Domain decomposition methods in science and engineering XXII

These are the proceedings of the 22nd International Conference on Domain Decomposition Methods, which was held in Lugano, Switzerland. With 172 participants from over 24 countries, this conference continued a long-standing tradition of internationally oriented meetings on Domain Decomposition Methods. The book features a well-balanced mix of established and new topics, such as the manifold theory of Schwarz Methods, Isogeometric Analysis, Discontinuous Galerkin Methods, exploitation of modern HPC architectures, and industrial applications. As the conference program reflects, the growing capabilities in terms of theory and available hardware allow increasingly complex non-linear and multi-physics simulations, confirming the tremendous potential and flexibility of the domain decomposition concept

Design and analysis of a lightweight parallel adaptive scheme for the solution of the monodomain equation

Numerical simulation of the nonlinear reaction-diffusion equations in computational electrocardiology requires locally high spatial resolution to capture the multiscale effects related to the electrical activation of the heart accurately, namely the strongly varying transmembrane potential. Here, we propose a novel lightweight adaptive algorithm which aims at ombining the plainness of structured meshes with the resolving capabilities of unstructered adaptive meshes. Our "patchwise adaptive" approach is based on locally structured mesh hierarchies which are glued along their interfaces by a nonconforming mortar element discretization. To further increase the overall efficiency, we keep the spatial meshes constant over suitable time windows in which error indicators are accumulated. This approach facilitates strongly varying mesh sizes in neighboring patches as well as in consecutive time steps. For the transfer of the dynamic variables between different spatial approximation spaces we compare the L2-projection and a local approximation. Finally, since an implicit-explicit time discretization is employed for stability reasons, we derive a spatial preconditioner which is tailored to the special structure of the patchwise adaptive meshes. We analyze the (parallel) performance and scalability of the resulting method by several examples from computational electrocardiology of different sizes. Additionally, we compare our method to a standard adaptive refinement strategy using unstructured meshes. As it turns out, our novel adaptive scheme provides a very good balance between reduction in degrees of freedom and overall (parallel) efficiency

DuoMab: a novel CrossMab-based IgG-derived antibody format for enhanced antibody-dependent cell-mediated cytotoxicity

High specificity accompanied with the ability to recruit immune cells has made recombinant therapeutic antibodies an integral part of drug development. Here we present a generic approach to generate two novel IgG-derived antibody formats that are based on a modification of the CrossMab technology. MoAbs harbor two heavy chains (HCs) resulting in one binding entity and one fragment crystallizable region (Fc), whereas DuoMabs are composed of four HCs harboring two binding entities and two Fc regions linked at a disulfide-bridged hinge. The latter bivalent format is characterized by avidity-enhanced target cell binding while simultaneously increasing the ‘Fc-load’ on the surface. DuoMabs were shown to be producible in high yield and purity and bind to surface cells with affinities comparable to IgGs. The increased Fc load directed at the surface of target cells by DuoMabs modulates their antibody-dependent cell-mediated cytotoxicity competency toward target cells, making them attractive for applications that require or are modulated by FcR interactions