The use of nanomaterials (NMs) in orally ingestible products raises concerns about potential hazards. Titanium dioxide (TiO2) particles (of which some are incidentally produced at the nanoscale) are used in cosmetics, biological remediation (photo-catalysis), toothpastes, ingestible pharmaceuticals and food products. The increased surface area to mass ratio of nanoparticles (NPs) potentially makes them more biologically reactive than their coarser (bulk) material counterparts. There is limited data available on the uptake kinetics across the mammalian gastrointestinal tract, and the potential hazard posed to humans. In this study, the uptake and accumulation of TiO2 (nano and bulk) into and across the human intestinal cell line, the isolated perfused rat jejunum and the whole rat were evaluated. Caco-2 monolayers exhibited time-dependent, accumulation, uptake and transport of Ti/TiO2 from TiO2 exposures of 1 mg L-1 over 24 h, which was influenced by the crystal type, irrespective of cell maturity and growth substrate (Chapters 2-3). Electron micrographs of the Caco-2 monolayer showed the presence of particles inside the cells within vesicles and energy dispersive spectroscopy (EDS) confirmed the composition as TiO2. Addition of pharmacological inhibitors altered the Ti concentration in the cells suggesting diffusion is not the primary mechanism of uptake, rather, an active process is responsible (Chapter 2). Whole gut sacs exposures of 1 mg L-1 bulk or nano TiO2 demonstrated the primary regions of the gut associated with accumulation are the small and large intestine, with 70 % or more of the TiO2 accumulating in the mucosa rather than the underlying muscularis. Perfused intestines exposed to 1 mg L-1 bulk or nano TiO2 for 4 h showed a time-dependent accumulation of Ti in the serosal perfusate with the initial rates of Ti flux from the nano exposures being 5 fold higher than the bulk form. Addition of pharmacological inhibitors caused increases in tissue Ti concentration and significantly reduced Ti serosal flux rates for NP exposures. Overall, the data suggests an active absorption mechanism is responsible for Ti uptake from both bulk and nano TiO2 exposures across the perfused rat intestine that is drug sensitive (Chapter 4). In vivo work demonstrated feed status and rat age effected Ti tissue concentrations. Critically, Ti tissue concentrations reduced with increasing age and removal of Ti containing feed caused transient decreases in Ti tissue concentrations in 23 day old rats. Transient decreases in Ti tissue concentration following feed removal were not observed in older rats suggesting young rats may be more sensitive to the uptake hazards presented by titanium (Chapter 5). Overall, the findings presented in this thesis demonstrate Ti/TiO2 from both bulk and nano TiO2 exposures are accumulated and transported across intestinal epithelium and these processes are drug sensitive and affected by crystal structure and particle size. The results in this thesis have contributed to a better understanding of the uptake kinetics and sub-lethal hazards presented by bulk and nano forms of TiO2 exposed to intestinal epithelium which could be used to partially inform policy makers on human dietary risk assessments.

Magister Scientiae - MSc / In South Africa there is a need within the milling industry for controlling food safety especially due to customer's demands and government's regulations. The best way to ensure food safety is with the implementation of a HACCP based food safety system. Therefore, the principal aim of this study was to develop a generic HACCP model for the flour milling industry. Afterwards this generic model can then be adapted for each specific mill and its needs. / South Africa

Magma plumbing systems represent the physical framework of magma transport and storage from the source region in the mantle, through the crust, until reaching the surface in a volcanic eruption. Characterising the different aspects of magma plumbing, in particular the distribution of magma storage zones throughout the crust, is of key importance to better understand the behaviour of individual volcanoes. In particular, shallow crustal magma storage and associated magma-crust interaction processes could potentially explain some of the worlds most unpredictable and explosive volcanoes. This thesis studies magma plumbing architecture in the Sunda Arc (Indonesia), and the North Atlantic Igneous Province, based on elemental and isotope geochemistry, and derived petrological modelling. In this study, I have employed petrological models, so called geothermobarometers, to calculate pressures and temperatures (P-T) of crustal magma storage. Geothermobarometers are calibrated thermodynamic formulations based on the composition of magmatic minerals and their co-existing melt as a function of the P-T conditions of crystallisation. Using the calculated P-T estimates, I was able to derive the depth of magma storage, and thereby reconstruct the architecture of magma storage systems. A number of different geothermobarometers based on different mineral phases, including plagioclase, clinopyroxene and olivine, were used for this purpose, The geothermobarometric modelling was combined with additional elemental and isotope geochemical analyses, as well as collaborations with geophysical investigations. These additional approaches were used to corroborate the findings of the geothermobarometric modelling, and also to model and quantify magma-crust interaction processes that take place during crustal magma storage, such as assimilation of crustal lithologies into the magmatic system. The findings of this thesis build upon the growing body of evidence in support of the prevalence of shallow magma storage in different volcanic settings worldwide. This realisation is relevant to volcano monitoring and hazard mitigation worldwide.

