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Anstelle von Untersuchungen zum fachbezogenen professionellen Handeln und zur fachlich-didaktischen Expertise der Lehrkräfte offenbart sich ein 'weißer Fleck' auf der Landkarte. In dieser Arbeit wird die These vertreten, dass sich an dieser Stelle ein besonderer 'Ansatzpunkt' findet, Unterricht zu verbessern. Das mag zunächst nur für einen Teilausschnitt aus dem Spektrum von Schule und Unterricht gelten: Für den Mathematikunterricht in der vierten Klasse der Grundschule. Aber aus der Beschäftigung mit diesem Teilausschnitt dürften sich Schlussfolgerungen ziehen lassen, die auch für die von den genannten interkulturellen Vergleichsstudien betrachteten Zusammenhänge durchaus Schlussfolgerungen für Gründe und Verbesserungschancen ermöglichen.
The smallholder-dominated landscapes of southwestern Ethiopia support a unique biodiversity with great importance to local livelihoods and high global conservation value. These landscapes, however, are severely threatened by deforestation, forest degradation and the adverse effects of farmland management regimes. These changes have fundamentally altered the structure of the landscapes and threaten their biodiversity and ecosystem services. Managing biodiversity and related services in such rapidly changing landscapes requires a thorough understanding of the effects of land use change and the reliance of local communities on biodiversity. This dissertation examines woody plant biodiversity patterns and services and presents several recommendations regarding biodiversity and multiple ecosystem services in smallholder-dominated landscapes of southwestern Ethiopia. Using a social-ecological systems approach, the author conducted four studies on the complex interactions of local people and woody plant diversity. First, he investigated the effects of human-induced forest degradation on woody plant species. His results suggest that forest biodiversity has been affected by the combined effects of coffee management intensity, landscape context and history at the local and landscape level. Specifically, richness of forest specialist species significantly has decreased with coffee management intensity and in secondary compared to old growth forests, but increased with current distance from forest edge in both primary and secondary forests. These findings highlight the need to maintain undisturbed forest sites to conserve forest biodiversity. Second, the author examined legacy effects of past agricultural land use on woody plant biodiversity. The results show that historical distance seems to be the most important variable affecting woody plant composition and distribution in farmland sections of the landscapes. The author found evidence for immigration credits for generalist and pioneer species but not for extinction debts for forest specialist species which might be rapidly paid off in farmland. The results suggest not only an unrecognized conservation value of old farmland but also a disturbing loss of forest specialist species. To slow this trend, it is necessary to shift to a cultural landscape development approach and to restore forest specialist species in the landscapes. Third, the author evaluated the supply of potential multiple ecosystem services and the relationships between the diversity of woody plant and ecosystem service in the three major land use types, namely forests with and without coffee management and farmland. The results revealed a high multifunctionality of landscapes and showed that ecosystem services significantly increase with woody plant diversity in all types of land use. These findings suggest that the woody plant diversity and multifunctionality in southwestern Ethiopian landscapes has to be maintained. Fourth, the author explored farmers' woody plant use to assess their dependency on and maintenance of woody plants and also considered the influence of property rights and management in this context. He found that local farmers used 95 species for eleven major purposes from all major land uses across the landscapes. He also found that most of the widely used tree species regenerated successfully throughout the landscapes, including in farmland. Local people felt, however, that their property and tree use rights were limited, especially in forests, and that some of the most widely used plant species, including important timber species, appeared to have been overharvested in forests. The results suggest that many species are important for local livelihoods, but a perceived low sense of property rights also seems to adversely affect the management of woody plants, particularly in forests. By focusing on woody plants and their ecosystem services to local people, this dissertation documents a dramatic loss of native forest biodiversity and rapid changes in the cultural landscapes of southwestern Ethiopia. Overall, the findings suggest the need for preservation of intact forest sites and for cultural landscapes development to safeguard biodiversity and multifunctionality of the landscapes in the future. This, in turn, requires holistic and integrated approaches that involve local people and recognize their basic needs of woody plants and their property rights to foster the management of biodiversity and ecosystem services. Maintaining primary forests in and using cultural landscape approaches to the rapidly changing rural setting of southwestern Ethiopia would also contribute to the global effort to halt biodiversity loss.
In this dissertation the relation between time headway in car following and the subjective experience of a driver was researched. Three experiments were conducted in a driving simulator. Time headways in a range of 0.5 to 4.0 seconds were investigated at 50km/h, 100km/h, and 150km/h under varied visibility conditions and at differing levels of driver control over the car. The main research questions addressed the possible existence of a threshold effect for the subjective experience of time headways and the influence of vehicle speed, forward visibility, and vehicle control on the position of time headway thresholds. Furthermore, the validity of zero-risk driver behavior models was investigated. Results suggest that a threshold exists for the subjective experience of time headways in car following. This implies that the subjective experience of time headways stays constant for a range of time headways above a critical threshold. The subjective experience of a driver is only influenced by time headway once this critical time headway threshold is passed. Speed does not influence preferred time headway distances in self- and assisted-driving, i.e. time headway thresholds are constant for different speeds. However, in completely automated driving preferred time headways are influenced by vehicle speed. For higher speeds preferred time headways decrease. A reduction of forward visibility leads to a shift in preferred time headways towards larger time headways. Results of this dissertation give credence to zero-risk models of driver behavior.
