Absolute Protein Amounts and Relative Abundance of Volume-regulated Anion Channel (VRAC) LRRC8 Subunits in Cells and Tissues Revealed by Quantitative Immunoblotting

The volume-regulated anion channel (VRAC) plays an important role in osmotic cell volume regulation. In addition, it is involved in various physiological processes such as insulin secretion, glia-neuron communication and purinergic signaling. VRAC is formed by hetero-hexamers of members of the LRRC8 protein family, which consists of five members, LRRC8A-E. LRRC8A is an essential subunit for physiological functionality of VRAC. Its obligate heteromerization with at least one of its paralogues, LRRC8B-E, determines the biophysical properties of VRAC. Moreover, the subunit composition is of physiological relevance as it largely influences the activation mechanism and especially the substrate selectivity. However, the endogenous tissue-specific subunit composition of VRAC is unknown. We have now developed and applied a quantitative immunoblot study of the five VRAC LRRC8 subunits in various mouse cell lines and tissues, using recombinant protein for signal calibration. We found tissue-specific expression patterns of the subunits, and generally relative low expression of the essential LRRC8A subunit. Immunoprecipitation of LRRC8A also co-precipitates an excess of the other subunits, suggesting that non-LRRC8A subunits present the majority in hetero-hexamers. With this, we can estimate that in the tested cell lines, the number of VRAC channels per cell is in the order of 10,000, which is in agreement with earlier calculations from the comparison of single-channel and whole-cell currents

Vertrauen in Roboter und dessen Beeinflussbarkeit durch sprachliches Framing

Collaborative robots (cobots) enable human-robot interactions in the workplace without safety fences. An appropriate level of trust by employees is critical to the success of these interactions. Anthropomorphic perceptions and fears of technological replacement affect trust formation. They can be influenced by linguistic framing, as this interdisciplinary empirical study shows

Implicit Incorporation of Heuristics in MPC-Based Control of a Hydrogen Plant

The replacement of fossil fuels in combination with an increasing share of renewable energy sources leads to an increased focus on decentralized microgrids. One option is the local production of green hydrogen in combination with fuel cell vehicles (FCVs). In this paper, we develop a control strategy based on Model Predictive Control (MPC) for an energy management system (EMS) of a hydrogen plant, which is currently under installation in Offenbach, Germany. The plant includes an electrolyzer, a compressor, a low pressure storage tank, and six medium pressure storage tanks with complex heuristic physical coupling during the filling and extraction of hydrogen. Since these heuristics are too complex to be incorporated into the optimal control problem (OCP) explicitly, we propose a novel approach to do so implicitly. First, the MPC is executed without considering them. Then, the so-called allocator uses a heuristic model (of arbitrary complexity) to verify whether the MPC's plan is valid. If not, it introduces additional constraints to the MPC's OCP to implicitly respect the tanks' pressure levels. The MPC is executed again and the new plan is applied to the plant. Simulation results with real-world measurement data of the facility's energy management and realistic fueling scenarios show its advantages over rule-based control.Comment: 8 pages, 3 figures. To be published in IEEE 3rd International Conference on Power Electronics, Smart Grid, and Renewable Energy (PESGRE 2023) proceeding

Vertrauen in Roboter und dessen Beeinflussbarkeit durch sprachliches Framing

Collaborative robots (cobots) enable human-robot interactions in the workplace without safety fences. An appropriate level of trust by employees is critical to the success of these interactions. Anthropomorphic perceptions and fears of technological replacement affect trust formation. They can be influenced by linguistic framing, as this interdisciplinary empirical study shows

Computer-aided Optical Plasma Postprocessing Applied on Model Spark Gaps

Spark gaps are used as surge protective devices (SPD class 1) for low voltage grids protection against surge currents and overvoltages. For practical research of the narrow gap plasma of spark gaps, high-speed camera recordings are used in modified transparent test models. In this test setup, current densities of 1010 A/m2 are generated. In order to optimize and automate the evaluation process of camera recordings, an image analysis tool is developed further in this contribution. After basic image improvement and segmentation, this research optimizes a detection algorithm for plasma location and distribution. As a result, the known plasma distribution gives access to significantly more information about the plasma behaviour and the spatial distribution of radiation

