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In the early 1990s the European Commission and the national governments of the EU member states initiated an extensive deregulation and liberalization process in the European railway industry. Prior to this process, the European railway industry was characterized by loosely connected national monopoly railway companies which faced severe losses of transportation market share and required increasing subsidies. Overall, this system was not what a single European market needed: an integrated transport system that provides reliable and fast cross-border transportation of goods, services, and people. The main elements of the reforms have been the separation of infrastructure management from transport operations, the implementation of interoperability among the national railway systems, the assurance of third-party access to the infrastructure, and the introduction of independent railway regulatory systems. In general, the intention of the reforms has been to enhance competition by opening the market and to improve the economic performance of the European railway industry. The objective of this thesis is to analyze the effectiveness of the European railway deregulation process in enhancing efficiency and productivity in the European railway industry. For that purpose three empirical papers are introduced that use non-parametric and parametric benchmarking methods to evaluate the impact of different production technologies and country- and firm-specific environmental and regulatory conditions on efficiency and productivity. The first paper, ‘Testing for Economies of Scope in European Railways: An Efficiency Analysis’, conducts a pan-European efficiency analysis to investigate the performance of European railways with a particular focus on economies of vertical integration. We test the hypothesis that integrated railways realize economies of scope and, thus, produce railway services with a higher level of efficiency. To determine whether joint or separate production is more efficient, we apply an innovative two-stage data envelopment analysis super-efficiency model which relates the efficiency for integrated production to a reference set consisting of separated firms which use a different production technology. We find that for a majority of European railways economies of scope exist. The second paper, ‘Productivity Growth in European Railways: Technological Progress, Efficiency Change and Scale Effects’, analyzes the efficiency and productivity of the European railway sector in the period of deregulation (1990-2005). Using a stochastic frontier panel data model that controls for unobserved heterogeneity a distance function model is estimated in order to evaluate the sources of productivity growth: technological progress, technical efficiency change and scale effects. The results indicate that technology improvements were by far the most important driver of productivity growth, followed by gains in technical efficiency, and to a lesser extent by exploitation of scale economies. Overall, we find an average productivity growth of 39 percent within the sample period. The third paper, ‘European Railway Deregulation: The Influence of Regulatory and Environmental Conditions on Efficiency’, investigates the impact of regulatory and environmental conditions on technical efficiency of European railways. Using a panel data set of 31 railway firms from 22 European countries from 1994 to 2005, a distance function model, including regulatory and environmental factors, is estimated using stochastic frontier analysis. The results obtained indicate positive and negative efficiency effects of different regulatory reforms. Furthermore, estimating models with and without regulatory and environmental factors indicates that the omission of environmental factors, such as network density, substantially changes parameter estimates and, hence, leads to biased estimation results. The last chapter of the thesis summarizes the results of the three empirical analyses. It contains overall conclusions, highlights implications for economic policy, and provides directions for further research.
The doctoral dissertation deals with the problems of the diagnosis of rolling bearings using recurrence analysis. The main topic is the influence of radial internal clearance on the change of dynamics in a self-aligning double-row ball bearing with a tapered bore, in which the axial preload can control this parameter in a wide range. The dissertation began with an analysis of the state of knowledge. In the next part of the dissertation, the thesis was formulated and activities related to its proving were defined. The theoretical part was supplemented with the basics related to vibroacoustic diagnostics of rolling bearings and presented methods that can be used for their diagnostics. The research on proving the thesis was started with the preparation of a mathematical model in which a change in the damping coefficient in the field of radial clearance was adopted, a difference in the clearance value for a given row of balls was proposed, and the influence of shape errors and radial shaft endplay on the dynamics of the tested bearing was taken into account. During the dynamics tests, the radial clearance was adopted as a bifurcation parameter, and on the basis of the bifurcation diagram, it was possible to indicate the characteristic areas of bearing operation due to the radial internal clearance. In order to verify the model, experimental tests were carried out with a series of bearings in which the radial clearance was changed in a wide range possible to be physically realized. Recurrence analysis was used for both the dynamic response obtained from model and experimental studies. Owing to the comparative analysis of the dynamic response, recurrence quantificators were selected that are most susceptible to changes in radial clearance to bearing dynamics. Moreover, as a result of the research, it was possible to select a narrow range of radial clearance, ensuring the smoothest operation of the tested bearing.
