This thesis examines how artists working for the War Artists' Advisory Committee (WAAC) represented aerial warfare. In contrast to the scholarly attention lavished on wartime films and posters, official war art remains a much neglected aspect of the propaganda war. The few studies that do exist, most notably by Brian Foss, survey the collection as a whole and consider it from an art history perspective. By focusing on the single theme of aviation, a central and defining experience of the Second World War, I embed the WAAC within the economic, social, military and cultural histories of the period and locate it within a longer time frame. Through bringing these usually disparate fields of study into dialogue, I am able to use the art to enrich broader understandings of the period, in particular, the ways in which aerial warfare was represented, how this image evolved during the war and how these cultural products related to economic, military and social factors. This thesis highlights the different roles the WAAC was expected to fulfil. Housed within the Ministry of Information, the WAAC was expected to perform a propagandist function. The committee distanced itself from propaganda and insisted that its primary function was to record for posterity the experience of living through the war. I assess exactly what kind of record the WAAC bequeathed by looking thematically at the key aspects of aerial warfare: aircraft production; the Battle of Britain; the Blitz and the bombing of Germany. I argue that whilst there was broad correlation between war art and propaganda, these images registered aspects of experience that were incongruent with and therefore absent from wartime propaganda, such as the fear of aerial bombardment and the true nature of the bombing of Germany. Moreover, propagandist constructions were not entirely separate to lived experience, rather they both reflected experience and shaped the way that individuals understood and made sense of the world around them. Therefore, in producing images that accorded with propagandist portrayals, the WAAC artists were recording a fundamental part of the experience of living through the war.

<p>Polarisation, which was first studied in optics, is a fundamental property of all electromagnetic fields. A convenient way to describe the polarisation of two dimensional electromagnetic fields is given by the Stokes parameters. This thesis deals with different aspects of wave polarisation and electromagnetic field measurements. A generalisation of the Stokes parameters to three dimensions is presented. The theory has been used to develop methods and systems for obtaining the polarisation parameters of electromagnetic waves. The methods can be applied for a wide range of electromagnetic fields, measured both on ground and onboard satellites. The applications include, e.g., direction-finding, polarisation analysis, radar, and several examples in the field of wireless communication. Further applications are given in the analysis of satellite data, where a whistler wave is considered. Whistlers are circularly polarised electromagnetic waves propagating in the magnetosphere along the geomagnetic field. Dispersion in the magnetospheric plasma make the whistler frequencies travel at different speeds and the signal takes the form of a chirp. From instantaneous polarisation analysis of the whistler´s magnetic wave field, the normal to the polarisation plane is obtained and found to precess around the geomagnetic field. A statistic analysis of ionospheric stimulated electromagnetic emissions (SEE) is also presented. SEE is generated by injecting a powerful high frequency radio wave into the ionosphere. It is shown that the SEE features have a statistical behaviour indistinguishable from the amplitude and phase distributions of narrow-band Gaussian noise. The results suggests that SEE cannot be explained by simple coherent processes alone. Finally, an expression for the complex Poynting theorem is derived for the general case of anharmonic fields. It is found that the complex Poynting theorem, for real fields and sources, is not a conservation law of the imaginary part of electromagnetic energy.</p>

