283 research outputs found

    Genomic Origin and Organization of the Allopolyploid Primula egaliksensis Investigated by in situ Hybridization

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    Background and Aims Earlier studies have suggested that the tetraploid Primula egaliksensis (2n = 40) originated from hybridization between the diploids P. mistassinica (2n = 18) and P. nutans (2n = 22), which were hypothesized to be the maternal and paternal parent, respectively. The present paper is aimed at verifying the hybrid nature of P. egaliksensis using cytogenetic tools, and to investigate the extent to which the parental genomes have undergone genomic reorganization. Methods Genomic in situ hybridization (GISH) and fluorescent in situ hybridization (FISH) with ribosomal DNA (rDNA) probes, together with sequencing of the internal transcribed spacer (ITS) region of the rDNA, were used to identify the origin of P. egaliksensis and to explore its genomic organization, particularly at rDNA loci. Key Results GISH showed that P. egaliksensis inherited all chromosomes from P. mistassinica and P. nutans and did not reveal major intergenomic rearrangements between the parental genomes (e.g. interchromosomal translocations). However, karyological comparisons and FISH experiments suggested small-scale rearrangements, particularly at rDNA sites. Primula egaliksensis lacked the ITS-bearing heterochromatic knobs characteristic of the maternal parent P. mistassinica and maintained only the rDNA loci of P. nutans. These results corroborated sequence data indicating that most ITS sequences of P. egaliksensis were of the paternal repeat type. Conclusions The lack of major rearrangements may be a consequence of the considerable genetic divergence between the putative parents, while the rapid elimination of the ITS repeats from the maternal progenitor may be explained by the subterminal location of ITS loci or a potential role of nucleolar dominance in chromosome stabilization. These small-scale rearrangements may be indicative of genome diploidization, but further investigations are needed to confirm this assumptio

    An introduction to the early Holocene eolian deposits of Grotta Romanelli, Apulia, Southern Italy

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    Due to its geographic position and geomorphological configuration, Grotta Romanelli acted as a sediment trap since at least MIS 5. The so-called 'terre brune' sequence is a deposit mainly of eolian origin bearing upper Palaeolithic artefacts and fossil re-mains of vertebrate fauna; it was deposited during the Glacial-Interglacial transition and the Holocene. Sedimentology and mineralogy of this deposit are investigated. The stratigraphic sequence provides a promising archive within which both human and climatic impacts can be studied

    Pediatric Stroke: Clinical Findings and Radiological Approach

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    This paper focuses on radiological approach in pediatric stroke including both ischemic stroke (Arterial Ischemic Stroke and Cerebral Sinovenous Thrombosis) and hemorrhagic stroke. Etiopathology and main clinical findings are examined as well. Magnetic Resonance Imaging could be considered as the first-choice diagnostic exam, offering a complete diagnostic set of information both in the discrimination between ischemic/hemorrhagic stroke and in the identification of underlying causes. In addition, Magnetic Resonance vascular techniques supply further information about cerebral arterial and venous circulation. Computed Tomography, for its limits and radiation exposure, should be used only when Magnetic Resonance is not available and on unstable patients

    Static modelling of geological structures for carbon sequestration purposes in the Lorestan area of Iran

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    One of the most important methods aimed at climate mitigation technology is carbon geological sequestration. During the process of site selection and characterization required for evaluation of capacity storage potential of a given region, geological static modelling plays an essential role by providing a better understanding of the structure in terms of petrophysical and geological characteristics. This work presents the 3D geological model of several anticlines in the Lorestan area (northwestern Zagros), to evaluate their carbon storage capacity potential. The 3D geological model is based on seismic data and well-log data from 2 wells drilled in the area, kindly provided by the National Iranian Oil company (NIOC). Preliminary well logs analysis allowed to identify potential target formations by considering pivotal criteria of CO2 storage such as depth, porosity, and other petrophysical characteristics. The 3D model will be followed by the construction of a geocellular model that will be populated by petrophysical data obtained from well logs. The reconstructed volume will be then used for injection simulations to obtain an evaluation of the volume available for storage. The dynamic simulation will also provide and support the evaluation of other important aspects such as the injection strategies and efficiency coefficient, comparing the observed theoretical and effective capacity

    Time-dependent metabolic disorders induced by short-term exposure to polystyrene microplastics in the Mediterranean mussel Mytilus galloprovincialis.

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    Abstract In the modern society, plastic has achieved a crucial status in a myriad of applications because of its favourable properties. Despite the societal benefits, plastic has become a growing global concern due to it is persistence and bioavailability as microplastics (MPs) to aquatic biota. In order to provide mechanistic insights into the early toxicity effects of MPs on aquatic invertebrates, a short-term (up to 72 h) exposure to 3 µm red polystyrene MPs (50 particles/mL) was conducted on marine mussels Mytilus galloprovincialis, selected as model organism for their ability to ingest MPs and their commercial relevance. The use of protonic Nuclear Magnetic Resonance (1H NMR)-based metabolomics, combined with chemometrics, enabled a comprehensive exploration at fixed exposure time-points (T24, T48, T72) of the impact of MPs accumulated in mussel digestive glands, chosen as the major site for pollutants storage and detoxification processes. In detail, 1H NMR metabolic fingerprints of MP-treated mussels were clearly separated from control and grouped for experimental time-points by a Principal Component Analysis (PCA). Numerous metabolites, including amino acids, osmolytes, metabolites involved in energy metabolism, and antioxidants, participating in various metabolic pathways significantly changed over time in MP-exposed mussel digestive glands related to control, reflecting also the fluctuations in MPs accumulation and pointing out the occurrence of disorders in amino acid metabolism, osmotic equilibrium, antioxidant defense system and energy metabolism. Overall, the present work provides the first insights into the early mechanisms of toxicity of polystyrene MPs in marine invertebrates

    An introduction to the early Holocene eolian deposits of Grotta Romanelli, Apulia, Southern Italy

    Get PDF
    Due to its geographic position and geomorphological configuration, Grotta Romanelli acted as a sediment trap since at least MIS 5. The so-called ‘terre brune’ sequence is a deposit mainly of eolian origin bearing upper Palaeolithic artefacts and fossil remains of vertebrate fauna; it was deposited during the Glacial-Interglacial transition and the Holocene. Sedimentology and mineralogy of this deposit are investigated. The stratigraphic sequence provides a promising archive within which both human and climatic impacts can be studied
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