Many public goods are characterized by rivalry and/or excludability. This paper introduces both non-excludable and excludable public inputs into a simple endogenous growth model. We derive the equilibrium growth rate and design the optimal tax and user-cost structure. Our results emphasize the role of congestion in determining this optimal financing structure and the consequences this has in turn for the government’s budget. The latter consists of fee and tax revenues that are used to finance the entire public production input and that may or may not suffice to finance the entire public input, depending upon the degree of congestion. We extend the model to allow for monopoly pricing of the user fee by the government. Most of the analysis is conducted for general production functions consistent with endogenous growth, although the case of CES technology is also considered.
Expatriate success
(2006)
Since its establishment, the African Union (AU) has assumed an important role in matters of peace and security on the continent. This doctoral dissertation is dedicated to its conflict and crisis interventions and seeks to identify as well as subsequently explain the broader patterns that have emerged. The dissertation posits that neither the AU's regime-serving roots, which emphasize the primacy of incumbents' parochial interests, nor the AU's problem-solving commitment, which emphasizes the pursuit of its declared organizational mission, can convincingly explain these patterns on their own. Instead, we should understand the AU as being driven by two different logics of cooperation at the same time: a problem-solving and a regime-serving logic. Across its three constitutive articles, the dissertation makes empirical as well as theoretical contributions to the existing literature. Empirically, it offers a broad and systematic analysis of AU interventions over time, across different intervention types, and without bias towards high-profile cases. The novel dataset, on which the dissertation builds, constitutes the hitherto most comprehensive effort to capture the AU's responses to crises and conflicts. Theoretically, the dissertation develops a set of testable theory-driven expectations based on the notion of two different logics of cooperation. While identifiable in the literature on the AU and linking to broader existing debates on international cooperation, the dissertation breaks ground by clearly outlining the implications of each logic and bringing them together under a single theoretical framework. Jointly, the articles provided strong evidence that the AU is indeed driven by both a problem-solving and a regime-serving logic of cooperation, and that this serves as the foundation for explaining the AU's broader intervention patterns. This contributes not only to a better understanding of AU interventions but also has a chance to enrich other important debates, including the debates on African regionalism, comparative regionalism, and multilateral interventions.
Exploring artful possibilities: a transdisciplinary research on culture, arts and sustainability
(2021)
The texts gathered in this manuscript offer a largely congruent set of insights on the cultural dimension of sustainability and on the important functions of the arts in relation to the cultural dimension of sustainability, not only in society – more particularly in cities – but also more self- reflexively in transdisciplinary sustainability research itself. The introduction paper (original text for the Cumulative Habilitation) presents all the published texts included in the cumulative habilitation manuscript, and discusses the challenges of transdisciplinary research, differentiating two schools of transdisciplinarity (the so-called the ‘ETH’ and ‘CIRET’ approaches) to which the author’s postdoctoral research relates. The four texts in the first part (PART 1 - Culture(s) and Aesthetics of sustainability)articulate the relations between culture and sustainability. They focus on a theoretical dimension of the author’s postdoctoral research that further developed an understanding of “cultures of sustainability” and of “aesthetics of complexity” that was initiated in the author’s PhD, bringing them in a dialogue with other ongoing and emerging discourses about “cultural sustainability” and “queer ecologies”. The four texts in the second part (PART 2 - The Arts in Relation to Culture(s) and Aesthetics of Sustainability) represent the part of the author’s research that constituted a closer examination of specific artistic practices: ecological art, musical practices, and contemporary interdisciplinary arts in urban arts organizations.
