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BackgroundTwo-dimensional shear wave elastography (2D-SWE) provides information on hepatic elastic modulus as shear wave velocity (SWV). Hypothesis/ObjectivesTo assess SWV using 2D-SWE in dogs with induced volume overload, investigate the relationship between this information and right atrial pressure (RAP) measured by invasive right heart catheterization, and also evaluate the difference in SWV before and after diuretic administration. AnimalsSix healthy beagles. MethodsProspective experimental study. Right heart catheterization and 2D-SWE were performed in 6 anesthetized beagles at baseline and after the induction of volume overload. Volume overload was induced by IV hydroxyethyl starch 70/0.5 infusion (100 mL/kg/h). Furosemide (4-6 mg/kg, IV) was administered, and the SWVs were measured. ResultsShear wave velocity showed a significant gradual increase during acute volume overload compared to baseline. SWV was significantly positively correlated with RAP (P < .0001, rho = 0.9729). The area under the curve of SWV to predict RAP at >10, >15, and >20 mm Hg was 0.9896 (95% confidence interval [95% CI], 0.9690-1.000), 0.9907 (95% CI, 0.9701-1.000), and 0.9722 (95% CI, 0.9280-1.000), respectively. The SWV after diuretic use decreased significantly. Conclusions and Clinical ImportanceTwo-dimensional shear wave elastography might be useful for noninvasive and reliable estimation of RAP in dogs with acute volume overload and has potential as a quantitative biomarker for evaluating therapeutic response in dogs with right sided congestive heart failure.

BackgroundTwo-dimensional shear wave elastography (2D-SWE) provides information on hepatic elastic modulus as shear wave velocity (SWV). Hypothesis/ObjectivesTo assess SWV using 2D-SWE in dogs with induced volume overload, investigate the relationship between this information and right atrial pressure (RAP) measured by invasive right heart catheterization, and also evaluate the difference in SWV before and after diuretic administration. AnimalsSix healthy beagles. MethodsProspective experimental study. Right heart catheterization and 2D-SWE were performed in 6 anesthetized beagles at baseline and after the induction of volume overload. Volume overload was induced by IV hydroxyethyl starch 70/0.5 infusion (100 mL/kg/h). Furosemide (4-6 mg/kg, IV) was administered, and the SWVs were measured. ResultsShear wave velocity showed a significant gradual increase during acute volume overload compared to baseline. SWV was significantly positively correlated with RAP (P < .0001, rho = 0.9729). The area under the curve of SWV to predict RAP at >10, >15, and >20 mm Hg was 0.9896 (95% confidence interval [95% CI], 0.9690-1.000), 0.9907 (95% CI, 0.9701-1.000), and 0.9722 (95% CI, 0.9280-1.000), respectively. The SWV after diuretic use decreased significantly. Conclusions and Clinical ImportanceTwo-dimensional shear wave elastography might be useful for noninvasive and reliable estimation of RAP in dogs with acute volume overload and has potential as a quantitative biomarker for evaluating therapeutic response in dogs with right sided congestive heart failure.

Two-dimensional (2D) hydraulic models solve the Shallow Water Equations (SWE) for the simulation of free surface flows. The necessity of considering in the calculations specific hydraulic structures, such as bridges, gates, weirs, culverts, etc., for representing more realistic flood scenarios, imply the integration in the 2D-SWE of empirical equations that represent the flow through these structures. These empirical equations are usually implemented as internal conditions over a 1D line, modifying the equations with which the flow is calculated in the edges of the mesh elements located at both sides of the line. This approach can be good enough for representing the hydraulic behavior in general. However, this 1D condition over a line, which only affects the element edges, is not a good approximation for simulating the hydrodynamics of pressurized flows, as it is the case of very wide bridges and lids over channelized rivers. New modelling strategies for simulating pressurized flows using the 2D-SWE, the Two-Component Pressure Approach method (TPA) and the Preissmann Slot Method (PSM), have been implemented in Iber. Both approaches were tested in a coverage of a channeled river characterized by several abrupt curvature changes and a contraction/expansion of their wide, and in a bridge located in a river reach that obstructs most of the floodplain. The TPA and PSM methods presented good numerical approaches for simulating pressurized flow for 2D-SWE-based models, fine-tuning the hydraulic behavior, and representing the most critical regions when a pressurized flow is generated in hydraulic structures., Postprint (published version)

