378 research outputs found

    Application of effect-based methods (EBMs) in a river basin: a preliminary study in Central Italy

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    Introduction. Effect-based methods (EBMs), i.e. in vitro and in vivo bioassays, represent innovative tools for the effect detection of environmental chemical pollutants on living organisms. The aim of this study was to evaluate the water quality of a river ecosystem implementing two in vivo bioassays on target freshwater animal species: the crustacean Daphnia magna and the small fish Danio rerio, also known as zebrafish. Materials and methods. The methods applied in this study, i.e. the Daphnia sp. Acute Immobilisation assay and the Fish Embryo Acute Toxicity (FET) test, are commonly used in water quality research and their application in short-term ecotoxicity detection is suggested by recent European projects. Two sampling sites were chosen in the urban part of the Tiber River in Rome, while a third one was chosen as a reference site in the Farfa River, a tributary upstream of the city. The sites in the Tiber River are potentially affected by different pollution sources, including urban and industrial wastewater discharges, the pesticide release, livestock waste products, and waste dumps. Results and discussion. The results of the study showed wide differences between the two applied bioassays. The FET test was generally more sensitive in detecting even low effects in all the water samples, but the strongest statistically results were observed with the D. magna Acute Immobilisation test. The results of this research confirm the effectiveness of EBMs in investigating and monitoring water chemical pollution, and stress the need for performing further studies, e.g. chemical analyses and other bioassays, to improve the knowledge of the health status of the Tiber River basin. Conclusions. Further results will aim to support the local authorities in adopting measures to reduce and to eliminate the sources of chemical pollution in the study area

    Near real-time analysis of active distribution networks in a Digital Twin framework. A real case study

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    The growth of distributed generation and the need of increasing Distribution Network (DN) resilience is encouraging Distribution System Operators (DSO) to increase awareness about the real-time status of the network as well as to actively manage flexible energy resources for improving system performances. In this context, Digital Twin (DT) is an enabling technology for a low-cost distributed framework that supports DN management. DT in the power system can be exploited taking advantage of the successful experiences in other sectors (e.g., smart manufacturing and building automation). This article presents a real case study of a DT development and its integration with an existing DN. The DT system architecture is based on the recent standards whilst main DT components have been originally developed, enabling near real-time services such as data collection, state estimation, and flexibility calculator. The individual performances of the integrated tools and the reliability of DT were tested and validated during one month of continuous operation. During the operation, good service continuity and accuracy performances were reported. Results from the flexibility calculator show the effectiveness of the proposed strategies that can improve the energy efficiency of the DN by increasing local self-consumption of Renewable Energy Sources (RES) production

    Fish-Kills in the Urban Stretch of the Tiber River After a Flash-Storm: Investigative Monitoring with Effect-Based Methods, Targeted Chemical Analyses, and Fish Assemblage Examinations

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    In 2020 and 2021, fish-kills events occurred in the Tiber river in the city of Rome. These events, which caused the death of thousands of fish of different species (e.g., Barbus spp., Cyprinus carpio, Squalius spp.), were preceded the days before by severe flash-storms. Heavy rains in urban areas in recent years are linked to climate change and fish-kills events. With the aim to investigate the causes of these events, effect-based methods (EBMs) and targeted chemical analyses have been performed on a specific site of river Tiber in the center of the city. Additionally, examination and classification of the floating dead fishes have been performed. The chemical analysis performed on several groups of contaminants showed the presence of some pharmaceuticals, insecticides, and PFAS at up to ng/L. Results with the Fish Embryo Toxicity (FET) test confirmed lethal and sub-lethal effects, while acute effects were not detected with the Daphnia magna acute test. The fish-kills events probably can be generated by several factors as a consequence of an increasing human anthropization of the area with the contribution of different stressors together with chemical releases and emissions. This study shows that in multiple stressor scenarios characterized by heavy rainfall, droughts, and strong anthropogenic pressures, the application of EBMs, chemical analysis, and fish assemblage examinations can represent a useful support in the investigation of the causes of extensive fish-kills events

