Sesión de Bioinformática

Comunicaciones a congreso

Coupled method for the numerical simulation of 1D shallow water and Exner transport equations in channels with variable cross-section

This work is focused on the a numerical finite volume scheme for the resulting coupled shallow water-Exner system in 1D applications with arbitrary geometry. The mathematical expression modeling the the hydrodynamic and morphodynamic components of the physical phenomenon are treated to deal with cross-section shape variations and empirical solid discharge estimations. The resulting coupled system of equations can be rewritten as a nonconservative hyperbolic system with three moving waves and one stationary wave to account for the source terms discretization. But, even for the simplest solid transport models as the Grass law, to find a linearized Jacobian matrix of the system can be a challenge if one considers arbitrary shape channels. Moreover, the bottom channel slope variations depends on the erosion-deposition mechanism considered to update the channel cross-section profile. In this paper a numerical finite volume scheme is proposed, based on an augmented Roe solver (first order accurate in time and space) and dealing with solid transport flux variations caused by the channel geometry changes. Channel crosssection variations lead to the appearance of a new solid flux source term which should be discretized properly. Comparison of the numerical results for several analytical and experimental cases demonstrate the effectiveness, exact wellbalanceness and accuracy of the scheme

A 1D numerical model for the simulation of unsteady and highly erosive flows in rivers

This work is focused on a numerical finite volume scheme for the coupled shallow water-Exner system in 1D applications with arbitrary geometry. The mathematical expressions modeling the hydrodynamic and morphodynamic components of the physical phenomenon are treated to deal with cross-section shape variations and empirical solid discharge estimations. The resulting coupled equations can be rewritten as a non-conservative hyperbolic system with three moving waves and one stationary wave to account for the source terms discretization. Moreover, the wave celerities for the coupled morpho-hydrodyamical system depend on the erosion-deposition mechanism selected to update the channel cross-section profile. This influence is incorporated into the system solution by means of a new parameter related to the channel bottom variation celerity. Special interest is put to show that, even for the simplest solid transport models as the Grass law, to find a linearized Jacobian matrix of the system can be a challenge in presence of arbitrary shape channels. In this paper a numerical finite volume scheme is proposed, based on an augmented Roe solver, first order accurate in time and space, dealing with solid transport flux variations caused by the channel geometry changes. Channel cross-section variations lead to the appearance of a new solid flux source term which should be discretized properly. The stability region is controlled by wave celerities together with a proper reconstruction of the approximate local Riemann problem solution, enforcing positive values for the intermediate states of the conserved variables. Comparison of the numerical results for several analytical and experimental cases demonstrates the effectiveness, exact well-balancedness and accuracy of the scheme

Luxación acromio-clavicular posterior con fractura clavicular asociada

Se presenta un caso infrecuente de luxación acromio- clavicular posterior asociada a una fractura de tercio medio clavicular ipsilateral en un varón de 17 años. El diagnóstico se basa en la sospecha clínica y en las pruebas de imagen, siendo la TAC de particular utilidad. La reducción abierta y fijación coraco-clavicular con resección del extremo distal clavicular dio excelentes resultados. Se compara el tratamiento realizado con otros publicados, realizando una revisión de la literatura al respecto.An unusual case of combined posterior acromioclavicular joint dislocation and an ipsilateral fracture of the middle third of the clavicle in a 17-year-old male is presented. Diagnosis is based on clinical suspicion and imaging test, being CT scan particularly useful. Open reduction and coracoclavicular fixation with excision of the distal clavicle led to successful results. Treatment is compared with previous reports. A review of the literature is made

Evidence of strong antiferromagnetic coupling between localized and itinerant electrons in ferromagnetic Sr2FeMoO6