Permeable pavements are a common solution for wearing course layers in roads and urban areas. They are composed by highly porous materials with permeability several orders of magnitude above of the natural terrain. This work presents, on one hand, the experimental characterisation of the hydraulic behaviour of a permeable asphalt concrete wearing course layer and, on the other hand, the development and validation of a two-dimensional coupled hydraulic-hydrological distributed numerical model to reproduce the effect of the infiltration in the rainfall-runoff transformation and in the overland flow propagation processes. Experiments show linear and potential trends for permeability-hydraulic head relations when considering constant and variable hydraulic heads, respectively, reaching permeability up to 0.04 m/s for 1 m of hydraulic head. Experiments are reproduced numerically by incorporating new infiltration formulas, which consider the infiltration rate as a function of the hydraulic head, and a specific numerical scheme for properly dealing the mass conservation when negative values of the water depth may occur numerically due to high infiltration rates. This two-dimensional coupled hydraulic-hydrological distributed numerical model is a validated tool for simulating the effect of permeable pavements not only in the rainfall-runoff process, but also for the overland flow propagation., Peer Reviewed, Postprint (published version)

[ES] La creciente preocupación por los riesgos naturales, como las avalanchas de nieve, ha propiciado el desarrollo de modelos numéricos ad hoc como una herramienta de soporte para su análisis y evaluación. Los modelos existentes para simulación de aludes se basan en la conservación de la masa y de la cantidad de movimiento, que son unas ecuaciones similares a las ecuaciones de Saint Venant para agua con diferencias sólo en los términos de fricción (modelo reológico). Este documento muestra las posibilidades de estas ecuaciones para simular avalanchas de placa-densa y el tratamiento numérico realizado en Iber. Se ha empleado una nueva metodología para equilibrar el término fuente y el vector de flujo evitando así oscilaciones espurias y movimientos no reales, y que modifica la pendiente de fondo en base a los parámetros del fluido y así detener su movimiento. La herramienta se ha probado en dos casos de estudio para analizar el comportamiento del fluido en función de los parámetros del mode, [EN] The growing concern about natural hazards, such as snow avalanches, has led to the development of ad hoc numerical models as a support tool for their analysis and evaluation. Existing models for avalanche simulation are based on the conservation of mass and the momentum, which are similar equations to the Saint Venant equations for water with differences only in terms of friction (rheological model). This document shows the possibilities of these equations to simulate dense-slab avalanches and the numerical treatment carried out in Iber. A new methodology has been used to balance the source term and the flow vector to avoid spurious oscillations and unreal movements, modifying the bottom slope based on the fluid parameters and thus stop its movement. The tool has been tested in two case studies to analyse the behaviour of the fluid depending on the parameters of the rheological model.

[ES] La creciente preocupación por los riesgos naturales, como las avalanchas de nieve, ha propiciado el desarrollo de modelos numéricos ad hoc como una herramienta de soporte para su análisis y evaluación. Los modelos existentes para simulación de aludes se basan en la conservación de la masa y de la cantidad de movimiento, que son unas ecuaciones similares a las ecuaciones de Saint Venant para agua con diferencias sólo en los términos de fricción (modelo reológico). Este documento muestra las posibilidades de estas ecuaciones para simular avalanchas de placa-densa y el tratamiento numérico realizado en Iber. Se ha empleado una nueva metodología para equilibrar el término fuente y el vector de flujo evitando así oscilaciones espurias y movimientos no reales, y que modifica la pendiente de fondo en base a los parámetros del fluido y así detener su movimiento. La herramienta se ha probado en dos casos de estudio para analizar el comportamiento del fluido en función de los parámetros del mode, [EN] The growing concern about natural hazards, such as snow avalanches, has led to the development of ad hoc numerical models as a support tool for their analysis and evaluation. Existing models for avalanche simulation are based on the conservation of mass and the momentum, which are similar equations to the Saint Venant equations for water with differences only in terms of friction (rheological model). This document shows the possibilities of these equations to simulate dense-slab avalanches and the numerical treatment carried out in Iber. A new methodology has been used to balance the source term and the flow vector to avoid spurious oscillations and unreal movements, modifying the bottom slope based on the fluid parameters and thus stop its movement. The tool has been tested in two case studies to analyse the behaviour of the fluid depending on the parameters of the rheological model.

