48 research outputs found

    Effects of disturbance on sandy coastal ecosystems of N-Adriatic coasts (Italy)

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    Coastal sand dune landscapes hold habitats of high economic, social and ecological value on a global scale. At the same time, they are among the most threatened ecosystems worldwide, facing escalating anthropogenic pressures, drawing attention to their resilience as a necessary condition for both biodiversity conservation and sustainable development. This study describes the vegetation zonation of the North-Adriatic coastal landscape which suffers from a severe and complex human utilization meanwhile holding high landscape, faunal and floral values. As plant communities, because of their specific nature, are considered good indicators of overall biodiversity and of ecosystem integrity of coastal dune environments, effects of both human and natural disturbance have been analysed through a comparison between real and potential coastal vegetation, using a hierarchical landscape classification approach. To provide a comprehensive framework for sustainable coastal management and development, a multiscale method for the assessment of the conservation status of sandy coastal environment has been applied. The assessing methodology focused first on landscape level by means of structural and compositional indicators. At a more detailed scale, floristic, vegetational and structural aspects of plant communities were analyzed along the main environmental gradient, which develops moving inland from the sea edge. Conservation status of N-Adriatic coastal zonation resulted fairly good at only few sites along the coast, mostly located where urban development and tourism are limited by legislation or simply because of the difficulty in reaching them. Elsewhere, real vegetation is deeply different from the potential zonation: erosion and tourism pressures truncate the first elements of the zonation, while towns and villages, coastal roads, pines plantations and agriculture truncate the last stages and sandy systems are trapped between erosion on the sea side and human settlements inlands, with no space for natural sediment dynamics and communities development

    PRINCIPALI SPECIE VEGETALI ALLOCTONE E INVASIVE PRESENTI NEGLI HABITAT NATURA 2000 DELLE DUNE DEL LITORALE NORD ADRIATICO (NE ITALIA)

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    Coastal sand dunes are one of the most threatened ecosystems worldwide due to habitat fragmentation and loss, and alien invasion. On the basis of several phytosociological surveys carried out over time along the Venetian coastline, we have compiled a list of the Natura 2000 habitats and a list of the alien plant taxa present therein. Three plant communities were found on mobile dunes, corresponding to three Natura 2000 habitats: 1210 (plant community: Salsolo-Cakiletum), 2110 (Sporobolo-Agropyretum), 2120 (Echinophoro-Ammophiletum). On fixed dunes there are 8 plant communities, corresponding to seven Natura 2000 habitats: 2130* (Tortulo-Scabiosetum), 2160 (Junipero-Hippophaetum), 2230 (Sileno-Vulpietum), 2250* (Viburno-Phillyreetum and Erico-Osyridetum), 2270* (pine woods), 62A0 (Teucrio-Chrysopogonetum) and 9340 (Vincetoxico-Quercetum). There are 31 alien species on these 10 habitats and the most frequent are Amorpha fruticosa, Oenothera stucchii, Ambrosia psilostachya, Xanthium orientale subsp. italicum, Erigeron canadensis, Senecio inaequidens, Cenchrus longispinus, and Spartina versicolor. For each of the most frequent species an explanatory file with information about the place of origin, period and pathways of introduction, present status for Italy and Veneto region, preferred habitats and some notes on the ecology and impacts has been provided

    Increase of multidrug-resistant bacteria after the COVID-19 pandemic in a major teaching Hospital in Sicily (2018-2021)

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    Introduction: The COVID-19 pandemic has further highlighted the continuing threat of antimicrobial resistance (AMR) to global health and economic development. In the last two decades, AMR has raised increasing concern, with an estimated 4.95 million deaths globally due to bacterial AMR in 2019 alone. The aim of this study was to analyse the impact of the pandemic on the spread of multidrug-resistant organisms (MDROs) using data from the Hospital "P. Giaccone" in Palermo, comparing pre-pandemic and pandemic periods. Methods: This observational study involved adult patients who were discharged from the hospital between 01 January 2018 and 31 December 2021. Hospital Discharge Cards were linked with microbiological laboratory reports to assess MDRO isolations. SARS-CoV-2 positivity during hospitalisation was evaluated using the National Institute of Health surveillance system. Results: A total of 58 427 hospitalisations were evaluated in this study. Half the patients were aged over 65 years (N=26 984) and most admissions were in the medical area (N=31 716). During the hospitalisation period, there were 2681 patients (5%) with MDROs isolations, and 946 patients (2%) were positive for SARS-CoV-2. Multivariable analyses showed that during 2020 and 2021, there was a significantly increased risk of isolation of Staphylococcus aureus, Acinetobacter baumannii, and Klebsiella pneumoniae. Age, weight of the Diagnosis-Related Group (DRG), wards with higher intensity of care, and length-of-stay were associated with a higher risk of MDRO isolation. Conclusion: This study provides new insights into the impact of the COVID-19 pandemic on MDRO isolation and has important implications for infection control and prevention efforts in healthcare facilities. Age, DRG-weight, and longer hospital stays further increased the risk of MDRO isolation. Thus, it is imperative to improve and follow hospital protocols to prevent healthcare-associated infections

