94 research outputs found

    The relationships between functional and physicochemical soil parameters in metal(loid) mine tailings from Mediterranean semiarid areas support the value of spontaneous vegetation colonization for phytomanagement

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    Spontaneous growth of native vegetation in abandoned metal(loid) mine tailings can be valuable for phytomanagement restoration projects. This study aimed to assess the degree to which spontaneous plant colonization of abandoned metal(loid) mine tailings from Mediterranean semiarid areas led to functional soil improvement, and to identify, if possible, a critical level indicating that this functionality was moving towards that of the vegetated soils from the surroundings. Vegetation ecological indexes, plant life forms and species functional roles, together with physicochemical and functional soils parameters, were studied in metal(loid) mine tailings abandoned ~40 years ago and surrounding forests in SE Spain. Vegetation patches showed only small differences in physicochemical parameters related to soil abiotic stress conditions (pH, salinity and metals), regardless of the vegetation. However, vegetation patches with greater species diversity and richness and presence of plants with contrasted life forms and functional traits that facilitate the growth of less stress-tolerant species showed an increase of the soil microbial functionality (higher microbial biomass C, β-glucosidase activity, bacterial metabolic activity and functional diversity). Moreover, these vegetation patches showed a functional soil status comparable to that of the forests outside the mine tailings. In this sense, the present study showed the value of preserving these vegetation patches since they may act as nucleation spots favoring positive plant-soil feedbacks that may help to accelerate the functional recovery of these degraded areas. Furthermore, strategies to promote the creation of new vegetation patches including a variety of species with contrasted life forms and functional traits should be considered in phytomanagement restoration projects for abandoned metal(loid) mine tailings.The present study was supported by the project RESCLICONT (CGL2016-80981-R), funded by the Ministry of Science, Innovation and Universities of Spain through FEDER funds; by the project METOXCLIM (PTDC/CTA-AMB/29557/2017), funded by FEDER, through COMPETE2020 - Programa Operacional Competitividade e Internacionalização (POCI), and by national funds (OE), through FCT/MCTES. Thanks are due to FCT/MCTES for the financial support to CESAM (UIDP/50017/2020+UIDB/50017/2020), through national funds. A. Peñalver-Alcalá was hired by the project RESCLICONT and received a grant from the Technical University of Cartagena for a short stay at the University of Aveiro. S. Peixoto holds a PhD grant (SFRH/BD/117738/2016) from FCT. I. Silva received a research fellowship from the METOXCLIM project (BI/CESAM/0063/METOXCLIM/2018). A.R.R. Silva received a research fellowship from the METOXCLIM project (BI/CESAM/00060/METOXCLIM/2018). M.N. González-Alcaraz holds a Saavedra Fajardo research contract from the Séneca Foundation of the Murcia Region. The authors thank F.J. Jiménez-Cárceles from Biocyma S.L. for his valuable help with vegetation fieldwork

    Mathematical analysis of a model of river channel formation.

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    The study of overland flow of water over an erodible sediment leads to a coupled model describing the evolution of the topographic elevation and the depth of the overland water film. The spatially uniform solution of this model is unstable, and this instability corresponds to the formation of rills, which in reality then grow and coalesce to form large-scale river channels. In this paper we consider the deduction and mathematical analysis of a deterministic model describing river channel formation and the evolution of its depth. The model involves a degenerate nonlinear parabolic equation (satisfied on the interior of the support of the solution) with a super-linear source term and a prescribed constant mass. We propose here a global formulation of the problem (formulated in the whole space, beyond the support of the solution) which allows us to show the existence of a solution and leads to a suitable numerical scheme for its approximation. A particular novelty of the model is that the evolving channel self-determines its own width, without the need to pose any extra conditions at the channel margin

    Evaluación de la Salud Gingival y dental en niños con Discapacidad que asisten al Centro Pedagógico "Los Pipitos" en Managua durante el período de Enero a Marzo 2017