Motivation | Societal and economic needs of East Africa rely entirely on the availability of water, which is governed by the regular onset and retreat of the rainy seasons. Fluctuations in the amounts of rainfall has tremendous impact causing widespread famine, disease outbreaks and human migrations. Efforts towards high resolution forecasting of seasonal precipitation and hydrological systems are therefore needed, which requires high frequency short to long-term analyses of available climate data that I am going to present in this doctoral thesis by three different studies. 15,000 years - Suguta Valley | The main study of this thesis concentrated on the understanding of humidity changes within the last African Humid Period (AHP, 14.8-5.5 ka BP). The nature and causes of intensity variations of the West-African (WAM) and Indian Summer monsoons (ISM) during the AHP, especially their exact influence on regional climate relative to each other, is currently intensely debated. Here, I present a high-resolution multiproxy lake-level record spanning the AHP from the remote Suguta Valley in the northern Kenya Rift, located between the WAM and ISM domains. The presently desiccated valley was during the AHP filled by a 300 m deep and 2200 km2 large palaeo-lake due to an increase in precipitation of only 26%. The record explains the synchronous onset of large lakes in the East African Rift System (EARS) with the longitudinal shift of the Congo Air Boundary (CAB) over the East African and Ethiopian Plateaus, as the direct consequence of an enhanced atmospheric pressure gradient between East-Africa and India due to a precessional-forced northern hemisphere insolation maximum. Pronounced, and abrupt lake level fluctuations during the generally wet AHP are explained by small-scale solar irradiation changes weakening this pressure gradient atmospheric moisture availability preventing the CAB from reaching the study area. Instead, the termination of the AHP occurred, in a non-linear manner due to a change towards an equatorial insolation maximum ca. 6.5 ka ago extending the AHP over Ethiopia and West-Africa. 200 years - Lake Naivasha | The second part of the thesis focused on the analysis of a 200 year-old sediment core from Lake Naivasha in the Central Kenya Rift, one of the very few present freshwater lakes in East Africa. The results revealed and confirmed, that the appliance of proxy records for palaeo-climate reconstruction for the last 100 years within a time of increasing industrialisation and therefore human impact to the proxy-record containing sites are broadly limited. Since the middle of the 20th century, intense anthropogenic activity around Lake Naivasha has led to cultural eutrophication, which has overprinted the influence of natural climate variation to the lake usually inferred from proxy records such as diatoms, transfer-functions, geochemical and sedimentological analysis as used in this study. The results clarify the need for proxy records from remote unsettled areas to contribute with pristine data sets to current debates about anthropologic induced global warming since the past 100 years. 14 years - East African Rift | In order to avoid human influenced data sets and validate spatial and temporal heterogeneities of proxy-records from East Africa, the third part of the thesis therefore concentrated on the most recent past 14 years (1996-2010) detecting climate variability by using remotely sensed rainfall data. The advancement in the spatial coverage and temporal resolutions of rainfall data allow a better understanding of influencing climate mechanisms and help to better interpret proxy-records from the EARS in order to reconstruct past climate conditions. The study focuses on the dynamics of intraseasonal rainfall distribution within catchments of eleven lake basins in the EARS that are often used for palaeo-climate studies. We discovered that rainfall in adjacent basins exhibits high complexities in the magnitudes of intraseasonal variability, biennial to triennial precipitation patterns and even are not necessarily correlated often showing opposite trends. The variability among the watersheds is driven by the complex interaction of topography, in particular the shape, length and elevation of the catchment and its relative location to the East African Rift System and predominant influence of the ITCZ or CAB, whose locations and intensities are dependent on the strength of low pressure cells over India, SST variations in the Atlantic, Pacific or Indian Ocean, QBO phases and the 11-year solar cycle. Among all seasons we observed, January-September is the season of highest and most complex rainfall variability, especially for the East African Plateau basins, most likely due to the irregular penetration and sensitivity of the CAB. / Motivation | Die sozialen und ökonomischen Bedürfnisse Ostafrikas sind in erster Linie von der Wasserverfügbarkeit abhängig, welche durch das regelmäßige Einsetzen der Regenzeiten bestimmt wird. Jegliche Veränderungen der Wasserverfügbarkeit innerhalb der Regenzeiten verursachen Hungersnöte, Ausbruch von Krankheiten oder auch Bevölkerungswanderungen. Klärung der Ursachen von Niederschlagsvariabilitäten erfordert die Auswertung von hochauflösenden Kurz- als auch Langzeitanalysen, welche ich in dieser Arbeit durch drei Studien präsentieren werde. 