The AEI 10 m prototype interferometer

A 10 m prototype interferometer facility is currently being set up at the AEI in Hannover, Germany. The prototype interferometer will be housed inside a 100 m^3 ultra-high vacuum envelope. Seismically isolated optical tables inside the vacuum system will be interferometrically interconnected via a suspension platform interferometer. Advanced isolation techniques will be used, such as inverted pendulums and geometrical anti-spring filters in combination with multiple-cascaded pendulum suspensions, containing an all-silica monolithic last stage. The light source is a 35 W Nd:YAG laser, geometrically filtered by passing it through a photonic crystal fibre and a rigid pre-modecleaner cavity. Laser frequency stabilisation will be achieved with the aid of a high finesse suspended reference cavity in conjunction with a molecular iodine reference. Coating thermal noise will be reduced by the use of Khalili cavities as compound end mirrors. Data acquisition and control of the experiments is based on the AdvLIGO digital control and data system. The aim of the project is to test advanced techniques for GEO 600 as well as to conduct experiments in macroscopic quantum mechanics. Reaching standard quantum-limit sensitivity for an interferometer with 100 g mirrors and subsequently breaching this limit, features most prominently among these experiments. In this paper we present the layout and current status of the AEI 10 m Prototype Interferometer project

Spectroscopic Properties of Self-Assembled Plasmonic and Semiconductive Nanocrystals for Nanophotonic Applications

The next generation of optoelectronic applications like stimuli-responsive sensors, functional displays or nanophotonic circuits demands a basic understanding of lightmatter interactions on the nanoscale. Top-down fabrication has been employed in the past to demonstrate coherent energy transfer in functional nanostructures, yet these fabrication methods are problematic due to their limited scalability and high costs as well as the high optical losses. This work adapted physical principles like radiation properties of metallic nanoantennas and Bragg diffraction in periodic nanostructures and realized these concepts using bottom-up self-assembly methods based on colloidal chemistry. With this approach, single plasmonic nanoparticles and semiconductor quantum emitters were co-assembled into complex structures. This work took the colloidal concept from plasmonics and introduced quantum dots in order to characterize the radiative and non-radiative decay processes as well as the arising light-matter interactions. Due to electromagnetic coupling between the components, hybridized modes were detected instead of the single particle resonances observed in the isolated case. It was furthermore shown that these colloidal building blocks can be assembled into functional optical grids on a large scale using template-assisted self-assembly. Thus, this work established spectroscopic principles for self-assembled colloidal building blocks that can be integrated in parallelized processes in the future

Outsourcing in humanitarian logistics – status quo and future directions

Purpose – Outsourcing of logistics has great importance in disaster relief. Aid agencies spend several billion US dollars every year on logistics services. However, the concept of outsourcing has not been established adequately in literature on humanitarian logistics, leading to a fragmented view of the practice. This paper provides a holistic perspective of the concept by constructing a conceptual framework to analyze both practice and research of outsourcing in humanitarian operations. Based on this analysis, we explore future trends and identify research gaps. Design/methodology/approach – The paper is based on a structured review of academic literature, a tworound Delphi study with 31 experts from aid agencies and a complementary full-day focus group with twelve experts from aid agencies and logistics service providers. Findings – The paper systemizes the current practice of outsourcing in humanitarian logistics according to a conceptual framework of five dimensions: subject, object, partner, design and context. In addition, it reveals ten probable developments of the practice over the next years. Finally, it describes eight important research gaps and presents a research agenda for the field. Research limitations/implications – The literature review considered peer-reviewed academic papers. Practitioner papers could provide additional insights into the practice. Moreover, the Delphi study focused on the perspective of aid agencies. Capturing the views of logistics service providers in more detail would be a valuable addition. Originality/value – The paper establishes the academic basis for the important practice of outsourcing in humanitarian logistics. It highlights essential research gaps and, thereby, opens up the field for future research

Untersuchungen zur gewebsspezifischen Expression von ASB10 in der Maus – Eine Reportergenanalyse

Hintergrund: Bei ASB10 handelt es sich um ein möglicherweise mit dem Glaukom assoziiertes Gen. Die Funktion von ASB10 liegt vermutlich in der Ubiquitinierung eines spezifischen Substrates, somit ist es Bestandteil zellulärer Abbauprozesse. In dieser Arbeit soll die Expression von ASB10 im Versuchsorganismus Maus (adult und embryonal) dargestellt werden. Methoden: Es wurde eine ASB10+/--Mauslinie verwendet, bei welcher eine promotergesteuerte LacZ-Kassette in das ASB10-Gen eingeschoben wurde. Somit konnte die Genexpression mittels einer LacZ-Färbung von Gefrierschnitten der einzelnen Organe sichtbar gemacht werden. Zudem wurden Kaiserschnitte von trächtigen Mäusen und anschließend LacZ-Färbungen der Embryonen durchgeführt, um die Expression von ASB10 im embryonalen Stadium zu zeigen. Ergebnisse: Es zeigte sich eine nahezu ubiquitäre Expression von ASB10 im embryonalen sowie im adulten Organismus der Maus. Die Intensität der durchgeführten LacZ-Färbung zeigt eine deutliche Varianz zwischen den einzelnen Organen, am stärksten ausgeprägt ist sie in Myokard, Nierenparenchym und Nervengewebe, kaum bis gar nicht vorhanden ist die Färbung in Skelettmuskulatur, Thymus- und Leberparenchym, die weiteren Organe zeigen eine intermediäre Intensität der Färbung. Dies kann sowohl auf eine unterschiedliche Expression von ASB10 in den einzelnen Organen als auch auf eine unterschiedliche Verteilung des Substrates bzw. der Substrate von ASB10 zurückzuführen sein. Zudem zeigte sich auch bei Genotypisierung der Embryonen kein homozygoter ASB10-/--Genotyp, sodass von einer Letalität der homozygoten ASB10-Defizienz in einem frühen embryonalen Stadium ausgegangen werden muss. Schlussfolgerung: Die gezeigte ubiquitäre Expression von ASB10 steht im Einklang mit der Hypothese, dass ASB10 an der Ubiquitinierung und damit an zellulären Abbauprozessen beteiligt ist. Bezüglich der Bedeutung von ASB10 als ein mit dem Glaukom assoziiertes Gen kann durch die Ergebnisse der vorliegenden Arbeit jedoch noch keine präzise Aussage getroffen werden