Die gleichberechtigte Teilhabe geflüchteter Familien an frühpädagogischen Angeboten ist erklärtes integrationspolitisches Ziel. Es gibt Hinweise darauf, dass diese besonderen Herausforderungen unterliegt und dass freiwillig Engagierte dabei häufig involviert sind. Dabei ist wenig über die Dynamiken bekannt, wie freiwillig Engagierte geflüchtete Familien im Bereich der frühkindlichen Bildung, Betreuung und Erziehung begleiten, insbesondere aus Perspektive von geflüchteten Eltern und ihren Begleitern. Vor diesem Hintergrund hat die vorliegende kumulative Dissertation das Ziel, durch die sinnverstehende Herausarbeitung von Deutungen der Begleiter und geflüchteten Eltern zu einem besseren Verständnis der durch freiwilliges Engagement begleiteten Teilhabe geflüchteter Familien an frühpädagogischen Angeboten beizutragen. Die Dissertation begreift freiwillig Engagierte als "Koproduzenten" von integrationspolitischen Zielen. Auf Grundlage von 34 Interviews mit Engagierten, Koordinatoren und geflüchteten Eltern, welche in neun Kommunen in Niedersachsen geführt wurden, wurden in drei Artikeln die folgenden Schwerpunkte bearbeitet: Deutungen der Zusammenarbeit zwischen zivilgesellschaftlichen und staatlichen Akteuren durch die Begleitern durch Anbindung an das Konzept Koproduktion (Artikel 1), Deutungen von Problemen und Lösungen durch die Begleitern anknüpfend an die Konzepte Vulnerabilität und Agency (Artikel 2) sowie Deutungen der Eltern als Zielgruppe, mit Blick auf deren Aufbau von Vertrauen gegenüber frühpädagogischen Angeboten (Artikel 3). Die Dissertation leistet dadurch einen wissenschaftlichen Beitrag zu Dynamiken der Umsetzung von Policies, wenn zivilgesellschaftliches Engagement dabei eine zentrale Funktion einnimmt, sowie zur Umsetzung integrationspolitischer Ziele im konkreten Bereich der Nutzung frühpädagogischer Angebote durch geflüchtete Familien. Es zeigt sich, dass freiwillig Engagierte zwar staatliche Akteuren ergänzen und damit maßgeblich zur Umsetzung integrationspolitischer Ziele beitragen. Gleichzeitig deutet dies aber auf strukturelle Hürden hin und wirft die Frage auf, inwieweit das freiwillige Engagement hier die Verantwortung für staatliche Aufgaben übernimmt. Dabei treten in der Zusammenarbeit zwischen zivilgesellschaftlichen und staatlichen Akteuren häufig Konflikte auf, welche auf divergierende Deutungen des Begriffs "Integration" und eine fehlende Ausdefinition konkreter sich aus den integrationspolitischen Zielen ableitender Bedarfe beruhen.
Systemprotest! Die Arbeit handelt von Kommunikation. Über Systeme, Schemata, Qualität, Nachhaltigkeit, Erziehung und Bildung für nachhaltige Entwicklung. Die Arbeit handelt von der Frage, was gute Bildung für nachhaltige Entwicklung ist. Die Arbeit handelt von den vielen Problemen die auftreten, wenn man solche Fragen stellt. Die Arbeit handelt von Auswegen aus den vielen Problemen, die sich aber erst dann zeigen, wenn man nicht nach ihnen sucht.
This cumulative dissertation investigates food policy councils (FPCs) as potential levers for sustainability transformation. The four research papers included here on this recent phenomenon in Germany present new insights regarding the process of FPCs' emergence (Emergence paper), the legal conditions which affect their establishment (Legal paper), the different roles of FPCs in policy-making processes (Roles paper) and FPCs' potential to democratise the food system (Food democracy paper). Drawing on and contextualizing the results of the four individual studies, the framework paper uses the leverage points concept originally developed by Meadows (1999) and adopted by Abson et al. (2016) as a lens to discuss FPCs’ potential as levers for sustainability transformation. This conceptual background includes three so-called realms of leverage, which are considered to be of particular importance in transformational, solution-oriented sustainability science: first, the change, stability and learning in institutions (re-structure), second, the interactions between people and nature (re-connect) and third, the ways in which knowledge is produced and used (re-think). Framing the findings of the four research papers in terms of these three realms, the framework paper shows that FPCs could serve as cross realm levers, i.e. as interventions that simultaneously address knowledge production, institutional reform and human-nature interactions.
