Hybrid simulations of a multi-span rc viaduct with plain bars and sliding bearings

This paper deals with the seismic response assessment of an old reinforced concrete viaduct and the effectiveness of friction-based retrofitting systems. Emphasis was laid on an old bridge, not properly designed to resist seismic action, consisting of 12 portal piers that support a 13-span bay deck for each independent roadway. On the basis of an OpenSEES finite element frame pier model, calibrated in a previous experimental campaign with cyclic displacement on three 1:4 scale frame piers, a more complex experimental activity using hybrid simulation has been devised. The aim of the simulation was twofold: (i) to increase knowledge of non-linear behavior of reinforced concrete frame piers with plain steel rebars and detailing dating from the late 1950s; and (ii) to study the effectiveness of sliding bearings for seismic response mitigation. Hence, to explore the performance of the as built bridge layout and also of the viaduct retrofitted with friction-based devices, at both serviceability and ultimate limit state conditions, hybrid simulation tests were carried out. In particular, two frame piers were experimentally controlled with eight-actuator channels in the as built case while two frame piers and eight sliding bearings were controlled with 18-actuator channels in the isolated case. The remaining frame piers were part of numerical substructures and were updated offline to accurately track damage evolution

Experimental investigation on the mechanical behavior of an innovative parabolic trough collector

In the present work an experimental program aimed at assessing the mechanical behavior of an innovative parabolic solar trough is presented. More specifically, a lightweight and low-cost collector making large use of adhesive joints, which can be easily assembled on-site, still performing at a high efficiency, was designed. Static and fatigue tests were performed on a full-scale prototype of the collector in the pre-production stage. The tests included differential torsion, concentrated and distributed bending, and distributed load (wind effect). During the tests, a network of strain gauges was placed in the most critical locations to measure the strain field, while laser sensors and cable transducers were placed in strategic positions to measure the displacements. The results demonstrate the strengths of the innovative parabolic trough collector and support the assessment of its structural integrity

Ecosystem processes: litter breakdown patterns in Mediterranean and Black Sea transitional waters

1 - Leaf litter decomposition rates, in aquatic ecosystems, are known to be related to many different abiotic and biotic factors. 2 - Here, we focus on the influence of abiotic factors, searching for patterns of reed litter decay rates on gradient of physiographic, hydrological and physico-chemical components of transitional water ecosystems. 3 - Field experiments were carried out in 16 water ecosystems in the Eastern Mediterranean and Black Sea in spring 2005. 4 - Significant differences of leaf litter decomposition were observed among ecosystems along univariate gradient of tidal range, index of sinuosity, water temperature and salinity. At least 71% of variance in the litter breakdown rate was explained by the considered abiotic factors. 5 - It is concluded that, at the macro-ecological scale of study, some key abiotic factors, such as tidal range and salinity, are suggested to play a major role as drivers of plant detritus decomposition processes. 6 - The relevance of the described abiotic drivers as descriptor of the most commonly used classification schemes for transitional water ecosystems (i.e., Confinement and Venice System classifications), is a further support to their role as environmental forcing factors

Rational design of a user-friendly aptamer/peptide-based device for the detection of staphylococcus aureus

The urgent need to develop a detection system for Staphylococcus aureus, one of the most common causes of infection, is prompting research towards novel approaches and devices, with a particular focus on point-of-care analysis. Biosensors are promising systems to achieve this aim. We coupled the selectivity and affinity of aptamers, short nucleic acids sequences able to recognize specific epitopes on bacterial surface, immobilized at high density on a nanostructured zirconium dioxide surface, with the rational design of specifically interacting fluorescent peptides to assemble an easy-to-use detection device. We show that the displacement of fluorescent peptides upon the competitive binding of S. aureus to immobilized aptamers can be detected and quantified through fluorescence loss. This approach could be also applied to the detection of other bacterial species once aptamers interacting with specific antigens will be identified, allowing the development of a platform for easy detection of a pathogen without requiring access to a healthcare environment

MediaChrom: exploring a new family of pyrimidoindolone-based polarity-sensitive dyes

The modern biological research asks for a continuous development of new fluorescent dyes characterized by improved performances and suitable to be used as markers or probes [1]. A particular class of dyes, called polarity-sensitive dyes have the unique features to display a different emission maximum as a function of the polarity of their molecular environment (media). This peculiarity makes polarity-sensitive dyes the ideal probes to monitor the local properties of particular cell districts as well as different type of biomolecular interactions [2]. Since many years, we have been interested in the development of new strategies for the synthesis and the functionalization of indoles and polycyclic indole-based heterocycles. In this context, we reported a domino approach to pyrimidoindolones [3] that displayed interesting fluorescence properties. Starting from these findings, a small library of original polarity-sensitive fluorescent dyes, nicknamed MediaChrom, has been prepared [4]. They are characterized by a pyrimidoindolone core fitted out with a conjugated push-pull system, and a linker for an easy coupling with biomolecules. The synthetic strategy involves a highly chemo- and regioselective gold catalyzed cycloisomerization as key step. The photophysical properties of MediaChrom dyes have been evaluated, and some potential biological applications have been spottily investigated. [1] Lakowicz, J. R. Principles of Fluorescence Spectroscopy, 3rd ed.; Springer: New York, 2006. [2] Klymchenko, A. S.; Mely, Y. In: Progress in Molecular Biology and Translational Science, Morris, M.C. Editor(s), Academic Press, 2013, Vol. 113, Cap. 2, 35. [3] Facoetti, D.; Abbiati, G.; d\u2019Avolio, L.; Ackermann, L.; Rossi, E. Synlett 2009, 2273. [4] Dell'Acqua, M.; Ronda, L.; Piano, R.; Pellegrino, S.; Clerici, F.; Rossi, E.; Mozzarelli, A.; Gelmi, M. L.; Abbiati, G. J. Org. Chem. 2015, 21, 10939. This work has been supported by Fondazione Cariplo, Grant No. 2012-0907

