Persönlichkeit, politische Involvierung und politische Partizipation in Deutschland und Österreich

This article investigates how the so-called Big Five indirectly affect involvement in electoral and non-electoral modes of participation by looking at political knowledge and interest as well as internal efficacy. The analyses rely on data collected by the Austrian (AUTNES) and the German Election Studies (GLES) using path models. Thus, they allow comparison of personality effects in Germany and Austria. Our results show that extraversion and openness to experience are central preconditions of political participation, which have an indirect effect mediated by political involvement. In addition, variation in the causal patterns across the two countries suggests that context matters

Channels of participation : Political participant types and personality

Acknowledgments: Authors in alphabetical order. We thank Emma Conforti, Johann Gründi, Steffen Kramer and Klaus Trenkwalder for their research assistance. Previous version of the paper, which were Supported by the Austrian National Election Study (AUTNES), a National Research Network (NFN) sponsored by the Austrian Science Fund (FWF) [S10902-G11], were presented at the 67th Annual Conference of the World Association for Public Opinion Research (Nice, 2-6 September 2014) and the Annual Conference of the Working Group ‘Election and Political Attitudes’ of the German Political Science Association (Düsseldorf, 11-12 June 2015).Peer reviewedPublisher PD

Ligand Photo-Isomerization Triggers Conformational Changes in iGluR2 Ligand Binding Domain

Neurological glutamate receptors bind a variety of artificial ligands, both agonistic and antagonistic, in addition to glutamate. Studying their small molecule binding properties increases our understanding of the central nervous system and a variety of associated pathologies. The large, oligomeric multidomain membrane protein contains a large and flexible ligand binding domains which undergoes large conformational changes upon binding different ligands. A recent application of glutamate receptors is their activation or inhibition via photo-switchable ligands, making them key systems in the emerging field of optochemical genetics. In this work, we present a theoretical study on the binding mode and complex stability of a novel photo-switchable ligand, ATA-3, which reversibly binds to glutamate receptors ligand binding domains (LBDs). We propose two possible binding modes for this ligand based on flexible ligand docking calculations and show one of them to be analogues to the binding mode of a similar ligand, 2-BnTetAMPA. In long MD simulations, it was observed that transitions between both binding poses involve breaking and reforming the T686-E402 protein hydrogen bond. Simulating the ligand photo-isomerization process shows that the two possible configurations of the ligand azo-group have markedly different complex stabilities and equilibrium binding modes. A strong but slow protein response is observed after ligand configuration changes. This provides a microscopic foundation for the observed difference in ligand activity upon light-switching

3D Hydrophobic Moment Vectors as a Tool to Characterize the Surface Polarity of Amphiphilic Peptides

AbstractThe interaction of membranes with peptides and proteins is largely determined by their amphiphilic character. Hydrophobic moments of helical segments are commonly derived from their two-dimensional helical wheel projections, and the same is true for β-sheets. However, to the best of our knowledge, there exists no method to describe structures in three dimensions or molecules with irregular shape. Here, we define the hydrophobic moment of a molecule as a vector in three dimensions by evaluating the surface distribution of all hydrophilic and lipophilic regions over any given shape. The electrostatic potential on the molecular surface is calculated based on the atomic point charges. The resulting hydrophobic moment vector is specific for the instantaneous conformation, and it takes into account all structural characteristics of the molecule, e.g., partial unfolding, bending, and side-chain torsion angles. Extended all-atom molecular dynamics simulations are then used to calculate the equilibrium hydrophobic moments for two antimicrobial peptides, gramicidin S and PGLa, under different conditions. We show that their effective hydrophobic moment vectors reflect the distribution of polar and nonpolar patches on the molecular surface and the calculated electrostatic surface potential. A comparison of simulations in solution and in lipid membranes shows how the peptides undergo internal conformational rearrangement upon binding to the bilayer surface. A good correlation with solid-state NMR data indicates that the hydrophobic moment vector can be used to predict the membrane binding geometry of peptides. This method is available as a web application on http://www.ibg.kit.edu/HM/