Diese Arbeit untersucht, wie die massenhafte Verbreitung von Web Videos das Verhältnis von audiovisueller Zeugenschaft und medialem Ereignis beeinflusst: Wie lässt sich das Zusammenspiel von Medien, sozialer Dynamik und Ereignissen beschreiben? Was wird wann unter welchen (medialen) Bedingungen wie zum Ereignis? Wer hat die Deutungshoheit über dieses Ereignis und wie erlangt man sie? Gibt es privilegierte Formen der Zeugenschaft? Und unter welchen Umständen haben diese Zeugnisse politische Relevanz? Keine dieser Fragen ist neu und dennoch stellen sie sich in digitalen Kulturen mit neuer Dringlichkeit und Bedeutung. Denn durch die Proliferation medialer Produktions- und Rezeptionspraktiken sowie die Medialisierung der Distribution multiplizieren Social Media-Plattformen ästhetische, narrative und institutionelle Kontextualisierungsprozesse von Ereignissen. Dies vergrößert mediale Partizipationsmöglichkeiten, geht aber zugleich einher mit Glaubwürdigkeits- respektive Geltungsverlusten herrschender sozialer Akteure und medialer Formen. Die daraus resultierenden medialen wie sozialen Repräsentationskrisen destabilisieren das Feld medialer Zeugenschaft. Sie bilden aber zugleich auch einen Resonanzboden für "Kritische Medienereignisse". Unter diesem Titel entwirft die Arbeit ein Konzept sozio-medialer Ereignisse, das weder Medien und Ereignis gegeneinander ausspielt noch das Ereignis zum massenmedialen Genre degradiert. Stattdessen erfasst der Begriff soziale und medienästhetische Dynamiken in einem gleichberechtigten Zusammenspiel. Dahinter steht die durch den Vergleich von Rainer Leschkes Theorie medialer Formen mit Pierre Bourdieus Praxistheorie gestützte Annahme, dass mediale und soziale Formen mehr miteinander gemeinsam haben, als es unversöhnliche Gegenüberstellungen von medialem und sozialem Apriori vermuten lassen. [Im Sinne einer medienmorphologisch geschulten Bourdieu-Lektüre kann dann von kritischen Medienereignissen die Rede sein, wenn ähnlich gelagerte Krisen in sozialen Kräfte- und medialen Formenfeldern zeitgleich eskalieren - wie es gegenwärtig im doppelten Glaubwürdigkeitsverlust politischer Repräsentanten (Akteuren) und medialer Repräsentationen (Formen) zu beobachten ist. Es handelt sich hierbei nicht deshalb um Medienereignisse, weil sie durch Medien repräsentiert werden, sondern vielmehr deshalb, weil sie der öffentlich sichtbare Ausdruck medialer Umbrüche sind, in denen soziale und mediale Felddynamiken synchronisiert werden und die Neuaufteilung des Sinnlichen mit der des Sozialen zusammenfällt. In diesem Zusammenhang spielen Web Videos deswegen eine privilegierte Rolle, weil sie als audiovisuelle und kommunikative Prothesen sowohl den Handlungsspielraum von Augenzeugen erweitern als auch das Publikum auf eine neue Art und Weise adressieren und einbinden. Man ist nicht länger nur distanzierte Beobachter einer Live-Berichterstattung, sondern wirkt aktiv mit am Geschehen und dessen Beglaubigung. Diese neuen, partizipativen Formen der Zeugenschaft erschöpfen sich somit nicht in einer dokumentarischen Funktion, sondern fordern immer auch zur Teilnahme am jeweiligen Ereignis auf. Sie zeichnen sich dabei durch eine radikal subjektive Ästhetik der Authentizität aus, die weniger auf Objektivität als auf affektive Mobilisierung abzielt. Web Videos verändern auf diese Weise das etablierte Kräfte- und Vertrauensverhältnis im soziomedialen Feld der Zeugenschaft in epistemologischer, ethischer und politischer Hinsicht, weil sie dieses Feld für (neue) Formen und Akteure öffnen, die mehr oder weniger bewusst die hegemoniale Position massenmedialer Institutionen und Formen in Frage stellen. Diese Erschütterungen der sozio-ästhetischen Ordnung im Feld der Zeugenschaft offenbaren einen grundsätzlich politischen Gehalt von Web Videos, der immer dann explizit hervortritt, wenn Web Videos Widerspruch und Protest gegen die herrschenden Verhältnisse artikulieren. In kritischen Medienereignissen wie der (gescheiterten) Grünen Revolution in Iran wird daher das politische Potential von Web Videos aktualisiert und situativ beschreibbar. Web Videos machen ihre Betrachter somit in einem doppelten Sinn zu Zeugen: Erstens dokumentieren sie ein Geschehen und geben somit der Synchronisation feldspezifischer Krisen des Sozialen und Medialen eine anschauliche mediale Form. Zweitens fungieren sie als Formen des symbolischen Austauschs, die an der Umwertung des symbolischen Kapitals in medialen und sozialen Feldern entscheidend mitwirken. Weil sie somit zugleich Ausdruck wie Katalysatoren dieser Legitimitätsverluste sind, fungieren sie gegenwärtig als ebenso umstrittene wie privilegierte Zeugnisse kritischer Medienereignisse.