The ten texts in the third part (PART 3 - Creative Sustainable Cities) share the insights gained in the parts of the author’s research work that focused on urban cultural and arts-related phenomena in their relationships to urban sustainability. Several of the texts lay out a critique of the “Creative City” and demonstrate an effort to develop an alternative understanding of the Creative City that would deserve to be also named a “Sustainable City”. Later texts share the insights from the author’s co-leading of the “Stadt als Möglichkeitsraum” (“City as Space of Possibilities”) research project (2015-2018).
The nine texts collected in the fourth part (PART 4 - Towards Artful Sustainability Research)reflect how the author’s ongoing research work included a transdisciplinary reflection and development in terms of epistemology and methodology, incorporating increasingly more elements of arts-based research and of phenomenology and integrating them with systems thinking and qualitative social-scientific research. This development brought the author to reflect further upon the imaginaries and research practices of sustainability researchers, and to advocate for an “artistic turn” in sustainability research (including the more specific field of sustainability science).
The conclusion paper (original text for the Cumulative Habilitation) summarizes the insights from all the published texts included in the cumulative habilitation manuscript, and suggests ways to address the transdisciplinary challenges presented in the introduction paper, suggesting ways to articulate the ‘ETH’ and ‘CIRET’ approaches to transdisciplinarity.
Destination websites, which are maintained by destination marketing/management organisations (DMOs), are a key source of information for tourists in the pre-trip phase. DMOs are increasingly applying experiential marketing on their websites to support positive pre-travel online destination experiences (ODEs) and make the vision of the holiday as vivid as possible. However, research into technology-driven travel experiences is still in its infancy. In particular, a theoretical understanding of the nature of ODEs arising from destination websites is still lacking. Therefore, this dissertation is dedicated to an extensive investigation of ODEs on destination websites in the pre-travel phase. The aims were to analyse the influences of experiential design on ODEs, explore the ODE dimensions, and develop and validate a measurement tool for assessing the ODE values of destination websites. In the first qualitative multi-method study (eye-tracking, retrospective think-aloud protocols, semi-structured interviews, and video observations), the objective was to gain an in-depth understanding of the ODE facets in the travel inspiration phase. It was found that the experience dimensions adopted in previous research regarding the product-brand context (sensory, affective, intellectual, social, and behavioural dimensions) also occurred in the ODE context but exhibited some particularities, such as a future-oriented affective component (affective forecasting). Moreover, a supplementary spatio-temporal experience dimension was identified. An online field experiment was subsequently conducted and aimed at assessing the effects of applying experiential marketing on destination websites on ODEs in the travel inspiration phase. Based on the findings of Study 1, an initial attempt at developing an ODE measurement instrument was made and the ODE dimensionality tested. The results showed the theoretically relevant experience dimensions to be less differentiated compared to the product-brand context; instead, they merged into a holistic ODE encompassing several experience facets. Furthermore, it was shown that the application of experiential design enhanced ODEs; however, considering the subjectivity of experiences, the effect was rather small. Accordingly, complex multi-media elements do not automatically increase the experiential effect. In the third study, a quasi-online field experiment was conducted, simulating the travel information phase (higher involvement than Study 2) to re-assess the ODE dimensions and develop and validate a measurement instrument. The results showed the overall ODE to be reflected by two interrelated dimensions that aligned with the dual process theory: hedonic and utilitarian experiences. The facets identified in the first study were largely reflected in these two overarching components. Moreover, a reliable, valid, and parsimonious second-order measure for assessing ODEs was proposed. Overall, the results yielded by this dissertation enhance the scientific understanding of the technology-empowered tourist experience in the currently under-researched pre-travel experience phase. In addition, by proposing a new scale for the measurement of ODEs, this dissertation provides useful methodological advancements that can pave the way for further research in this field.
This paper contributes to the flourishing literature on exports and productivity by using a unique newly available panel of exporting establishments from the manufacturing sector of Germany from 1995 to 2004 to test three hypotheses derived from a theoretical model by Hopenhayn (Econometrica 1992): (H1) Firms that stop exporting in year t were in t-1 less productive than firms that continue to export in t. (H2) Firms that start to export in year t are less productive than firms that export both in year t-1 and in year t. (H3) Firms from a cohort of export starters that still export in the last year of the panel were more productive in the start year than firms from the same cohort that stopped to export in between. While results for West Germany support all three hypotheses, this is only the case for (H1) and (H2) in East Germany.
