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Includes supplementary material The thesis investigates the feasibility of duty cycling the GPS receiver onboard small satellites like NPSAT1 in order to repurpose power savings in ways that would better serve the satellite’s mission. Orbital propagation software run on onboard computer hardware produces accurate ephemeris data over short periods without continued GPS input. Longer periods relying on propagator ephemeris translate to greater power savings, but it also means increasing positional error. In order to better define the trade space between time and error of common propagators, Systems Tool Kit software was used to test the accuracy of the Two-Body and Simplified General Perturbations-4 propagators over time against positions measured by the Joint Space Operations Center. Two-Body propagators’ error response varies as a function of altitude and inclination, with the worst case requiring GPS updates up to twice an orbit. Simplified General Perturbations-4 propagators’ error depends strongly on the accuracy of the B* drag term, but is still sufficiently accurate to operate a day or more without a GPS update. Savings in the GPS power budget were found to exceed 96% and 99% for Two-Body and Simplified General Perturbations-4 propagators, respectively, and should be considered for use in future satellites. Lieutenant, United States Navy Approved for public release; distribution is unlimited.

Factor C is a multi-domain serine protease which recognizes Gram-negative bacteria via binding to lipopolysaccharides and triggers hemolymph clotting cascade in the horseshoe crab. A closely related molecule was also found to be present in the genome of the tick Ixodes scapularis. In this work, the full sequence of Factor C ortholog from Ixodes ricinus (IrFC) was determined. IrFC is mainly expressed in tick hemocytes and the heavy chain of the activated molecules is present in tick hemolymph as confirmed by Western blotting with antibodies raised against recombinant fragments of IrFC. The function of the IrFC in tick innate immunity was assessed using its silencing by RNA interference.

Studies utilizing genetic and pharmacological manipulations in rodent models and neuronal cultures have revealed myriad roles of brain-derived neurotrophic factor (BDNF). Currently, this knowledge of BDNF function is being translated into improvement strategies for several debilitating neurological disorders in which BDNF abnormalities play a prominent role. Common among the BDNF-related disorders are irregular trafficking and release of mature BDNF (mBDNF) and/or its prodomain predecessor, proBDNF. Thus, investigating the conditions required for proper trafficking and release of BDNF is an essential step toward understanding and potentially improving these neurological disorders. This paper will provide examples of disorders related to BDNF release and serve as a review of the techniques being used to study the trafficking and release of BDNF.

Extracellular adenosine is an important signaling molecule in various physiological processes. When not regulated properly it can cause various pathologies such as Severe Combined Immunodeficiency. To study the effects of increased extracellular adenosine level a Drosophila model has been established. This model is based on mutation in the main adenosine deaminase gene in Drosophila (ADGF-A, Adenosine Deaminase-related Growth Factor A). This work is a consequence of large screening for the suppressors of adgf-a mutant phenotype and presents a more detailed study of 3 previously identified regions containing dominant suppressors.

Im Rahmen einer vergleichenden Beobachtungsstudie wurden in der vorliegenden Arbeit die Kinetiken der mikrobiologischen Kontaminationen der Narkosesysteme erfasst und der Einfluss unterschiedlich langer Wechselintervalle der Schlauchsysteme dokumentiert. Die aus den Systemen isolierten Keime wurden mit den routinemäßig gewonnenen Patientenproben verglichen, um die diskutierte Vektorfunktion der Geräte zu untersuchen., Introduction: Daily change of breathing circuits in the operating theatre requires a lot of resources and is time and labour consuming. The extended use of breathing circuits could reduce the workload of the staff and health care costs. The aim of the present study was to evaluate the contamination rate of anaesthesia breathing circuits changed after 24, 48 or 72h of use. Materials: The study was performed as an experimental observational study. Microbiological samples were taken from 112 breathing systems including both parts of the ventilator circuit (inspiration and expiration) and analysed using microbiological standard techniques. Breathing circuits were changed according to three different schedules. In the 24-h group, breathing circuits were changed every day, whereas in the 48-h group changing of the circuits took place on Mondays, Wednesdays and Fridays. A period of 72 h operating use was tested on weekends. Results: A total of 112 breathing systems comprised of 224 samples from the ventilator circuit were tested for bacteria and yeast contamination. A non-significant increase in the contamination rate was observed with the extended use for breathing circuits (24 h: 3.33%, 48 h: 4.35% and 72 h: 5.56%; P for trend50.66). Similarly, no significant increase in contamination rate could be observed with the extended use of filters (24 h: 1.67%, 48 h: 3.26% and 72 h: 2.78%; P for trend50.71). Conclusion: The extended use of breathing circuits for 48 and 72 h does not increase significantly the risk of contamination, provided that HME filters are changed separately for every patient.

