Districting Problems - New Geometrically Motivated Approaches

This thesis focuses on districting problems were the basic areas are represented by points or lines. In the context of points, it presents approaches that utilize the problem\u27s underlying geometrical information. For lines it introduces an algorithm combining features of geometric approaches, tabu search, and adaptive randomized neighborhood search that includes the routing distances explicitly. Moreover, this thesis summarizes, compares and enhances existing compactness measures

International Retirement Migration: mapping the spatio-temporal growth of foreign-owned properties in Cotacachi, Ecuador

International Retirement Migration (IRM) is a growing phenomenon in the Global South. Using the example of the city of Cotacachi in the Ecuadorian Andes, this paper analyzes the spatio-temporal growth of the properties acquired by foreign retirees. We have developed a multi-temporal map that visualizes the spatio-temporal patterns of foreign-owned real estate properties and explains them in the historical context of land tenure. As no official spatial data is available for foreign-owned properties in Cotacachi, the mapping was developed based on data triangulation from remote sensing, participatory mapping, document analysis (e.g. a cadastral database), and semi-structured interviews with key stakeholders. With this origin approach, the map reveals a significant growth in the number of properties and the size of the land acquired by foreigners particularly since the 2008 United States' housing crisis. Most of the foreign-owned properties are located at the urban fringe and have been built on former colonial hacienda lands in direct proximity to existing indigenous communities

The Effects of International Retirement Migration on Indigenous Communities: Empirical Insights from Cotacachi, Ecuador

Abstract International retirement migration (IRM) is known as an important factor for regional economic development in some low- and middle-income countries. However, IRM’s effects on land prices and real-estate markets, especially housing, are controversial. Using the case study of the Andean city of Cotacachi, Ecuador, this paper discusses the economic and socio-spatial effects of IRM-related construction of comparatively high-priced retirement homes on indigenous communities’ access to land and housing prices in the urban area. Based on the analysis and collection of quantitative and qualitative data, the paper identifies that IRM-related foreign investments result in increased prices of (agricultural) land and urban housing. This especially affects indigenous communities as they are historically marginalized in access to land. In order to entangle the IRM-related effects, we contextualize and discuss these in light of the historical control of land by landowning élites. Our data shows that recent IRM-oriented real-estate development – paired with highly uneven postcolonial distribution of land – has unequal socio-spatial effects: land-rich élites (hacendados) benefit from selling land to both local and foreign investors, while landless and land-poor indigenous communities face increasing difficulty in accessing land for agriculture. Resumen La migración internacional de jubilados (MIJ) es conocida como un factor importante para el desarrollo económico regional en algunos países. Sin embargo, sus efectos sobre los precios del suelo y los mercados inmobiliarios, son controversiales. A partir de un estudio en la ciudad de Cotacachi, Ecuador, este artículo analiza los efectos económicos y socio-espaciales de la construcción de viviendas de alto valor para jubilados extranjeros, en relación con el acceso a la tierra en las comunidades indígenas y el precio de la vivienda. El artículo identifica que las inversiones extranjeras relacionadas con la MIJ provocan un aumento en los precios de la tierra y la vivienda urbana. Esto a su vez, afecta especialmente a las comunidades indígenas. Con el fin de entender los efectos relacionados con la MIJ, discutimos los mismos, a la luz del control histórico de la tierra por parte de las élites terratenientes. Nuestros datos reflejan que el desarrollo inmobiliario relacionado con la MIJ - junto con la distribución postcolonial de la tierra tiene efectos socio-espaciales desiguales: las grandes élites terratenientes (hacendados) se benefician de la venta de tierras, mientras que las comunidades indígenas (sin) o pobres en tierras enfrentan grandes dificultades para continuar con la agricultura

Fe-III, Cu-II and Zn-II Complexes of the Rigid 9-Oxido-phenalenone Ligand-Spectroscopy, Electrochemistry, and Cytotoxic Properties

The three complexes [Fe(opo)(3)], [Cu(opo)(2)], and [Zn(opo)(2)] containing the non-innocent anionic ligand opo(-) (opo(-) = 9-oxido-phenalenone, Hopo = 9-hydroxyphenalonone) were synthesised from the corresponding acetylacetonates. [Zn(opo)(2)] was characterised using H-1 nuclear magnetic resonance (NMR) spectroscopy, the paramagnetic [Fe(opo)(3)] and [Cu(opo)(2)] by electron paramagnetic resonance (EPR) spectroscopy. While the EPR spectra of [Cu(opo)(2)] and [Cu(acac)(2)] in dimethylformamide (DMF) solution are very similar, a rather narrow spectrum was observed for [Fe(opo)(3)] in tetrahydrofuran (THF) solution in contrast to the very broad spectrum of [Fe(acac)(3)] in THF (Hacac = acetylacetone, 2,4-pentanedione; acac(-) = acetylacetonate). The narrow, completely isotropic signal of [Fe(opo)(3)] disagrees with a metal-centred S = 5/2 spin system that is observed in the solid state. We assume spin-delocalisation to the opo ligand in the sense of an opo(-) to Fe-III electron transfer. All compounds show several electrochemical opo-centred reduction waves in the range of -1 to -3 V vs. the ferrocene/ferrocenium couple. However, for Cu-II and Fe-III the very first one-electron reductions are metal-centred. Electronic absorption in the UV to vis range are due to pi-pi* transitions in the opo core, giving Hopo and [Zn(opo)(2)] a yellow to orange colour. The structured bands ranging from 400 to 500 for all compounds are assigned to the lowest energy pi-pi* transitions. They show markedly higher intensities and slight shifts for the Cu-II (brown) and Fe-III (red) complexes and we assume admixing metal contributions (MLCT for Cu-II, LMCT for Fe-III). For both complexes long-wavelength absorptions assignable to d-d transitions were detected. Detailed spectroelectrochemical experiments confirm both the electrochemical and the optical assignments. Hopo and the complexes [Cu(opo)(2)], [Zn(opo)(2)], and [Fe(opo)(3)] show antiproliferative activities against HT-29 (colon cancer) and MCF-7 (breast cancer) cell lines in the range of a few mu M, comparable to cisplatin under the same conditions