The majority of empirical studies that centre on exporter performance and the determinants of export performance have focused mainly on the manufacturing sector, largely because there are very few datasets that facilitate a detailed investigation into the service sector. In 2008, however, the German Federal Statistical Office and the statistical offices of the Federal States released the German business services statistics panel (this dataset is described in more details in Chapter 2). Thus, for the first time, appropriate panel analyses of the export behaviour of German business services firms became possible. This thesis uses this panel dataset and contributes to the literature on the microeconometrics of international trade by providing evidence concerning the German business services sector. Overall, the results noted for exporter performance in the German business services sector correspond with those from the manufacturing sector. Chapter 3 shows that, similar to the manufacturing sector, exporting German business services firms are more productive and clearly larger (in terms of turnover and number of employed persons) than non-exporters, even when it is controlled for size and industry. Further, business services enterprises that export pay higher average wages (even when controlling for size and industry). When controlling for unobserved, time-invariant characteristics, the significant differences between exporters and non-exporters relative to productivity or average wages disappear, while significant export premia associated with the size variables continue to exist, but on a much smaller scale. Concerning the hypothesis that better performing enterprises self-select into export markets, the results indicate that in the business services sector as in the manufacturing sector, enterprises that begin to export are larger than non-exporters, even two years before they commence exporting operations. Regarding productivity (in terms of turnover per employed person) and average wages, the results were statistically significant only for business services enterprises in Germany’s western region. Aside from these similarities with the manufacturing sector, Chapter 4 presents evidence which suggests that, contrary to firms in the manufacturing industries, German business services firms do not benefit from exporting in terms of higher rates of profit. Chapter 4 documents a negative profitability differential of services exporters compared to non-exporters, and finds that export-starters in the business services sector are less profitable than non-exporters, even two years before they begin to export. Further, the estimated dose-response function, which is used to investigate the causal impact of exports on profits, shows an s-shaped relationship between profitability and firms’ export-sales ratio. Enterprises with a very small share of exports in total sales have a lower rate of profit than non-exporting firms. Then, with an increase in export intensity, the rate of profit increases as well. However, even at the maximum, the average profitability of the exporters is not, or is only slightly, higher than the average rate of profit of the non-exporting firms. Chapter 5 investigates the question which factors determine the export performance of German business services firms by estimating a model of the firms’ export intensity decision. Overall, the results support most of the explanations of export behaviour found in the literature for both service firms and manufacturing firms, such as the positive effects of size, human capital, and productivity. Yet when controlling for unobserved heterogeneity, the picture changes; notably, in the model with fixed effects, the significance of productivity and human capital disappears. This indicates that these variables are not positively related to the export performance per se, but are related instead to unobserved time-constant characteristics. Size still has a significant positive effect on exporting when controlling for unobserved effects. Finally, Chapter 6 considers the impact of the 2004 EU enlargement on service enterprises close to Germany’s eastern border by using regression-adjusted difference-in-differences estimators. The results suggest a small negative impact associated with the EU enlargement on export intensity and the turnover of large enterprises with an annual turnover of €250,000 or more, and no effect on the share of exporters and the turnover profitability of these enterprises. For small enterprises close to Germany’s eastern border, an increase in turnover and a decrease in profitability relative to other small enterprises are noted.
We use comparable micro level panel data for 14 countries and a set of identically specified empirical models to investigate the relationship between exports and productivity. Our overall results are in line with the big picture that is by now familiar from the literature: Exporters are more productive than non-exporters when observed and unobserved heterogeneity are controlled for, and these exporter productivity premia tend to increase with the share of exports in total sales; there is strong evidence in favour of self-selection of more productive firms into export markets, but nearly no evidence in favour of the learning-by-exporting hypothesis. We document that the exporter premia differ considerably across countries in identically specified empirical models. In a meta-analysis of our results we find that countries that are more open and have more effective government report higher productivity premia. However, the level of development per se does not appear to be an explanation for the observed cross-country differences.
