The aim of the thesis is to describe, analyse and discuss the development of spatial population dynamics in the Czech Republic between 1989 and 2007. Demographic structure and migration, the two components of spatial population dynamics, are analysed using two spatial dimensions, the urban-suburban-rural gradient and the core-periphery region distinction, using quantitative analyses, including gravity regression modelling of migration. The analysis primarily focuses on domestic migration as the main vehicle of spatial population dynamics. It discusses the structure, determinants, and temporal evolution of migration and its consequences on the population structure in different spatial categories. The thesis indicates that suburbanisation has recently become the main factor influencing Czech spatial population dynamics. The key factor determining migration destination is the social status of migrants, whereas age has only secondary importance. However, since Czechs are not very mobile, population dispersal is less large-scale than in Western-Europe. This explains why recent domestic migration patterns have had only a small measurable influence on the social or demographic structures of the population across spatial categories.

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The object of this dissertation is to provide an observational study of the effects of interstellar magnetic fields on star-formation regions. This is part of a long-standing research project that uses the techniques of radio astronomy to measure magnetic field strengths in the interstellar medium of our galaxy. Interstellar magnetic fields are believed to play a crucial role in the star-formation process therefore a comprehensive study of magnetic fields is necessary in understanding the origins of stars. These projects use observational data obtained from the Very Large Array (VLA) in Socorro, NM. The data reveal interstellar magnetic field strengths via the Zeeman effect in radio frequency spectral lines. This information provides an estimate of the magnetic energy in star-forming interstellar clouds in the Galaxy, and comparisons can be made with these energies and the energies of self-gravitation and internal motions. From these comparisons, a better understanding of the role of magnetic fields in the origins of stars will emerge. The regions observed include the giant molecular clouds and star-forming regions of Cygnus X and NGC 6334. NGC 6334 A is a compact HII region at the center of what is believed to be a large, rotating molecular torus (based on studies by Kramer et al. (1997)). This is a continuing study based on initial measurements of the HI and OH Zeeman effect (Sarma et al. (2000)). The current study includes OH observations performed by the VLA at a higher spatial resolution than previously published data, and allows for a better analysis of the spatial variations of the magnetic field. A new model of the region is also developed based on OH opacity studies, dust continuum maps, radio spectral lines, and infrared (IR) maps. The VLA has been used to study the Zeeman effect in the 21cm HI line seen in absorption against radio sources in the Cygnus-X region. These sources are mostly galactic nebulae or HII regions, and are bright and compact in this region of the spectrum. HI absorption lines are strong against these regions and the VLA is capable of detecting the weak Zeeman effect within them.

Globally, stream invertebrate communities have been shown to respond to habitat degradation as a result of land use hanges. The effects of land use changes on stream communities have been well documented in temperate regions, however, their effects in the tropics are relatively unknown, particularly where land use activities can differ markedly (e.g., tea, maize and Eucalyptus plantations). To understand how land use affects tropical highland Nigerian stream communities, I surveyed 55 second and third order streams across four land use categories, ranging from continuous tropical montane forest to intensive crops/pasture. Streams were sampled in the dry season (October to March) for physico-chemical parameters (i.e., temperature, pH, conductivity, turbidity, current velocity, channel morphometry and riparian characteristics) and ecological characteristics (i.e., fine particulate organic matter [FPOM], coarse particulate organic matter [CPOM], algae and benthic invertebrates). Water temperature in all streams was high (up to 25oC) while levels of dissolved oxygen were frequently low (15–79 %). Physico-chemical conditions varied across land uses with continuous forested streams being cooler, with higher dissolved oxygen, larger bed substrate and more stable channels. Similarly, benthic invertebrate communities showed a strong response with the highest taxonomic diversity in forested streams and the lowest in streams within intensive crops (e.g., cabbage crops). Several of the taxa which occurred in forested streams (e.g., the mayflies Heptageniidae and Oligoneuridae and brachyuran crabs) were rare or absent in streams with more intensive land use. In contrast, damselflies and several true bugs (e.g., Notonectidae and Corixidae) were rare in forested streams but more common in other land uses. In order to test land use impacts on stream processes leaf litter decomposition experiments were carried out in nine streams, three in forest, three in tea plantations and three in maize fields. Leaf breakdown rates were slow compared with other reports for tropical streams, however leaves in forested streams broke down significantly faster (on a degree day basis) than in other land uses. This faster break down seemed to be driven by greater shredder densities in forested streams. Significantly lower densities of invertebrates were found in leaf bags incubated in streams draining tea plantation and maize fields than in forest streams. In the same nine streams food web components were sampled and analysed using gut content and stable isotope (N and C) analyses. Stream food webs in continuous forest were more complex than plantation and maize field streams. Stable isotope analysis indicated that primary consumers assimilated a mixture of autochthonous and allochthonous carbon resources, but the proportion varied among sites. Overall, my results suggest that in Nigerian highland tropical streams more intensive land use activities strongly affect the diversity and composition of benthic stream communities and ecosystem function, in similar ways to those reported in temperate streams.

