105 research outputs found

    Studio sull’impatto ambientale delle attività di maricoltura nel Golfo di Oristano

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    L’obiettivo del presente lavoro è stato di simulare la dispersione e il tempo di residenza delle sostanze organiche immesse nell’ambiente a seguito delle attività di acquacoltura all’interno del Golfo di Oristano (Sardegna, Italia). A questo scopo è stato implementato un modello numerico di circolazione, con moduli di dispersione e diffusione euleriana e lagrangiana. Il modello ha evidenziato il ruolo fondamentale della direzione e dell’intensità del vento sulla dispersione dei rifiuti organici. A parità d’intensità, la direzione del vento influenza in maniera decisiva la distanza alla quale i rifiuti organici vengono trasportati e depositati. In tutti gli scenari di vento, il mangime non consumato, indipendentemente dalla sua dimensione, si deposita in un’area direttamente sotto le gabbie ma con una distribuzione spaziale che dipende dalle correnti indotte. In tutti i casi, la materia organica disciolta si diluisce ed è trasportata al di fuori del golfo. Con i venti da Maestrale i rifiuti organici sono spinti verso, l’interno del golfo per poi uscirne in forma disciolta da sud. Negli scenari di Libeccio e Scirocco i rifiuti organici disciolti tendono a diluirsi ed essere trasportati al di fuori del golfo dalla parte nord. In tutti gli scenari, la capacità di ricambio delle acque interne al golfo risulta elevata, con la maggior parte delle sostanze organiche disciolte presenti in concentrazioni molto basse dopo dieci ore dalla loro produzione. Dal punto di vista del ricambio d’acqua e conseguentemente per la dispersone di agenti inquinanti, quasi tutti i 13 siti simulati, ad esclusione dei due in prossimità dei capi, hanno tempi di residenza idonei per il posizionamento delle gabbie. Sono comunque da preferire le regioni più a sud perché i tempi di transito sono più bassi creando un impatto minore. Infine considerando che il golfo è ricoperto quasi interamente da Posidonia, i siti meno impattanti sono quelli che si trovano su un fondale fangoso e in prossimità del fiume Tirso (Sito 3 e 4). L’utilizzo di modelli numerici ha permesso di portare a termine studi a priori (tempi di transito, zone di deposizione, dispersioni inquinanti) per la pianificazione della disposizione ottimale delle gabbie, avente come conseguenza una più proficua produzione (maggiore redditività) e un minore impatto ambientale. Si può infine affermare che nonostante l’assenza di studi antecedenti al presente, le gabbie all’interno del Golfo di Oristano siano state posizionate correttamente, in una regione ottimale per produzione e impatto ambientale

    Blockchain-Oriented Services Computing in Action: Insights from a User Study

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    Blockchain architectures promise disruptive innovation but factually they pose many architectural restrictions to classical service-based applications and show considerable design, implementation, and operations overhead. Furthermore, the relation between such overheads and user benefits is not clear yet. To shed light on the aforementioned relations, a service-based blockchain architecture was designed and deployed as part of a field study in real-life experimentation. An observational approach was then performed to elaborate on the technology-acceptance of the service-based blockchain architecture in question. Evidence shows that the resulting architecture is, in principle, not different than other less complex equivalents; furthermore, the architectural limitations posed by the blockchain-oriented design demand a significant additional effort to be put onto even the simplest of functionalities. We conclude that further research shall be invested in clarifying further the design principles we learned as part of this study as well as any trade-offs posed by blockchain-oriented service design and operation

    Quality Assurance of Heterogeneous Applications: The SODALITE Approach

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    A key focus of the SODALITE project is to assure the quality and performance of the deployments of applications over heterogeneous Cloud and HPC environments. It offers a set of tools to detect and correct errors, smells, and bugs in the deployment models and their provisioning workflows, and a framework to monitor and refactor deployment model instances at runtime. This paper presents objectives, designs, early results of the quality assurance framework and the refactoring framework.Comment: 5 pages. Accepted for the publication. 8th European Conference On Service-Oriented And Cloud Computing (https://esocc-conf.eu/). EU Trac

    A modelling study of the barotropic tidal dynamics in the Strait of Messina

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    This paper is devoted to a model case study of the barotropic tidal dynamics. A non-hydrostatic (i.e. fully three dimensional) ocean model, based on the finite-element method was applied in the Strait of Messina (Italy), where intense tidal flows interact with complex geometries of coasts and bathymetry. A simplified model configuration including only the tidal signal at the open boundaries was able to provide evidences that the barotropic tides, interacting with coastlines and bottom topography in such narrow sea strait, generate high amplitude overtones of the main tidal constituents as well as relatively intense tide-induced residual circulations. The spatial and temporal distribution of tidal flows was analysed with a numerical simulation of a whole synodic month. The vertical component of tidal flows, explicitly computed, was shown in cross-sections in order to emphasized the direct effect of boundaries constraints on the vertical acceleration. The presented model results endorse previous model approaches and observations and they remind the significance of the barotropic tidal dynamics in this domain of investigatio

    Testing a novel aggregated methodology to assess hydrodynamic impacts on a high-resolution marine turtle trajectory