Abstract: A recent survey of 54 micro-econometric studies reveals that exporting firms are more productive than non-exporters. On the other hand, previous empirical studies show that exporting does not necessarily improve productivity. One possible reason for this result is that most previous studies are restricted to analysing the relationship between a firm’s export status and the growth of its labour productivity, using the firms’ export status as a binary treatment variable and comparing the performance of exporting and non-exporting firms. In this paper, we apply the newly developed generalised propensity score (GPS) methodology that allows for continuous treatment, that is, different levels of the firms’ export activities. Using the GPS method and a large panel data set for German manufacturing firms, we estimate the relationship between a firm’s export-sales ratio and its labour productivity growth rate. We find that there is a causal effect of firms’ export activities on labour productivity growth. However, exporting improves labour productivity growth only within a sub-interval of the range of firms’ export-sales ratios.
Using unique recently released nationally representative high-quality longitudinal data at the plant level, this paper presents the first comprehensive evidence on the relationship between exports and productivity for Germany, a leading actor on the world market for manufactured goods. It applies and extends the now standard approach from the international literature to document that the positive productivity differential of exporters compared to non-exporters is statistically significant, and substantial, even when observed firm characteristics and unobserved firm specific effects are controlled for. For West German plants (but not for East German plants) some empirical evidence for self-selection of more productive firms into export markets is found. There is no evidence for the hypothesis that plants which start to export perform better in the three years after the start than their counterparts which do not start to sell their products on the world market. Results for West Germany support the hypothesis that the productivity differential between exporters and nonexporters is at least in part the result of a market driven selection process in which those export starters that have low productivity at starting time fail as a successful exporter in the years after the start, and only those that were more productive at starting time continue to export.
While the role of exports in promoting growth in general, and productivity in particular, has been investigated empirically using aggregate data for countries and industries for a long time, only recently have comprehensive longitudinal data at the firm level been used to look at the extent and causes of productivity differentials between exporters and their counterparts which sell on the domestic market only. This papers surveys the empirical strategies applied, and the results produced, in 45 microeconometric studies with data from 33 countries that were published between 1995 and 2004. Details aside, exporters are found to be more productive than non-exporters, and the more productive firms self-select into export markets, while exporting does not necessarily improve productivity.
This paper presents the first empirical test with German establishment level data of a hypothesis derived by Helpman, Melitz and Yeaple in a model that explains the decision of heterogeneous firms to serve foreign markets either trough exports or foreign direct investment: only the more productive firms choose to serve the foreign markets, and the most productive among this group will further choose to serve these markets via foreign direct investments. Using a non-parametric test for first order stochastic dominance it is shown that, in line with this hypothesis, the productivity distribution of foreign direct investors dominates that of exporters, which in turn dominates that of national market suppliers.
This dissertation analyses external appointees and successions on boards and consists of three papers which are all empirical in nature. It provides insights into the present literature from a meta-perspective, enlarges the understanding of external successions to German executive bank boards and extends the rare number of studies on the internal supervisory bodies of bank institutions. The first paper highlights the existing literature: conducting a literature search process, the paper aggregates 102 empirical results from 28 journal articles and working papers published between 1990 and 2017. The meta-analysis focuses on how researchers address the build-in issue that outsiders are not randomly assigned to firms. The results reveal that the relationship of outside successions and performance varies significantly with the methodological characteristics of the original studies. The following two papers concentrate on successions in banking institutions. More specifically, the second study examines the appointments of executive directors external to the bank and the consequences of that appointment on bank performance. The study addresses in particular alternative explanations, i.e. outside selection and/or joint endogeneity, while examining external executive appointments and their consequences on bank performance. The second empirical paper lend significant support to the view that some outsiders are better predisposed to helping the bank turn around poor performance and that the selected proxies of managerial ability, which are based on the historical return on assets and risk-return efficiency measured at outsiders' former banks, are able to identify such good outsiders. Finally, the third paper considers the link between the executive and the supervisory board. The study points to the conclusion that newly appointed executives to the supervisory board differ from their non-appointed counterparts with a particular set of experiences. The study provides evidence for the view that the pre-appointment financial situation, measured by several proxies of bank risk and performance, has significant influence on the decision to appoint such an experienced member to the supervisory board. This dissertation is framed by an introduction and concluding chapter where the author reflects on the research questions of her empirical studies, summarizes the results and identifies some possibilities for future research.
