440 research outputs found

    Phosphatidic acid metabolism in rat liver cell nuclei

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    AbstractThe aim of the present research was to analyze the pathways for phosphatidic acid metabolism in purified nuclei from liver. Lipid phosphate phosphatase, diacylglycerol lipase, monoacylglycerol lipase and PA-phospholipase type A activities were detected. The presence of lysophosphatidic acid significantly reduced DAG production while sphingosine 1-phoshate and ceramide 1-phosphate reduced MAG formation from PA. Using different enzymatic modulators (detergents and ions) an increase in the PA metabolism by phospholipase type A was observed. Our findings evidence an active PA metabolism in purified liver nuclei which generates important lipid second messengers, and which could thus be involved in nuclear processes such as gene transcription

    Regulation of Phosphatidic Acid Metabolism by Sphingolipids in the Central Nervous System

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    This paper explores the way ceramide, sphingosine, ceramide 1-phosphate, and sphingosine 1-phosphate modulate the generation of second lipid messengers from phosphatidic acid in two experimental models of the central nervous system: in vertebrate rod outer segments prepared from dark-adapted retinas as well as in rod outer segments prepared from light-adapted retinas and in rat cerebral cortex synaptosomes under physiological aging conditions. Particular attention is paid to lipid phosphate phosphatase, diacylglycerol lipase, and monoacylglycerol lipase. Based on the findings reported in this paper, it can be concluded that proteins related to phototransduction phenomena are involved in the effects derived from sphingosine 1-phosphate/sphingosine or ceramide 1-phosphate/ceramide and that age-related changes occur in the metabolism of phosphatidic acid from cerebral cortex synaptosomes in the presence of either sphingosine 1-phosphate/sphingosine or ceramide 1-phosphate/ceramide. The present paper demonstrates, in two different models of central nervous system, how sphingolipids influence phosphatidic acid metabolism under different physiological conditions such as light and aging

    Aumento da sustentabilidade da produção de raças suínas locais através do uso de rótulos de qualidade - Estudo de caso e desenvolvimento de uma marca comercial no projecto TREASURE

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    The interest for traditional genetic resources, here comprised local pig breeds, has been increased in the last decades. Yet, at the time being, majority of local pig breeds still need to be supported with subsidies to ensure their conservation. However, the best strategy is if breeds could reach self-sustainability which is possible by an efficient marketing strategy of their products. The majority of studied breeds in project TREASURE are untapped, so the ambition is to develop an “umbrella” collective trademark that would gather together all breeds and that would create added values for their products. Major socio-economic aspects related to the implementation of the collective trademark include rights, responsibilities and expected added value for end-users. Based on the results obtained by an internal survey conducted in TREASURE, we have identified the main features of the collaborative trademark: 1) it should attract end-users such as farmers, breeders associations and meat processors; 2) it should be developed and promoted by an operational committee of end-users, under the coordination and supervision of TREASURE Consortium; 3) it should emphasize local pig genetic resources as the key common point, considering also production systems and nutrition; 4) it should explore possible collaboration or conflict with existing EU protected products (PDO, PGI, TSG) in order to optimally promote local products. An overview of intellectual property rights (IPR) in the context of pork value chains existing in the European Union is presented and prospects for TREASURE trademark analysed

    A 4-pronged approach to foster healthy aging in older adults.

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    Monitoring patients\u27 health, mobility, mentation, and ability to maintain social connections can help you promote healthy aging for your older patients

    Reversible morphology-resolved chemotactic actuation and motion of Janus emulsion droplets

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    We report, for the first time, a chemotactic motion of emulsion droplets that can be controllably and reversibly altered. Our approach is based on using biphasic Janus emulsion droplets, where each phase responds differently to chemically induced interfacial tension gradients. By permanently breaking the symmetry of the droplets’ geometry and composition, externally evoked gradients in surfactant concentration or effectiveness induce anisotropic Marangoni-type fluid flows adjacent to each of the two different exposed interfaces. Regulation of the competitive fluid convections then enables a controllable alteration of the speed and the direction of the droplets’ chemotactic motion. Our findings provide insight into how compositional anisotropy can affect the chemotactic behavior of purely liquid-based microswimmers. This has implications for the design of smart and adaptive soft microrobots that can autonomously regulate their response to changes in their chemical environment by chemotactically moving towards or away from a certain target, such as a bacterium.<br

    Ensayos de toxicidad de sedimentos con Hyalella pseudoazteca con cobre como tĂłxico de referencia