    Thermophilic methane oxidation is widespread in Aotearoa-New Zealand geothermal fields

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    Geothermal areas represent substantial point sources for greenhouse gas emissions such as methane. While it is known that methanotrophic microorganisms act as a biofilter, decreasing the efflux of methane in most soils to the atmosphere, the diversity and the extent to which methane is consumed by thermophilic microorganisms in geothermal ecosystems has not been widely explored. To determine the extent of biologically mediated methane oxidation at elevated temperatures, we set up 57 microcosms using soils from 14 Aotearoa-New Zealand geothermal fields and show that moderately thermophilic (>40°C) and thermophilic (>60°C) methane oxidation is common across the region. Methane oxidation was detected in 54% (n = 31) of the geothermal soil microcosms tested at temperatures up to 75°C (pH 1.5–8.1), with oxidation rates ranging from 0.5 to 17.4 μmol g−1 d−1 wet weight. The abundance of known aerobic methanotrophs (up to 60.7% Methylacidiphilum and 11.2% Methylothermus) and putative anaerobic methanotrophs (up to 76.7% Bathyarchaeota) provides some explanation for the rapid rates of methane oxidation observed in microcosms. However, not all methane oxidation was attributable to known taxa; in some methane-consuming microcosms we detected methanotroph taxa in conditions outside of their known temperature range for growth, and in other examples, we observed methane oxidation in the absence of known methanotrophs through 16S rRNA gene sequencing. Both of these observations suggest unidentified methane oxidizing microorganisms or undescribed methanotrophic syntrophic associations may also be present. Subsequent enrichment cultures from microcosms yielded communities not predicted by the original diversity studies and showed rates inconsistent with microcosms (≤24.5 μmol d−1), highlighting difficulties in culturing representative thermophilic methanotrophs. Finally, to determine the active methane oxidation processes, we attempted to elucidate metabolic pathways from two enrichment cultures actively oxidizing methane using metatranscriptomics. The most highly expressed genes in both enrichments (methane monooxygenases, methanol dehydrogenases and PqqA precursor peptides) were related to methanotrophs from Methylococcaceae, Methylocystaceae and Methylothermaceae. This is the first example of using metatranscriptomics to investigate methanotrophs from geothermal environments and gives insight into the metabolic pathways involved in thermophilic methanotrophy

    Toxicity and genotoxicity of wastewater from gasoline stations

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    The toxicity and genotoxicity of wastewater from eight gasoline stations in BrasĂ­lia, Brazil's capital city, was studied by assessing chromosomal aberrations, chromosomal malsegregation and the mitotic index in Alliumcepa root cells, and the occurrence of micronucleus and nuclear abnormalities in peripheral erythrocytes of tilapia fish (Oreochromis niloticus). The content of gasoline station effluents was also analyzed based on several physico-chemical parameters. None of the wastewater samples was genotoxic to A. cepa root cells, although cell proliferation was significantly inhibited, especially at the highest concentrations. Likewise, no micronuclei were observed in O. niloticus peripheral erythrocytes, even after exposure to high concentrations, but there was an increase in the number of nuclear abnormalities and fish mortality. These results show that although the effluent from gasoline stations is processed by an oil/water separation system before being discharged into the main sewage system, the wastewater still contains toxic compounds

    A gamma-lactamase from cereal infecting Fusarium spp. catalyses the first step in the degradation of the benzoxazolinone class of phytoalexins

