Central Schemes for Nonconservative Hyperbolic Systems

In this work we present a new approach to the construction of high order finite volume central schemes on staggered grids for general hyperbolic systems, including those not admitting a conservation form. The method is based on finite volume space discretization on staggered cells, central Runge-Kutta time discretization, and integration over a family of paths, associated to the system itself, for the generalization of the method to nonconservative systems. Applications to the one and the two layers shallow water models as prototypes of systems of balance laws and systems with source terms and nonconservative products respectively, will be illustrated

Применение интерферометрического метода исследования в изучении кинетики реакций бромидов бария и рубидия с хлористым водородом

The two-layer shallow water system looses hyperbolicity if the mag- nitude of the shear velocity is above a certain threshold, which is es- sentially determined by the density difference between the two layers. The focus of the paper is to explore a technique to possibly recover hyperbolicity by adapting the model in regions of strong shear. The approach is to introduce an additional, third layer in such regions. We demonstrate that this adaptive two/three-layer approach can cure some of the shortcomings of the two-layer model but needs further improvement with respect to the model

A Class of Well-Balanced Algorithms for Relativistic Fluids on a Schwarzschild Background

For the evolution of a compressible fluid in spherical symmetry on a Schwarzschild curved background, we design a class of well-balanced numerical algorithms up to third-order accuracy. We treat both the relativistic Burgers–Schwarzschild model and the relativistic Euler–Schwarzschild model and take advantage of the explicit or implicit forms available for the stationary solutions of these models. Our schemes follow the finite volume methodology and preserve the stationary solutions. Importantly, they allow us to investigate the global asymptotic behavior of such flows and determine the asymptotic behavior of the mass density and velocity field of the fluid.Part of this paper was written during the Academic year 2018–2019 when PLF was a visiting fellow at the Courant Institute for Mathematical Sciences, New York University. The authors were supported by an Innovative Training Network (ITN) under the grant 642768 “ModCompShock”. The research of CP and EPG was also partially supported by the Spanish Government (SG), the European Regional Development Fund (ERDF), the Regional Government of Andalusia (RGA), and the University of Málaga (UMA) through the projects RTI2018-096064-B-C21 (SG-ERDF), UMA18-Federja-161 (RGA-ERDF-UMA), and P18-RT-3163 (RGA-ERDF). Funding for open access charge: Universidad de Málaga/CBUA

Caracterização de paisagens e solos representativos do Estado do Rio de Janeiro para fins de estimativa de estoques de carbono no solo.

Oito áreas representativas do Estado do Rio de Janeiro foram selecionadas para caracterização e amostragem por classe de solo e uso atual, para fins de estudo de estimativa da magnitude do estoque de carbono orgânico sequestrado pelos solos, bem como a sua distribuição vertical nos perfis de solos e a distribuição espacial na paisagem. Dezesseis (16) perfis de solo foram caracterizados, amostrados e analisados quanto à composição química e condições físicas, compreendendo análises completas, granulométrica, densidade do solo e de partículas, e distribuição vertical do carbono orgânico nos perfis, às profundidades de 0-10, 10-20, 20-40, 40-60, 60-80 e 80-100 cm.bitstream/CNPS-2010/14904/1/bpd66-2005-caract-paisagens.pd

Catch-up growth in juvenile rats, fat expansion, and dysregulation of visceral adipose tissue

BACKGROUND: Accelerated catch-up growth following intrauterine restriction increases the risk of developing visceral adiposity and metabolic abnormalities. However, the underlying molecular mechanisms of such metabolic programming are still poorly understood. METHODS: A Wistar rat model of catch-up growth following intrauterine restriction was used. A gene expression array was performed in the retroperitoneal adipose tissue sampled at postnatal day (PD) 42. RESULTS: Five hundred and forty-six differentially expressed genes (DEGs) were identified (adjusted p value < 0.05). Gene ontology enrichment analysis identified pathways related to immune and lipid metabolic processes, brown fat cell differentiation, and regulation of PI3K. Ccl21, Npr3, Serpina3n, Pnpla3, Slc2a4, and Serpina12 were validated to be upregulated in catch-up pups (all p < 0.01) and related to several fat expansion and metabolic parameters, including body weight at PD42, postnatal body weight gain, white and brown adipose tissue mass, plasma triglycerides, and insulin resistance index (all p < 0.05). CONCLUSIONS: Genes related to immune and metabolic processes were upregulated in retroperitoneal adipose tissue following catch-up growth in juvenile rats and were found to be associated with fat expansion and metabolic parameters. Our results provide evidence for several dysregulated genes in white adipose tissue that could help develop novel strategies to prevent the metabolic abnormalities associated with catch-up growth

The correlation of RNase A enzymatic activity with the changes in the distance between Nepsilon2-His12 and N delta1-His119 upon addition of stabilizing and destabilizing salts.

The effect of stabilizing and destabilizing salts on the catalytic behavior of ribonuclease A (RNase A) was investigated at pH 7.5 and 25 degrees C, using spectrophotometric, viscometric and molecular dynamic methods. The changes in the distance between N(epsilon2) of His(12) and N(delta1) of His(119) at the catalytic center of RNase A upon the addition of sodium sulfate, sodium hydrogen sulfate and sodium thiocyanate were evaluated by molecular dynamic methods. The compactness and expansion in terms of Stokes radius of RNase A upon the addition of sulfate ions as kosmotropic salts, and thiocyanate ion as a chaotropic salt, were estimated by viscometric measurements. Enzyme activity was measured using cytidine 2', 3'-cyclic monophosphate as a substrate. The results from the measurements of distances between N(epsilon2) of His(12) and N(delta1) of His(119) and Stokes radius suggest (i) that the presence of sulfate ions decreases the distance between the catalytic His residues and increases the globular compactness, and (ii) that there is an expansion of the enzyme surface as well as elongation of the catalytic center in the presence of thiocyanate ion. These findings are in agreement with activity measurements

Current progress on the numerical simulation of detached flows around airplanes

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