15,000 Jahre - Suguta Valley | Die Hauptstudie dieser Doktorarbeit befasste sich mit dem Verständnis von Feuchtigkeitsschwankungen innerhalb der Afrikanischen Feuchtperiode (AHP, 5.5 - 14.8 ka BP). In dieser Studie präsentiere ich einen hoch-auflösenden Seespiegel Datensatz aus dem abgeschiedenen, unbewohnten Suguta Tal im nördlichen Grabenbruch in Kenia. Das momentan extrem trockene Tal war während der AHP mit einem 300 m tiefen und 2200 km2 großen Paläo-See bedeckt, was aus nur 26% zusätzlichem Niederschlag resultierte. Diese Erhöhung wurde vermutlich aus der Kombination aus erhöhter atmosphärer Feuchteverfügbarkeit infolge erhöhter früh-Holozäner präzessionsgesteuerten Einstrahlung auf der nördlichen Hemisphere sowie der Verschiebung der feuchten Kongo Luftmassengrenze (CAB) ostwärts über das Ostafrikanische und Äthiopische Plateau erreicht als direkte Folge eines erhöhten atmosphärischen Druckgradienten. Abrupte, starkte Seespiegelschwankungen innerhalb der generellen Feuchtphase sind auf geringe Veränderungen in der solaren Ausstrahlung zurückzufühen, welche zu einer Schwächung des Druckgradienten führten und damit den Einfluss der CAB im Untersuchungsgebiet verhinderten zusammen mit einer allgemeinene Reduktion der atmosphärischen Feuchteverfügbarkeit. Das Ende der AHP erfolgte im Gegensatz dazu eher nicht-linear aufgrund des Wechsels zu einem äquatorialen Einstrahlungsmaximum vor 6.5 ka, welches die AHP in Äthiopien und West-Afrika verlängerte. 200 Jahre - Lake Naivasha | Der zweite Teil dieser Arbeit konzentrierte sich auf die Analyse eines Sedimentkern des Naivasha See aus dem zentralen Kenia Rift über die letzten 200 Jahre, einem der wenigen Frischwasserseen in Ostafrika. Die natürliche Klimavariabilität sollte mittels Proxy-Datensätzen von Diatomeen, Transferfunktionen, geochemischen und sedimentologischen Analysen in dieser Studie aufgedeckt werden. Die Ergebnisse zeigten, dass seit Mitte des 20. Jahrhundert der zunehmende Einfluss des Menschen um den Naivasha See zu kultureller Eutrophierung geführt, welche den Einfluss der natürlichen Klimavariabilität auf den See überprägte. Die Gründe liegen in der Zeit, welche von steigender Industrialisierung und deshalb erhöhtem menschlichen Einfluss auf die Proxy-Daten enthaltenden Seen geprägt ist. Die Ergebnisse verdeutlichen die Notwendigkeit von Proxy-Daten aus unbesiedelten Gebieten, wenn man ,reine‘ Daten zur momentanen Debatte über den anthropogen gesteuerten Klimawandel der letzten 100 Jahre beitragen will. 14 Jahre - Ostafrikanisches Rift | Um räumliche Unregelmäßigkeiten in Proxy-Daten von Ostafrika richtig zu verstehen, konzentrierte sich der dritte Teil dieser Arbeit auf die Auswertung von ausschließlich fernerkundlich erworbenen heutigen, täglichen Niederschlagsreihen (1996-2010). Dies erlaubt ein besseres Verständnis über die möglichen klimatischen Einflussmechanismen und die Abschätzung ihres Einflusses auf die Paläo-Variabilität. Die Studie beschäftigt sich mit der Dynamik saisonaler Niederschlagsverteilung innerhalb der Einzugsgebiete von elf Seebecken im Ostafrikanischen Riftsystem, welche oft für Paläo-Klimastudien benutzt werden. Die Studie ergab, dass Niederschläge in angrenzenden Becken tatsächlich höchst unterschiedlich in ihrer Intensität sein können und dabei zwei- bis dreijährigen Niederschlagsmuster folgen oder sogar gegensätzliche Trends zeigen. Die Variabilität der einzelnen Seebecken wird durch die komplexe Wechselwirkung der Topographie, Form, Länge und Höhe des Einzugsgebietes, der relativen Lage im EARS, sowie dem Einfluss und Intensität der ITCZ und CAB bestimmt, welche z.B. abhängig von der Entwicklung besonders starker Tiefdruckgebiet über Indien, Veränderungen der Meeres-oberflächentemperaturen, QBO und dem 11-Jahres Sonnenzyklus sind. Im direkten Vergleich aller untersuchten Monate stellte sich heraus, dass Juli-September die Jahreszeit mit komplexester Niederschlagsvariabilität ist, besonders für die Becken des Ostafrikanischen Plateau, was durch den unregelmäßigen Einfluss der CAB verursacht wird.

