3,523 research outputs found

    Implications of different nitrogen input sources for potential production and carbon flux estimates in the coastal Gulf of Mexico (GOM) and Korean Peninsula coastal waters

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    The coastal Gulf of Mexico (GOM) and coastal sea off the Korean Peninsula (CSK) both suffer from human-induced eutrophication. We used a nitrogen (N) mass balance model in two different regions with different nitrogen input sources to estimate organic carbon fluxes and predict future carbon fluxes under different model scenarios. The coastal GOM receives nitrogen predominantly from the Mississippi and Atchafalaya rivers and atmospheric nitrogen deposition is only a minor component in this region. In the CSK, groundwater and atmospheric nitrogen deposition are more important controlling factors. Our model includes the fluxes of nitrogen to the ocean from the atmosphere, groundwater and rivers, based on observational and literature data, and identifies three zones (brown, green and blue waters) in the coastal GOM and CSK with different productivity and carbon fluxes. Based on our model results, the potential primary production rate in the inner (brown water) zone are over 2 gC m−2 d−1 (GOM) and 1.5 gC m−2 d−1 (CSK). In the middle (green water) zone, potential production is from 0.1 to 2 (GOM) and 0.3 to 1.5 gC m−2 d−1 (CSK). In the offshore (blue water) zone, productivity is less than 0.1 (GOM) and 0.3 (CSK) gC m−2 d−1. Through our model scenario results, overall oxygen demand in the GOM will increase approximately 21 % if we fail to reduce riverine N input, likely increasing considerably the area affected by hypoxia. Comparing the results from the USA with those from the Korean Peninsula shows the importance of considering both riverine and atmospheric inputs of nitrogen. This has direct implications for investigating how changes in energy technologies can lead to changes in the production of various atmospheric contaminants that affect air quality, climate and the health of local populations

    Origen de la casiterita detrítica en los aluviones recientes de Tirados de la Vega-Golpejas (Salamanca)

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    9 páginas, 6 figuras, 5 tablas.[ES] En el sector Tirados de la Vega-Golpejas han sido detectadas dos anomalías de casiterita en los aluviones del Regato de los Lentiscos y en otros existentes al sur de Tirados de la Vega. El estudio granométrico y morfométrico de éstas casiteritas. contrastado con el de la casiterita procedente del granito de Golpejas. permite asegurar que la anomalía del Regato de los Lentiscos se debe a la dispersión de la casiterita de aquel granito. mientras que la de Tirados de la Vega procede de filones estanníferos. La aplicación del análisis factoral corrobora este hecho y permite diferenciar las casiteritas que proceden de rocas graníticas de aquellas que vienen de filones estanníferos. Según esto se puede indicar que la capacidad de migración de la casiterita desde el yacimiento estannífero de Golpejas es de unos 3 Kms.[EN] Two cassiterite anomalies have been detected in the Regato de los Lentisco and Tirados de la Vega alluviums, in the Golpejas area (Salamanca). The granometric and morphometric parameters of these cassiterites have been compared with those shown by the cassiterite crystal ocurrying in the Golpejas granite. The comparison between the two groups of data allow us to conclude that the anomaly observed in the Regato de los Lentistos has been originated by the disperssion of the cassiterite from the primary deposit of Golpejas. On the contrary, the anomaly ocurring in the alloviums to the south of Tirados de la Vega shows a different origin, and is coming from stanniferous veins. The factor anylisis corroborates the differentiation mentionated above, and indicates a migration capacite of about 3 kms. from the stannifeous deposits of Golpejas for the alluvial cassiterite.Peer reviewe

    High Throughput Techniques for Discovering New Glycine Receptor Modulators and their Binding Sites

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    The inhibitory glycine receptor (GlyR) is a member of the Cys-loop receptor family that mediates inhibitory neurotransmission in the central nervous system. These receptors are emerging as potential drug targets for inflammatory pain, immunomodulation, spasticity and epilepsy. Antagonists that specifically inhibit particular GlyR isoforms are also required as pharmacological probes for elucidating the roles of particular GlyR isoforms in health and disease. Although a substantial number of both positive and negative GlyR modulators have been identified, very few of these are specific for the GlyR over other receptor types. Thus, the potential of known compounds as either therapeutic leads or pharmacological probes is limited. It is therefore surprising that there have been few published studies describing attempts to discover novel GlyR isoform-specific modulators. The first aim of this review is to consider various methods for efficiently screening compounds against these receptors. We conclude that an anion sensitive yellow fluorescent protein is optimal for primary screening and that automated electrophysiology of cells stably expressing GlyRs is useful for confirming hits and quantitating the actions of identified compounds. The second aim of this review is to demonstrate how these techniques are used in our laboratory for the purpose of both discovering novel GlyR-active compounds and characterizing their binding sites. We also describe a reliable, cost effective method for transfecting HEK293 cells in single wells of a 384-well plate using nanogram quantities of plasmid DNA
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