[ES] La creciente preocupación por los riesgos naturales, como las avalanchas de nieve, ha propiciado el desarrollo de modelos numéricos ad hoc como una herramienta de soporte para su análisis y evaluación. Los modelos existentes para simulación de aludes se basan en la conservación de la masa y de la cantidad de movimiento, que son unas ecuaciones similares a las ecuaciones de Saint Venant para agua con diferencias sólo en los términos de fricción (modelo reológico). Este documento muestra las posibilidades de estas ecuaciones para simular avalanchas de placa-densa y el tratamiento numérico realizado en Iber. Se ha empleado una nueva metodología para equilibrar el término fuente y el vector de flujo evitando así oscilaciones espurias y movimientos no reales, y que modifica la pendiente de fondo en base a los parámetros del fluido y así detener su movimiento. La herramienta se ha probado en dos casos de estudio para analizar el comportamiento del fluido en función de los parámetros del mode, [EN] The growing concern about natural hazards, such as snow avalanches, has led to the development of ad hoc numerical models as a support tool for their analysis and evaluation. Existing models for avalanche simulation are based on the conservation of mass and the momentum, which are similar equations to the Saint Venant equations for water with differences only in terms of friction (rheological model). This document shows the possibilities of these equations to simulate dense-slab avalanches and the numerical treatment carried out in Iber. A new methodology has been used to balance the source term and the flow vector to avoid spurious oscillations and unreal movements, modifying the bottom slope based on the fluid parameters and thus stop its movement. The tool has been tested in two case studies to analyse the behaviour of the fluid depending on the parameters of the rheological model.

[ES] La creciente preocupación por los riesgos naturales, como las avalanchas de nieve, ha propiciado el desarrollo de modelos numéricos ad hoc como una herramienta de soporte para su análisis y evaluación. Los modelos existentes para simulación de aludes se basan en la conservación de la masa y de la cantidad de movimiento, que son unas ecuaciones similares a las ecuaciones de Saint Venant para agua con diferencias sólo en los términos de fricción (modelo reológico). Este documento muestra las posibilidades de estas ecuaciones para simular avalanchas de placa-densa y el tratamiento numérico realizado en Iber. Se ha empleado una nueva metodología para equilibrar el término fuente y el vector de flujo evitando así oscilaciones espurias y movimientos no reales, y que modifica la pendiente de fondo en base a los parámetros del fluido y así detener su movimiento. La herramienta se ha probado en dos casos de estudio para analizar el comportamiento del fluido en función de los parámetros del mode, [EN] The growing concern about natural hazards, such as snow avalanches, has led to the development of ad hoc numerical models as a support tool for their analysis and evaluation. Existing models for avalanche simulation are based on the conservation of mass and the momentum, which are similar equations to the Saint Venant equations for water with differences only in terms of friction (rheological model). This document shows the possibilities of these equations to simulate dense-slab avalanches and the numerical treatment carried out in Iber. A new methodology has been used to balance the source term and the flow vector to avoid spurious oscillations and unreal movements, modifying the bottom slope based on the fluid parameters and thus stop its movement. The tool has been tested in two case studies to analyse the behaviour of the fluid depending on the parameters of the rheological model.

[ES] La creciente preocupación por los riesgos naturales, como las avalanchas de nieve, ha propiciado el desarrollo de modelos numéricos ad hoc como una herramienta de soporte para su análisis y evaluación. Los modelos existentes para simulación de aludes se basan en la conservación de la masa y de la cantidad de movimiento, que son unas ecuaciones similares a las ecuaciones de Saint Venant para agua con diferencias sólo en los términos de fricción (modelo reológico). Este documento muestra las posibilidades de estas ecuaciones para simular avalanchas de placa-densa y el tratamiento numérico realizado en Iber. Se ha empleado una nueva metodología para equilibrar el término fuente y el vector de flujo evitando así oscilaciones espurias y movimientos no reales, y que modifica la pendiente de fondo en base a los parámetros del fluido y así detener su movimiento. La herramienta se ha probado en dos casos de estudio para analizar el comportamiento del fluido en función de los parámetros del mode, [EN] The growing concern about natural hazards, such as snow avalanches, has led to the development of ad hoc numerical models as a support tool for their analysis and evaluation. Existing models for avalanche simulation are based on the conservation of mass and the momentum, which are similar equations to the Saint Venant equations for water with differences only in terms of friction (rheological model). This document shows the possibilities of these equations to simulate dense-slab avalanches and the numerical treatment carried out in Iber. A new methodology has been used to balance the source term and the flow vector to avoid spurious oscillations and unreal movements, modifying the bottom slope based on the fluid parameters and thus stop its movement. The tool has been tested in two case studies to analyse the behaviour of the fluid depending on the parameters of the rheological model.

