Coastal erosion describes the displacement of land caused by destructive sea waves, currents or tides. Due to the global climate change and associated phenomena such as melting polar ice caps and changing current patterns of the oceans, which result in rising sea levels or increased current velocities, the need for countermeasures is continuously increasing. Today, major efforts have been made to mitigate these effects using groins, breakwaters and various other structures. This thesis will find a novel approach to address this problem by applying shape optimization on the obstacles. Due to this reason, results of this thesis always contain the following three distinct aspects: The selected wave propagation model, i.e. the modeling of wave propagation towards the coastline, using various wave formulations, ranging from steady to unsteady descriptions, described from the Lagrangian or Eulerian viewpoint with all its specialties. More precisely, in the Eulerian setting is first a steady Helmholtz equation in the form of a scattering problem investigated and followed subsequently by shallow water equations, in classical form, equipped with porosity, sediment portability and further subtleties. Secondly, in a Lagrangian framework the Lagrangian shallow water equations form the center of interest. The chosen discretization, i.e. dependent on the nature and peculiarity of the constraining partial differential equation, we choose between finite elements in conjunction with a continuous Galerkin and discontinuous Galerkin method for investigations in the Eulerian description. In addition, the Lagrangian viewpoint offers itself for mesh-free, particle-based discretizations, where smoothed particle hydrodynamics are used. The method for shape optimization w.r.t. the obstacle’s shape over an appropriate cost function, constrained by the solution of the selected wave-propagation model. In this sense, we rely on a differentiate-then-discretize approach for free-form shape optimization in the Eulerian set-up, and reverse the order in Lagrangian computations.

This thesis focuses on the issues in price measurement and consists of three chapters. Due to outdated weighting information, a Laspeyres-based consumer price index (CPI) is prone to accumulating upward bias. Therefore, chapter 1 introduces and examines simple and transparent revision approaches that retrospectively address the source of the bias. They provide a consistent long-run time series of the CPI and require no additional information. Furthermore, a coherent decomposition of the bias into the contributions of individual product groups is developed. In a case study, the approaches are applied to a Laspeyres-based CPI. The empirical results confirm the theoretical predictions. The proposed revision approaches are adoptable not only to most national CPIs but also to other price-level measures such as the producer price index or the import and export price indices. Chapter 2 is dedicated to the measurement of import and export price indices. Such indices are complicated by the impact of exchange rates. These indices are usually also compiled by some Laspeyres type index. Therefore, substitution bias is an issue. The terms of trade (ratio of export and import price index) are therefore also likely to be distorted. The underlying substitution bias accumulates over time. The present article applies a simple and transparent retroactive correction approach that addresses the source of the substitution bias and produces meaningful long-run time series of import and export price levels and, therefore, of the terms of trade. Furthermore, an empirical case study is conducted that demonstrates the efficacy and versatility of the correction approach. Chapter 3 leaves the field of index revision and studies another issue in price measurement, namely, the economic evaluation of digital products in monetary terms that have zero market prices. This chapter explores different methods of economic valuation and pricing of free digital products and proposes an alternative way to calculate the economic value and a shadow price of free digital products: the Usage Cost Model (UCM). The goal of the chapter is, first of all, to formulate a theoretical framework and incorporate an alternative measure of the value of free digital products. However, an empirical application is also made to show the work of the theoretical model. Some conclusions on applicability are drawn at the end of the chapter.