This research is aimed at the formulation of a model for the processing of demography as a determinant of the education system. The inadequate understanding of demography in the education system causes flawed management of the target group by educational providers worldwide. Enrolment rates, school life expectancy, put-through rates and school completion rates (especially in developing countries) are not up to standard in most countries. Although developed regions manage most of these imperatives satisfactory, other education system aspects are experienced as challenges, for example inclusivety and equality. To steer the formulation of the model for the processing, a literature study was undertaken to elucidate demography in the context of the education system. The concept demography is investigated from a theoretical perspective. Research about the worldwide demographic tendencies was undertaken and the different aspects concerning demographic challenges were exposed. This was followed by a study concerning demographic challenges with respect to the four components of the education system. The literature clearly showed that the way in which demographic imperatives influence the four components, determines the criteria according to which a particular education system might measure it's success. Within this context demography as determinant of the education system is explained and an awareness is cultivated about how demographic demands of the target group can be approached by the education provider. A local investigation was undertaken to understand demographic demands in regional context. The North-West Province was used as a case study to present a local perspective of demographic demands on the education system. As the North-West Province is one of the nine provinces of South Africa, it was also necessary to indicate the wider South African demographic trends. Although the North-West Province does experience certain demographic challenges similar to those of the South African set-up as a whole, it also possesses has a number of unique aspects, for instance its geography and economy, which have direct demographic influence on the education system. The general population data and the education data of the province was scrutinised in the context of the educational region to emphasis the implications for the Department of Education. Typical examples of demographic imperatives (especially migration between regions of the province and migration to and from the province) which operate in the North-West Province can be attributed to the farming and mining activities prevalent in the province. The empirical investigation of the research was aimed at the experiences of schools in the North-West Province concerning demographic challenges. The investigation is focused on the leadership of schools and the management of the school leaders regarding demography. The demographic impact in the school- and regional context is also investigated in detail. Administrative problems experienced by principals as a result of inefficient planning are investigated and a policy analysis is done from a management perspective. The responses regarding the above-mentioned aspects show the challenges facing the Department of Education because of the demographic impact. A model is formulated with general demographic guidelines, relevant demographic imperatives and a structural education system approach. Suggestions are made about the adequate application of the model. This contribution to demographic processing is intended to broaden the understanding of educational providers regarding demography as a determinant of the education system and to address the gaps in educational provision and management. / Thesis (Ph.D. (Education))--North-West University, Potchefstroom Campus, 2005.

The existence of anchor ice in supercooled water can have a profound impact on the management of water resource infrastructures in cold regions. For example, it can raise a tailrace water level and cause significant losses in generation revenue. So far, there have been limited studies on anchor ice, therefore, many problems still exist and much more study is needed. In the present research, experimental and mathematical studies of anchor ice were carried out. Experiments were conducted in a counter-rotating flume, located in a cold room at the University of Manitoba. The experiments were mainly focused on anchor ice evolution around rocks and on gravel beds under different hydro-meteorological conditions. The results are compared to a mathematical model developed herein and some important parameters such as anchor ice porosity and frazil ice deposition coefficient are examined. The growth process of anchor ice was monitored by two CCD cameras. A digital processing program was developed to analyze anchor ice images and determine the growth rate of anchor ice. In addition, anchor ice density, an important factor when studying anchor ice, was estimated and the effect of air temperature, Froude number and Reynolds number is explored. By analyzing torque load signals from the counter-rotating flume, the variation of bed roughness with the growth of anchor ice is elucidated. The deposition coefficient of anchor ice growth was also determined from the experiments. A mathematical model was developed based on a two-stage method to simulate the process of frazil ice transportation and deposition. Both frazil ice attachment and heat transfer between the supercooled water and ice crystals are considered in the model. Four governing equations related to the distribution of velocity and frazil ice transportation and deposition inside and outside the roughness layers were built. A fourth-order Runge- Kutta numerical method was used and programmed in Matlab to solve the governing equations. The growth rate of anchor ice under different hydro-meteorological conditions can be simulated by this numerical model. The proposed experimental and mathematical studies of anchor ice are presented intuitively in this paper and the results from this study contribute to a better understanding of the anchor ice growth mechanism. This study will help to develop better management strategies to mitigate ice related complications associated with hydroelectric generating stations and other hydraulic structures in cold regions.