La creciente preocupación por los riesgos naturales, como las avalanchas de nieve, ha propiciado el desarrollo de modelos numéricos ad hoc como una herramienta de soporte para su análisis y evaluación. Los modelos existentes para simulación de aludes se basan en la conservación de la masa y de la cantidad de movimiento, que son unas ecuaciones similares a las ecuaciones de Saint Venant para agua con diferencias sólo en los términos de fricción (modelo reológico). Este documento muestra las posibilidades de estas ecuaciones para simular avalanchas de placa-densa y el tratamiento numérico realizado en Iber. Se ha empleado una nueva metodología para equilibrar el término fuente y el vector de flujo evitando así oscilaciones espurias y movimientos no reales, y que modifica la pendiente de fondo en base a los parámetros del fluido y así detener su movimiento. La herramienta se ha probado en dos casos de estudio para analizar el comportamiento del fluido en función de los parámetros del modelo reológico., Peer Reviewed, Postprint (published version)

Background Two-dimensional shear wave elastography (2D-SWE) can noninvasively evaluate hepatic elastic modulus as shear wave velocity (SWV). Additionally, it may predict the presence of clinical relevant hepatic fibrosis (>= F2) in dogs with hepatic disease. Objectives To investigate whether SWV measured by 2D-SWE can differentiate between dogs with (>= F2) and without (F0-1) clinically relevant hepatic fibrosis. Animals Twenty-eight client-owned dogs with hepatic disease and 8 normal healthy Beagle dogs were enrolled. Methods In this cross-sectional prospective study, SWVs were measured using 2D-SWE in all dogs. Hepatic fibrosis stages and necroinflammatory activity grades were histopathologically evaluated using a histological scoring scheme that was adapted from the Ishak schema used in human medicine. Results Median SWVs were significantly higher in dogs with clinically relevant hepatic fibrosis (2.04 m/s; range, 1.81-2.26 m/s) than in healthy dogs (1.51 m/s; range, 1.44-1.66 m/s; P = .007), and dogs without clinically relevant hepatic fibrosis (1.56 m/s; range, 1.37-1.67 m/s; P < .001). However, no significant difference was found in the SWVs between dogs without clinically relevant hepatic fibrosis and healthy dogs (P = .99). Furthermore, median SWVs were not significantly different among dogs with necroinflammatory activity, those without necroinflammatory activity, and healthy dogs (Kruskal-Wallis test, P = .12). Conclusions and Clinical Importance The 2D-SWE may be useful for predicting the presence of hepatic fibrosis in dogs with hepatic disease.

Background Two-dimensional shear wave elastography (2D-SWE) can noninvasively evaluate hepatic elastic modulus as shear wave velocity (SWV). Additionally, it may predict the presence of clinical relevant hepatic fibrosis (>= F2) in dogs with hepatic disease. Objectives To investigate whether SWV measured by 2D-SWE can differentiate between dogs with (>= F2) and without (F0-1) clinically relevant hepatic fibrosis. Animals Twenty-eight client-owned dogs with hepatic disease and 8 normal healthy Beagle dogs were enrolled. Methods In this cross-sectional prospective study, SWVs were measured using 2D-SWE in all dogs. Hepatic fibrosis stages and necroinflammatory activity grades were histopathologically evaluated using a histological scoring scheme that was adapted from the Ishak schema used in human medicine. Results Median SWVs were significantly higher in dogs with clinically relevant hepatic fibrosis (2.04 m/s; range, 1.81-2.26 m/s) than in healthy dogs (1.51 m/s; range, 1.44-1.66 m/s; P = .007), and dogs without clinically relevant hepatic fibrosis (1.56 m/s; range, 1.37-1.67 m/s; P < .001). However, no significant difference was found in the SWVs between dogs without clinically relevant hepatic fibrosis and healthy dogs (P = .99). Furthermore, median SWVs were not significantly different among dogs with necroinflammatory activity, those without necroinflammatory activity, and healthy dogs (Kruskal-Wallis test, P = .12). Conclusions and Clinical Importance The 2D-SWE may be useful for predicting the presence of hepatic fibrosis in dogs with hepatic disease.