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    The suitability of Hyalella pseudoazteca as a test organism for sediment toxicity bioassays and the employment of the sediment from Las Flores stream as a solid control matrix were evaluated. The animals were collected from Las Flores stream and acclimated to the conditions of the laboratory. The toxicity of spiked sediments with two concentrations of Cu2+ (25 y 75 mg Cu2+/Kg dry sediment) was tested. The samples used were physicochemically analyzed and their contaminants content determined. The assay was run with five replicates on each treatment at constant temperature and photoperiod (23±1ÂșC; 16L/8D). The exposition time lasted ten days and for each replicate it was determined survival, biomass (dry weight) and length increase rates as end points. On the assay’s initial and final time, hardness, pH, DO, NH4 + concentration, and conductivity were measured. The statistical significance relative to control was evaluated by means of ANOVA and Tukey’s comparison test. No effect on survival was registered. There was a significant decrease of the biomass of the animals exposed to 75 mg Cu2+/Kg. The length showed a tendency to decrease in both concentrations. From the obtained results it could be concluded that Hyalella pseudoazteca is a sensitive species for the assessment of spiked sediment toxicity assays with Cu2+, being this toxic apt as reference in assays with this species. Las Flores stream’s sediment proved to be adequate as negative control sediment because of its negligible level of chemical pollution and its granulometric composition.The suitability of Hyalella pseudoazteca as a test organism for sediment toxicity bioassays and the employment of the sediment from Las Flores stream as a solid control matrix were evaluated. The animals were collected from Las Flores stream and acclimated to the conditions of the laboratory. The toxicity of spiked sediments with two concentrations of Cu2+ (25 y 75 mg Cu2+/Kg dry sediment) was tested. The samples used were physicochemically analyzed and their contaminants content determined. The assay was run with five replicates on each treatment at constant temperature and photoperiod (23±1ÂșC; 16L/8D). The exposition time lasted ten days and for each replicate it was determined survival, biomass (dry weight) and length increase rates as end points. On the assay’s initial and final time, hardness, pH, DO, NH4 + concentration, and conductivity were measured. The statistical significance relative to control was evaluated by means of ANOVA and Tukey’s comparison test. No effect on survival was registered. There was a significant decrease of the biomass of the animals exposed to 75 mg Cu2+/Kg. The length showed a tendency to decrease in both concentrations. From the obtained results it could be concluded that Hyalella pseudoazteca is a sensitive species for the assessment of spiked sediment toxicity assays with Cu2+, being this toxic apt as reference in assays with this species. Las Flores stream’s sediment proved to be adequate as negative control sediment because of its negligible level of chemical pollution and its granulometric composition

    Ensayos de toxicidad de sedimentos con Hyalella pseudoazteca con cobre como tĂłxico de referencia

    Get PDF
    The suitability of Hyalella pseudoazteca as a test organism for sediment toxicity bioassays and the employment of the sediment from Las Flores stream as a solid control matrix were evaluated. The animals were collected from Las Flores stream and acclimated to the conditions of the laboratory. The toxicity of spiked sediments with two concentrations of Cu2+ (25 y 75 mg Cu2+/Kg dry sediment) was tested. The samples used were physicochemically analyzed and their contaminants content determined. The assay was run with five replicates on each treatment at constant temperature and photoperiod (23±1ÂșC; 16L/8D). The exposition time lasted ten days and for each replicate it was determined survival, biomass (dry weight) and length increase rates as end points. On the assay’s initial and final time, hardness, pH, DO, NH4 + concentration, and conductivity were measured. The statistical significance relative to control was evaluated by means of ANOVA and Tukey’s comparison test. No effect on survival was registered. There was a significant decrease of the biomass of the animals exposed to 75 mg Cu2+/Kg. The length showed a tendency to decrease in both concentrations. From the obtained results it could be concluded that Hyalella pseudoazteca is a sensitive species for the assessment of spiked sediment toxicity assays with Cu2+, being this toxic apt as reference in assays with this species. Las Flores stream’s sediment proved to be adequate as negative control sediment because of its negligible level of chemical pollution and its granulometric composition.Facultad de Ciencias Naturales y Muse

    Multi-Center non-BPS Black Holes - the Solution

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    We construct multi-center, non-supersymmetric four-dimensional solutions describing a rotating anti-D6-D2 black hole and an arbitrary number of D4-D2-D0 black holes in a line. These solutions correspond to an arbitrary number of extremal non-BPS black rings in a Taub-NUT space with a rotating three-charge black hole in the middle. The positions of the centers are determined by solving a set of "bubble" or "integrability" equations that contain cubic polynomials of the inter-center distance, and that allow scaling solutions even when the total four-dimensional angular momentum of the scaling centers is non-zero.Comment: 16 pages, LaTe
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