Stuck Bit Error Identification for the TerraSAR-X and TanDEM-X Onboard Memory

Errors in memory storage devices in the form of erroneous bits induced by radiation are a common issue for every space- craft in orbit. Therefore, well established techniques detect and directly correct these errors in the storage hardware. Sporadically single memory cells can temporarily get “stuck” at a false bit in which case they cannot be corrected. Those stuck bits can persist up to several months generating the same errors during every memory scrubbing cycle. In order to assess the current memory status a method to distinguish between regular and stuck-bit errors is needed. This paper therefore presents a classification approach based on the DBSCAN method where stuck bits are identified as outliers and clustered accordingly. The approach first is verified with simulated data that resembles the error structure of memory errors on TerraSAR-X and TanDEM-X. Subsequently, the method is validated with the memory errors recorded by both satellites throughout their lifetime

Status on molten nitrate salts above 600 °C

Molten nitrate salts are state-of-the-art heat transfer fluids (HTF) and thermal energy storage (TES) in Concentrating Solar Power (CSP) plants. Only recently, the authors of this work demonstrated that higher operating temperatures of at least 620°C can be realized, compared to state-of-the-art temperatures of 565 °C. The development principally enables the transformation of conventional power plants (e.g. coal) into Storage Power Plants that can absorb peak currents from fluctuating renewable sources. The presentation outlines the potential of nitrate salts in these new fields of application with a particular view on the material research level. In the last years the scientific community has made important progress in understanding the fundamental reaction mechanisms in nitrate salts at temperatures above 600 °C. Yet, the schematic description is far from complete and in the presentation we will outline the recent progress and timeline required for the successful implementation of Molten Salt storage above 600 °C

Solar Salt above 600 ◦C: Impact of Experimental Design on Thermodynamic Stability Results

Thermal energy storage (TES) based on molten salts has been identified as a key player in the transition from fossil fuels to renewable energy sources. Solar Salt, a mixture of NaNO3 (60 wt%) and KNO3 (40 wt%), is currently the most advanced heat transfer and storage material used in concentrating solar power (CSP) plants. Here, it is utilized to produce electricity via a Rankine cycle, with steam temperatures reaching 550 °C. The goal of this study is to increase the operating temperature of solar salt to over 600 °C, allowing it to be adapted for use in high-temperature Rankine cycles with steam temperatures greater than 600 °C. Yet, this goal is impaired by the lack of available thermodynamic data given the salt's complex high-temperature decomposition and corrosion chemistry. The study explores the thermodynamics of the decomposition reactions in solar salt, with a focus on suppressing decomposition into corrosive oxide ions up to a temperature of 620 °C. The results provide a new understanding of the stabilization of solar salt at previously unexplored temperatures with effective utilization of gas management technique

Experimental Demonstration of Nadir Echo Removal in SAR Using Waveform Diversity and Dual-Focus Postprocessing

Synthetic aperture radar (SAR) provides high-resolution images for remote sensing applications regardless of sunlight and weather conditions. The pulsed operation of SAR may lead to an occurrence of nadir echoes in SAR images that significantly affect the image quality in case the pulse repetition frequency (PRF) is not properly constrained within the SAR system design. As an alternative, pulse-to-pulse variation of the transmitted waveform and dual-focus postprocessing can be exploited to remove the nadir echo and alleviate the PRF constraints (also in ScanSAR operation). This work provides a demonstration of the latter concept through an experimental acquisition of the TerraSAR-X satellite. The experiment is designed by selecting the scene and the acquisition parameters in order to have the nadir echo appearing in the SAR image. The waveform variation is achieved by alternating up- and down-chirps on transmit. The analysis of the results shows the effectiveness of dual-focus postprocessing for nadir echo suppression