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This study proposes a novel framework of the lattice Boltzmann model for multilayer shallow water equations, considering the mass and momentum exchanges between layers (LABMSWE+). Compared with the original LABMSWE model consisting of N two-dimensional lattice Boltzmann method for shallow water equation (LABSWE) models, the new model includes 1+N LABSWE models. The singular LABSWE model with unit relaxation time is introduced to update the total water depth, and thus, the layer water depths can be obtained explicitly through the fixed layer ratios. The N-layer LABSWE models with the multiple-relaxation-time operator evolve the layer velocities. These two modules are coupled by the total water depth and depth-averaged velocities. The constructed model avoids the freely variable layer thicknesses, which is considered as the main source of the instability. In addition, the mass exchanges enable this model to simulate vertical circulation flows, which are beyond the application of the LABMSWE model. Several numerical tests are then conducted to validate the proposed model. The results show that it exactly satisfies the C-property. In addition, the central difference scheme is more stable and accurate than the upwind and nonequilibrium schemes in the computing of the mass exchanges. The numerical results have an excellent agreement with analytical solutions and reference data, while some unstable and nonphysical results are obtained by the original LABMSWE model. Moreover, the computational time is about 40%–60% of that for the MIKE3, a finite volume solver for the three-dimensional shallow water equations by the Danish Hydraulic Institute. [ABSTRACT FROM AUTHOR]

This paper discusses the seismic analysis of concrete dams with consideration of material nonlinearity. Based on a consistent rate-dependent model and two thermodynamics-based models, two thermodynamics-based rate-dependent constitutive models were developed with consideration of the influence of the strain rate. They can describe the dynamic behavior of concrete and be applied to nonlinear seismic analysis of concrete dams taking into account the rate sensitivity of concrete. With the two models, a nonlinear analysis of the seismic response of the Koyna Gravity Dam and the Dagangshan Arch Dam was conducted. The results were compared with those of a linear elastic model and two rate-independent thermodynamics-based constitutive models, and the influences of constitutive models and strain rate on the seismic response of concrete dams were discussed. It can be concluded from the analysis that, during seismic response, the tensile stress is the control stress in the design and seismic safety evaluation of concrete dams. In different models, the plastic strain and plastic strain rate of concrete dams show a similar distribution. When the influence of the strain rate is considered, the maximum plastic strain and plastic strain rate decrease.

The molecular mechanism for the microgravity‐induced decrease in bone formation remains unclear and there is a lack of effective specific preventative therapies. We recently reported that primary cilia of osteoblasts became shorter and even disappeared when the cells were exposed to random positioning machine (RPM)‐simulated microgravity and that the microgravity‐induced loss of osteogenic potential of osteoblasts could be attenuated when the resorption of primary cilia was prevented by treatment with 0.1 μM cytochalasin D. In the current study, it was further found that the loss of the osteogenic capacity of rat calvarial osteoblasts (ROBs) was associated with the inhibition of the BMP‐2/Smad1/5/8 signalling pathway, of which most of the signalling proteins including BMP‐2, BMPRII, Smad1/5/8 and p‐Smad1/5/8 were found localized to primary cilia. Accompanying the resorption of primary cilia following the cells being exposed to simulated microgravity, the expression levels of these signalling proteins were reduced significantly. Furthermore, the expression of miRNA‐129‐3p, a microRNA previously reported to control cilium biogenesis, was found to be reduced quickly and changed in a similar tendency with the length of primary cilia. Moreover, overexpression of miRNA‐129‐3p in ROBs significantly attenuated microgravity‐induced inhibition of BMP‐2 signalling and loss of osteogenic differentiation and mineralization. These results indicated the important role of miRNA‐129‐3p in microgravity‐induced resorption of primary cilia of osteoblasts and the potential of replenishing the miRNA‐129‐3p as an effective countermeasure against microgravity‐induced loss of primary cilia and impairment of osteoblast function. [ABSTRACT FROM AUTHOR]

ABSTRACT. The persistently low pay-performance sensitivity between executive compensation and firm performance has puzzled both practitioners and academics. We propose a hybrid model that incorporates both moral hazard and adverse [...]

Abstract Background A high concentration of cisplatin (CDDP) induces apoptosis in many tumor cell lines. CDDP has been administered by infusion to avoid severe toxicity. Recently, it has been reported that changes in survivin expression or function may lead to tumor sensitization to chemical and physical agents. The aim of this study was to determine whether a dominant-negative mouse survivin mutant could enhance the anti-tumor activity of CDDP. Methods A plasmid encoding the phosphorylation-defective dominant-negative mouse survivin threonine 34→alanine mutant (survivin T34A) complexed to a DOTAP-chol liposome (Lip-mS) was administered with or without CDDP in Lewis Lung Carcinoma (LLC) cells and in mice bearing LLC tumors, and the effects on apoptosis, tumor growth and angiogenesis were assessed. Data were analyzed using one-way analysis of variance(ANOVA), and a value of P < 0.05 was considered to be statistically significant. Results LLC cells treated with a combination of Lip-mS and CDDP displayed increased apoptosis compared with those treated with Lip-mS or CDDP alone. In mice bearing LLC tumors and treated with intravenous injections of Lip-mS and/or CDDP, combination treatment significantly reduced the mean tumor volume compared with either treatment alone. Moreover, the antitumor effect of Lip-mS combined with CDDP was greater than their anticipated additive effects. Conclusion These data suggest that the dominant-negative survivin mutant, survivin T34A, sensitized LLC cells to chemotherapy of CDDP. The synergistic antitumor activity of the combination treatment may in part result from an increase in the apoptosis of tumor cells, inhibition of tumor angiogenesis and induction of a tumor-protective immune response.