Non-closure of constraint algebra in N=1 supergravity

The algebra of constraints arising in the canonical quantization of N=1 supergravity in four dimensions is investigated. Using the holomorphic action, the structure functions of the algebra are given and it is shown that the algebra does not close formally for two chosen operator orderings.Comment: 10 pages, no figures, LaTeX; minor changes: more clear exposition of eq. (14): \omega^{AB}_i = ..., extension of discussion with regard to the interpretation of unregularized calculations, emphasis on the fact that this method also yields the structure functions of the classical algebra, minor typographical changes; published in Int.J.Mod.Phys.D, Vol. 6, No. 1 (1997), 107-117, posted with kind permission of World Scientific Publishing C

High-Sensitivity Fluorometry to Resolve Ion Channel Conformational Dynamics

Fluorescent labels offer the capability to follow conformational dynamics of membrane proteins, but signal detection in such recordings is inherently difficult to achieve in a cell membrane and lacks sufficient time resolution to follow physiologically relevant transitions. Here, we develop high-sensitivity patch-clamp fluorometry (hsPCF), a fluorescence-based approach that results in up to 10-fold increased signals and affords 50-fold faster fluorescence recordings than previous methods. The increased time resolution is paired with a very high versatility in terms of the choice of fluorescent dye, cell type, and protein of interest. We highlight this versatility by providing insight into the conformational dynamics of both ligand- and voltage-gated ion channels using fluorescent labels introduced in extracellular or transmembrane positions while changing either the extra- or intracellular solutions. Together, hsPCF will thus enable the future study of membrane-embedded proteins with sufficient temporal resolution to resolve conformational dynamics

Verkürzung der Zeitintervalle bis zur Erstdefibrillation und Intubation bei der kardiopulmonalen Reanimation durch ein Ventilations- Kompressionsverhältnis von 5:50 statt 2:15 - eine kontrollierte Studie der Arbeitsabläufe unter BLS am Modell

In der ersten Phase einer kardiopulmonalen Reanimation durch zwei professionelle Helfer müssen Advanced-Cardiac-Life-Support (ACLS) -Maßnahmen (Frühdefibrillation, Intubation und die Medikamentenapplikation) möglichst ohne Unterbrechung der Basic-Life-Support (BLS) -Maßnahmen (Beatmung und die externe Herzdruckmassage) durchgeführt werden. Das Ziel dieser Studie war es, den Unterschied zwischen den Zeitintervallen vom Beginn der BLS-Maßnahmen bis zur 1. Defibrillation und vom Beginn der BLS -Maßnahmen bis zur Intubation bei zwei unterschiedlichen Ventilations-Kompressionsverhältnisse zu untersuchen. Es wurden die Ventilations-Kompressionsverhältnisse 2:15 (Methode A: heutiger Standard) und 5:50 (Methode B: alternatives Verfahren) ausgewählt. In einer randomisierten Studie führten 40 in kardiopulmonaler Reanimation trainierte Helfer (Rettungsassistenten/-sanitäter) wechselweise eine standardisierte Reanimation mit BLS- und ACLS-Maßnahmen mit einem Ventilations-Kompressionsverhältnisses von 2:15 und 5:50 gemäß den heute gültigen Richtlinien von der ILCOR (International Liaison Committee of Resuscitation) an einem Reanimationsmodell (Resusci Skillreporter Anne, Laerdal, Norwegen) durch. Die BLS-Maßnahmen wurden mit der Ventilation mittels Beatmungsbeutel und -maske begonnen, ein halbautomatischer Defibrillator (Corpuls 08/16S biphasic) wurde konnektiert, die EKG Analyse (Kammerflimmern) durchgeführt, 3 Schocks ausgelöst und die endotracheale Intubation vorbereitet. Ventilation und kardiale Kompressionen wurden nur für die EKG Analyse und die Defibrillation unterbrochen. Das Atemminutenvolumen (AMV) und die Anzahl der Kompressionen wurden erhoben und die Zeit der obengenannten Zeitintervallen mittels eines gepaarten t-Test verglichen. Zusätzlich wurde das Rettungsdienstpersonal über den Arbeitsablauf und den emotionalen Stress während des Tests vergleichend befragt. Die Zeitintervalle vom Start der BLS-Maßnahmen bis zum 1. Schock waren 78s (2:15) gegenüber 63s (5:50), p0,1 und die durchschnittliche Anzahl der Kompressionen 65/min (2:15) bzw 68/min (5:50), p>0,1. Der Arbeitsablauf verlief bei 5:50 subjektiv ruhiger und der emotionale Stress während der Versuche wurde von dem Rettungsdienstpersonal als signifikant geringer bei 5:50, p<0,0001 eingestuft. Zusammenfassend kann man sagen, dass die Frühdefibrillation und die Intubation bei der alternativen Methode B (5:50) signifikant eher erfolgte bei gleichbleibendem AMV und durchschnittlichen Anzahl der Kompressionen. Weiterhin wurde der Arbeitsablauf während der ersten Phase der Reanimation bei der Methode B verbessert und der Stress der Helfer verringert