Understanding the interactions of predators and their prey and their responses to environmental changes is one of the striking features of ecological research. In this thesis, spring dynamics of phytoplankton and its consumers, zooplankton, were considered in dependence on the environmental conditions in a deep lake (Lake Constance) and a shallow marine water (mesocosms from Kiel Bight), using descriptive statistics, multiple regression models, and process-oriented dynamic simulation models. The development of the spring phytoplankton bloom, representing a dominant feature in the plankton dynamics in temperate and cold oceans and lakes, may depend on temperature, light, and mixing intensity, and the success of over-wintering phyto- and zooplankton. These factors are often correlated in the field. Unexpectedly, irradiance often dominated algal net growth rather than vertical mixing even in deep Lake Constance. Algal net losses from the euphotic layer to larger depth were induced by vertical mixing, but were compensated by the input from larger depth when algae were uniformly distributed over the water column. Dynamics of small, fast-growing algae were well predicted by abiotic variables, such as surface irradiance, vertical mixing intensity, and temperature. A simulation model additionally revealed that even in late winter, grazing may represent an important loss factor of phytoplankton during calm periods when losses due to mixing are small. The importance of losses by mixing and grazing changed rapidly as it depended on the variable mixing intensity. Higher temperature, lower global irradiance and enhanced mixing generated lower algal biomass and primary production in the dynamic simulation model. This suggests that potential consequences of climate change may partly counteract each other. The negative effect of higher temperatures on phytoplankton biomass was due to enhanced temperature-sensitive grazing losses. Comparing the results from deep Lake Constance to those of the shallow mesocosm experiments and simulations, confirmed the strong direct effect of light in contrast to temperature, and the importance of grazing already in early spring as soon as moderate algal biomasses developed. In Lake Constance, ciliates dominated the herbivorous zooplankton in spring. The start of ciliate net growth in spring was closely linked to that of edible algae, chlorophyll a and the vertical mixing intensity but independent of water temperature. The duration of ciliate dominance in spring was largely controlled by the highly variable onset of the phytoplankton bloom, and little by the less variable termination of the ciliate bloom by grazing of meta-zooplankton. During years with an extended spring bloom of algae and ciliates, they coexisted at relatively high biomasses over 15-30 generations, and internally forced species shifts were observed in both communities. Interception feeders alternated with filter feeders, and cryptomonads with non-cryptomonads in their relative importance. These dynamics were not captured by classical 1-predator-1-prey models which consistently predict pronounced predator-prey cycles or equilibria with either the predator or the prey dominating or suppressed. A multi-species predator-prey model with predator species differing in their food selectivity, and prey species in their edibility reproduced the observed patterns. Food-selectivity and edibility were related to the feeding and growth characteristics of the species, which represented ecological trade-offs. For example, the prey species with the highest edibility also had the highest maximum growth rate. Data and model revealed endogenous driven ongoing species alternations, which yielded a higher variability in species-specific biomasses than in total predator and prey biomass. This holds for a broad parameter space as long as the species differ functionally. A more sophisticated model approach enabled the simulation of a continuum of different functional types and