Stress gilt als zentrales Gesundheitsrisiko des 21. Jahrhunderts und wird in der Forschung als multidimensionales Konstrukt auf psychologischer und biologischer Ebene untersucht. Wäh-rend die subjektive Wahrnehmung von Stress nicht mit der biologischen Stressreaktivität zu-sammenhängen muss, ist der negative Einfluss stressassoziierter biologischer Prozesse auf Wohlbefinden und Gesundheit gut belegt. Bereits im Grundschulalter zeigen Kinder eine mit Erwachsenen vergleichbare Stressbelastung und gesundheitliche Folgen, Bewältigungsstrategien sind in diesem Alter allerdings noch nicht vollständig entwickelt. Präventionsprogramme im Grundschulalter sollen Kinder in ihren sich entwickelnden Stressbewältigungsfähigkeiten fördern, wobei sowohl emotionsfokussierte und problemorientierte Ansätze als auch soziale Unterstützung wichtige Faktoren darstellen könnten. Das einleitende Literatur-Review evaluiert bisherige Stresspräventionsstudien und verdeutlicht, dass zwar die Wirksamkeit und Anwendbarkeit von mehrfaktoriellen Stresspräventionsprogrammen im Rahmen psychometrischer Erhebungen gezeigt werden konnten, biologische Prozesse in der Forschung bisher allerdings nicht erhoben und außer Acht gelassen wurden. Die empirische Untersuchung in Studie 1 zeigt, dass eine multidimensionale psychobiologische Betrachtungsweise sinnvoll ist, indem sowohl die Psychometrie, als auch psychobiologische Prozesse der Stressreaktion miteinbezogen und die Auswirkungen von Stressprävention auf den verschiedenen Ebenen untersucht wurden. Zwei Kurzinterventionen wurden dazu miteinander verglichen und ihre Wirkung auf psychophysiologischen Ebenen (z.B. Kortisol, α-Amylase und Herzrate) in einem Prä-Post Design geprüft. Eine statistisch signifikante Abnahme psychophysiologischer Stressreaktivität, sowie stressassoziierter psychologischer Symptome verdeutlichte die multidimensionale Wirksamkeit von Stressmanagementtrainings. Studie 2 wurde im Rahmen der Covid-19-Pandemie entworfen. Die in Studie 1 trainierten Kinder wurden mittels Online-Fragebogenerhebung mit einer Kontrollgruppe hinsichtlich ihrer Stressbelastung verglichen. Die Ergebnisse zeigten eine geringere Belastung und vermehrte günstige Bewältigungsstrategien trainierter Kinder im Vergleich zur Kontrollgruppe. Diese Ergebnisse heben die Relevanz einer multidimensionalen Betrachtung kindlichen Stresses hervor. Es wurde gezeigt, dass Stresspräventionsprogramme auf den unterschiedlichen Ebenen der Stressreaktion wirken und sogar in gesamtgesellschaftlichen Krisensituationen stresspro-tektiv wirken können. Zukünftige Studien sollten Stresspräventionen im Grundschulalter psychophysiologisch evaluieren und deren Wirkung in Längsschnittstudien beurteilen, um das Verständnis der zugrundeliegenden Mechanismen zu verbessern.

Climate fluctuations and the pyroclastic depositions from volcanic activity both influence ecosystem functioning and biogeochemical cycling in terrestrial and marine environments globally. These controlling factors are crucial for the evolution and fate of the pristine but fragile fjord ecosystem in the Magellanic moorlands (~53°S) of southernmost Patagonia, which is considered a critical hotspot for organic carbon burial and marine bioproductivity. At this active continental margin in the core zone of the southern westerly wind belt (SWW), frequent Plinian eruptions and the extremely variable, hyper-humid climate should have efficiently shaped ecosystem functioning and land-to-fjord mass transfer throughout the Late Holocene. However, a better understanding of the complex process network defining the biogeochemical cycling at this land-to-fjord continuum principally requires a detailed knowledge of substrate weathering and pedogenesis in the context of the extreme climate. Yet, research on soils, the ubiquitous presence of tephra and the associated chemical weathering, secondary mineral (trans)formation and organic matter (OM) turnover processes is rare in this remote region. This complicates an accurate reconstruction of the ecosystem´s potentially sensitive response to past environmental impacts, including the dynamics of Late Holocene land-to-fjord fluxes as a function of volcanic activity and strong hydroclimate variability. Against this background, this PhD thesis aims to disentangle the controlling factors that modulate the terrigenous element mobilization and export mechanisms in the hyper-humid Patagonian Andes and assesses their significance for fjord primary productivity over the past 4.5 kyrs BP. For the first time, distinct biogeochemical characteristics of the regional weathering system serve as major criterion in paleoenvironmental reconstruction in the area. This approach includes broad-scale mineralogical and geochemical analyses of basement lithologies, four soil profiles, volcanic ash deposits, the non-karst stalagmite MA1 and two lacustrine sediment cores. In order to pay special attention to the possibly important temporal variations of pedosphere-atmosphere interaction and ecological consequences initiated by volcanic eruptions, the novel data were evaluated together with previously published reconstructions of paleoclimate and paleoenvironmental