158 research outputs found

    Short-Term Response of Chlorophyll a Concentration Due to Intense Wind and Freshwater Peak Episodes in Estuaries: The Case of Fangar Bay (Ebro Delta)

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    Estuaries and coastal bays are areas of large spatio-temporal variability in physical and biological variables due to environmental factors such as local wind, light availability, freshwater inputs or tides. This study focuses on the effect of strong wind events and freshwater peaks on short-term chlorophyll a (Chl a) concentration distribution in the small-scale and microtidal, Fangar Bay (Ebro Delta, northwestern Mediterranean). The hydrodynamics of this bay are primarily driven by local wind episodes modulated by stratification in the water column. Results based on field-campaign observations and Sentinel-2 images revealed that intense wind episodes from both NW (offshore) and NE-E (onshore) caused an increase in the concentration of surface Chl a. The mechanisms responsible were horizontal mixing and the bottom resuspension (also linked to the breakage of the stratification) that presumably resuspended Chl a containing biomass (i.e., micropyhtobentos) and/or incorporated nutrients into the water column. On the other hand, sea-breeze was not capable of breaking up the stratification, so the chlorophyll a concentration did not change significantly during these episodes. It was concluded that the mixing produced by the strong winds favoured an accumulation of Chl a concentration, while the stratification that causes a positive estuarine circulation reduced this accumulation. However, the spatial-temporal variability of the Chl a concentration in small-scale estuaries and coastal bays is quite complex due to the many factors involved and deserve further intensive field campaigns and additional numerical modelling efforts.info:eu-repo/semantics/publishedVersio

    Friendly Strategy to Prepare Encoded One Bead−One Compound Cyclic Peptide Library

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    One bead−one peptide libraries allow the screening of suitable ligands for any target protein. Short cyclic peptides are ideal ligands for affinity chromatography because of their high affinity and selectivity for the target protein and stability against proteases. We designed a library synthesis strategy to facilitate the identification of cyclic peptides by MS consisting of (a) sequential incorporation of a mixture of Fmoc-Ala-OH and Fmoc-Asp[2-phenylisopropyl (OPp)]-OH (15:85) to Gly-oxymethylbenzamide-ChemMatrix (Gly-HMBA-CM) resin, (b) synthesis of the combinatorial library on the resin by the divide−couple−recombine method, (c) removal of OPp with 4% TFA, (d) peptide cyclization on solid phase through side-chain Asp and amino terminus, and (e) removal of side chain protecting groups with a 95% TFA cocktail. Peptides were cleaved from the beads with ammonia and the linear code was sequenced by MALDI-TOF MS/MS. The high capacity of ChemMatrix resin together with the sensitivity of MS allows code sequencing from a single bead.Fil: Giudicessi, Silvana Laura. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂ­mica; Argentina; Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; Argentina;Fil: Gurevich Messina, Juan Manuel. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂ­mica. Departamento de MicrobiologĂ­a, InmunologĂ­a y BiotecnologĂ­a; Argentina;Fil: MartĂ­nez Ceron, MarĂ­a Camila. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂ­mica; Argentina; Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; Argentina;Fil: Erra Balsells, Rosa. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono; Argentina; Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; Argentina;Fil: Albericio, F.. Instituto de InvestigaciĂłn BiomĂ©dica; España; Universidad de Barcelona; España; Centro de InvestigaciĂłn BiomĂ©dica en Red en BioingenierĂ­a, Biomateriales y Nanomedicina; España;Fil: Cascone, Osvaldo. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂ­mica. Departamento de MicrobiologĂ­a, InmunologĂ­a y BiotecnologĂ­a; Argentina; Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; Argentina;Fil: Camperi, Silvia Andrea. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂ­mica. Departamento de MicrobiologĂ­a, InmunologĂ­a y BiotecnologĂ­a; Argentina; Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; Argentina

    Use of a hydrodynamic model for the management of water renovation in a coastal system