The suspension systems of the interferometric gravitational-wave detector GEO 600

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Nicotine: Molecular and physiological effects of nicotine in central nervous system - A stereospecific chemosensory model suited to analyze nicotine perception, ‘liking’ and sensory induced craving

Die Nikotinabhängigkeit ist von großer Bedeutung für die aktuelle Gesellschaft, weil sie die Nummer eins der vermeidbaren Todesursachen unserer Zeit ist. Viele Mechanismen, die ihr zugrunde liegen, werden in neuerer Zeit auch mit der Pathophysiologie verschiedener psychiatrischer Störungsbilder wie z.B. Morbus Alzheimer oder ADHS in Verbindung gebracht. Nikotinerg-cholinerge Schaltkreise stellen sich außerdem zunehmend als entscheidender Faktor für kognitive Prozesse wie Gedächtnis, Lernen, Aufmerksamkeit und Wahrnehmung heraus. Viele grundlegende Mechanismen sind jedoch nach wie vor unbekannt. Die vorliegende Arbeit beschäftigt sich mit neurophysiologischen und psychophysiologischen Reaktionen von Rauchern, Rauchern im Entzug und Nichtrauchern auf olfaktorische und trigeminale Nikotinreize sowie auf Kontrollsubstanzen. Hierfür wurden die evozierten Antworten mit EEG und funktioneller Magnetresonanztomographie aufgezeichnet und analysiert. Der kombinierte Einsatz verschiedenster Verfahren zur Messung von Reaktionen des menschlichen Gehirns in verschiedenen Zuständen (Rauchen, Nichtrauchen, im Entzug) auf intranasale Reize ist neuartig und liefert neben der Bestätigung bereits vorliegender Ergebnisse eine Reihe neuer Erkenntnisse, die sowohl für die Forschung als auch für die Praxis wertvolle Anregungen geben können.As the number one preventable death cause of our time nicotine dependence is of great importance to today´s society. Many mechanisms underlying nicotine dependence are latterly also linked to the pathophysiology of varying psychiatric diseases such as Alzheimer´s disease or ADHD. Additionally, nicotinic-cholinergic circuits increasingly emerge as a decisive factor for cognitive processes such as memory, learning, attention and perception. However, until now, a lot of basal mechanisms are still unknown. The present study deals with the neurophysiologic and psychophysiologic reactions of smokers, smokers on withdrawal and nonsmokers to olfactory and trigeminal nicotine stimuli as well as control stimuli. For this purpose evoked reactions were recorded and analysed with EEG and functional magnetic resonance imaging. The combined application of different methods of examining reactions of the human brain in different smoking states (smokers, smokers on withdrawal, nonsmokers) to intranasal stimuli is a new and unique approach. In addition to confirming already existing data, the study provides a set of new findings which might also stimulate future research and support clinical practice

Mode-Cleaning and Injection Optics of the Gravitational-Wave Detector GEO600

The British–German interferometric gravitational-wave detector GEO600 uses two high-finesse triangular ring cavities of 8 m optical pathlength each, as an optical mode-cleaning system. The modecleaner system is housed in an ultrahigh-vacuum environment to avoid contamination of the optics and to minimize both the influence of refractive index variations of the air and acoustic coupling to the optics. To isolate the cavities from seismic noise, all optical components are suspended as double pendulums. These pendulums are damped at their resonance frequencies at the upper pendulum stage with magnet-coil actuators. A suspended reaction mass supports three coils matching magnets bonded onto the surface of one mirror of each cavity, allowing length control of the modecleaner cavities to maintain resonance with the laser light. A fully automated control system stabilizes the frequency of the slave laser to that of the master laser, the frequency of the master laser to the length of the first modecleaner and the length of the first to the length of the second modecleaner. The control system uses the Pound–Drever–Hall sideband technique and operates autonomously over long time periods with only infrequent human interaction. The duty cycle of the system was measured to be 99.7% during an 18 day period. The throughput of the whole modecleaner system is about 50%. In this article, we give an overview of the mechanical and optical setup and the achieved performance of the double modecleaner system