299 research outputs found

    Coexisting with the alien: Evidence for environmental control on trophic interactions between a native (Atherina boyeri) and a non-indigenous fish species (Gambusia holbrooki) in a Mediterranean coastal ecosystem

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    Biological invasions are a widespread problem worldwide, as invasive non-indigenous species (NIS) may affect native populations through direct (e. g., predation) or indirect (e.g., competition) trophic interactions, leading to changes in the food web structure. The trophic relationships of the invasive eastern mosquitofish Gambusia holbrooki and the native big-scale sand smelt Atherina boyeri coexisting in three Mediterranean coastal ponds characterized by different trophic statuses (from oligotrophic to hypereutrophic) were assessed in spring through isotopic niche analysis and Bayesian mixing models. The two fish relied on the distinctive trophic pathways in the different ponds, with the evidence of minimal interspecific niche overlap indicating site-specific niche divergence mechanisms. In more detail, under hypereutrophic and mesotrophic conditions, the two species occupied different trophic positions but relying on a single trophic pathway, whereas, under oligotrophic conditions, both occupied a similar trophic position but belonging to distinct trophic pathways. Furthermore, the invaders showed the widest niche breadth while the native species showed a niche compression and displacement in the ponds at a higher trophic status compared to the oligotrophic pond. We argue that this may be the result of an asymmetric competition arising between the two species because of the higher competitive ability of G. holbrooki and may have been further shaped by the trophic status of the ponds, through a conjoint effect of prey availability and habitat complexity. While the high trophic plasticity and adaptability of both species to different environmental features and resource availability may have favored their coexistence through site-specific mechanisms of niche segregation, we provide also empirical evidence of the importance of environmental control in invaded food webs, calling for greater attention to this aspect in future studies

    Analysis of the Blood Viscosity Behavior in the Sicilian Study on Juvenile Myocardial Infarction

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    Considering the role of hemorheology in coronary circulation, we studied blood viscosity in patients with juvenile myocardial infarction. We examined whole blood viscosity at high shear rate using the cone-on-plate viscosimeter Wells-Brookfield \ubd LVT and at low shear rate employing a viscometer Contraves LS30 in 120 patients (aged <46 years) with myocardial infarction, at the initial stage and subsequently 3 and 12 months after. At the initial stage, patients had an increased whole blood viscosity in comparison to normal controls. This hemorheological profile was not influenced by the cardiovascular risk factors, nor by the extent of coronary lesions, even if some differences were evident between patients with ST-segment elevation myocardial infarction (STEMI) and non-STEMI (NSTEMI). The blood viscosity pattern at the initial stage did not influence recurring ischemic events or the onset of heart failure during an 18 months\u2019 follow-up. The neutrophil to lymphocyte ratio did not affect the blood viscosity pattern. We reevaluated 83 patients 3 months after and 70 patients 12 months after the acute coronary syndrome, and we found that the hemorheological parameters were still altered in comparison to normal controls at both times. We observed an impairment of the hemorheological pattern in young patients with myocardial infarction, partially influenced by the infarction type (STEMI and NSTEMI) and persisting in the long term

    An evaluation of coronary atherosclerosis using coronary CT in subjects with asymptomatic carotid lesions.

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    The evaluation of coronary lesions in patients with asymptomatic carotid plaque represents a very promising line of research to assess cardiovascular risk and the possible implementation of a more aggressive prevention therapy. METHODS: In this study we enrolled 102 patients with intermediate to high cardiovascular risk but no history of coronary artery disease. The first group, consisting of 51 patients, underwent a Coronary CT scan (CCT-group) as well as carotid ultrasonography. The second group, also consisting of 51 patients, underwent coronary angiography (CA) and carotid ultrasonography. RESULTS: The absence of a statistically significant difference between the involvement of both coronary and carotid sites, assessed by CCT and CA, confirms the role of coronary CT as a useful method in the preclinical evaluation of cardiovascular risk. In the CCT group, the correlation between atherosclerosis of carotid artery and coronary disease, as well as between the mean carotid intimal medial thickness and the number of involved coronary vessels, and between the maximum values of carotid plaque and the presence of coronary artery stenosis > 50%, were statistically significant. The Agatson calcium score was also statistically associated with carotid plaque size. CONCLUSION: The imaging biomarkers have a key role in the evaluation of subclinical atherosclerotic disease. Moreover, carotid ultrasound examination and a CT-scan of coronary arteries, in a particular sub-group of patients with intermediate to high cardiovascular risk, can play a crucial role to assess the preventive therapeutic strategies

