51 research outputs found
Port-Hamiltonian discretization for open channel flows
A finite-dimensional Port-Hamiltonian formulation for the dynamics of smooth open channel flows is presented. A numerical scheme based on this formulation is developed for both the linear and nonlinear shallow water equations. The scheme is verified against exact solutions and has the advantage of conservation of mass and energy to the discrete level
Port-Hamiltonian formulation of shallow water equations with Coriolis force and topography
We look into the problem of approximating the shallow water equations with Coriolis forces and topography. We model the system as an infinite-dimensional port-Hamiltonian system which is represented by a non-constant Stokes-Dirac structure. We here employ the idea of using different finite elements for the approximation of geometric variables (forms) describing a distributed parameter system, to spatially discretize the system and obtain a lumped parameter port-Hamiltonian system. The discretized model then captures the physical laws of its infinite-dimensional couterpart such as conservation of energy. We present some preliminary numerical results to justify our claims
Genetic Variability Overrides the Impact of Parental Cell Type and Determines iPSC Differentiation Potential
Reports on the retention of somatic cell memory in induced pluripotent stem cells (iPSCs) have complicated the selection of the optimal cell type for the generation of iPSC biobanks. To address this issue we compared transcriptomic, epigenetic, and differentiation propensities of genetically matched human iPSCs derived from fibroblasts and blood, two tissues of the most practical relevance for biobanking. Our results show that iPSC lines derived from the same donor are highly similar to each other. However, genetic variation imparts a donor-specific expression and methylation profile in reprogrammed cells that leads to variable functional capacities of iPSC lines. Our results suggest that integration-free, bona fide iPSC lines from fibroblasts and blood can be combined in repositories to form biobanks. Due to the impact of genetic variation on iPSC differentiation, biobanks should contain cells from large numbers of donors.Peer reviewe
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