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    We designed a novel aggregated methodology to infer the impact of ocean motions on the movements of satellite-tracked marine turtles adopting available oceanographic observations and validated products of a numerical oceanographic forecasting system. The method was tested on an 11-months trajectory of a juvenile loggerhead turtle (LT) wandering in the Tyrrhenian Sea (Mediterranean Sea) that was reconstructed with a high-resolution GPS tracking system. The application of ad-hoc designed metrics revealed that the turtle's route shape, ground speed and periodicities of its explained variance mimic the inertial motions of the sea, showing that this methodology is able to reveal important details on the relation between turtle movements and oceanographic features. Inertial motions were also identified in the observed trajectory of a surface drifting buoy sampling the Tyrrhenian Sea in a common period. At each sampling point of the turtle trajectory, the sea current eddy kinetic energy (EKE) and a Sea Current Impact index were computed from a validated set of high-resolution ocean modeling products and their analysis showed the relevant effects of the highly variable local sea currents mechanical action. Specifically, the metric we adopted revealed that the turtle trajectory was favorably impacted by the encountered sea current advection for about 70% of its length. The presented oceanographic techniques in conjunction with high-resolution tracking system provide a practicable approach to study marine turtle movements, leading the way to discover further insights on turtle behavior in the ocean

    Molecular approaches in the diagnosis of sepsis in neutropenic patients with haematological malignances

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    Introduction. Sepsis is a major cause of significant morbidity and mortality in neutropenic patients. Blood culture remains the gold standard in the microbiological diagnosis of bacterial or fungal bloodstream infections, but it has clear limits of rapidity and sen- sitivity. The objective of the study was to compare the real-time polymerase chain reaction (RT-PCR) with automated blood cul- tures (BC) method in detection in whole blood of pathogens in febrile neutropenic patients with hematological malignancies. Methods. A total of 166 consecutive febrile neutropenic patients were enrolled. Blood samples for cultures and SeptiFast testing were obtained at the onset of fever, before the implementation of empirical antibiotic therapy. Results. Forty (24.1%) samples out of the 166 blood samples tested, were positive by at least one method. Twenty-three (13.9%) samples were positive by blood culture and 38 (22.9%) by multi- plex real-time PCR. The analysis of concordance evidenced a low correlation between the two methods (n = 21; 52.5%), mainly due to samples found negative by culture but positive with the Septi- Fast assay. Sensitivity, specificity, and positive and negative pre- dictive values of RT-PCR were 91.3%, 88.1%, 55.3%, and 98.4%, respectively, compared with BC. Discussion. Multiplex real-time PCR assay improved detection of the most bacteria associated with febrile neutropenia episodes. Fur- ther studies are needed to assess the real advantages and clinical benefits that molecular biology tests can add in diagnosis of sepsis. The full article is free available on www.jpmh.or

    Safety and Immunogenicity of Conventional Subunit and MF59-adjuvanted Influenza Vaccines in Human Immunodeficiency Virus-1-seropositive Patients

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    In this study of influenza vaccination, 37 human immunodeficiency virus (HIV)-1-seropositive patients were randomized to receive either a vaccine with a conventional subunit or one adjuvanted with MF59. Blood samples were collected at the time of vaccination, and then 30 and 180 days later, to evaluate immunogenicity, CD4+ T-lymphocyte count and HIV-1 RNA levels. Seroconversion rates against the three viral strains included in the vaccine ranged between 44% and 72% and 53% and 68% for the adjuvanted vaccine and the subunit vaccine, respectively. Other criteria of the European Medicines Evaluation Agency were also met. Vaccination was not associated with serious adverse events. Local and systemic effects were mild and of short duration. CD4+ T-lymphocyte counts and viraemia levels were not negatively affected by vaccination. These results confirmed the safety and immunogenicity of these currently available vaccines in HIV-1-seropositive patients, thus supporting the recommendation for influenza immunization in this high-risk category

    SODALITE@RT: Orchestrating Applications on Cloud-Edge Infrastructures

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    AbstractIoT-based applications need to be dynamically orchestrated on cloud-edge infrastructures for reasons such as performance, regulations, or cost. In this context, a crucial problem is facilitating the work of DevOps teams in deploying, monitoring, and managing such applications by providing necessary tools and platforms. The SODALITE@RT open-source framework aims at addressing this scenario. In this paper, we present the main features of the SODALITE@RT: modeling of cloud-edge resources and applications using open standards and infrastructural code, and automated deployment, monitoring, and management of the applications in the target infrastructures based on such models. The capabilities of the SODALITE@RT are demonstrated through a relevant case study

    Marine and Coastal Hazard Assessment for Three Coastal Oil Rigs

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    A forecasting and hazard assessment system for oil dispersion from Italian oil rigs was set up within the framework of a national research project. The system is based on 3D hydrodynamic, mesoscale resolving models providing forcing fields for a Lagrangian module of oil dispersion and slick evolution (oil transport and transformation). The tool provides,daily, the outputs of numerical simulations of possible oil spills from extraction platform sites. In this work we present the results for the 3 platforms closest to the Italian coast. Aside the operational usage, the numerical outputs are also stored and adopted to compute statistics of the slick distributions in the coastal and marine areas of interest. The hazard was assessed by means of two different indices (Hazard Index and Occurrence Index) based on the operational system outputs, for the estimation of the hazard at sea (marine hazard or aerial hazard). As short forecasts (2 days long) often do not allow the oil to reach the coast, an extra set of long-period simulations has been performed in order to compute a third Hazard Index (Coastal Hazard Index) suitable to estimate the hazard along the shorelines. The adopted methodology allowed, as a whole, to assess both coastal and marine oil spill hazard due to oil spill extraction activities. The indices constitute a basic informative layer on which the environmental risk could be also evaluated, once opportunely combined with coastal vulnerability and sensitivity layers
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