adaptability of predator and prey communities to altered environmental conditions, and the maintenance of a rather low model complexity, i.e., low number of equations and free parameters. The community compositions were described by mean functional traits --- prey edibility and predator food-selectivity --- and their variances. The latter represent the functional diversity of the communities and thus, the potential for adaptation. Oscillations in the mean community trait values indicated species shifts. The community traits were related to growth and grazing characteristics representing similar trade-offs as in the multi-species model. The model reproduced the observed patterns, when nonlinear relationships between edibility and capacity, and edibility and food availability for the predator were chosen. A constant minimum amount of variance represented ongoing species invasions and thus, preserved a diversity which allows adaptation on a realistic time-span. / Eine der großen Herausforderungen der heutigen ökologischen Forschung ist es, Veränderungen von Ökosys­temen vorher­zusagen, die mit dem Klimawandel einhergehen. Dafür sind ein umfassendes Verständnis der ver­schiedenen Steuerungsfaktoren des entsprechenden Systems und Kenntnisse zur Anpassungs­fähigkeit des Systems nötig. Auf der Grundlage dieses Wissens, können mit mathemati­schen Modellen Klima­szenarien gerechnet und Vorhersagen erstellt werden. Die vorliegende Arbeit untersuchte die Regulation des Phytoplanktons (kleine freischwebende einzellige Algen) und seiner Konsumenten (Zooplankton, tierische Kleinstlebewesen) sowie deren Wechselspiel während des Frühjahrs mit Bezug auf den Klimawandel. Als Basis dienten langjährige Daten von einem großen tiefen See (Bodensee) sowie Daten von Versuchen mit Organis­men aus einem flachen marinen Ge­wässer (Kieler Förde, Ostsee). Diese Daten wurden mit statistischen Verfahren und mathematischen Modellen ausge­wertet. In Gewässern sind Algen als Primärproduzenten die Nahrungsgrundlage für tieri­sche Organismen bis hin zu Fischen und Meeresfrüchten, und bestimmen die Wasserqualität der Ge­wässer. Daher ist es wichtig zu verstehen, welche Mechanismen die Dynamik der Algen steuern. Der Grundstein für die saisonale Entwicklung von Phyto- und Zooplankton in Gewässern un­serer Breiten wird mit dem Be­ginn des Wachstums im Frühjahr gelegt. Diese Arbeit zeigt, dass es bereits im zeitigen, noch kalten Frühjahr ein Wechselspiel physikalischer und biologischer Steuerungsmechanismen für die Algenent­wicklung gibt. Physikalische Faktoren sind die Wassertemperatur, die Globalstrahlung und die Durchmischung des Gewässers, die durch die Stärke des Windes beeinflusst wird. All diese Steue­rungsmechanismen sind eng miteinander verwoben und werden unterschiedlich stark vom Klimawan­del beeinflusst. Mit mathematischen Modellen gelang es den Einfluss einzelner Faktoren voneinander zu trennen und zu zeigen, dass Effekte durch den Klimawandel sich gegenseitig aufheben oder aber auch verstärken können. Schon geringe Änderungen an der Basis der Nahrungsnetze können weitrei­chende Auswirkungen auf höhere Ebenen habe. Wie stark diese Auswirkungen im Einzelnen sind, hängt entscheidend von der Anpassungsfähigkeit gesamter Ökosysteme und ihrer Artengemeinschaf­ten sowie einzelner Individuen ab. Beispielsweise reagiert die Algengemeinschaft auf einen starken Fraßdruck ihrer Räuber mit einer Verschiebung zu weniger gut fressbaren Algenarten. Diese weniger gut fressbaren Arten unterscheiden sich jedoch auch in anderen Eigenschaften, wie zum Beispiel der Ressourcenausnutzung, von besser fressbaren Algen. In dieser Arbeit wurden Modellansätze entwi­ckelt, die diese Fähigkeit zur Anpassung berücksichtigen. Auf dieser Grundlage und mit Einbeziehung der physikalischen Steuerungsfaktoren können Klimaszenarien gerechnet werden und Vorhersagen für den Einfluss des Klimawandels auf unsere Gewässer gemacht werden, die letztlich auch Perspektiven für Handlungsmöglichkeiten aufzeigen.