Bewusst oder unbewusst wird in der Betriebswirtschaftslehre in vielfacher Weise auf gedankliche Vorgehensweisen und Begrifflichkeiten des Militärs zurückgegriffen, um Sachverhalte oder Handlungsalternativen auszudrücken. Sowohl mit der wirtschaftlichen Seite bekannt, als auch mit der militärischen Seite beschäftigt, ist der Begriff des "Interessenbereichs" in das Zentrum meines Interesses gerückt. Die militärische Verwendung des Interessenbereichs sowohl explizit als auch implizit ist dabei so gebräuchlich, dass zunächst eine weitere Beachtung meinerseits unterblieb, es sich jedoch rasch zeigte, dass auch hier Denkansätze für die Bewältigung betriebswirtschaftlicher Problemstellungen möglicherweise zu nutzen sind.
Online advertising has become one of the most important dimension of corporate communications. In recent years, a new form of advertising on the Internet has emerged: real-time advertising. Among others, it allows companies to identify potential customers and target them with respect to their interests. In this way, real-time advertising can increase advertising effectiveness and it could, at the same time, improve user experience. With the emerge of this new form of advertising, statistical models have become even more important because they are now being increasingly used to predict online user behavior. The articles included in this dissertation analyze user-level clickstream data generated during multi-channel advertising campaigns (including TV advertising) and during real-time auctions. The goal of the analyses conducted here is to better understand advertising effects and to support decision-making in this context. Most of the analyses are based on Bayesian models. These models allow for a very flexible structure, which enables researchers to model, for instance, heterogeneity across different types of users or non-linear parameters such as users´ reaction times and exponential decay of advertising effects. In addition, these models allow for the inclusion of prior knowledge of parameter distributions, and, therefore, they are well suited for iterative analyses based on clickstream data. Bayesian models can be evaluated in different ways. Instead of only relying on statistical metrics, the articles included in this dissertation aim to estimate the economic value of these models based on their predictive performance. Although this measure can only approximate their true economic value, this approach can be used to compare and evaluate different models and to illustrate the impact of predictive analyses for companies in the context of big data. This dissertation contributes to both information systems research and marketing research and has many managerial implications. First, a process is developed to determine optimal sample sizes representing the best balance between computational costs and predictive accuracy in e-commerce in particular and big data contexts in general. In practice, this process can be used to reduce infrastructure and computational costs. Second, the articles included here describe models that can be used to measure the impact of television ads on users' online shopping behavior. The models can provide insights concerning the effectiveness of individual television ads, the interactions between different advertising channels and the difference in user behavior of TV-induced customers and their non-TV-induced counterparts. Thereby, the models could support decision-making with respect to future advertising campaigns and targeting. Third, the articles describe several possibilities to extend and improve decision support systems currently used in e-commerce and marketing. These improvements enable practitioners to predict users´ interests for arbitrary products and services by using corresponding websites as dependent variables. This approach can be used to improve the effectiveness of real-time advertising campaigns, especially those intended to raise brand awareness among customers.
In response to the challenges of the energy transition, the German electricity network is subjected to a process of substantial transformation. Considering the long latency periods and lifetimes of electricity grid infrastructure projects, it is more cost-efficient to combine this need for transformation with the need to adapt the grid to future climate conditions. This study proposes the spatially varying risk of electricity grid outages as a guiding principle to determine optimal levels of security of electricity supply. Therefore, not only projections of future changes in the likelihood of impacts on the grid infrastructure were analyzed, but also the monetary consequences of an interruption. Since the windthrow of trees was identified a major source for atmospherically induced grid outages, a windthrow index was developed, to regionally assess the climatic conditions for windthrow. Further, a concept referred to as Value of Lost Grid was proposed to quantify the impacts related to interruptions of the distribution grid. In combination, the two approaches enabled to identify grid entities, which are of comparably high economic value and subjected to a comparably high likelihood of windthrow under future climate conditions. These are primarily located in the mid-range mountain areas of North-Rhine Westphalia, Baden-Württemberg and Bavaria. In comparison to other areas of less risk, the higher risk in these areas should be reflected in comparably more resilient network structures, such as buried lines instead of overheadlines, or more comprehensive efforts to prevent grid interruptions, such as structural reinforcements of pylons or improved vegetation management along the power lines. In addition, the outcomes provide the basis for a selection of regions which should be subjected to a more regionally focused analysis inquiring spatial differences (with respect to the identified coincidence of high windthrow likelihoods and high economic importance of the grid) among individual power lines or sections of a distribution network.