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    In this contribution we investigate the hydrodynamic response in Alfacs Bay (Ebro Delta, NW Mediterranean Sea) to different anthropogenic modifications in freshwater flows and inner bay–open sea connections. The fresh water coming from rice field irrigation contains nutrients and pesticides and therefore affects in multiple ways the productivity and water quality of the bay. The application of a nested oceanographic circulation modelling suite within the bay provides objective information to solve water quality problems that are becoming more acute due to temperature and phytoplankton concentration peaks during the summer period when seawater may exceed 28 ∘C, leading to high rates of mussel mortality and therefore a significant impact on the local economy. The effects of different management “solutions” (like a connection channel between the inner bay and open sea) are hydrodynamically modelled in order to diminish residence times (e-flushing time) and water temperatures. The modelling system, based on the Regional Ocean Modeling System (ROMS), consists of a set of nested domains using data from CMEMS-IBI for the initial and open boundary conditions (coarser domain). One full year (2014) of simulation is used to validate the results, showing low errors with sea surface temperature (SST) and good agreement with surface currents. Finally, a set of twin numerical experiments during the summer period (when the water temperature reaches 28 ∘C) is used to analyse the effects of proposed nature-based interventions. Although these actions modify water temperature in the water column, the decrease in SST is not enough to avoid high temperatures during some days and prevent eventual mussel mortality during summer in the shallowest regions. However, the proposed management actions reveal their effectiveness in diminishing water residence times along the entire bay, thus preventing the inner areas from having poor water renewal and the corresponding ecological problems.info:eu-repo/semantics/publishedVersio

    Use of a hydrodynamic model for the management of water renovation in a coastal system

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    In this contribution we investigate the hydrodynamic response in Alfacs Bay (Ebro Delta, NW Mediterranean Sea) to different anthropogenic modifications in freshwater flows and inner bay–open sea connections. The fresh water coming from rice field irrigation contains nutrients and pesticides and therefore affects in multiple ways the productivity and water quality of the bay. The application of a nested oceanographic circulation modelling suite within the bay provides objective information to solve water quality problems that are becoming more acute due to temperature and phytoplankton concentration peaks during the summer period when seawater may exceed 28&thinsp;∘C, leading to high rates of mussel mortality and therefore a significant impact on the local economy. The effects of different management “solutions” (like a connection channel between the inner bay and open sea) are hydrodynamically modelled in order to diminish residence times (e-flushing time) and water temperatures. The modelling system, based on the Regional Ocean Modeling System (ROMS), consists of a set of nested domains using data from CMEMS-IBI for the initial and open boundary conditions (coarser domain). One full year (2014) of simulation is used to validate the results, showing low errors with sea surface temperature (SST) and good agreement with surface currents. Finally, a set of twin numerical experiments during the summer period (when the water temperature reaches 28&thinsp;∘C) is used to analyse the effects of proposed nature-based interventions. Although these actions modify water temperature in the water column, the decrease in SST is not enough to avoid high temperatures during some days and prevent eventual mussel mortality during summer in the shallowest regions. However, the proposed management actions reveal their effectiveness in diminishing water residence times along the entire bay, thus preventing the inner areas from having poor water renewal and the corresponding ecological problems.</p

    Gestational Diabetes Mellitus and Diet: A Systematic Review and Meta-analysis of Randomized Controlled Trials Examining the Impact of Modified Dietary Interventions on Maternal Glucose Control and Neonatal Birth Weight

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    OBJECTIVE: Medical nutrition therapy is a mainstay of gestational diabetes mellitus (GDM) treatment. However, data are limited regarding the optimal diet for achieving euglycemia and improved perinatal outcomes. This study aims to investigate whether modified dietary interventions are associated with improved glycemia and/or improved birth weight outcomes in women with GDM when compared with control dietary interventions. RESEARCH DESIGN AND METHODS: Data from published randomized controlled trials that reported on dietary components, maternal glycemia, and birth weight were gathered from 12 databases. Data were extracted in duplicate using prespecified forms. RESULTS: From 2,269 records screened, 18 randomized controlled trials involving 1,151 women were included. Pooled analysis demonstrated that for modified dietary interventions when compared with control subjects, there was a larger decrease in fasting and postprandial glucose (−4.07 mg/dL [95% CI −7.58, −0.57]; P = 0.02 and −7.78 mg/dL [95% CI −12.27, −3.29]; P = 0.0007, respectively) and a lower need for medication treatment (relative risk 0.65 [95% CI 0.47, 0.88]; P = 0.006). For neonatal outcomes, analysis of 16 randomized controlled trials including 841 participants showed that modified dietary interventions were associated with lower infant birth weight (−170.62 g [95% CI −333.64, −7.60]; P = 0.04) and less macrosomia (relative risk 0.49 [95% CI 0.27, 0.88]; P = 0.02). The quality of evidence for these outcomes was low to very low. Baseline differences between groups in postprandial glucose may have influenced glucose-related outcomes. As well, relatively small numbers of study participants limit between-diet comparison. CONCLUSIONS: Modified dietary interventions favorably influenced outcomes related to maternal glycemia and birth weight. This indicates that there is room for improvement in usual dietary advice for women with GDM
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