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    The benzoxazolinone class of phytoalexins are released by wheat, maize, rye and other agriculturally important species in the Poaceae family upon pathogen attack. Benzoxazolinones show antimicrobial effects on plant pathogens, but certain fungi have evolved mechanisms to actively detoxify these compounds which may contribute to the virulence of the pathogens. In many Fusarium spp. a cluster of genes is thought to be involved in the detoxification of benzoxazolinones. However, only one enzyme encoded in the cluster has been unequivocally assigned a role in this process. The first step in the detoxification of benzoxazolinones in Fusarium spp. involves the hydrolysis of a cyclic ester bond. This reaction is encoded by the FDB1 locus in F. verticillioides but the underlying gene is yet to be cloned. We previously proposed that FDB1 encodes a Îł-lactamase, and here direct evidence for this is presented. Expression analyses in the important wheat pathogen F. pseudograminearum demonstrated that amongst the three predicted Îł-lactamase genes only the one designated as FDB1, part of the proposed benzoxazolinone cluster in F. pseudograminearum, was strongly responsive to exogenous benzoxazolinone application. Analysis of independent F. pseudograminearum and F. graminearum FDB1 gene deletion mutants, as well as biochemical assays, demonstrated that the Îł-lactamase enzyme, encoded by FDB1, catalyses the first step in detoxification of benzoxazolinones. Overall, our results support the notion that Fusarium pathogens that cause crown rot and head blight on wheat have adopted strategies to overcome host-derived chemical defences

    Percutaneous coronary intervention for cardiogenic shock in the SHOCK trial

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    AbstractObjectivesWe examined the clinical, angiographic, and procedural characteristics determining survival after percutaneous coronary intervention (PCI) for cardiogenic shock.BackgroundThe SHOCK (SHould we emergently revascularize Occluded coronaries for Cardiogenic shocK?) trial prospectively enrolled patients with shock complicating acute myocardial infarction (MI). Patients were randomized to a strategy of early revascularization or initial medical stabilization.MethodsPatients randomized to early revascularization underwent PCI or bypass surgery on the basis of predefined clinical criteria. Patients randomized to early revascularization who underwent PCI and had angiographic films available for analysis are the subject of this report (n = 82).ResultsThe median time from MI to PCI was 11 h. The majority of patients had occluded culprit arteries (Thrombolysis In Myocardial Infarction [TIMI] grade 0 or 1 flow in 62%) and multivessel disease (81%). One-year mortality in PCI patients was 50%. Mortality was 39% if PCI was successful but 85% if unsuccessful (p < 0.001). Mortality was 38% if TIMI flow grade 3 was achieved, 55% with TIMI grade 2 flow, and 100% with TIMI grade 0 or 1 flow (p < 0.001). Mortality was 67% if severe mitral regurgitation was documented. Independent correlates of mortality were as follows: increasing age (p < 0.001), lower systolic blood pressure (p = 0.009), increasing time from randomization to PCI (p = 0.019), lower post-PCI TIMI flow (0/1 vs. 2/3) (p < 0.001), and multivessel PCI (p = 0.040).ConclusionsRestoration of coronary blood flow is a major predictor of survival in cardiogenic shock. Benefit appears to extend beyond the generally accepted 12-h post-infarction window. Surgery should be considered in shock patients with severe mitral insufficiency or multivessel disease not amenable to relatively complete percutaneous revascularization

    Incidence, Predictors, and Significance of Abnormal Cardiac Enzyme Rise in Patients Treated With Bypass Surgery in the Arterial Revascularization Therapies Study (ARTS)

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    BACKGROUND: Although it has been suggested that elevation of CK-MB after percutaneous coronary intervention is associated with adverse clinical outcomes, limited data are available in the setting of coronary bypass grafting. The aim of the present study was to determine the incidence, predictors, and prognostic significance of CK-MB elevation following multivessel coronary bypass grafting (CABG). METHODS AND RESULTS: The population comprises 496 patients with multivessel coronary disease assigned to CABG in the Arterial Revascularization Therapies Study (ARTS). CK-MB was prospectively measured at 6, 12, and 18 hours after the procedure. Thirty-day and 1-year clinical follow-up were performed. Abnormal CK-MB elevation occurred in 61.9% of the patients. Patients with increased cardiac-enzyme levels after CABG were at increased risk of both death and repeat myocardial infarction within the first 30 days (P=0.001). CK-MB elevation was also independently related to late adverse outcome (P=0.009, OR=0.64). CONCLUSIONS: Increased concentrations of CK-MB, which are often dismissed as inconsequential in the setting of multivessel CABG, appear to occur very frequently and are associated with a significant increase in both repeat myocardial infarction and death beyond the immediate perioperative period
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