Measuring the impact of learning at the workplace on organisational performance

Purpose: The purpose of this article is to explore the importance of workplace learning in the context of performance measurement on an organisational level. It shows how workplace learning analytics can be grounded on professional identity transformation theory and integrated into performance measurement approaches to understand its organisation-wide impact. Design/methodology/approach: In a conceptual approach, a framework to measure the organisation-wide impact of workplace learning interventions has been developed. As a basis for the description of the framework, related research on relevant concepts in the field of performance measurement approaches, workplace learning, professional identity transformation, workplace and social learning analytics are discussed. A case study in a European Public Employment Service is presented. The framework is validated by qualitative evaluation data from three case studies. Finally, theoretical as well as practical implications are discussed. Findings: Professional identity transformation theory provides a suitable theoretical framework to gain new insights into various dimensions of workplace learning. Workplace learning analytics can reasonably be combined with classical performance management approaches to demonstrate its organisation-wide impact. A holistic and streamlined framework is perceived as beneficial by practitioners from several European Public Employment Services. Research limitations/implications: Empirical data originates from three case studies in the non-profit sector only. The presented framework needs to be further evaluated in different organisations and settings. Practical implications: The presented framework enables non-profit organisations to integrate workplace learning analytics in their organisation-wide performance measurement, which raises awareness for the importance of social learning at the workplace. Originality/value: The paper enriches the scarce research base about workplace learning analytics and its potential links to organisation-wide performance measurement approaches. In contrast to most previous literature, a thorough conceptualisation of workplace learning as a process of professional identity transformation is used

Discussion on Electric Power Supply Systems for All Electric Aircraft

The electric power supply system is one of the most important research areas within sustainable and energy-efcient aviation for more- and especially all electric aircraft. This paper discusses the history in electrication, current trends with a broad overview of research activities, state of the art of electrication and an initial proposal for a short-range aircraft. It gives an overviewof the mission prole, electrical sources, approaches for the electrical distribution system and the required electrical loads. Current research aspects and questions are discussed, including voltage levels, semiconductor technology, topologies and reliability. Because of the importance for safety possible circuit breakers for the proposed concept are also presented and compared, leading to a initial proposal. Additionally, a very broad review of literature and a state of the art discussion of the wiring harness is given, showing that this topic comes with a high number of aspects and requirements. Finally, the conclusion sums up the most important results and gives an outlook on important future research topics

Abstrahlverhalten einer transienten Funkenstrecke - Ein grundlegender Versuch zur EMV-Abschätzung

Es wurde ein Versuchsaufbau vorgestellt, mit dem eine transiente Funkenstrecke reproduzierbar erzeugt und ihr Abstrahlverhalten gemessen werden kann. Wesentlicher Bestandteil der Vermessung des Magnetfeldes ist dabei die Kalibrierung einer geeigneten Magnetfeld-Schnüffelsonde mit Anwendung auf Transienten. Mit diesem grundlegenden Versuch konnte eine einfache rechnerische Abschätzung für Magnetfelder, die durch eine solche Funkenstrecke erzeugt werden, verifiziert werden. Die Abschätzungen sind dabei unterteilt in einen quasistationären und einen gestrahlten Term, welche je nach Frequenzbereich Anwendung finden sollten. Weiterhin zu untersuchen bleiben Variationen der Funkenstrecke, beispielswiese bezüglich der Anstiegszeiten des Stromes I(t) und dem Abstand der Elektroden. Denkbar wäre auch eine Erweiterung der rechnerischen Abschätzung mit dem Skalarpotenzial unter Berücksichtigung der gemessenen Elektrodenspannung. Interessant ist sicherlich auch eine Charakterisierung der raum- und zeitvarianten Funkenentladung selbst mit Hilfe von High-Speed-Kameras. Einige Arbeiten am Institut für Hochspannungstechnik und Elektrische Energieanlagen sind diesbezüglich durchaus vielversprechend und könnten zur Verfeinerung von rechnerischen Abschätzungen beitragen