconoscimento globale sembrano riassumere in larga parte queste proposizioni.

La crisi finanziaria globale coinvolge e sconvolge le economie reali e quindi anche i sistemi valoriali alla base delle strumentazioni di governo delle trasformazioni urbane e territoriali stressando le sperimentazioni di governance dei modelli di sviluppo place based a seconda delle tipologie territoriali e dei loro livelli di declino. Il turismo sostenibile sembra inserirsi in modo utile nelle strategie di resilienza dei territori. Nella prima parte si sottolinea il rapporto tra pianificazione territoriale e agricoltura che torna ad essere centrale. Le ICT spingono la condizione sociale a mutare verso quella di cittadini del mondo che vivono lo spazio ed il tempo immergendosi dentro una vita in costante movimento. Il turismo sembra scomparire al crescere della possibilità di scoprire e intrattenere nel tempo nuove relazioni umane che collaborano a minimizzare gli impatti del turismo sia sul patrimonio costruito che su quello rurale. Nella seconda parte è messa in luce la potenzialità ed il ruolo che l’agricoltura e la produzione alimentare di qualità gioca nelle politiche di sviluppo locale. Nella terza parte è illustrato un caso di studio della Sicilia centrale in cui è necessario e possibile tracciare strategie di recupero del patrimonio culturale, colturale e di alimentazione su livelli di eccellenza, grazie a politiche e pratiche trans-settoriali integrate. Nelle conclusioni si sottolinea la convenienza dell’approccio di turismo relazionale integrato. La visione rur-urbana che ne deriva ha l’ambizione di divenire un quadro di riferimento per nuovi scenari di riorganizzazione degli equilibri fra area urbana e area rurale.