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    Evaluación de la salud gingival y dental en niños con discapacidad que asisten al centro pedagógico" Los pipitos "en Managua durante el periodo de Enero a Marzo 2017 Bonilla Salazar Xóchiití Valie Corrales Nazaretí Mejía Rodríguez Katherine Luciat De acuerdo a la Organización Mundial de la Salud (OMS) por discapacidad debemos entender "cualquier restricción o impedimento para la realización de una actividad, ocasionados por una deficiencia dentro del ámbito considerado normal para el ser humano". Con el propósito de evaluar la salud dental y gingival, se presenta una investigación observacional, descriptiva, prospectiva, transversal, correlacional con enfoque filosófico cuantitativo. Realizada con 140 niños con discapacidad atendidos en el Centro Pedagógico "Los Pipitos" La edad más frecuente fue de 2 a 3 años, predominó muy levemente el sexo masculino, la procedencia dominante fue urbana. Basados en los índices CPOD y ceod la salud dental fue "buena" en un 90°/o; Ia clasificación "encías sanas" fue del 61%. Las variable salud dental y salud de las encías son independientes entre sí. Finalmente no existe correlación estadística entre las variables estudiadas para salud dental y gingival con el tipo de discapacidad de los niños estudiados. Paiabras claves: Caries, Gingivitis, Discapacidad, Correlaciona

    Resistin-Like Molecule-β Inhibits SGLT-1 Activity and Enhances GLUT2-Dependent Jejunal Glucose Transport

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    International audienceOBJECTIVE: An increased expression of RELM-beta (resistin-like molecule-beta), a gut-derived hormone, is observed in animal models of insulin resistance/obesity and intestinal inflammation. Intestinal sugar absorption is modulated by dietary environment and hormones/cytokines. The aim of this study was to investigate the effect of RELM-beta on intestinal glucose absorption. RESEARCH DESIGN AND METHODS: Oral glucose tolerance test was performed in mice and rats in the presence and the absence of RELM-beta. The RELM-beta action on glucose transport in rat jejunal sacs, everted rings, and mucosal strips was explored as well as downstream kinases modulating SGLT-1 and GLUT2 glucose transporters. RESULTS: Oral glucose tolerance test carried out in rodents showed that oral administration of RELM-beta increased glycemia. Studies in rat jejunal tissue indicated that mucosal RELM-beta promoted absorption of glucose from the gut lumen. RELM-beta had no effect on paracellular mannitol transport, suggesting a transporter-mediated transcellular mechanism. In studies with jejunal mucosa mounted in Ussing chamber, luminal RELM-beta inhibited SGLT-1 activity in line with a diminished SGLT-1 abundance in brush border membranes (BBMs). Further, the potentiating effect of RELM-beta on jejunal glucose uptake was associated with an increased abundance of GLUT2 at BBMs. The effects of RELM-beta were associated with an increased amount of protein kinase C betaII in BBMs and an increased phosphorylation of AMP-activated protein kinase (AMPK). CONCLUSIONS: The regulation of SGLT-1 and GLUT2 by RELM-beta expands the role of gut hormones in short-term AMPK/protein kinase C mediated control of energy balance

    Reversal of diastereoselectivity in the synthesis of Peptidomimetic 3‑Carboxamide-1,4-benzodiazepin-5-ones

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    Enantiopure 3-carboxamide-1,4-benzodiazepin-5-ones were synthesized via the Ugi reaction followed by the Staudinger/aza-Wittig or reduction reactions in only two steps. A complete reversal of diastereoselectivity was achieved depending on the cyclization methodology employed. The different orientation of the C3 substituent in our 3-substituted 1,4-benzodiazepin-5-ones with respect to the most studied 1,4-benzodiazepin-2-ones makes them complementary in the development of new drugs because the primary source of binding selectivity of 1,4-benzodiazepines is the selective recognition of ligand conformations by the receptor.Ministerio de Economía y Competitividad, Spain (Project CTQ2012-31611), Junta de Castilla y León, Consejería de Educación y Cultura y Fondo Social Europeo (Project BU246A12-1) and the European Commission, Seventh Framework Programme (Project SNIFFER FP7-SEC-2012-312411)
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