This dissertation deals with the investigation of success factors in the field of entrepreneurship, especially entrepreneurship training, from a psychological perspective. In particular, I argue that the identification of certain psychological aspects helps to better understand the underlying mechanisms for successful entrepreneurship trainings and thus, enables successful entrepreneurship. In the second chapter I theoretically examined planning as a fundamental action an entrepreneur hast to undertake in order to succeed. Scholars are in disagreement about the question if planning is crucial for the entrepreneurship. Thus, I provide a comprehensive overview of the advantages and disadvantages of planning in entrepreneurship from a psychological perspective. I explain negative aspects (e.g., lack of knowledge, difficulty to predict the future, and inflexibility) as well as positive aspects (e.g., legitimating, action-regulatory, and learning function) about planning in entrepreneurship. Furthermore, I develop a theoretical model that combines both the positive and negative aspects of planning in entrepreneurship. With this theoretical model, I integrate different types of planning (e.g., formal and informal plans) as well as positive and negative functions of planning (e.g., learning or stickiness, inflexibility) to provide a first approximation for a theory of entrepreneurial planning. In the third chapter, to focus on the field of entrepreneurial trainings, I empirically examine the under-researched field of the relation between trainer and trainee. I use the transformational leadership theory (Bass, 1985) and a theory of learning outcome (Kraiger, Ford, & Salas, 1993), to hypothesize that the trainers´ charisma has a positive effect on the trainees´ entrepreneurial self-efficacy. Additionally, I search for possible moderators for the hypothesized trainer-trainee-relationship in an explorative manner, using insight from different research areas (e.g., pedagogy, philosophy). To test the hypotheses, I conducted a 12-week entrepreneurship training by which I had 12 measurement waves across four classes with 161 students and 12 trainers, which lead to 919 observations. In the fourth chapter, to broaden the perspective on the mechanisms within entrepreneurship training, which lead to a successful outcome, I empirically examined the short- and long-term effects of entrepreneurship training on life satisfaction. To do so, I developed a theoretical model based on theories of life satisfaction, that explain the underlying mechanisms of the short- and long-term effects of the entrepreneurship training on life satisfaction. With this model I hypothesize, that entrepreneurship training has a positive short- effect on life satisfaction, which is mediated through entrepreneurial self-efficacy. I furthermore hypothesize, that the long-term effect of the entrepreneurship training is mediated through self-employment. The short term-effect acts like a boost and vanishes over time, whereas the long-term effect holds in the long run. To test these hypotheses, I conducted entrepreneurship training as part of a randomized controlled field experiment with five measurement waves over a total period of 2.5 years. Using discontinuous growth modeling to take into account the temporality of our hypothesized effects we statistically analyzed the 1,092 observations from 312 students. Chapter 5 concludes this dissertation with general discussion of the three chapters.
The objective of the work described in this thesis is to improve our understanding of factors that affect the depletion of gaseous elemental mercury (GEM) from the atmosphere during the Arctic springtime. This was accomplished through research undertaken and described in three publications. Atmospheric mercury depletion events (AMDEs) are now an established phenomenon in the high Arctic whereby the long-lived GEM is oxidized in the air through a series of photochemically-initiated reactions involving halogens and ozone. This chemistry produces reactive gaseous mercury (RGM) and particulate bound mercury (PHg) which both have shorter atmospheric residence times than GEM and deposit more readily to the snow and ice surfaces. This is a means by which mercury can be transferred from the atmosphere to the Arctic environment that was unknown prior to 1995 when AMDEs were discovered. An extensive review paper was completed that summarizes mercury work in the high Arctic in the ten years following the discovery of AMDEs. This review was followed by two papers investigating the processes around atmospheric mercury in the Arctic springtime
In der vorliegenden Arbeit werden Untersuchungsergebnisse von niedersächsischen Gewässern auf Triphenylzinn (TPT) präsentiert. Betrachtet werden die Matrices Wasser, Schwebstoff, Sediment und aquatische Organismen, wie Makrozoobenthos und Fische, um eine möglichst umfassende Aussage hinsichtlich des Akkumulationsverhaltens von TPT zu erhalten. Da TPT ein ähnlich endokrin wirksames Potential wie Tributylzinn (TBT) aufweist, über TBT aber wesentlich mehr Informationen und Erkenntnisse als über TPT vorliegen, sind zudem vergleichende Betrachtungen zwischen diesen beiden Organozinnspezies angestellt worden. Die wichtigsten Aussagen dieser Arbeit sind, dass sich TPT in den Kompartimenten Wasser, Schwebstoff und Sediment unauffällig verhält, es jedoch über ein sehr hohes Bioakkumulationsverhalten verfügt. Aus diesen Ergebnissen ist zu fordern, dass Gewässerüberwachungsprogramme unbedingt um die Stufe eines Biomonitorings, in dem aquatische Organismen als Endglieder der Nahrungskette auf Schadstoffe untersucht werden, zu erweitern sind.
Woman, Stand Straight: An Integrated Lutheran Feminist Theological Concept of Human Flourishing
(2022)
Beginning with the theology of Martin Luther and drawing on a selection of feminist theologians, this thesis proposes a relational, agential model of human flourishing. It is rooted in Luther's doctrines of the hiddenness of God and of God’s alien and proper work in the lives of believers. Such an approach gives rise to questions concerning human freedom and agency, sin, and the nature of our relationship with God and with other persons. Many feminist theologies provide an inadequate account of sin and its effects on the person and their relationships. This thesis asserts that taking sin and its effects seriously is essential to developing a secure and healthy self, and a healthy relationship with God and other persons. It therefore proposes a reworked understanding of religious incurvature as a relational model of sin which supports the goal of human flourishing. This concept of the self curved either inwards, or towards another, speaks to the nature of sin in its traditional understanding of sin as pride, as well as addressing feminist criticisms that the notion of sin as pride is not relevant to the needs and experiences of women. The model of human flourishing proposed here is specifically Christian in its assertion that we do not exist as persons, are not fully human, without our being in relationship with the triune God and other created persons. We flourish in community. Further, it supports the idea that true Christian freedom consists of a life dedicated to service of God and others.