Expatriate success divided into two criteria, expatriate adjustment and expatriate job performance, is analyzed in relation to extraversion and its facets. Measurements of the Big Five and scales of adjustment as well as job performance were used by interviewing a sample of 80 German, Austrian and Swiss expatriates working in Costa Rica. The overall extraversion trait, gregariousness, assertiveness, and activity show meaningful effects on expatriate job performance. By analyzing expatriate adjustment and its relationship with extraversion and corresponding facets moderate effects were found between activity and interaction adjustment. Positive emotions with interaction adjustment as well as positive emotions with general adjustment show the largest effects. Furthermore, small effects were found for activity and warmth in respect to expatriate adjustment. Finally, suggestions for further research concerning extraversion in expatriate management are given.
To be prepared for one´s own career is a major task during career development. However, existing research has primarily focused on adolescence in the transition from school to work while research on career preparation among university students, that are challenged by successfully transiting from university to work, are lacking so far. Thus, this cumulative dissertation studies career preparation in terms of career decidedness, planning, confidence, and career engagement using large samples of German university students and alumni as well as a variety of quantitative methods like latent state-trait analysis, cross-lagged analysis, and mediation analysis with multiple mediators. In the first paper, the stable component of career indecision is investigated with longitudinal data stemming from two samples with different time lags (Sample 1: N = 363, 7 weeks; Sample 2: N = 591, 6 months). Furthermore, the combined and unique effects of career indecisiveness and generalized indecisiveness on life satisfaction are examined using a sample consisting of 469 university students. Results indicate that career indecision is determined by a stable component (i.e., trait career indecisiveness) that is associated with lower core self-evaluations, lower occupational self-efficacy, and higher perception of career barriers. Additionally, results indicate that the stable career indecision component explains 5% of the variance in student life satisfaction beyond self-evaluated generalized indecisiveness. The second paper deals with the relationships of vocational interest characteristics - interest congruence, interest differentiation, and general interest level (elevation) - with several indicators of career preparedness (i.e., career planning, occupational self-efficacy beliefs, career decidedness, and career engagement) among a sample of 239 university students. Controlling for sociodemographic variables, multiple regression analyses revealed that differentiation is positively associated with career decidedness and career engagement and elevation is positively related to occupational self-efficacy beliefs and career engagement. The third paper investigates how protean career orientation (PCO) is related to vocational identity clarity and occupational self-efficacy. Study 1 reports a 1-year, three-wave cross-lagged study among 563 university students and established that PCO preceded changes in identity and self-efficacy - but not the other way around. Based on a 6-month longitudinal study of 202 employees, Study 2 shows that identity clarity and self-efficacy mediated the effects of PCO on career satisfaction and proactive career behaviors. PCO only possessed incremental predictive validity regarding proactive career behaviors. However, specific direct or mediated effects of PCO on job satisfaction could not be confirmed. The fourth paper explores the relationships between narcissism and two indicators of career success (i.e., salary and career satisfaction) among a group of young professionals (N = 314). A model proposing that the effect of narcissism on career success is mediated by increased occupational self-efficacy beliefs and career engagement was assessed. While correlations between narcissism and the two indicators of career success were minimal, the results show a significant indirect effect on salary via occupational self-efficacy and indirect effects on career satisfaction via self-efficacy and career engagement. Overall, the different studies corroborate the crucial role of career preparation for a successful start into working life. In sum, this dissertation contributes to literature on vocational psychology by providing novel insights in terms of facilitators and outcomes of career preparation among university students and graduates. Theoretical and practical implications are discussed, and promising directions for future research are identified.