    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 response of plant community diversity to alien invasion: evidence from a sand dune time series

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    This study examines the process of invasion of coastal dunes in north-eastern Italy along a 60-year time series considering alien attributes (origin, residence time, invasive status, and growth form strategy) and habitat properties (species richness, diversity and evenness, proportion of aliens, and proportion of focal species). Vegetation changes through time were investigated in four sandy coastal habitats, using a fine-scale diachronic approach that compared vegetation data collected by use of the same procedure, in four time periods, from the 1950s to 2011. Our analysis revealed an overall significant decline of species richness over the last six decades. Further, both the average number of species per plot and the mean focal species proportion were proved to be negatively affected by the increasing proportion of alien species at plot level. The severity of the impact, however, was found to be determined by a combination of species attributes, habitat properties, and human disturbance suggesting that alien species should be referred to as ‘‘passengers’’ and not as ‘‘drivers’’ of ecosystem change. Passenger alien species are those which take advantage of disturbances or other changes to which they are adapted but that lead to a decline in native biodiversity. Their spread is facilitated by widespread anthropogenic environmental alterations, which create new, suitable habitats, and ensure human-assisted dispersal, reducing the distinctiveness of plant communities and inducing a process of biotic homogenization

    An Efficient Damper of Thermal Oscillations for Two-Stage Pulse Tube Cryocoolers

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    We have developed a passive system to efficiently reduce the amplitude of temperature oscillations in low-frequency Pulse Tube (PT) cryocoolers. It consists of a small, well-insulated tank of liquid 4He, placed between the cold head of the PT and the user. As a result, we have been able to reduce the amplitude of thermal oscillations by a factor of 192, from 173 mK to 0.9 mK. The same damping efficiency can be obtained even if a thermal power of up to 100 mW is dissipated over it: the temperature oscillations remain consistently small as long as the Helium remains in its liquid phase. Even after its transition to the gas phase, the thermal oscillations continue to be stable, and despite increasing in amplitude by one order of magnitude, reaching 9 mK, they remain 19 times lower than those at the cold head of the PT. The advantage of this tool resides in the fact that it is a small, very compact sealed Helium reservoir, free of moving parts and external links

    Addendum to: The brightness temperature of Mercury at 150 and 240 GHz. The brightness temperature of Mars at millimetre wavelengths

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    We present new measurements of Mars at 1.25 and 2mm of wavelength, in addition to the previous ones performed on Mercury and already published in our paper "The brightness temperature of Mercury at 150 and 240GHz". A brief description of the observational strategy is given, and brightness temperature of the planet is reported

    Millimetric Site Testing at Dome C: Results and Plans

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    AbstractResults relative to three campaigns at Dome Concordia, aimed to measure the millimetric sky noise, are presented. The atmospheric noise during summer seems to be definitely lower with respect to that measured with the same instrumentation in other geographical locations. We illustrate the scientific results obtained

    The response of plant community diversity to alien invasion: Evidence from a sand dune time series

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    This study examines the process of invasion of coastal dunes in north-eastern Italy along a 60-year time series considering alien attributes (origin, residence time, invasive status, and growth form strategy) and habitat properties (species richness, diversity and evenness, proportion of aliens, and proportion of focal species). Vegetation changes through time were investigated in four sandy coastal habitats, using a fine-scale diachronic approach that compared vegetation data collected by use of the same procedure, in four time periods, from the 1950s to 2011. Our analysis revealed an overall significant decline of species richness over the last six decades. Further, both the average number of species per plot and the mean focal species proportion were proved to be negatively affected by the increasing proportion of alien species at plot level. The severity of the impact, however, was found to be determined by a combination of species attributes, habitat properties, and human disturbance suggesting that alien species should be referred to as “passengers” and not as “drivers” of ecosystem change. Passenger alien species are those which take advantage of disturbances or other changes to which they are adapted but that lead to a decline in native biodiversity. Their spread is facilitated by widespread anthropogenic environmental alterations, which create new, suitable habitats, and ensure human-assisted dispersal, reducing the distinctiveness of plant communities and inducing a process of biotic homogenization
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