On a Model for Phase Separation on Biological Membranes and its Relation to the Ohta-Kawasaki Equation

We provide a detailed mathematical analysis of a model for phase separation on biological membranes which was recently proposed by Garcke, R\"atz, R\"oger and the second author. The model is an extended Cahn-Hilliard equation which contains additional terms to account for the active transport processes. We prove results on the existence and regularity of solutions, their long-time behaviour, and on the existence of stationary solutions. Moreover, we investigate two different asymptotic regimes. We study the case of large cytosolic diffusion and investigate the effect of an infinitely large affinity between membrane components. The first case leads to the reduction of coupled bulk-surface equations in the model to a system of surface equations with non-local contributions. Subsequently, we recover a variant of the well-known Ohta-Kawasaki equation as the limit for infinitely large affinity between membrane components.Comment: 41 page

Three-dimensional structure and flexibility of a membrane-coating module of the nuclear pore complex.

The nuclear pore complex mediates nucleocytoplasmic transport in all eukaryotes and is among the largest cellular assemblies of proteins, collectively known as nucleoporins. Nucleoporins are organized into distinct subcomplexes. We optimized the isolation of a putative membrane-coating subcomplex of the nuclear pore complex, the heptameric Nup84 complex, and analyzed its structure by EM. Our data confirmed the previously reported 'Y' shape. We discerned additional structural details, including specific hinge regions at which the particle shows great flexibility. We determined the three-dimensional structures of two conformers, mapped the localization of two nucleoporins within the subcomplex and docked known crystal structures into the EM maps. The free ends of the Y-shaped particle are formed by beta-propellers; the connecting segments consist of alpha-solenoids. Notably, the same organizational principle is found in the clathrin triskelion, which may share a common evolutionary origin with the heptameric complex

The Well-Being of Children as Viewed Through Their Conceptions of Death

An explorative study was conducted to try and understand how young children’s emerging death concepts form including, (a) what family demographics and child factors contributed to family well-being, (b) did family well-being influence children’s social competence, and (c) did family well-being and children’s social competence influence children’s death conceptions. Although the subject of death contains many unique characteristics, it is not easily separated from other aspects of life; death is inseparable from the whole human experience (DeSpelder & Strickland, 2002). It was the assumption of this paper that children develop their conceptions of death based on the appreciation they hold for life; based on children’s growth in pro-social behavior, self-worth, spirituality, values, and morals. The results indicated positive correlations between family spirituality and family pro-social behavior with a children’s general social adaptation, as well as children’s social competence and their death concepts as indicated through their artwork. In addition, several qualitative themes of children’s death concepts emerged including friendship-like relationships with God and visions of Heaven and Hell. Most importantly noted were the associations between parent and child death concepts

Projekt MUSE: Muster und Strukturen in der Schuleingangsphase erkunden

Inwieweit profitieren – insbesondere die schwächeren – Kinder in der Schuleingangsphase von der Förderung der Muster- und Strukturierungsfähigkeit? Ziel dieses Projekts im Schnittfeld von Forschung und Entwicklung ist die Konzeption und Erprobung von Aufgaben und Materialien zur Förderung von Muster- und Strukturierungsfähigkeiten im Rahmen des mathematischen Anfangsunterrichts. Vorgestellt werden das Konzept und erste Ergebnisse einer Interventionsstudie