The global coffee market is connected to many sustainability issues like the persisting poverty of coffee farmers, and degrading ecosystems. Many interventions, from state-led regulation to industry-led certification processes, exist, that try to change global value chains to shift societies back on more sustainable trajectories. To this date, it is still under debate if these interventions are an effective means to change global value chains. With climate change and persisting issues of social justice as strong accelerators, calls are increasingly made for a radical transformation of global production and consumption patterns. Many frameworks try to inform research and real-world policies for a transformation of global value chains. In this dissertation, the author uses the framework of the practical, political and personal sphere proposed by O'Brien and Sygna (2013) highlighting that the interactions between these three spheres bare the greatest potential for a transformation towards sustainability. However, in this dissertation, the author argues that it is exactly at the nexus between the three spheres of transformation where barriers towards a fundamental shift of systems occur. He, therefore, uses three perspectives to bring empirical nuance to the problems that arise on the interplay between the different spheres of transformation. (1) The scientific perspective: using a systematic review of alternative trade arrangements; (2) the producer perspective: facilitating a participatory network analysis of social-ecological challenges of Ugandan coffee farmers and their adaptive management practices; (3) the consumer perspective: through the use of a German consumer survey and a structural equation model to investigate into the Knowledge-Doing-Gap end-consumers are facing. Through the results from the scientific perspective, the author is able to show that most of the research is investigating the certified market and that the effectiveness of labels rarely exceeding the practical sphere. His empirical research on the producer perspective highlights that Ugandan coffee farmers facilitate a variety of on-farm crop management (practical sphere) but their support structures rarely exceed informal exchange with neighboring communities (political sphere). Exchange with governmental actors and global traders is happening but has been assessed as not sufficient to cope with the social-ecological challenges the producers are facing. Through the results of the consumer perspective, the author is able to highlight that even though end-consumers have pro-sustainable attitudes (personal sphere) they are facing situational constraints (political sphere) that create a gap between their attitudes and the respective behavior. Using these empirical insights about drivers and barriers for a transformation he proposes that frameworks, aiming to inform research and policies, need to include two aspects: (1) the notion of a forced transformation; and (2) the translational capacity of the frameworks to create meaningful interdisciplinary discourses in different contexts. The author, therefore, propose two approaches:(1) a fourth sphere, called the "planetary force" to include the notion of a forced transformation that is already happening in different contexts, highlighted by the producer perspective in this dissertation; and (2) the consequent use of methods that create interdisciplinary exchange and rigorous testing.
Uranine (sodium fluorescein, UR) has been routinely used in hydrological research to monitor surface and subsurface water flow, transport and mixing processes since the end of nineteenth century. Based on such obtained data, further conclusions can be drawn on the spread and behavior of pollutants (partly on models). Use of UR for qualitative (visual) studies of underground contamination is common, however data available on its environmental behavior (e.g., conversion, degradation or formation and fate of the transformation products, TPs) are incomplete or not readily comparable. UR observations of biodegradation are still speculative. S-metolachlor (SM) is a popular worldwide chloroacetamide herbicide, which highly correspond to the global pesticide use. It is offered on the French market as an effective multicrop herbicide against annual grasses and certain broadleaf weeds under the trade name Mercantor Gold (MG). Photodegradation contributes to the fate of SM in the aquatic environment. TPs were already found in surface and groundwater. However, further fate and assessment of the TPs was not done. Moreover, adjuvants in MG´s formula can affect the solubility, biodegradation, photolysis and sorption properties of the active compound SM. TPs can have different properties (e.g. more mobile, toxic or present at higher concentrations) that enable them to reach the environmental compartments not affected by the parent compound (PC) itself. To assess the ecological impact of pesticides, tracers, and their respective TPs on water organisms, their behavior can be investigated in laboratory screening biodegradation tests. Yet, incomplete