495 research outputs found

    A 3-D boundary element model for the dynamic analysis of arch dams with porous sediments

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    A three-dimensional boundary element technique for dynamic analysis of arch dams including dynamic interaction and sediments on the bottom of the reservoir is presented. The dam and the foundation rock are assumed to be viscoelastic domains with linear behaviour. The water is assumed to be compressible and the sediment is considered as a two-phase poroelastic material according to Biot's theory. The four domains (dam, foundation rock, water and bottom sediments) are discretized and the interaction between them is rigorously represented. The effects of sediments on the dynamic response of arch dams are evaluated for rigid and compliant foundation. Upstream, vertical and cross-stream excitation are considered. The influence of the degree of saturation of the sediment is analysed. Other modelling of the sediment as a single-phase scalar medium are considered in order to reduce the degrees of freedom of the system.Ministerio de Ciencia y Tecnología PB96-1322-C03-0

    Be analysis of bottom sediments in dynamic fluid-structure interaction problems

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    Sediment materials play an important role on the dynamic response of large structures where fluid-soil-structure interaction is relevant and materials of that kind are present. Dam-reservoir systems and harbor structures are examples of civil engineering constructions where those effects are significant. In those cases the dynamic response is determined by hydrodynamic water pressure, which depends on the absorption effects of bottom sediments. Sediments of very different mechanical properties may exist on the bottom. A three-dimensional BE model for the analysis of sediment effects on dynamic response of those structures is presented in this paper. One of the most extended models for sediment materials corresponds to Biot’s fluid-filled poroelastic solid. The BE formulation for dynamics of poroelastic solids is reviewed including a weighted residual formulation more general and concise than those previously existing in literature. Systems consisting of water, other pressure wave propagating materials, viscoelastic solids and fluid-filled poroelastic zones, are studied. Coupling conditions at interfaces are taken into account in a rigorous way. A simple geometry coupled problem is first studied to asses the effects of sediments on its dynamic response and to determine the influence of parameters such as sediment depth, consolidation, compressibility and permeability. A fully 3-D arch dam-reservoir-foundation system where sediments and radiation damping play an important role is also studied in this paper. Obtained results show the importance of a realistic representation of sediments and the influence of their consolidation degree, compressibility and permeability on the system dynamic response.Ministerio de Ciencia y Tecnología BIA2004-03955-C02-01/0

    Grafitos sobre Terra Sigillata Hispánica hallados en un vertedero del siglo I en la casa de Hippolytus (Complutum)

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    Presentamos en este estudio un conjunto de materiales inéditos del yacimiento romano de "hippolytus". Estos grafitos, presentes en la mayoría de los establecimientos romanos, no han recibido, en algunas ocasiones, la debida atención por parte de los investigadores. Su análisis pormenorizado, junto a la evidente ventaja de provenir de un contexto arqueológico cerrado y bien definido, nos acerca al conocimiento de las relaciones sociales, parentesco y origen de los moradores de este nuevo enclave altoimperial complutense

    On soil-structure interaction in large non-slender partially buried structures

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    This paper addresses the seismic analysis of a deeply embedded non-slender structure hosting the pumping unit of a reservoir. The dynamic response in this type of problems is usually studied under the assumption of a perfectly rigid structure using a sub-structuring procedure (three-step solution) proposed specifically for this hypothesis. Such an approach enables a relatively simple assessment of the importance of some key factors influencing the structural response. In this work, the problem is also solved in a single step using a direct approach in which the structure and surrounding soil are modelled as a coupled system with its actual geometry and flexibility. Results indicate that, quite surprisingly, there are significant differences among prediction using both methods. Furthermore, neglecting the flexibility of the structure leads to a significant underestimation of the spectral accelerations at certain points of the structure

    Programa de conservación mediante trasplante de embriones de la raza Serrana de Teruel