Polarisation, which was first studied in optics, is a fundamental property of all electromagnetic fields. A convenient way to describe the polarisation of two dimensional electromagnetic fields is given by the Stokes parameters. This thesis deals with different aspects of wave polarisation and electromagnetic field measurements. A generalisation of the Stokes parameters to three dimensions is presented. The theory has been used to develop methods and systems for obtaining the polarisation parameters of electromagnetic waves. The methods can be applied for a wide range of electromagnetic fields, measured both on ground and onboard satellites. The applications include, e.g., direction-finding, polarisation analysis, radar, and several examples in the field of wireless communication. Further applications are given in the analysis of satellite data, where a whistler wave is considered. Whistlers are circularly polarised electromagnetic waves propagating in the magnetosphere along the geomagnetic field. Dispersion in the magnetospheric plasma make the whistler frequencies travel at different speeds and the signal takes the form of a chirp. From instantaneous polarisation analysis of the whistler´s magnetic wave field, the normal to the polarisation plane is obtained and found to precess around the geomagnetic field. A statistic analysis of ionospheric stimulated electromagnetic emissions (SEE) is also presented. SEE is generated by injecting a powerful high frequency radio wave into the ionosphere. It is shown that the SEE features have a statistical behaviour indistinguishable from the amplitude and phase distributions of narrow-band Gaussian noise. The results suggests that SEE cannot be explained by simple coherent processes alone. Finally, an expression for the complex Poynting theorem is derived for the general case of anharmonic fields. It is found that the complex Poynting theorem, for real fields and sources, is not a conservation law of the imaginary part of electromagnetic energy.

A technique for real time object tracking in a mobile computing environment and its application to video see-through Augmented Reality (AR) has been designed, verified through simulation, and implemented and validated on a mobile computing device. Using position based visual position and orientation (POSE) methods and the Extended Kalman Filter (EKF), it is shown how this technique lends itself to be flexible to tracking multiple objects and multiple object models using a single monocular camera on different mobile computing devices. Using the monocular camera of the mobile computing device, feature points of the object(s) are located through image processing on the display. The relative position and orientation between the device and the object(s) is determined recursively by an EKF process. Once the relative position and orientation is determined for each object, three dimensional AR image(s) are rendered onto the display as if the device is looking at the virtual object(s) in the real world. This application and the framework presented could be used in the future to overlay additional informational onto displays in mobile computing devices. Example applications include robotic aided surgery where animations could be overlaid to assist the surgeon, in training applications that could aid in operation of equipment or in search and rescue operations where critical information such as floor plans and directions could be virtually placed onto the display. Current approaches in the field of real time object tracking are discussed along with the methods used for video see-through AR applications on mobile computing devices. The mathematical framework for the real time object tracking and video see-through AR rendering is discussed in detail along with some consideration to extension to the handling of multiple AR objects. A physical implementation for a mobile computing device is proposed detailing the algorithmic approach along with design decisions. The real time object tracking and video see-through AR system proposed is verified through simulation and details around the accuracy, robustness, constraints, and an extension to multiple object tracking are presented. The system is then validated using a ground truth measurement system and the accuracy, robustness, and its limitations are reviewed. A detailed validation analysis is also presented showing the feasibility of extending this approach to multiple objects. Finally conclusions from this research are presented based on the findings of this work and further areas of study are proposed.

A technique for real time object tracking in a mobile computing environment and its application to video see-through Augmented Reality (AR) has been designed, verified through simulation, and implemented and validated on a mobile computing device. Using position based visual position and orientation (POSE) methods and the Extended Kalman Filter (EKF), it is shown how this technique lends itself to be flexible to tracking multiple objects and multiple object models using a single monocular camera on different mobile computing devices. Using the monocular camera of the mobile computing device, feature points of the object(s) are located through image processing on the display. The relative position and orientation between the device and the object(s) is determined recursively by an EKF process. Once the relative position and orientation is determined for each object, three dimensional AR image(s) are rendered onto the display as if the device is looking at the virtual object(s) in the real world. This application and the framework presented could be used in the future to overlay additional informational onto displays in mobile computing devices. Example applications include robotic aided surgery where animations could be overlaid to assist the surgeon, in training applications that could aid in operation of equipment or in search and rescue operations where critical information such as floor plans and directions could be virtually placed onto the display. Current approaches in the field of real time object tracking are discussed along with the methods used for video see-through AR applications on mobile computing devices. The mathematical framework for the real time object tracking and video see-through AR rendering is discussed in detail along with some consideration to extension to the handling of multiple AR objects. A physical implementation for a mobile computing device is proposed detailing the algorithmic approach along with design decisions. The real time object tracking and video see-through AR system proposed is verified through simulation and details around the accuracy, robustness, constraints, and an extension to multiple object tracking are presented. The system is then validated using a ground truth measurement system and the accuracy, robustness, and its limitations are reviewed. A detailed validation analysis is also presented showing the feasibility of extending this approach to multiple objects. Finally conclusions from this research are presented based on the findings of this work and further areas of study are proposed.