This doctoral thesis contributes to the vibrant discourse on boundary-crossing collaboration in the German teacher education system. It offers theoretical advancements, programmatic guidelines, and empirical findings which advocate for a transdisciplinary perspective. In order to do so, the framing paper critically links persistent challenges and current reform processes in the teacher education system with theoretical foundations and conceptual positions of transdisciplinarity. Against this backdrop, four articles provide further insights on: a) how to expand the prevalent systematic of innovation and transfer approaches (top-down, bottom-up, cooperative) by a transdisciplinary perspective, b) outlining guiding principles for the realization of transdisciplinary collaboration in the context of a boundary-crossing research and development project, c) providing empirical findings on effect relationships between transdisciplinary dimensions of integration characteristics, and d) identifying empirical types of actors based on specific assessment patterns towards these characteristics.
Hochtemperatur-Aquiferwärmespeicher erleichtern Wärmesystemen durch eine saisonale Lastverschiebung die Erschließung und Integration von erneuerbaren Wärmequellen. Ein mittleres Temperaturniveau von >50 Grad Celsius ermöglicht zumeist eine direkte Entladung ohne einen anschließenden Temperaturhub über eine Wärmepumpe. Aufgrund der thermischen Trägheit von ATES-Systemen ist die Berücksichtigung von Lastfalländerungen durch jährlich variierende Lastprofile besonders in der Einschwingphase sinnvoll. Da es bis zu 20 Jahre dauern kann, bis der Aquifer einen quasistationären Zustand erreicht, konnte in Langzeitstudien ein großer Einfluss von unterschiedlichen Lastprofilen auf energetische und finanzielle Simulationsergebnisse nachgewiesen werden. Zur Verbesserung der Investitionsplanung wurde ein Verfahren entwickelt, das sowohl die Prognosefähigkeit als auch die Prognosegenauigkeit von Energiesystem- und Wirtschaftlichkeitsanalysen erhöht, indem über einen wahrscheinlichkeitsbasierten Ansatz (Monte-Carlo-Temperaturschätzung) Normalverteilungsfunktionen für gewünschte Auswertungsgrößen (z.B. Kapitalwert) abgeleitet werden können. Aus 2000 Simulationsjahren wurde über konzeptspezifische Verteilungsfunktionen der wahrscheinlichste Eintrittsfall abgeleitet und zu einem repräsentativen Szenario aggregiert. Das aggregierte Szenario mündet in ein konzeptspezifisches Gleichungssystem, das mit den Freiheitsgraden Energiepreise, Kalkulationszinssatz und Förderanteil gelöst wird. Im Gegensatz zu der etablierten Methode, die Wirtschaftlichkeitsberechnung im Anschluss an eine energetische Systemsimulation anzuhängen, wurde in dieser Arbeit ein holistisches Modell in TRNSYS entwickelt, das für jeden Simulationszeitschritt simultan Energie- und Zahlungsströme berechnet. In dem Modell konnten Verbesserungen in der Prognosegenauigkeit um den Faktor 20 nachgewiesen werden. Mit dem neuen Verfahren kann die Frage der Wirtschaftlichkeit nicht nur mit ja oder nein beantwortet werden, sondern zusätzlich mit der jeweiligen Eintrittswahrscheinlichkeit belegt werden.