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    En el marco de un proyecto cuyo objetivo global era el establecimiento de un programa sostenible de caracterización y preservación de la raza bovina en peligro de extinción Serrana de Teruel, se ha creado un banco de embriones. Para ello, sobre un total de 12 hembras, seleccionadas desde un punto de vista morfológico y ascendencia racial documentada, se realizó un protocolo de superovulación en dosis partida, con objeto de minimizar el estrés provocado por el excesivo manejo que conllevan los protocolos de superovulación tradicionales, previamente a la colecta de embriones. Se recogieron 171 embriones en total, de ellos 84 transferibles (75 de calidad 1 y 9 de calidad 2), procedentes de 12 hembras y 5 machos. Se confirmó la utilidad de este tratamiento en animales no habituados al manejo frecuente, así como la viabilidad post-congelación de los embriones obtenidos

    A proposal for normalized impedance functions of inclined piles in non-homogeneous media

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    10th International Conference on Structural Dynamics (EURODYN). Sapienza University Rome, September, 10-13, 2017.This work presents impedance functions for inclined pile groups embedded in different half spaces whose stiffness continuously increases with depth. The results are obtained through a three-dimensional harmonic model where the soil response is modelled through the reciprocity theorem in elastodynamics and the use of Green’s functions for the layered half space, while the piles are represented by finite elements as Timoshenko’s beams. Linear behaviour of soil and piles is assumed. The use of several normalization schemes for the representation of the impedance functions is discussed, highlighting the benefits and drawbacks of each choice and their effects on the interpretation of the obtained results. As a result, expressions for the dimensionless impedance functions and frequency are proposed in order to synthesize the results of the different soil profiles into the same curves. The final objective of the proposed normalization is to transform the well-known impedance functions for the homogeneous halfspace into the corresponding curves for a specific non-homogeneous profile that can be used, e.g., in a substructuring methodology. Despite the fact that the presence of soil non-homogeneity increases the dependence of the impedance functions on the frequency, good agreements between the homogeneous and non-homogeneous profiles can be achieved for a range of frequency of interest.This work was supported by Subdirección General de Proyectos de Investigación of the Ministerio de Economía y Competitividad (MINECO) of Spain and FEDER through research project BIA2014-57640-R. G.M. Álamo is a recipient of FPU research fellowship FPU14/06115 from the Ministerio de Educación, Cultura y Deporte of Spain

    His452Tyr polymorphism in the human 5-HT2A receptor affects clozapine-induced signaling networks revealed by quantitative phosphoproteomics

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    Antipsychotic drugs remain the current standard for schizophrenia treatment. Although they directly recognize the orthosteric binding site of numerous monoaminergic G protein-coupled receptors (GPCRs), these drugs, and particularly second-generation antipsychotics such as clozapine, all have in common a very high affinity for the serotonin 5-HT receptor (5-HTR). Using classical pharmacology and targeted signaling pathway assays, previous findings suggest that clozapine and other atypical antipsychotics behave principally as 5-HTR neutral antagonists and/or inverse agonists. However, more recent findings showed that antipsychotics may also behave as pathway-specific agonists. Reversible phosphorylation is a common element in multiple signaling networks. Combining a quantitative phosphoproteomic method with signaling network analysis, we tested the effect of clozapine treatment on the overall level of protein phosphorylation and signal transduction cascades in vitro in mammalian cell lines induced to express either the human 5-HTR or the H452Y variant of the gene encoding the 5-HTR receptor. This naturally occurring variation within the 5-HTR gene was selected because it has been repeatedly associated with schizophrenia patients who do not respond to clozapine treatment. Our data show that short time exposure (5 or 10 min) to clozapine (10 M) led to phosphorylation of numerous signaling components of pathways involved in processes such as endocytosis, ErbB signaling, insulin signaling or estrogen signaling. Cells induced to express the H452Y variant showed a different basal phosphoproteome, with increases in the phosphorylation of mTOR signaling components as a translationally relevant example. However, the effect of clozapine on the functional landscape of the phosphoproteome was significantly reduced in cells expressing the 5-HTR-H452Y construct. Together, these findings suggest that clozapine behaves as an agonist inducing phosphorylation of numerous pathways downstream of the 5-HTR, and that the single nucleotide polymorphism encoding 5-HTR-H452Y affects these clozapine-induced phosphorylation-dependent signaling networks
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