    Detection of influenza virus in urban wastewater during the season 2022/2023 in Sicily, Italy

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    Introduction: Seasonal influenza generally represents an underestimated public health problem with significant socioeconomic implications. Monitoring and detecting influenza epidemics are important tasks that require integrated strategies. Wastewater-based epidemiology (WBE) is an emerging field that uses wastewater data to monitor the spread of disease and assess the health of a community. It can represent an integrative surveillance tool for better understanding the epidemiology of influenza and prevention strategies in public health. Methods: We conducted a study that detected the presence of Influenza virus RNA using a wastewater-based approach. Samples were collected from five wastewater treatment plants in five different municipalities, serving a cumulative population of 555,673 Sicilian inhabitants in Italy. We used the RT-qPCR test to compare the combined weekly average of Influenza A and B viral RNA in wastewater samples with the average weekly incidence of Influenza-like illness (ILI) obtained from the Italian national Influenza surveillance system. We also compared the number of positive Influenza swabs with the viral RNA loads detected from wastewater. Our study investigated 189 wastewater samples. Results: Cumulative ILI cases substantially overlapped with the Influenza RNA load from wastewater samples. Influenza viral RNA trends in wastewater samples were similar to the rise of ILI cases in the population. Therefore, wastewater surveillance confirmed the co-circulation of Influenza A and B viruses during the season 2022/2023, with a similar trend to that reported for the weekly clinically confirmed cases. Conclusion: Wastewater-based epidemiology does not replace traditional epidemiological surveillance methods, such as laboratory testing of samples from infected individuals. However, it can be a valuable complement to obtaining additional information on the incidence of influenza in the population and preventing its spread

    Structure and Function of Iron-Loaded Synthetic Melanin

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    We describe a synthetic method for increasing and controlling the iron loading of synthetic melanin nanoparticles and use the resulting materials to perform a systematic quantitative investigation on their structure 12property relationship. A comprehensive analysis by magnetometry, electron paramagnetic resonance, and nuclear magnetic relaxation dispersion reveals the complexities of their magnetic behavior and how these intraparticle magnetic interactions manifest in useful material properties such as their performance as MRI contrast agents. This analysis allows predictions of the optimal iron loading through a quantitative modeling of antiferromagnetic coupling that arises from proximal iron ions. This study provides a detailed understanding of this complex class of synthetic biomaterials and gives insight into interactions and structures prevalent in naturally occurring melanins

    Postnatal Aversive Experience Impairs Sensitivity to Natural Rewards and Increases Susceptibility to Negative Events in Adult Life

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    Evidence shows that maternal care and postnatal traumatic events can exert powerful effects on brain circuitry development but little is known about the impact of early postnatal experiences on processing of rewarding and aversive stimuli related to the medial prefrontal cortex (mpFC) function in adult life. In this study, the unstable maternal environment induced by repeated cross-fostering (RCF) impaired palatable food conditioned place preference and disrupted the natural preference for sweetened fluids in the saccharin preference test. By contrast, RCF increased sensitivity to conditioned place aversion (CPA) and enhanced immobility in the forced swimming test. Intracerebral microdialysis data showed that the RCF prevents mpFC dopamine (DA) outflow regardless of exposure to rewarding or aversive stimuli, whereas it induces a strong and sustained prefrontal norepinephrine (NE) release in response to different aversive experiences. Moreover, the selective mpFC NE depletion abolished CPA, thus indicating that prefrontal NE is required for motivational salience attribution to aversionrelated stimuli. These findings demonstrate that an unstable maternal environment impairs the natural propensity to seek pleasurable sources of reward, enhances sensitivity to negative events in adult life, blunts prefrontal DA outflow, and modulates NE release in the reverse manner depending on the exposure to rewarding or aversive stimuli
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