48 research outputs found

    Singular Cucker-Smale Dynamics

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    The existing state of the art for singular models of flocking is overviewed, starting from microscopic model of Cucker and Smale with singular communication weight, through its mesoscopic mean-filed limit, up to the corresponding macroscopic regime. For the microscopic Cucker-Smale (CS) model, the collision-avoidance phenomenon is discussed, also in the presence of bonding forces and the decentralized control. For the kinetic mean-field model, the existence of global-in-time measure-valued solutions, with a special emphasis on a weak atomic uniqueness of solutions is sketched. Ultimately, for the macroscopic singular model, the summary of the existence results for the Euler-type alignment system is provided, including existence of strong solutions on one-dimensional torus, and the extension of this result to higher dimensions upon restriction on the smallness of initial data. Additionally, the pressureless Navier-Stokes-type system corresponding to particular choice of alignment kernel is presented, and compared - analytically and numerically - to the porous medium equation

    Alteration in the plasma concentration of a DAAO inhibitor, 3-methylpyrazole-5-carboxylic acid, in the ketamine-treated rats and the influence on the pharmacokinetics of plasma d-tryptophan

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    A determination method for 3-methylpyrazole-5-carboxylic acid (MPC), an inhibitor of d-amino acid oxidase (DAAO), in rat plasma was developed by using high-performance liquid chromatography-mass spectrometry (LC-MS). The structural isomer of MPC, 3-methylpyrazole-4-carboxylic acid, was used as an internal standard, and the intra- and inter-day accuracies and precisions were satisfactory for the determination of plasma MPC

    Effective Programs in Elementary Mathematics: A Best-Evidence Synthesis

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    One-dimensional compressible flow with temperature dependent transport coefficients

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    Abstract We establish existence of global-in-time weak solutions to the one dimensional, compressible Navier-Stokes system for a viscous and heat conducting ideal polytropic gas (pressure p = Kθ/τ , internal energy e = cvθ), when the viscosity µ is constant and the heat conductivity κ depends on the temperature θ according to κ(θ) =κθ β , with 0 ≤ β < . This choice of degenerate transport coefficients is motivated by the kinetic theory of gasses. Approximate solutions are generated by a semi-discrete finite element scheme. We first formulate sufficient conditions that guarantee convergence to a weak solution. The convergence proof relies on weak compactness and convexity, and it applies to the more general constitutive relations µ(θ) =μθ α , κ(θ) =κθ β , with α ≥ 0, 0 ≤ β < 2 (μ,κ constants). We then verify the sufficient conditions in the case α = 0 and 0 ≤ β < 3 2 . The data are assumed to be without vacuum, mass concentrations, or vanishing temperatures, and the same holds for the weak solutions

    Deficiency of TLR4 homologue RP105 aggravates outward remodeling in a murine model of arteriovenous fistula failure

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    Abstract Arteriovenous access dysfunction is a major cause of morbidity for hemodialysis patients. The pathophysiology of arteriovenous fistula (AVF) maturation failure is associated with inflammation, impaired outward remodeling (OR) and intimal hyperplasia. RP105 is a critical physiologic regulator of TLR4 signaling in numerous cell types. In the present study, we investigated the impact of RP105 on AVF maturation, and defined cell-specific effects of RP105 on macrophages and vascular smooth muscle cells (VSMCs). Overall, RP105−/− mice displayed a 26% decrease in venous OR. The inflammatory response in RP105−/− mice was characterized by accumulation of anti-inflammatory macrophages, a 76% decrease in pro- inflammatory macrophages, a 70% reduction in T-cells and a 50% decrease in MMP-activity. In vitro, anti-inflammatory macrophages from RP105−/− mice displayed increased IL10 production, while MCP1 and IL6 levels secreted by pro-inflammatory macrophages were elevated. VSMC content in RP105−/− AVFs was markedly decreased. In vitro, RP105−/− venous VSMCs proliferation was 50% lower, whereas arterial VSMCs displayed a 50% decrease in migration, relative to WT. In conclusion, the impaired venous OR in RP105−/− mice could result from of a shift in both macrophages and VSMCs towards a regenerative phenotype, identifying a novel relationship between inflammation and VSMC function in AVF maturation
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