29 research outputs found

    Variation of leaf litter decomposition among rivers, lagoons and sea: an experiment from Corfu island (Greece)

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    In aquatic ecosystems, the decomposition of organic detritus represents one of the most important ecosystem functions, which support complex detritus-based food webs that determine the critical balance between carbon mineralization and sequestration. The performance of the decomposition process is usually expressed as rate of decomposition, being a synthetic measure that take into account both abiotic and biotic factors. Decomposition rates have been also applied to evaluate the ecological status in terms of ecological functionality. However, despite a growing number of studies have tested the rate of decomposition between leaves of different riparian tree species in different aquatic ecosystems including rivers, transitional waters and sea, no comparative study among ecosystems typology is available up to date. Here, we compare decomposition rates from rivers, lagoons and sea of Corfu island (Greece). Five sampling sites were fixed in each of the three of the most important rivers and lagoons; other five sampling sites were fixed in the sea around the island. Twelve leaf packs containing 3±0.005 g of oven-dried Phragmites australis leaves were submerged in April 2014 and retrieved in May 2014 (after 30 days). Abiotic parameters were recorded in both sampling times. The retrieved leaf packs were cleaned and the macroinvertebrates retained were removed, counted, identified at lower taxonomic level and weighted. Leaf pack decomposition rates were calculated, and their variability was compared within each aquatic ecosystem, within each ecosystem typology (river, lagoon, sea) and among ecosystem typology. The results are going to be presented on the poster

    Associations between Maternal and Offspring Hair Cortisol Concentrations and Child Behavioral Symptoms in Mother-Child Pairs with Perinatal Mental Disorders

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    Maternal perinatal mental disorders (PMD) are associated with developmental and behavioral problems in children, probably mediated by the programming of the hypothalamic–pituitary– adrenal (HPA) axis. Increased cortisol concentrations during the antenatal and perinatal periods have been related to long-term effects on children’s behavior and stress response. We aimed to investigate the association of hair cortisol concentrations (HCC) between mothers, with (n = 16) and without PMD (n = 30), and their children, aged between 18 and 48 months. Participants were evaluated with a clinical interview and questionnaires for the Depression Anxiety Stress Scale and the Child Behavior Checklist for ages 112 –5. Maternal and child HCCs were compared between the two groups. Children of the PMD group had increased symptoms of attention deficit hyperactivity disorder. A positive linear association between maternal and child HCC was observed only in the total sample of mother–child dyads and the control group. In the PMD group, children’s HCCs were significantly associated with child anxiety/depression symptoms. Aggressive behavior and oppositional/defiant problems correlated significantly with children’s own HCCs, and their mother’s too. These findings suggest that a chronic dysregulation of maternal and child HPA axis and their associations in the PMD dyads may underlie the linkage among prolonged maternal stress, child behavioral/emotional problems and stress responses. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

    Models of Solar Wind Structures and Their Interaction with the Earth's Space Environment

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    The discipline of "Space Weather" is built on the scientific foundation of solar-terrestrial physics but with a strong orientation toward applied research. Models describing the solar-terrestrial environment are therefore at the heart of this discipline, for both physical understanding of the processes involved and establishing predictive capabilities of the consequences of these processes. Depending on the requirements, purely physical models, semi-empirical or empirical models are considered to be the most appropriate. This review focuses on the interaction of solar wind disturbances with geospace. We cover interplanetary space, the Earth's magnetosphere (with the exception of radiation belt physics), the ionosphere (with the exception of radio science), the neutral atmosphere and the ground (via electromagnetic induction fields). Space weather relevant state-of-the-art physical and semi-empirical models of the various regions are reviewed. They include models for interplanetary space, its quiet state and the evolution of recurrent and transient solar perturbations (corotating interaction regions, coronal mass ejections, their interplanetary remnants, and solar energetic particle fluxes). Models of coupled large-scale solar wind-magnetosphere-ionosphere processes (global magnetohydrodynamic descriptions) and of inner magnetosphere processes (ring current dynamics) are discussed. Achievements in modeling the coupling between magnetospheric processes and the neutral and ionized upper and middle atmospheres are described. Finally we mention efforts to compile comprehensive and flexible models from selections of existing modules applicable to particular regions and conditions in interplanetary space and geospace
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