This thesis explores different expressions of regionalism(s) and regionalization processes in a Swedish and a westernized context. The case studies in the study conducted are represented by two different kinds of regions, Värmland and The Eight Million City. Värmland is a rather typical administrative and political bordered region at the subnational level in the Midwest of Sweden. The Eight Million City in turn exemplifies an imaginary cross border region, stretching from Oslo in the north, to Gothenburg, Malmö and Copenhagen in the south, connected in a network by a larger infrastructure corridor. It is also an example of how new planning practices stretching over already institutionalized national as well as local and regional borders, can be seen as challenging earlier planning and policy structures connected to the state. It is possible to see how different kinds of strategies related to strategic spatial planning practices are used to enhance the competitiveness of each region. In both cases this produce and reproduce different perceptions about what represents and constitute a competitive region. The empirical material analyzed in the study has been generated by interviews, participant observations, and document analysis based on discourse theory and discourse analysis. Different imaginaries are institutionalized in each region by different means and practices. In Värmland new perceptions about regional citizenship, regional identity and the idea of what constitutes a modern region are being institutionalized into the regional context by building a brand for the region. In The Eight Million City the project idea is based on an enlarged labor market connecting the larger cities in the region together in a network. As well as in Värmland, the knowledge produced in the project contributes to institutionalize different perceptions of citizenship and what makes up a competitive and attractive region. / Den här avhandlingen tar sin utgångspunkt i olika uttryck av samtida regionaliseringsprocesser och regionalism(er). Studien belyser två olika regionaliseringskontexter i form av Värmland och Åttamiljonerstaden. Två i grund och botten mycket olika regioner. Värmland utgör en subnationell administrativ region och därigenom ett exempel och ett uttryck för en decentralisering av statliga uppgifter rörande regional utveckling och tillväxt till den regionala nivån. Åttamiljonerstaden är en imaginär gränsöverskridande region som sträcker sig från Oslo i norr, över Göteborg och Malmö till Köpehamn i söder, där målet är att skapa en sammanhängande och funktionell arbetsmarknadsregion. Trots de båda regionernas olikheter, så kan de båda studerade regionerna ses som ett uttryck för en alltmer normativ policyagenda som grundas på begrepp som globalisering, internationalisering och en konkurrensutsatt marknad. Detta har lett fram till olika former av rumslig strategisk planering som ska stärka respektive regions konkurrenskraft med olika medel. I sin tur leder detta till att olika diskursiva kunskapsrationaliteter om vad som utgör den ”attraktiva regionen” i form av nya styrningsformer, regional organisering och den gode regionmedborgaren implementeras och institutionaliseras i respektive regional kontext.

Freshwater ice (river and lake ice), a key component of the cryosphere, plays a dominant role in the hydrology of northern climates. Although freshwater ice has been modelled at small geographic scales, it remains the only major unquantified component of the cryosphere. Therefore, the goal of this thesis is to quantify peak freshwater ice across the Northern Hemisphere using a regionally defined degree-day ice-growth model. To address this the ecological and climatic importance of freshwater ice are reviewed, as well as the physical processes that govern freshwater-ice growth, the existing approaches to modelling freshwater ice, and the major climate classification methods. Using a degree-day ice-growth model, ice-growth coefficients are defined by hydro-climatic region, and validated using maximum observed seasonal ice thickness values from across the Northern Hemisphere. The maximum seasonal extent of freshwater ice is then estimated over a 44-year temporal period and the areal extent and volume of freshwater ice quantified. / Graduate

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