The limnological knowledge of waters in arid regions, especially Mongolia, is still insufficient. It was the goal of the Mongolian-German research project “Limnological Particularities of Characteristic Waterbodies in the Uvs Nuur Basin” to develop a systematic inventory of waters, describe their morphological, hydrophysical, chemical and biological characteristics and to generalize the framework of abiotic and biotic factors that determine their character. During the field work, carried out from 1996 to 1999, samples of water, sediments, benthic and planktonic biota were taken from 76 places at 15 stagnant water bodies, 21 streams and several groundwater bodies; morphological, hydrological, physical and hydrochemical measurements were made. Chemical and biological analyses were carried out in Germany. The most important taxonomical groups were determined by German and international specialists. The results of the work are presented and discussed separately for running waters, lakes and groundwater. Based on these findings, several general topics are dealt with: factors shaping the character of water bodies, food webs, biogeography, spatial sequence of water bodies, typology and protection issues. A checklist of 596 taxa was compiled; 109 additional taxa from the Russian and Mongolian literature were included. Two species (Cyclops glacialis Flößner 2001 and Acanthocorbis mongolica Paul 2011) were new for the science and 103 species were new reports for Mongolia. A regional stream typology with 11 different types was developed using the criteria ecoregion, altitude and catchment area. The typology developed for stagnant waters comprises 9 types based on altitude, lake area, existence of an outflow and relative depth. This dissertation comprises 139 pages and an appendix of 59 pages, 50 tables, 94 figures and a map.

A graphical model is simply a representation of the results of an analysis of relationships between sets of variables. It can include the study of the dependence of one variable, or a set of variables on another variable or sets of variables, and can be extended to include variables which could be considered as intermediate to the others. This leads to the concept of representing these chains of relationships by means of a graph; where variables are represented by vertices, and relationships between the variables are represented by edges. These edges can be either directed or undirected, depending upon the type of relationship being represented. The thesis investigates a number of outstanding problems in the area of statistical modelling, with particular emphasis on representing the results in terms of a graph. The thesis will study models for multivariate discrete data and in the case of binary responses, some theoretical results are given on the relationship between two common models. In the more general setting of multivariate discrete responses, a general class of models is studied and an approximation to the maximum likelihood estimates in these models is proposed. This thesis also addresses the problem of measurement errors. An investigation into the effect that measurement error has on sample size calculations is given with respect to a general measurement error specification in both linear and binary regression models. Finally, the thesis presents, in terms of a graphical model, a re-analysis of a set of childhood growth data, collected in South Wales during the 1970s. Within this analysis, a new technique is proposed that allows the calculation of derived variables under the assumption that the joint relationships between the variables are constant at each of the time points.