Resource Efficiency within Current Production

In times of global warming and the increasing shortage of resources, sustainable production is becoming more and more inevitable. Companies cannot only heighten their competitiveness but also contribute positively to environmental protection through efficient energy and resource consumption. Regarding this, technical solutions are often preferred during production, although organizational and process-related approaches also offer great potential. This project focuses on reducing resource usage, with a special emphasis on the human factor. It is the aspiration to develop a methodology that systematically implements and embeds suitable and individual measures and methods regarding resource efficiency throughout the entire production. The measures and methods established help employees handle resources and energy more sensitively. With this in mind, this paper also deals with the difficulties that can occur during the sensitization of employees and the implementation of these measures and methods. In addition, recommendations are given on how to avoid such difficulties

Resource Efficiency within Current Production

In times of global warming and the increasing shortage of resources, sustainable production is becoming more and more inevitable. Companies cannot only heighten their competitiveness but also contribute positively to environmental protection through efficient energy and resource consumption. Regarding this, technical solutions are often preferred during production, although organizational and process-related approaches also offer great potential. This project focuses on reducing resource usage, with a special emphasis on the human factor. It is the aspiration to develop a methodology that systematically implements and embeds suitable and individual measures and methods regarding resource efficiency throughout the entire production. The measures and methods established help employees handle resources and energy more sensitively. With this in mind, this paper also deals with the difficulties that can occur during the sensitization of employees and the implementation of these measures and methods. In addition, recommendations are given on how to avoid such difficulties

Resource Efficiency within Current Production

In times of global warming and the increasing shortage of resources, sustainable production is becoming more and more inevitable. Companies cannot only heighten their competitiveness but also contribute positively to environmental protection through efficient energy and resource consumption. Regarding this, technical solutions are often preferred during production, although organizational and process-related approaches also offer great potential. This project focuses on reducing resource usage, with a special emphasis on the human factor. It is the aspiration to develop a methodology that systematically implements and embeds suitable and individual measures and methods regarding resource efficiency throughout the entire production. The measures and methods established help employees handle resources and energy more sensitively. With this in mind, this paper also deals with the difficulties that can occur during the sensitization of employees and the implementation of these measures and methods. In addition, recommendations are given on how to avoid such difficulties

Resource Efficiency within Current Production

In times of global warming and the increasing shortage of resources, sustainable production is becoming more and more inevitable. Companies cannot only heighten their competitiveness but also contribute positively to environmental protection through efficient energy and resource consumption. Regarding this, technical solutions are often preferred during production, although organizational and process-related approaches also offer great potential. This project focuses on reducing resource usage, with a special emphasis on the human factor. It is the aspiration to develop a methodology that systematically implements and embeds suitable and individual measures and methods regarding resource efficiency throughout the entire production. The measures and methods established help employees handle resources and energy more sensitively. With this in mind, this paper also deals with the difficulties that can occur during the sensitization of employees and the implementation of these measures and methods. In addition, recommendations are given on how to avoid such difficulties

Grounded Design - a praxeological IS research perspective

In this paper, we propose Grounded Design - a particular design research (DR) approach rooted in a practice-theoretical tradition. It assesses the quality of information technology (IT) design through evaluation of emerging changes in social practices, which result from the appropriation and use of IT artifacts. The paper starts with a systematic analysis of the reasons for persistent limitations of traditional information systems DR, specifically in coping with problems of contingency and self-referentiality. Following this critique, the principles of Grounded Design are presented. Grounded Design is applied in case studies where we reconstruct the social practices observed before and during the design and appropriation of innovative IT artifacts. We call these context-specific research endeavors ‘design case studies.’ In conducting these case studies, Grounded Design builds upon well-established research methods such as ethnographical field studies, participatory design and action research. To support the transferability of its situated findings, Grounded Design suggests documenting increasing numbers of design case studies to create an extended, comparative knowledge base. Comparing cases allows for the emergence of bottom-up concepts dealing with the design and appropriation of innovative IT artifacts in social practice

Friedel Oscillations and superconducting-gap enhancement by impurity scattering

Experiments observe an enhanced superconducting gap over impurities as compared to the clean-bulk value. In order to shed more light on this phenomenon, we perform simulations within the framework of Bogoliubov-deGennes theory applied to the attractive Hubbard model. The simulations qualitatively reproduce the experimentally observed enhancement effect; it can be traced back to an increased particle density in the metal close to the impurity site. In addition, the simulations display significant differences between a thin (2D) and a very thick (3D) film. In 2D pronounced Friedel oscillations can be observed, which decay much faster in (3D) and therefore are more difficult to resolve. Also this feature is in qualitative agreement with the experiment