Organ-Derived Extracellular Matrix (ECM) Hydrogels:Versatile Systems to Investigate the Impact of Biomechanics and Biochemistry on Cells in Disease Pathology

The extracellular matrix (ECM) provides instructive and constructive support to cells in all organs. The ECM’s composition and structure are organ-dependent. The adhesion of cells to ECM with, e.g., integrins triggers cellular mechanosignalling. The role of mechanical properties of ECM hydrogels in vivo remains scarce. To replicate the ECM-cell interactions requires organ and tissue-specific ECM hydrogels. Such 3D culture systems allow the monitoring of ECM dynamics, i.e., turnover and mechanical changes (stiffness and stress relaxation). Compression testing allows to determine stiffness and stress relaxation. Hydrogels’ stress relaxation is governed by displacement of water, large macromolecules, and cells in a time-and organ origin-dependent fashion. The ECM biochemistry also regulates cell fate and function, e.g., through integrin signalling and via small molecules like growth factors that bind to specific ECM components. Organ-derived ECM hydrogels gain increasing interest due to their promising prospects for clinical use to augment tissue regeneration.</p

Redistribution of Meshes’ Nodes Using Moving Surfaces

Surface processing tools based on Partial Differential Equations (PDEs) are emerging recently in computer graphics, digital animation, computer aided modelling, and computer vision. In this work we propose an algorithm to move and redistribute the nodes of a mesh representing a surface in R3. This is obtained by a surface evolution process according to normal and tangential velocities with two aims: • to obtain a more homogeneous surface representation and a more, numerically easy to process, mesh • to move the surface in space avoiding mesh nodes’ collision. The evolution of the surface is formulated in a Lagrangian framework using a couple of PDEs applied to the surfaces’ spatial characteristics. In the first equation a scalar field which follows the spatial features of the mesh, i.e. mean curvature or local elements’ areas, is determined solving an intrinsic Poisson equation. In the second equation the actual surface evolution is computed using the field. Numerical schemes based on finite element discretization in space will be considered, together with several strategies for tangential velocities. The numerical results illustrate how this framework is able both to improve the uniformity of the mesh nodes, and to control the surface evolution avoiding nodes’ collision. Finally, to stress the importance of our approach in a computer graphics context, we consider simple applications to surface smoothing and remeshing in morphing processes. This work has been implemented integrating COMSOL functions into a MATLAB environment. A COMSOL Multiphysics solution is also tested

Organ-Derived Extracellular Matrix (ECM) Hydrogels: Versatile Systems to Investigate the Impact of Biomechanics and Biochemistry on Cells in Disease Pathology

The extracellular matrix (ECM) provides instructive and constructive support to cells in all organs. The ECM’s composition and structure are organ-dependent. The adhesion of cells to ECM with, e.g., integrins triggers cellular mechanosignalling. The role of mechanical properties of ECM hydrogels in vivo remains scarce. To replicate the ECM-cell interactions requires organ and tissue-specific ECM hydrogels. Such 3D culture systems allow the monitoring of ECM dynamics, i.e., turnover and mechanical changes (stiffness and stress relaxation). Compression testing allows to determine stiffness and stress relaxation. Hydrogels’ stress relaxation is governed by displacement of water, large macromolecules, and cells in a time-and organ origin-dependent fashion. The ECM biochemistry also regulates cell fate and function, e.g., through integrin signalling and via small molecules like growth factors that bind to specific ECM components. Organ-derived ECM hydrogels gain increasing interest due to their promising prospects for clinical use to augment tissue regeneration

Online Learning and Metacognition: A Design Framework

Online learning experiences are becoming the norm for an increasing number of higher education students. Although there are clear advantages to online learning in terms of flexibility and access, many students struggle to succeed, especially in purely online learning environments. To a large extent student success in online learning environments is dependent on students' ability to self-regulate and ‘learn for themselves'- both abilities related to academic metacognition. Unfortunately, even at university, many students do not have well developed metacognition. It is therefore important to consider carefully metacognitive scaffolding in the design of online learning experiences. However, the models of instructional design commonly used in online learning tend not to place great emphasis on the importance of metacognitive scaffolding. The aim of the present chapter is therefore to increase awareness of metacognition, as one of the important considerations in the design of online learning environments that can help to maximize chances of student success. Towards this end, a framework of instructional design that is more sensitive to metacognition is developed.No Full Tex