conditions. The devastative high-tephra loading of a single eruption from Mt. Burney volcano (MB2 at 4.216 kyrs BP) sustainably transformed this vulnerable fjord ecosystem, while acidic peaty Andosols developed from ~2.5 kyrs BP onwards after the recovery from millennium-scale acidification. The special setting is dominated by most variable redox-pH conditions, profound volcanic ash weathering and intense OM turnover processes, which are closely linked and ultimately regulated by SWW-induced water-level fluctuations. Constant nutrient supply though sea spray deposition represents a further important control on peat accumulation and OM turnover dynamics. These extreme environmental conditions constrain the biogeochemical framework for an extended land-to-fjord export of leachates comprising various organic and inorganic colloids (i.e., Al-humus complexes and Fe-(hydr)oxides). Such tephra- and/or Andosol-sourced flux contains high proportions of terrigenous organic carbon (OCterr) and mobilized essential (micro)nutrients, e.g., bio-available Fe, that are beneficial for fjord bioproductivity. It can be assumed that this supply of bio-available Fe produced by specific Fe-(hydr)oxide (trans)formation processes from tephra components may outlast more than 6 kyrs and surpasses the contribution from basement rock weathering and glacial meltwaters. However, the land-to-fjord exports of OCterr and bio-available Fe occur mostly asynchronous and are determined by the frequency and duration of redox cycles in soils or are initiated by SWW-induced extreme weather events. The verification of (crypto)tephra layers embedded stalagmite MA1 enabled the accurate dating of three smaller Late Holocene eruptions from Mt. Burney (MB3 at 2.291 kyrs BP and MB4 at 0.853 kyrs BP) and Aguilera (A1 at 2.978 kyrs BP) volcanoes. Irrespective of the improvement of the regional tephrochronology, the obtained precise 230Th/U-ages allowed constraints on the ecological consequences caused by these Plinian eruptions. The deposition of these thin tephra layers should have entailed a very beneficial short-term stimulation of fjord bioproductivity with bio-available Fe and other (micro)nutrients, which affected the entire area between 52°S and 53°S 30´, respectively. For such beneficial effects, the thickness of tephra deposited to this highly vulnerable peatland ecosystem should be below a threshold of 1 cm. The Late Holocene element mobilization and land-to-fjord transport was mainly controlled by (i) volcanic activity and tephra thickness, (ii) SWW-induced and southern hemispheric climate variability and (iii) the current state of the ecosystem. The influence of cascading climate and environmental impacts on OCterr and Fe-(hydr)oxide fluxes to can be categorized by four individual, in part overlapping scenarios. These different scenarios take into account the previously specified fundamental biogeochemical mechanisms and define frequently recurring patterns of ecosystem feedbacks governing the land-to-fjord mass transfer in the hyper-humid Patagonian Andes on the centennial-scale. This PhD thesis provides first evidence for a primarily tephra-sourced, continuous and long-lasting (micro)nutrient fertilization for phytoplankton growth in South Patagonian fjords, which is ultimately modulated by variations in SWW-intensity. It highlights the climate sensitivity of such critical land-to-fjord element transport and particularly emphasizes the important but so far underappreciated significance of volcanic ash inputs for biogeochemical cycles at active continental margins.

The present dissertation was developed to emphasize the importance of self-regulatory abilities and to derive novel opportunities to empower self-regulation. From the perspective of PSI (Personality Systems Interactions) theory (Kuhl, 2001), interindividual differences in self-regulation (action vs. state orientation) and their underlying mechanisms are examined in detail. Based on these insights, target-oriented interventions are derived, developed, and scientifically evaluated. The present work comprises a total of four studies which, on the one hand, highlight the advantages of a good self-regulation (e.g., enacting difficult intentions under demands; relation with prosocial power motive enactment and well-being). On the other hand, mental contrasting (Oettingen et al., 2001), an established self-regulation method, is examined from a PSI perspective and evaluated as a method to support individuals that struggle with self-regulatory deficits. Further, derived from PSI theory`s assumptions, I developed and evaluated a novel method (affective shifting) that aims to support individuals in overcoming self-regulatory deficits. Thereby affective shifting supports the decisive changes in positive affect for successful intention enactment (Baumann & Scheffer, 2010). The results of the present dissertation show that self-regulated changes between high and low positive affect are crucial for efficient intention enactment and that methods such as mental contrasting and affective shifting can empower self-regulation to support individuals to successfully close the gap between intention and action.