58 research outputs found

    The rapid spread of SARS-COV-2 Omicron variant in Italy reflected early through wastewater surveillance

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    The SARS-CoV-2 Omicron variant emerged in South Africa in November 2021, and has later been identified worldwide, raising serious concerns. A real-time RT-PCR assay was designed for the rapid screening of the Omicron variant, targeting characteristic mutations of the spike gene. The assay was used to test 737 sewage samples collected throughout Italy (19/21 Regions) between 11 November and 25 December 2021, with the aim of assessing the spread of the Omicron variant in the country. Positive samples were also tested with a real-time RT-PCR developed by the European Commission, Joint Research Centre (JRC), and through nested RT-PCR followed by Sanger sequencing. Overall, 115 samples tested positive for Omicron SARS-CoV-2 variant. The first occurrence was detected on 7 December, in Veneto, North Italy. Later on, the variant spread extremely fast in three weeks, with prevalence of positive wastewater samples rising from 1.0% (1/104 samples) in the week 5–11 December, to 17.5% (25/143 samples) in the week 12–18, to 65.9% (89/135 samples) in the week 19–25, in line with the increase in cases of infection with the Omicron variant observed during December in Italy. Similarly, the number of Regions/Autonomous Provinces in which the variant was detected increased from one in the first week, to 11 in the second, and to 17 in the last one. The presence of the Omicron variant was confirmed by the JRC real-time RT-PCR in 79.1% (91/115) of the positive samples, and by Sanger sequencing in 66% (64/97) of PCR amplicons. In conclusion, we designed an RT-qPCR assay capable to detect the Omicron variant, which can be successfully used for the purpose of wastewater-based epidemiology. We also described the history of the introduction and diffusion of the Omicron variant in the Italian population and territory, confirming the effectiveness of sewage monitoring as a powerful surveillance tool

    The rapid spread of SARS-COV-2 Omicron variant in Italy reflected early through wastewater surveillance

    Get PDF
    The SARS-CoV-2 Omicron variant emerged in South Africa in November 2021, and has later been identified worldwide, raising serious concerns. A real-time RT-PCR assay was designed for the rapid screening of the Omicron variant, targeting characteristic mutations of the spike gene. The assay was used to test 737 sewage samples collected throughout Italy (19/21 Regions) between 11 November and 25 December 2021, with the aim of assessing the spread of the Omicron variant in the country. Positive samples were also tested with a real-time RT-PCR developed by the European Commission, Joint Research Centre (JRC), and through nested RT-PCR followed by Sanger sequencing. Overall, 115 samples tested positive for Omicron SARS-CoV-2 variant. The first occurrence was detected on 7 December, in Veneto, North Italy. Later on, the variant spread extremely fast in three weeks, with prevalence of positive wastewater samples rising from 1.0% (1/104 samples) in the week 5-11 December, to 17.5% (25/143 samples) in the week 12-18, to 65.9% (89/135 samples) in the week 19-25, in line with the increase in cases of infection with the Omicron variant observed during December in Italy. Similarly, the number of Regions/Autonomous Provinces in which the variant was detected increased from one in the first week, to 11 in the second, and to 17 in the last one. The presence of the Omicron variant was confirmed by the JRC real-time RT-PCR in 79.1% (91/115) of the positive samples, and by Sanger sequencing in 66% (64/97) of PCR amplicons. In conclusion, we designed an RT-qPCR assay capable to detect the Omicron variant, which can be successfully used for the purpose of wastewater-based epidemiology. We also described the history of the introduction and diffusion of the Omicron variant in the Italian population and territory, confirming the effectiveness of sewage monitoring as a powerful surveillance tool

    Engineering Self-adaptive Systems: From Experiences with MUSA to a General Design Process

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    Designing and developing complex self-adaptive systems require design processes having specific features fitting and representing the complexity of these systems. Changing requirements, users’ needs and dynamic environment have to be taken in consideration, also considering that, due of the self-adaptive nature of the system, the solution is not fixed at design time but it is a run-time outcome. Traditional design approach and life cycles are not suitable to design software systems where requirements continuously change at runtime. A new design process paradigm is needed to design such systems. In this Chapter, we present a retrospective analysis based on three projects developed in the last five years with the middleware MUSA in order to identify specific features of the design process for supporting continuous change and self-adaptation. The result is a general approach allowing to reduce the gap between design time and run-time

    Building Agents with Agents and Patterns

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    The use of design patterns proved successful in lowering the development time and number of errors when producing software with the object-oriented paradigm. Now the need for a reuse technique is occurring for the emergent agent paradigm, for which a great effort is currently spending in methodology definitions. In this work we present our experiences in the identification, description, production and use of agents patterns. A repository of patterns was enriched during these years so to request a classification criteria and a documentation template useful to help user during the selection

    An expert system for the design of agents

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    The growing interest for the design and development of multi-agent systems has brought to the creation of a specific research area called Agent-Oriented Software Engineering (AOSE), specifically conceived for the development of complex systems. The development of such systems needs the support of appropriate tools that could help the designer in producing the design artefacts. We developed a tool called Metameth that may be used to define a new (agent-oriented) design process as well as to apply it. In this paper, we describe only a slice of this complex tool, specifically addressing the interaction with human actors (the designers). This subsystem is conceived as a collaborative multi-agent expert system, where each agent is capable of reasoning and adapting itself in order to support the designer in performing different kinds of design activities, regarding the use of various notations, and process life-cycles. \ua92007 IEEE

    The PASSI and agile PASSI MAS meta-models compared with a unifying proposal

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    A great number of processes for multi-agent systems design have been presented in last years to support the different approaches to agent-oriented design; each process is specific for a particular class of problems and it instantiates a specific MAS meta-model. These differences produce inconsistences and overlaps: a MAS meta-model may define a term not referred by another, or the same term can be used with a different meaning. We think that the lack of a standardization may cause a significant delay to the diffusion of the agent paradigm outside research context. Working for this unification goal, it is also necessary to define in unambiguous way the terms of the agent model and their relationships thus obtaining a unified MAS meta-model. In this work we propose the PASSI MAS meta-model, the results of its adaptation to the needs of an agile process (Agile PASSI), and a comparison with an existing unifying proposal of MAS meta-model composed by considering three different processes (ADELFE, Gaia and PASSI). \ua9 Springer-Verlag Berlin Heidelberg 2005

    Ceramiche fini e iscrizioni da Alberone di Ro (Fe) e dal territorio copparese, inquadramento preliminare

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    Il contributo prende in esame alcuni aspetti del popolamento di etĂ  romana ad Alberone di Ro (FE) e nel territorio copparese. In particolare, esso fornisce nuovi dati inediti sulle ceramiche fini (vernice nera, terra sigillata, pareti sottili) e sulle iscrizioni ritrovate negli scavi e nelle ricognizioni, realizzati sul territorio
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