418 research outputs found

    A spatially distributed analysis of erosion susceptibility and sediment yield in a river basin by means of geomorphic parameters and regression relationships

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    International audienceIn the present work, an application of statistical regression relationships utilising geomorphic parameters is attempted in a spatially distributed mode, in order to predict the amount of river sediment supply at varying sections of the drainage network. Simple and multiple regression relationships utilising drainage density Dd and hierarchical anomaly index ?a as independent variables were applied to the Calvano watershed (Central Italy) at different degree of subdivision in tributary drainage basins, so as to assess their contribution to the whole watershed sediment yield balance. In the same way, the role of small hill-reservoirs as sediment-trap and that of areas affected by badlands and of tributary basins exposure were also investigated. Results were tested on the basis of sedimentation estimates from selected reservoirs. The relationships provided a yearly specific sediment yield (SSY) value for the Calvano stream which is according to the average observed SSY in river basins of central Italy flowing to the Adriatic Sea. The use of simple statistical relationships, such as those here adopted, can allow to recognise the sections along the main stream which are more critical in terms of sediment accumulation, which, on turn, can cause sudden water discharge increments and dangerous floods. This approach can provide a tool enabling to locate the hydraulic risk and to point out the areas where soil conservation practices or hydraulic works, such as periodic maintenance of riverbeds, are needed in order to reduce soil erosion and sediment accumulation

    Producing a Digital Hydrographic Map Aiming at Renewable Energy Potential Mapping of Lesotho

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    AbstractSome of the first outcomes of a project aiming at mapping the renewable energy potential in Lesotho are hereby presented. In particular, the present paper deals with the task of the project devoted to produce a digital hydrographic map of Lesotho and an associated geographic database. Different geographical, meteorological and hydrological data were collected in the first steps of the project. The hydrographic network was derived in vector format from a digital elevation model of Lesotho using geoprocessing tools in GIS environment. Results were compared with existing cartography and satellite images. Moreover, a methodology proposed in literature for the assessment of the theoretical maximum hydroelectric producibility at watershed level in Italy was applied to one of the main catchment areas of Lesotho. The activities planned to fulfil the objectives of the project are finally outlined

    Metabolomics and chemometrics of seven aromatic plants:carob, eucalyptus, laurel, mint, myrtle, rosemary and strawberry tree

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    Introduction: Arbutus unedo L. (strawberry tree), Ceratonia siliqua L. (carob), Eucalyptus camaldulensis Dehnh. (eucalyptus), Laurus nobilis L. (laurel), Mentha aquatica L. (water mint), Myrtus communis L. (common myrtle), and Rosmarinus officinalis L. (rosemary) are aromatic plants from the Mediterranean region whose parts and preparations are used for their nutritional properties and health benefits. Objectives: To evaluate and compare the metabolites profile, total phenol content (TPC), and antioxidant activity of plant leaves for their future use. Gas chromatography–mass spectrometry (GC–MS) was used for metabolomics. Data comparison was performed by chemometrics. Methodology: Polar and apolar extracts were analysed using untargeted GC–MS metabolomics followed by chemometrics (principal component analysis, heatmap correlation and dendrogram) to identify, quantify and compare the major organic compounds in the plants. Additionally, nuclear magnetic resonance (NMR) spectroscopy was used for the laurel polar extract to identify d-gluco-l-glycero-3-octulose whose presence was unclear from the GC–MS data. TPC and antioxidant assays were performed using classical methods (Folin–Ciocalteu, 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH)) and correlated to the phytochemical profiles. Results: Forty-three metabolites were identified including amino acids, organic acids, carbohydrates, phenols, polyols, fatty acids, and alkanes. Eight metabolites (d-fructose, d-glucose, d-mannose, gallic acid, quinic acid, myo-inositol, palmitic and stearic acids) were in common between all species. d-Gluco-l-glycero-3-octulose (37.29 ± 1.19%), d-pinitol (31.33 ± 5.12%), and arbutin (1.30 ± 0.44%,) were characteristic compounds of laurel, carob, and strawberry tree, respectively. Carob showed the highest values of TPC and antioxidant activity. Conclusion: GC–MS metabolomics and chemometrics analyses are fast and useful methods to determine and compare the metabolomics profiling of aromatic plants of food and industrial interest.</p

    Metabolomic analysis and antioxidant activity of wild type and mutant Chia (Salvia hispanica L.) stem and flower grown under different irrigation regimes

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    BACKGROUND: Chia (Salvia hispanica L.) is a functional food from Central America. Interest in it is growing rapidly due to the many health benefits from the seed. However, when chia is grown at high latitudes, seed yield may be low whereas a high stem biomass and immature inflorescences are produced. Little is known about the chemical composition and the properties of stems and flowers. In this work, the metabolite profile, the antioxidant activity, and the total polyphenol content of stems and inflorescences were evaluated in a factorial experiment with different chia populations (commercial black chia and long-day flowering mutants G3, G8, and G17) and irrigation (100% and 50% of evapotranspiration).RESULTS: The results show the influence of irrigation and seed source on the antioxidant activity and total polyphenol content of chia flower and stem. Inflorescences exhibit higher antioxidant activity, suggesting their potential use as natural antioxidant. The mutants G3 and G8, at 50% irrigation, contained the highest amounts of compounds with nutraceutical value, especially within the flower. The mutant G17 showed lower antioxidant activity and polyphenol content compared to other seed sources but exhibited high omega 3 content in flowers but low in stems. This indicates that chia varieties should be chosen according to the objective of cultivation.CONCLUSION: These findings, indicating a close relation of metabolite content with irrigation and seed source, may provide the basis for the use of chia flower and stem for their nutraceutical value in the food, feed, and supplement industries.</p