Background: Changing service demands require United Kingdom ambulance services to redefine their role and response strategies, in order to reduce unnecessary Emergency Department attendances. Treat and Refer guidelines have been developed with this aim in mind. However, these guidelines have been developed in the absence of reliable evidence or guiding mid-range theory. This has resulted in inconsistencies in clinical practice. One condition frequently included in Treat and Refer guidelines is hypoglycaemia. Therefore this thesis aimed to investigate prehospital hypoglycaemic emergencies in order to develop an evidence base for future interventions and guideline development. Research approach: A pragmatic and inductive applied health services research approach was employed. Multiple methods were used in a sequential explanatory design. Three linked studies were undertaken with the results of previous studies informing the development of the next. Study one: A scoping review of prehospital treatment of hypoglycaemic events. Aims: i) To describe the demographics of the patient population requiring ambulance service assistance for hypoglycaemic emergencies; ii) To determine the extent to which post-hypoglycaemic patients with diabetes, who are prescribed oral hypoglycaemic agents (OHA), experience repeat hypoglycaemic events (RHE) after being treated in the prehospital environment. Methods: A scoping literature review was conducted using an overlapping retrieval strategy that included both published and unpublished literature. Findings: Twenty-three papers and other relevant material were included. Hypoglycaemia related ambulance calls account for 1.3% to 5.2% of ambulance calls internationally. Transportation rates varied between studies (25%-73%). Repeat hypoglycaemic emergencies are experienced by 2-7% of patients within 48 hours. There was insufficient detail to determine any relationship between repeat events and OHA. The low quality of included papers means that the results should be cautiously interpreted. The safety of leaving patients on OHA at home post hypoglycaemic emergency is unknown. Consequently patients taking OHAs who experience a hypoglycaemic emergency should be transported to hospital for observation. There was a lack of knowledge about the Scottish demographics of the patient population. Study two: A retrospective cross-sectional observational study of diabetes related emergency calls. Aims: To investigate i) the patient demographics and characteristics of hypoglycaemia related emergency calls; ii) the incidence of repeat hypoglycaemic events; and iii) the factors associated with emergency calls that result in individuals being left at home. Methods: A retrospective observational cross-sectional study conducted using Medical Priority Dispatch System® call data from West of Scotland Ambulance Control Centre over a 12 month period. Data were extracted on age, gender, dispatch code, time of call, deprivation category, and immediate outcome (home or hospital). Multiple regression analysis was used to determine predictors of remaining at home. Findings: 1319 calls for hypoglycaemia were received. Patient demographics were similar to the scoping review findings. Most patients remained at home (N = 916 vs N = 380; p < .001). RHE’s were experience by 3.1% within 48 hours, and 10.6% within two weeks. The most significant independent predictor for patients remaining at home was a prior call to the ambulance service (OR of 2.4 [95%CI 1.5 to 3.7]). Patients’ reasons for remaining at home and the causes of subsequent severe events are unknown. It is likely that non-clinical factors may explain some of this behaviour. Study 3: Investigating patients’ experiences of prehospital hypoglycaemic care. Aim: To investigate the experiences of patients who are attended by ambulance clinicians for a hypoglycaemic emergency. Methods: In-depth interviews with adults with diabetes who had recently experienced a hypoglycaemic emergency treated by ambulance clinicians. Participants were recruited from Greater Glasgow and Clyde and Lanarkshire Health Board areas. Data were analysed using Framework Analysis. Findings: Twenty six patients were interviewed. Three key themes were developed. Firstly, an explanation for help seeking behaviour; patients’ impaired awareness of hypoglycaemia as well as the inability of friends and relatives to cope can contribute to an ambulance call-out. Secondly, the perceptions of ambulance service care; patients felt the service provided was good; however ambulance clinicians’ advice was inconsistent. Thirdly, the influences on uptake of follow-up care; patient preferences for follow-up care were influenced by previous experiences of home, hospital and primary care. Post-hoc analysis identified three psychological theories that may explain these findings and provide a useful basis for intervention development: Common Sense Model (Leventhal et al, 1998); Health Belief Model (Rosenstock, 1966); Ley’s cognitive hypothesis model of communication (Ley and Llewelyn, 1995; 1981). Conclusion: Most people treated for severe hypoglycaemia by ambulance clinicians remain at home and do not follow-up their care. A few experience repeat hypoglycaemic emergencies. Key causal, but modifiable factors, contributing to this include:- impaired awareness of hypoglycaemia; inconsistent delivery of ambulance clinician referral advice; and patients’ perceptions of the costs and benefits of follow-up care. Ambulance services cannot address all these factors in isolation. The studies in this thesis have generated an evidence base and identified plausible candidate theories. This will support the future development of novel interventions to improve severe hypoglycaemic emergency follow-up.