In my dissertation I explore conceptual and economic aspects of resilience, i.e. a system’s ability to maintain its basic functions and controls under disturbances. I provide methodological considerations on the conceptual level and general insights derived from stylized ecological-economic models. In doing so, I demonstrate how to frame resilience so as to economically evaluate and investigate it as an important property of ecological-economic systems. Is conceptual vagueness an asset or a liability? In chapter 1 I address this question by weighing arguments from philosophy of science and applying them to the concept of resilience. I first sketch the wide spectrum of resilience concepts that ranges from concise concepts to the vague perspective of “resilience thinking”. Subsequently, I set out the methodological arguments in favor and against conceptual vagueness. While traditional philosophy of science emphasizes precision and conceptual clarity as precondition for empirical science, alternative views highlight vagueness as fuel for creative and pragmatic problem-solving. Reviewing this discussion, I argue that a trade-off between vagueness and precision exists, which is to be solved differently depending on the research context. In some contexts research benefits from conceptual vagueness while in others it depends on precision. Assessing the specific example of “resilience thinking” in detail, I propose a restructuring of the conceptual framework which explicitly distinguishes descriptive and normative knowledge. Chapter 2 investigates the common assumption that the optimization problem within a simple selfprotection problem (spp) is convex. It is shown that the condition given in the literature to legitimate this assumption may have implausible consequences. Via a simple functional specification we analyze the (non-)convexity of the spp more thoroughly and find that for reasonable parameter values strict convexity may not be justified. In particular, we demonstrate numerically that full self-protection is often optimal. Neglecting these boundary solutions and analyzing only the comparative statics of interior maxima may entail misleading policy implications such as underinvestment in self-protection. Thus, we highlight the relevance of full self-protection as a policy option even for non-extreme losses. Chapter 3 starts from the observation that ecosystem resilience is often interpreted as insurance: by decreasing the probability of future drops in the provision of ecosystem services, resilience insures risk-averse ecosystem users against potential welfare losses. Using a general and stringent definition of “insurance” and a simple ecological-economic model, we derive the economic insurance value of ecosystem resilience and study how it depends on ecosystem properties, economic context, and the ecosystem user’s risk preferences. We show that (i) the insurance value of resilience is negative (positive) for low (high) levels of resilience, (ii) it increases with the level of resilience, and (iii) it is one additive component of the total economic value of resilience. Chapter 4 performs a model analysis to study the origins of limited resilience in coupled ecologicaleconomic systems. We demonstrate that under open access to ecosystems for profit-maximizing harvesting forms, the resilience properties of the system are essentially determined by consumer preferences for ecosystem services. In particular, we show that complementarity and relative importance of ecosystem services in consumption may significantly decrease the resilience of (almost) any given state of the system. We conclude that the role of consumer preferences and management institutions is not just to facilitate adaptation to, or transformation of, some natural dynamics of ecosystems. Rather, consumer preferences and management institutions are themselves important determinants of the fundamental dynamic characteristics of coupled ecological-economic systems, such as limited resilience. Chapter 5 describes how real option techniques and resilience thinking can be integrated to better understand and inform decision making around environmental risks within complex systems. Resilience thinking offers a promising framework for framing environmental risks posed through the non-linear responses of complex systems to natural and human-induced disturbance pressures. Real options techniques offer the potential to directly model such systems including consideration of the prospect that the passage of time opens new options while closing others. Examples are provided which illustrate the potential for integrated resilience and real options approaches to contribute to understanding and managing environmental risk.
Sustainability and Justice: Conceptual Foundations and Cases in Biodiversity and Fishery Policy
(2014)
Sustainability aims at justice in a threefold sense: intragenerational justice, intergenerational justice, and justice towards nature. However, the justification, specific content and practical implications of justice claims and obligations in the sustainability context often remain underspecified. This dissertation therefore asks: How can the concept of justice be structured systematically? How can justice be specified in the context of sustainability? Which specific problems of justice arise in sustainability policy? And what are the respective contributions of (sustainability) economics and (sustainability) ethics? The five papers of this cumulative dissertation approach these issues from different angles, working at the conceptual level and at the level of cases from biodiversity and fishery policy. In Paper 1, a formal conceptual structure of justice is developed, which lists the conceptual elements of justice conceptions: the community of justice including claim holders and claim addressees, their claims (and corresponding obligations), the judicandum (that which is to be judged as just or unjust), the informational base for the assessment, the principles of justice, and on a more practical level, the instruments of justice. By specifying these conceptual elements of justice, it is possible to analyse and compare different conceptions of justice. In Paper 2, the normative dimension of sustainability is discussed in terms of justice. Based on the identification of certain core characteristics of the concept of sustainability, we determine the specific challenges of justice in the context of sustainability along the conceptual structure of justice (from Paper 1). Inter alia, we show that sustainability calls for the integration of justice claims in the relationships with contemporaries, future humans and nature in a non-ideal context characterized by uncertainty, systemic mediation and limits. Paper 3 addresses the contribution of economics to the assessment of trade-offs between intergenerational and intragenerational justice. Economic analysis can delineate the opportunity set of politics with respect to the two justice objectives and identify the opportunity cost of attaining one justice to a higher degree. While the two justices are primary normative objectives, the criterion of efficiency - when directed at the attainment of these justice objectives - has the status of a secondary normative objective. Paper 4 constitutes a case study, reconstructing the ´biopiracy´ debate from a justice perspective. The paper links to the so called Access and Benefit-Sharing framework of the Convention on Biological Diversity, and addresses the question, which problems of justice arise regarding the utilization of genetic resources and traditional knowledge, especially if associated with patenting. It is shown that the predominant perspective of justice-in-exchange is insufficient and therefore complementary conceptions, namely of distributive justice, corrective justice and structural justice have to be taken into account. Paper 5 empirically assesses the justice notions of stakeholders in the Newfoundland fishery, building on qualitative semi-structured interviews and a combination of inductive and deductive coding. A central result is that inshore fishers are seen as the main claim holders, with a claim to participate and being listened to, and the opportunity to make a living from the fishery. Recognition, participation and distribution are all important domains of justice in the context of the Newfoundland fishery. The paper also discusses the relationship between normative theorizing and empirical justice research. Overall, this thesis integrates ideal and non-ideal normative theorizing, economic analysis, empirical justice research and hints at institutional implementation in the debate on sustainability and justice.
