Advanced Carbon Reinforced Concrete Technologies for Façade Elements of Nearly Zero-Energy Buildings.

The building sector accounts for approx. 40% of total energy consumption and approx. 36% of all greenhouse gas emissions in Europe. As the EU climate targets for 2030 call for a reduction of greenhouse gas emissions by more than half compared to the emissions of 1990 and also aim for climate neutrality by 2050, there is an urgent need to achieve a significant decrease in the energy use in buildings towards Nearly Zero-Energy Buildings (nZEBs). As the energy footprint of buildings includes the energy and greenhouse gas consumption both in the construction phase and during service life, nZEB solutions have to provide energy-efficient and less carbon-intensive building materials, specific thermal insulation solutions, and a corresponding design of the nZEB. Carbon reinforced concrete (CRC) materials have proven to be excellent candidate materials for concrete-based nZEBs since they are characterized by a significantly lower CO2 consumption during component production and much a longer lifecycle. The corresponding CRC technology has been successively implemented in the last two decades and first pure CRC-based buildings are currently being built. This article presents a novel material system that combines CRC technology and suitable multifunctional insulation materials as a sandwich system in order to meet future nZEB requirements. Because of its importance for the life cycle stage of production, cost-efficient carbon fibers (CF) from renewable resources like lignin are used as reinforcing material, and reinforcement systems based on such CF are developed. Cutting edge approaches to produce ultra-thin lightweight CF reinforced concrete panels are discussed with regard to their nZEB relevance. For the life cycle stage of the utilization phase, the thermal insulation properties of core materials are optimized. In this context, novel sandwich composites with thin CRC layers and a cellular lightweight concrete core are proposed as a promising solution for façade elements as the sandwich core can additionally be combined with an aerogel-based insulation. The concepts to realize such sandwich façade elements will be described here along with a fully automated manufacturing process to produce such structures. The findings of this study provide clear evidence on the promising capabilities of the CRC technology for nZEBs on the one hand and on the necessity for further research on optimizing the energy footprint of CRC-based structural elements on the other hand.

Structure predictions and interaction studies indicate homology of separase N-terminal regulatory domains and Drosophila THR.

The final resolution of sister chromatid cohesion during mitotic and meiotic divisions is mediated by activation of separase which cleaves a cohesin complex subunit. The structural basis of separase regulation is unknown. Separases from different eukaryotes share almost no sequence similarity, especially within the large N-terminal domain that precedes the protease domain except in Drosophila melanogaster. Moreover, sequence similarity among securin proteins, which associate as regulatory subunits with separase, is restricted to the signals that promote the mitotic degradation required for separase activation. Here, we address the surprising divergence of separase and securin sequences. The absence of an extended N-terminal separase domain in dipteran species is shown to be correlated with the expression of an extra regulatory subunit (THR). The interactions of THR with separase and securin in Drosophila melanogaster are analogous to those of the human N-terminal separase domain with its C-terminal domain and securin. Even heterologous interactions between Drosophila and human separase complex components occur in yeast two-hybrid experiments. Tertiary structure predictions reveal alpha-alpha superhelix folds in both THR and the N-terminal domains of nondipteran separases. The compatibility of these folds with a wide range of primary sequences has likely allowed the rapid divergence of THR/N-terminal separase sequences and securins, which contact this region.

The Drosophila melanogaster condensin subunit Cap-G interacts with the centromere-specific histone H3 variant CID.

The centromere-specific histone H3 variant CENP-A plays a crucial role in kinetochore specification and assembly. We chose a genetic approach to identify interactors of the Drosophila CENP-A homolog CID. Overexpression of cid in the proliferating eye imaginal disk results in a rough eye phenotype, which is dependent on the ability of the overexpressed protein to localize to the kinetochore. A screen for modifiers of the rough eye phenotype identified mutations in the Drosophila condensin subunit gene Cap-G as interactors. Yeast two-hybrid experiments also reveal an interaction between CID and Cap-G. While chromosome condensation in Cap-G mutant embryos appears largely unaffected, massive defects in sister chromatid segregation occur during mitosis. Taken together, our results suggest a link between the chromatin condensation machinery and kinetochore structure.