Best Poisson Approximation of Poisson Mixtures. A Linear Operator Approach -- On Some Classes of Diffusion Equations and Related Approximation Problems -- Recent Developments in Barycentric Rational Interpolation -- Approximation on Simplices and Orthogonal Polynomials -- (0, 2) Pál-type Interpolation: A General Method for Regularity -- Sufficient Convergence Conditions for Certain Accelerated…