In the face of future uncertainties, many places are struggling with decisions about how to prepare for and adapt to climate change. The purpose of this research is to shed light on the concept of resilience, and uncover lessons for resilience-building exposed by a past disaster, Hurricane Wilma. The dissertation begins with an introduction (Chapter 1) detailing the research problem, key terms and overall research design. The study was conducted in three distinct phases. The first phase (Chapter 2), explored the concept of resilience to understand how it was defined in three South Florida communities. Content analyses of city and county documents were conducted to extract explicit definitions of resilience as well as implicit definitions based on carefully selected keywords. Results showed the engineering resilience concept was most prevalent across all three study areas. Furthermore, keywords related to the dimension of the built environment were most common in Broward and Lee Counties. While this may indicate a need for communities to shift toward more progressive, social-ecological conceptualizations of resilience, a more central conclusion was that local applications of resilience frameworks need to be more explicit about how they define resilience, and what resilience-building looks like in that particular context. Phase two (Chapter 3) explored the interplay between specified resilience, addressing resistance to known disturbances, and general resilience, addressing a system's capacity to deal with less predictable shocks. This phase entailed a content analysis of 172 Sun-Sentinel newspaper articles about Hurricane Wilma. Prominent themes that emerged included distribution of benefits and risks, social learning and memory, cross-scale issues, vulnerability and social networks. This chapter concludes with four specific recommendations for Broward County to enhance resilience to future storms and less predictable disturbances, like climate change and sea level rise. During the third phase (Chapter 4) a modified resilience activation framework was applied to analyze social factors that may limit or promote adaptive capacity in South Florida. Focus groups with homeowners were used to gain insight about past experiences with Hurricane Wilma, as well as perceptions and expectations regarding local climate adaptation efforts. Results showed that risk perceptions, insurance practices, and social networks may influence the willingness and ability of individuals to prepare for and adapt to disasters. Social limits to adaptation among participants included inaccurate risk perceptions based on past experiences and feelings of helplessness, and a lack of political trust at the state level. Social resources that can be leveraged to enhance adaptive capacity included knowledge reserves of long-term residents, strong bonding capital, and trust in local, non-elected government employees. Results from each phase of research were synthesized to create a novel procedural roadmap to guide how communities integrate resiliency into their planning documents.

Produced since the 1950’s, per- and polyfluoroalkyl (PFASs) substances are persistent, bioaccumulative and toxic compounds that are ubiquitous in the environment. Being proteinophilic with a tendency to partition to protein-rich tissues, PFASs have been found in human serum worldwide and in wildlife with a predominance of long-chain perfluoroalkyl carboxilic acids (C7-C14 PFCAs) and perfluoroalkyl sulfonic acids (C6-C9 PFSAs). Due to rising concern regarding their hazardous properties, several regulatory actions and voluntary industrial phase-outs have been conducted since early 2000s, shifting the production towards other fluorinated alternatives. This thesis explores the human exposure to long-chain PFASs and their alternatives using different modelling methods and aims to 1) link comprehensively the past and current industrial production with the human body burden and 2) assess the potential hazardous properties of legacy PFASs replacements, on which information is very limited. In Paper I, the historical daily intakes in Australia and USA were reconstructed from cross-sectional biomonitoring data of perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA) andperfluorohexanesulfonic acid (PFHxS). The results indicate that humans experienced similar exposure levels and trends to PFOS and PFOA in both regions, suggesting a common historical exposure possibly dominated by consumer products. The model could not be fitted to PFHxS concentration in serum. In Paper II, the relative contribution of indirect (i.e. subsequent metabolism of precursors into legacy PFASs) versus direct exposure was evaluated on occupationally exposed ski wax technicians. The indirect exposure contributed by up to 45% to the total body burden of PFOA. In Paper III, the physicochemical properties, the persistence and the long-range transport of fluorinated alternatives were predicted using different in silico tools. Findings suggest that fluorinated alternatives are likely similar to their predecessors, in terms of physicochemical properties and environmental fate. Finally, Paper IV compares the toxic potency of PFOS, PFOA and their alternatives as a function of external and internal dose. While alternatives are less potent than their predecessors when considering the administered dose, they become similarly potent when the assessment is based on levels in the target tissue. This thesis demonstrates that pharmacokinetic models are effective tools to comprehensively reconnect the body burden to the exposure of phased-out chemicals. More importantly, the studies on fluorinated alternatives raise the necessity to provide more information and data on the potential hazard of these novel and emerging products. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: Manuscript. Paper 4: Manuscript.</p>