Im Rahmen dieser Arbeit wurden Transporteigenschaften von Nanostrukturen basierend auf modulationsdotierten GaAs/AlGaAs Heteroübergängen untersucht. Derartige Heterostrukturen zeichnen sich durch ein hochbewegliches zweidimensionales Elektronengas (2DEG) aus, das sich wenige 10 nm unterhalb der Probenoberfläche ausbildet. Mittels Elektronenstrahl-Lithographie und nasschemischer Ätztechnik wurde dieses Ausgangsmaterial strukturiert. Eindimensionale Leiter mit Kanalweiten von wenigen 10 nm wurden auf diese Weise hergestellt. Die Vorzüge derartiger Strukturen zeigen sich im ballistischen Elektronentransport über mehrere 10 µm und einer hohen Elektronenbeweglichkeit im Bereich von 10^6cm^2/Vs. Als nanoelektronische Basiselemente wurden eingehend eindimensionale Quantendrähte sowie y-förmig verzweigte Strukturen untersucht, deren Kanalleitwert über seitliche Gates kontrolliert werden kann. Dabei wurden die Transportmessungen überwiegend im stark nichtlinearen Transportregime bei Temperaturen zwischen 4,2 K und Raumtemperatur durchgeführt. Der Fokus dieser Arbeit lag insbesondere in der Untersuchung von Verstärkungseigenschaften und kapazitiven Kopplungen zwischen Nanodrähten, der Realisierung von komplexen Logikfunktionen wie Zähler- und Volladdiererstrukturen, dem Einsatz von Quantengates sowie der Analyse von rauschaktiviertem Schalten, stochastischen Resonanzphänomenen und Magnetfeldasymmetrien des nichtlinearen mesoskopischen Leitwertes., This thesis reports on transport features of nanoelectronic devices based on modulation doped GaAs/AlGaAs heterostructures with a two dimensional electron gas (2DEG) a few 10 nm below the sample surface. Using electron beam lithography and wet chemical etching techniques low dimensional conductors were designed with a channel width of a few 10 nm. Such conductors enable ballistic transport up to 10 µm with high electron mobilities in the range of 10^6cm^2/Vs. One dimensional quantum wires as well as y-branched structures were used as nanoelectronic basic elements, which were controlled by lateral side-gates. Transport measurements were mainly performed in the strong nonlinear transport regime at temperatures between 4.2 K and room temperature. Experimental investigations were focused on gain, capacitive couplings between single nanowires, the realisation of complex logic functions like counter and fulladder devices, quantum-gate applications, noise activated switching, stochastic resonance phenomena and magnetic field asymmetries of the nonlinear mesoscopic transport.

This study was conducted by the Kercher Center for Social Research at Western Michigan University for The Michigan Department of Community Health. Data collection was subcontracted to EPIC MRA Inc. of Lansing, Michigan. The views expressed are those of the author and do not necessarily reflect those of any of the above organizations., The 2006 Survey of Gambling Behaviors in Michigan is the fourth iteration of a project begun in 1997 and primarily designed to provide an estimate of problem gambling in the state.