Derivatives are contracts between two parties, a buyer and a seller. The contract will be fulfilled in some point in the future at a predetermined price. The value of those contracts is based on an underlying entity which can be a traded asset or even the weather. Derivatives contain chances, but also risks, investor should be aware off. This thesis aims to deeply analyze two derivative products in the German market and one risk for each which influences the prices of those products. The first part of this thesis focuses on warrants and the issuer's credit risk involved. It finds evidence that the issuer's credit risk influences the connection between warrant characteristic and its prices. Over time this connection is unstable partly driven by the issuer's credit risk. The second paper of this thesis shows that issuers seem to use their credit risk systematically to influence warrant prices. Evidence is found that the changes in credit risk are not fully included in the prices directly, but that the adjustment to the new level of credit risk takes several days. In addition, the issuer's adjustment to changes in credit risk are different for credit risk increases than for credit risk decreases. Especially after financial crisis, in more stable times, evidence is found for such adverse pricing pattern. The third part of the thesis focuses on energy derivatives traded at the Europe Energy Exchange and analyses the influence of weather parameters on energy derivatives with different load profiles and time horizons. This part of the thesis finds that especially wind speed and sun hours have a strong influence on energy derivatives. However, not all products are influenced in the same manner. Products with a longer time horizon are influenced less than the product with a short horizon. Moreover, products comprising hours of the day where energy consumption is expected to be higher are influenced stronger than products comprising hours of a day with lower time consumption. The thesis shows that derivatives are not alike and that it is needed for future research to differentiate between products and the risks which are involved. Since even though we classify them all as derivatives the risks influencing the derivative´s prices do vary tremendously.
Algae-bacteria-based biotechnology has received more and more attention in recent years, especially in the subtropical and tropical regions, as an alternative method of conventional multistep wastewater treatment processes. Moreover, the algal biomass generated during wastewater treatment is regarded as a sustainable bioresource which could be used for producing biofuel, agricultural fertilizers or animal feeds. Although this technology is attractive, a number of obstacles need to be solved before large-scale applications. The main purposes of this work are to find more effective biomass harvesting strategies and develop high-effective algal-bacterial systems to improve wastewater treatment performance, biomass generation rate and biomass settleability. A wastewater-borne algal-bacterial culture, cultivated and trained through alternate mixing and non-mixing strategy, was used to treat pretreated municipal wastewater. After one month cultivation and training, the acclimatized algal-bacterial system showed high carbon and nutrient removal capacity and good settleability within 20 minutes of sedimentation. Algal biomass uptake was the main removal mechanism of nitrogen and phosphorus. The biomass productivity, nitrogen and phosphorus accumulation in biomass during the wastewater treatment process were investigated. The characterization of the microbial consortium composition in the enriched algal-bacterial system provided new insights in this research field. Aerobic activated sludge which already showed good settleability was used as bacterial inoculum to enhance the wastewater treatment performance and biomass settleability of algal-bacterial culture. The influence of different algae and sludge inoculum ratios on the treatment efficiency and biomass settleability was investigated. There was no significant effect of the inoculation ratios on the chemical oxygen demand (COD) removal. But algae/sludge inoculum ratio of 5 showed the best nitrogen and phosphorus removal efficiencies (91.0 ± 7.0% and 93.5 ± 2.5%, respectively) within 10 days. Furthermore, 16S rDNA gene analysis showed that the bacterial communities were varying with different algae and sludge inoculation ratios and some specific bacteria species were enriched during the operation. Four commonly used and high-potential microalgae species including one cyanobacteria (Phormidium sp.) and three green microalgae species (Chlamydomonas reinhardtii, Chlorella vulgaris and Scenedesmus rubescens) were cultivated and trained through alternate mixing and non-mixing strategy for tertiary municipal wastewater treatment. After one month of cultivation, the four microalgae species were compared in terms of biomass settleability, nutrient removal rates and biomass productivity. The three green microalgae showed good settleability within 1 h sedimentation and had higher biomass generation rates (above 6 g/m2/d). The nutrient removal efficiencies were 99% for the four selected microalgae species but within different retention time, resulting in 3.66 ± 0.17, 6.39 ± 0.20, 4.39 ± 0.06 and 4.31 ± 0.18 mg N/l/d (N removal rate) and 0.56 ± 0.07, 0.89 ± 0.05, 0.76 ± 0.09 and 0.60 ± 0.05 mg P/l/d (P removal rate) for Phormidium sp., Chlamydomonas reinhardtii, Chlorella vulgaris and Scenedesmus rubescens, respectively. A mixed algal culture composed of three selected high-effective green microalgae (Chlamydomonas reinhardtii, Chlorella vulgaris and Scenedesmus rubescens) was used for tertiary municipal wastewater treatment. The key biotic factor (algal inoculum concentration) and abiotic factors such as illumination cycle, mixing velocity and nutrient strength were studied. Based on the nitrogen and phosphorus balance, it was found that assimilation into algal biomass was the main removal mechanism.