The interest in telecommuting stems from the potential benefits in alleviating traffic congestion, decreasing vehicle miles traveled (VMT), and improving air quality by reducing the necessity for travel between home and the workplace. Despite the potential economic, environmental, and social benefits, telecommuting has not been widely adopted, and there is little consensus on the actual impacts of telecommuting. One of the major hurdles is lack of a sound instrument to quantify the impacts of telecommuting on individuals’ travel behavior. As a result, the telecommuting phenomenon has not received proper attention in most transportation planning and investment decisions, if not completely ignored. This dissertation addresses the knowledge gap in telecommuting studies by examining several factors. First, it proposes a comprehensive outline to reveal and represent the complexity in telecommuting patterns. There are various types of telecommuting engagement, with different impacts on travel outcomes. It is necessary to identify and distinguish between those people for whom telecommuting involves a substitution of work travel and those for whom telecommuting is an ancillary activity. Secondly, it enhances the current modeling framework by supplementing the choice/frequency approach with daily telework dimensions, since the traditional approach fails to recognize the randomness of telecommuting engagement in a daily context. A multi-stage modeling structure is developed, which incorporates choice, frequency, engagement, and commute, as the fundamental dimensions of telecommuting activity. One pioneering perspective of this methodology is that it identifies non-regular telecommuters, who represent a significant share of daily telecommuters. Lastly, advanced statistical modeling techniques are employed to measure the actual impacts of each telecommuting arrangement on travelers’ daily activity-travel behavior, focusing on time-use analysis and work trip departure times. This research provides a systematic and sound instrument that advances the understanding of the benefits and potentials of telecommuting and impacts on travel outcomes. It is expected to facilitate policy and decision makers with higher accuracy and contribute to the better design and analysis of transportation investment decisions.

Tropical Cyclones are a continuing threat to life and property. Willoughby (2012) found that a Pareto (power-law) cumulative distribution fitted to the most damaging 10% of US hurricane seasons fit their impacts well. Here, we find that damage follows a Pareto distribution because the assets at hazard follow a Zipf distribution, which can be thought of as a Pareto distribution with exponent 1. The Z-CAT model is an idealized hurricane catastrophe model that represents a coastline where populated places with Zipf- distributed assets are randomly scattered and damaged by virtual hurricanes with sizes and intensities generated through a Monte-Carlo process. Results produce realistic Pareto exponents. The ability of the Z-CAT model to simulate different climate scenarios allowed testing of sensitivities to Maximum Potential Intensity, landfall rates and building structure vulnerability. The Z-CAT model results demonstrate that a statistical significant difference in damage is found when only changes in the parameters create a doubling of damage.

This thesis analyzes gamble gaming, bets and lottery in the Czech Republic. Historic context of hazzard and view of economic theory and the game theory is described in details. This thesis deals with the economic, social and legislative impacts of gamble gaming and bets. Current changes and issues are analyzed in depth, there are also views of the particular subjects included within this analyze. The thesis proves via argumentation the inadequacy of the current legislative framework in the field of gambling and predicts what possible consequences the extensive legislative changes may bring. The Thesis studies the approach of former works dealing with the subject and methods of hazzard social expenses quantification. Current environment of gambling is analyzed on the country level as well as on the municipal level (As an example town Třešť and Jihlava were chosen).

This thesis deals with questions of funding sport from lottery incomes and other similar games. The aim of this study is to present a relation between gambling and sport in a complex way. The preliminary theoretic part explains terminology and principle of venture operations, including historical evolution. Furthermore, this thesis is focused on determination of positive and negative externalities of gambling towards sport. Practical part describes a crucial legal form of gambling in Czech Republic. Apart from that this thesis evaluates consequences caused of legal modifications in recent years. Following is the analysis of funding sport from incomes of loterries in selected EU countries. The final part deals with (de)regulation of betting sector in Europe.

This thesis deals with flood maps and their use in the context of property insurance. There are flood maps presented in comparison with similar projects of the European Union, the flood hazard maps and flood risk maps. There is also assessed the impact of flood maps on Flood Prevention Strategy in the Czech Republic. This thesis analyzes the offers insurance companies in the property insurance according to 4 risk flood zones. Finally, it evaluates the importance of flood maps not only from the perspective of insurance companies, but also from the perspective of others (people, companies etc.).