Magnetic dc susceptibility ($\chi$) and electron spin resonance (ESR) measurements in the paramagnetic regime, are presented. We found a Curie-Weiss (CW) behavior for $\chi$(T) with a ferromagnetic $\Theta = 446(5)$ K and $\mu_{eff} = 4.72(9) \mu_{B}/f.u.$, this being lower than that expected for either $Fe^{3+}(5.9\mu_{B})$ or $Fe^{2+}(4.9\mu_{B})$ ions. The ESR g-factor $g = 2.01(2)$, is associated with $Fe^{3+}$. We obtained an excellent description of the experiments in terms of two interacting sublattices: the localized $Fe^{3+}$ ($3d^{5}$) cores and the delocalized electrons. The coupled equations were solved in a mean-field approximation, assuming for the itinerant electrons a bare susceptibility independent on $T$. We obtained $\chi_{e}^{0} = 3.7$ $10^{-4}$ emu/mol. We show that the reduction of $\mu_{eff}$ for $Fe^{3+}$ arises from the strong antiferromagnetic (AFM) interaction between the two sublattices. At variance with classical ferrimagnets, we found that $\Theta$ is ferromagnetic. Within the same model, we show that the ESR spectrum can be described by Bloch-Hasegawa type equations. Bottleneck is evidenced by the absence of a $g$-shift. Surprisingly, as observed in CMR manganites, no narrowing effects of the ESR linewidth is detected in spite of the presence of the strong magnetic coupling. These results provide evidence that the magnetic order in $Sr_{2}FeMoO_{6}$ does not originates in superexchange interactions, but from a novel mechanism recently proposed for double perovskites

A 2D finite volume simulation tool to enable the assessment of combined hydrological and morphodynamical processes in mountain catchments

Nowadays, the great power of modern computers allows to develop computational models able to deal with simulations of several coupled phenomena over detailed complex topography. An efficient and properly calibrated computational model represents a useful tool to provide insight into the catchment dynamics at hydrological and geomorphological levels. In addition, it allows to develop detailed risk management and conservation plans. In this work, we present a coupled surface-groundwater distributed flow model with hydrological (rainfall and infiltration) and geomorphological (suspended and bed load sediment transport) components. The coupled model is applied to well characterized experimental catchments that are used as realistic test cases. The calibration of the water flow model response to rainfall is performed by means of the fitting to experimental outlet hydrographs of the results supplied by a coupled formulation of 2D Shallow Water Equations and 2D Darcy's law for saturated porous media connected via suitable infiltration laws. The calibration of a suspended and bed load model is also addressed by means of the fitting to experimental outlet sedigraphs. The numerical results show a good agreement between numerical and observed hydrographs and sedigraphs, significantly improving previous published simulations. Additionally, the need to repeat the simulations in the calibration processes is no longer an unapproachable problem

María Isabel Porras Gallo, María José Báguena Cervellera, Mariano Ayarzagúena Sanz y Noelia María Martín Espinosa, coords. La erradicación y el control de las enfermedades infecciosas. Madrid : Libros de la Catarata; 2018, 272 p. ISBN: 978-84-9097-201-4

Obra ressenyada: María Isabel PORRAS GALLO, María José BÁGUENA CERVELLERA, Mariano AYARZAGÚENA SANZ y Noelia María MARTÍN ESPINOSA (coords.), La erradicación y el control de las enfermedades infecciosas. Madrid : Libros de la Catarata, 2018

Consideraciones clínicas sobre la resorción radicular externa por impactación dentaria

[email protected] resorción externa por presión (RREP) consiste en una pérdida de tejido dentinario y cementario de las raíces dentarias que se origina a nivel del ligamento periodontal, ocasionada por presiones prolongadas y mantenidas sobre la raíz. Presentamos tres casos con diferente repercusión y tratamiento. Según el distinto grado de afectación se describe y clasifica el tratamiento de RREP a causa de dientes impactados. En cuanto a la restauración de RREP se perfila la cavidad clase V de diseño 5 y el empleo de cermet o amalgamas de plata para su relleno.Pressure external root resorption (PERR) is a loss of dental root tissues (dentine and cementum) that begin in the periodontal area caused by a impacted teeth. We show three cases with differents clinical situations and therapeutical aspects. Pulpal injurie and difficulty in the post-endodontic cavity acces are characteristiques of these processes. Depending on the level of tissue destruction we discusse the therapeutical orientation in each case. Some treatments like class V type 5 cavities or fillings with cermet glass-ionomer in the more atipical situations (generally after an endodontic treatment) are a good choice in these [email protected] [email protected]