Between a rock and a hard place: Environmental and engineering considerations when designing coastal defence structures

Coastal defence structures are proliferating as a result of rising sea levels and stormier seas. With the realisation that most coastal infrastructure cannot be lost or removed, research is required into ways that coastal defence structures can be built to meet engineering requirements, whilst also providing relevant ecosystem services—so-called ecological engineering. This approach requires an understanding of the types of assemblages and their functional roles that are desirable and feasible in these novel ecosystems. We review the major impacts coastal defence structures have on surrounding environments and recent experiments informing building coastal defences in a more ecologically sustainable manner. We summarise research carried out during the THESEUS project (2009–2014) which optimised the design of coastal defence structures with the aim to conserve or restore native species diversity. Native biodiversity could be manipulated on defence structures through various interventions: we created artificial rock pools, pits and crevices on breakwaters; we deployed a precast habitat enhancement unit in a coastal defence scheme; we tested the use of a mixture of stone sizes in gabion baskets; and we gardened native habitat-forming species, such as threatened canopy-forming algae on coastal defence structures. Finally, we outline guidelines and recommendations to provide multiple ecosystem services while maintaining engineering efficacy. This work demonstrated that simple enhancement methods can be cost-effective measures to manage local biodiversity. Care is required, however, in the wholesale implementation of these recommendations without full consideration of the desired effects and overall management goals

Validation and psychometric evaluation of the Italian version of the Bergen–Yale Sex Addiction Scale

Excessive problematic sexual behavior in the form of compulsive sexual behavior disorder (CSBD), hypersexuality (HS), and sex addiction has gained increasing credibility in recent years and has led to the development of various psychometric instruments to assess such behavior. However, there is still considerable controversy over the operational definition of such concepts and whether they can be used interchangeably to describe the behavior. One recently developed tool is the Bergen–Yale Sex Addiction Scale (BYSAS) based on the “components model of addiction.” The present study validated the Italian version of the BYSAS. The BYSAS was administered to a large Italian-speaking sample of Italian adults [N = 1230, aged 18 to 67 years] along with psychometric instruments assessing the “Big Five” personality traits, self-esteem, depression, and two other measures of addictive sexual behavior (i.e., PATHOS and Shorter PROMIS Questionnaire–Sex Subscale). Confirmatory factorial analysis supported a one-factor solution. Furthermore, the scale had good internal consistency (Cronbach’s α = 0.787). The BYSAS was positively associated with extroversion, openness to experience, depression, and problematic sexual behavior, and negatively associated with self-esteem, conscientiousness, emotional stability, agreeableness, and age. Based on the findings, the BYSAS is a brief, psychometrically reliable and valid measure for assessing sex addiction among Italian adults

Espansioni e contrazioni della partecipazione scolastica in Italia dall’inizio del XX secolo ad oggi. Il ruolo delle riforme scolastiche e delle vicende economiche

In questo articolo si presentano i risultati di un\u2019indagine intesa a illustrare le dinamiche della domanda collettiva di istruzione in Italia a partire dagli inizi del XX secolo. L\u2019analisi si \ue8 proposta di misurare, attraverso procedure di analisi controfattuale basate sul metodo delle serie storiche interrotte, il peso assunto in queste dinamiche dalle riforme scolastiche e dall\u2019andamento dell\u2019economia. Sono stati presi in esame i tassi di partecipazione e i tassi di passaggio ai diversi ordini e gradi in cui si articolava e si articola il sistema scolastico italiano. Le analisi svolte mostrano come le riforme scolastiche attuate dal 1900 ad oggi abbiano contribuito in misura non trascurabili sull\u2019espansione della scolarit\ue0, mentre l\u2019influenza della crisi economica si \ue8 fatta sentire soprattutto per quanto riguarda gli accessi all\u2019universit\ue0

The colonisation of human-made structures by the invasive alga Codium fragile ssp. tomentosoides in the North Adriatic Sea (NE Mediterranean)

Human-made structures, such as groynes, breakwaters, seawalls, pier pilings and floating pontoons, are becoming common features of the landscape in urbanised coastal and estuarine areas. Despite this tendency few studies have focused on their ecology or on their potential impacts on natural assemblages of organisms. When artificial structures are introduced in areas with little or no hard substrata, they not only provide novel habitats, which enables the colonisation of sandy areas by hard-bottom dwelling species, but they can also provide suitable habitats for exotic species. Along the north-east coast of Italy, sandy shores are protected from erosion by a line of breakwaters, which runs almost uninterrupted for about 300 km. These structures provide habitat for a variety of macroalgae and invertebrates and also for the invasive green alga Codium fragile ssp. tomentosoides. The aim of this study was, therefore, to investigate patterns of distribution of this alga on breakwaters in Cesenatico. In particular, we compared the density of thalli, biomass, length and degree of branching of C. fragile ssp. tomentosoides between the landward and the seaward sides of breakwaters, to test the hypothesis that sheltered habitats (landward) represent more suitable habitats than exposed habitats (seaward). In general, the landward side of breakwaters supported greater numbers of thalli of C. fragile ssp. tomentosoides than seaward sides. Thalli grew longer and more branched in sheltered habitats, leading to an overall larger biomass of the alga on the landward side of breakwaters. The presence of sheltered human-made hard substrata in the vicinity of major trading ports and sources of eutrophication could enhance the dispersal of invasive species across regional and geographic scales. Thus, the effects of artificial structures and introduced species on coastal assemblages cannot be evaluated separately, but their synergistic nature should be considered in planning strategies for conservation of biodiversity in coastal habitats