    Spectroscopic and multivariate data-based method to assess the metabolomic fingerprint of Mediterranean plants

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    Introduction: Most secondary metabolites from plants have a prominent defensive role and repellency against predators and microbial pathogens. These properties largely vary among plant species and offer potential applications as biologically active compounds in medicine as well in agriculture. Objectives: We propose a new procedure that combine different spectroscopic techniques and multivariate data analysis to determine the chemical composition and the relative amounts of each metabolites and/or each class of organic compounds. The approach was used for a rapid identification of secondary metabolites from leaf and root of eight Mediterranean plants species. Methodology: The polar and the apolar extracts of two leaves and roots of each plant were analysed by proton nuclear magnetic resonance (1H-NMR) and gas chromatography coupled to mass spectrometry (GC–MS), respectively. Multivariate data analysis was used for a faster interpretation of data. Results: The metabolic fingerprint of the Mediterranean plants, Acanthus mollis, Dittrichia viscosa, Festuca drymeja, Fraxinus ornus, Fagus sylvatica, Hedera helix, Quercus ilex, and Typha latifolia, showed a complex chemical composition, being specific for each species and plant tissue. Two alditols, mannitol and quercitol, were found in manna ash (Fraxinus ornus) and holm oak (Q. ilex) polar leaf extracts, respectively. The highest levels of aromatic compounds were found in D. viscosa and T. latifolia. Fatty acids were the predominant class of compounds in all apolar extracts under investigation. Triterpene were almost exclusively found in roots, except for holm oak, where they constitute 58% of total extract. Steroids were widespread in leaf extracts. Conclusion: The major advantages of the proposed approach are versatility and rapidity, thus making it suitable for a fast comparison among species and plant tissue types.</p

    Pyrenosetin D, a new pentacyclic decalinoyltetramic acid derivative from the algicolous fungus Pyrenochaetopsis sp. FVE-087

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    The fungal genus Pyrenochaetopsis is commonly found in soil, terrestrial, and marine environments, however, has received little attention as a source of bioactive secondary metabolites so far. In a recent work, we reported the isolation and characterization of three new anticancer decalinoyltetramic acid derivatives, pyrenosetins A–C, from the Baltic Fucus vesiculosus-derived endophytic fungus Pyrenochaetopsis sp. FVE-001. Herein we report a new pentacyclic decalinoylspirotetramic acid derivative, pyrenosetin D (1), along with two known decalin derivatives wakodecalines A (2) and B (3) from another endophytic strain Pyrenochaetopsis FVE-087 isolated from the same seaweed and showed anticancer activity in initial screenings. The chemical structures of the purified compounds were elucidated by comprehensive analysis of HR-ESIMS, FT-IR, [α]D, 1D and 2D NMR data coupled with DFT calculations of NMR parameters and optical rotation. Compounds 1–3 were evaluated for their anticancer and toxic potentials against the human malignant melanoma cell line (A-375) and the non-cancerous keratinocyte cell line (HaCaT). Pyrenosetin D (1) showed toxicity towards both A-375 and HaCaT cells with IC50 values of 77.5 and 39.3 µM, respectively, while 2 and 3 were inactive. This is the third chemical study performed on the fungal genus Pyrenochaetopsis and the first report of a pentacyclic decalin ring system from the fungal genus Pyrenochaetopsis

    0235 : In vivo overexpression of a cardiac sodium channel mutant in mice

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    Loss-of-function mutations in the cardiac Na+ channel α-subunit gene, SCN5A, cause Brugada syndrome (BrS), a hereditary disease characterized by ventricular fibrillation and sudden cardiac death. We previously evidenced, in HEK cells, the dominant-negative effect of the R104W BrS mutation in Nav1.5, inducing the retention of the wild-type (WT) channel and the proteasomal degradation of the mutant protein. To explore this dominant-negative effect in vivo, we created a murine model using adeno-associated viruses (AAV).We used a dual AAV vector strategy combining viral DNA recombination and trans-splicing. One-week old mice were injected with two AAV serotypes capsid 9: one, packaging the cardiac specific troponin-T promoter, the 5’ half of hSCN5A, the 5’ donor site of a synthetic intron and a highly recombinogenic sequence; and another, packaging the same recombinogenic sequence, the 3’ acceptor site of the synthetic intron, the 3’ half of hSCN5A, the gfp gene as a reporter, and the SV40 polyA signal. Six weeks after injection, the hSCN5A full-gene expression and the percentage of transduced cardiac cells were assessed by qPCR, western blot (WB) analysis and immunohistochemistry on transduced heart tissues. The Na+ current was recorded by the patchclamp technique in isolated cardiomyocytes.Both WT and mutant human Nav1.5 transcripts and proteins were observed by RT-qPCR, WB and immunohistochemistry on injected-mice heart tissues. Patch-clamp recordings in WT-channel injected mice evidenced a two-fold increase of the Na+ current. In contrast, the cardiac Na+ current of R104Winjected mice was impaired (i.e. the current density was decreased by 45% and the activation was shifted by -4mV).Our data suggest that the trans-splicing and viral DNA recombination strategy using AAV9 serotype and a cardiac-specific promoter is successful to overexpress WT or mutant Na+ channels in mouse hearts. This approach allowed us to modulate the cardiac Na+ current in adult mice
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