data was available on SM, MG and UR transformation or their photo- TPs´ fate in surface and water-sediment systems. The combination of photolysis with aerobic biodegradation in order to identify persistent photo-TPs could provide new insight into the environmental behavior of the selected compounds. Therefore, principle of this thesis was to 1) identify the impact of MG´s adjuvants on the biodegradation, photolysis (Xe lamp) and sorption compared to the SM alone, 2) examine the photolysis and biodegradability of UR 3) monitor the primary elimination (photolysis) of the PCs by HPLC (-UV, -FLD) and measure the degree of mineralization by means of nonpurgeable organic carbon (NPOC) 4) elucidate the photo-TPs of SM, MG and UR by using LCMS/ MS 5) analyze biodegradability of the photo-TPs in order to determine their fate and persistence in aquatic environment 6) conduct in silico toxicity predictions (pesticides) in human (carcinogenicity, genotoxicity and mutagenicity) and eco-toxicity (microtoxicity, bioconcentration factor and toxicity in rainbow trouts). SM, MG and UR were found not readily biodegradable in Closed Bottle test (CBT), Manometric Respiratory test (MRT) and in water-sediment test (WST). Chemical analysis of photolysis samples showed higher elimination of SM in MG compared to SM alone whereas UR displayed high primary elimination rate in general. The overall low degree of mineralization indicated that abundant photo-TPs were formed. Furthermore, the photo-TPs were found not biodegradable in performed biodegradation tests. Only small degradation rates for UR could be observed in the CBT and WST. Additionally, in the MRT and WST new bio-TPs were generated from the photo-TPs of SM and SM in MG. Obtained results suggest that the MG formulation did not significantly affect the biodegradation, however it influenced the diffusion of the active substance (SM) to sediment and potentially affected the photolysis efficiency, which might result in faster formation of photo-TPs in the environment. In silico predictions showed that for many endpoints, biotransformation might lead to an increased toxicity in humans and to water organisms compared with the parent compound SM. No indications were found for UR toxicity. Still, target-oriented investigations on long term impacts of photo-TPs from UR are warranted. The present work demonstrates that a combination of laboratory tests, analytical analysis and in silico tools result in valuable information regarding environmental fate of the TPs from selected compounds. Furthermore, it was shown that photo-TPs formed in the aquatic environment should be taken into account not only the parent compound and its decay.
The principle of this thesis was to study the environmental fate of three highly used psychotropic drugs and this achieved through: 1) examining the biodegradability of TMI, DMI and CPTX, 2) studying the behaviour of TMP, DMI and CPTX in photodegradation tests using Xe and UV lamps with studying the effect of different environmental conditions on their UV-photodegradation behaviour, 3) monitoring the primary elimination of TMP, DMI and CPTX during photodegradation and biodegradation tests using HPLC, and measuring their degree of mineralization by means of dissolved organic carbon analyser (DOC), 4) elucidating the structures of the transformation products (TPs) which formed during the degradation of TMI, DMI and CPTX by using LC-MS/MS analysis, 5) analysing the biodegradability of their TPs by laboratory tests and in-silico assessments in order to determine the fate and persistence of these TPs in the aquatic environment, 6) conducting in-silico toxicity predictions for the selected psychotropic drugs and their TPs in human (carcinogenicity, genotoxicity and mutagenicity) and in eco-system (toxicity to microorganisms and toxicity in rainbow trouts). As an overall conclusion, the present work demonstrates that a combination of laboratory simulation tests, LC-MS/MS analysis and in-silico tools result in valuable new information regarding environmental fate of three important psychotropic drugs and their TPs. This dissertation also highlights that different environmental conditions such as temperature, initial drug concentration and pH can differently affect the degradation behaviour of pharmaceuticals even when they are highly structurally related. Therefore, one cannot conclude from one pharmaceutical to another but each one needs to be investigated individually and this present a great challenge for risk assessment kinetics of chemicals in the aquatic environment. The results presented here showed that the investigated pharmaceuticals and their TPs can negatively affect the environment which may be harmful to the ecosystem as they might have been present for decades in the aquatic environment without any knowledge of their environmental fate or connected risk. Therefore, further work needs to be done including analysis of environmental samples (e.g., surface waters), as well as laboratory toxicity tests to further expand knowledge on their exact environmental impact.