Open Access

Pre-service teachers need to develop professional competence to be able to provide students with the best possible learning environment. Professional competence manifests itself when teachers combine theory with practice productively. Professional competence encompasses dispositions (i.e., knowledge, beliefs, motivational components, and self-regulatory skills), situation-specific skills (e.g., professional vision), and actual performance. Professional competence can be fostered productively by authentic, practice-based learning opportunities. Teaching practicums can offer practice-based learning opportunities. Educational research has shown that reflection and feedback are crucial for substantial development of pre-service teachers’ professional competence. However, reflection and feedback sessions are not a standard element of teaching practicums due to time- and location-constraints. Digital practicum environments can lift these constraints. Digital reflection and feedback environments have typically applied either textual accounts or video sequences of classroom practice, with varying effects. Consequently, the studies presented in this cumulative dissertation are focused on how the use of text- or video-based digital reflection and feedback environments during a practicum influence specific components of pre-service teachers’ professional competence (i.e., beliefs about teaching and learning, self-efficacy, professional vision of classroom management, feedback competence). All studies followed a quasi-experimental, pre-test-post-test design. Pre-service teachers at the fourth-semester bachelor level in a German university took part in the studies. Pre-service teachers participated in a four-week teaching practicum at local schools. During the teaching practicum, pre-service teachers were divided into five different groups. The control group (CG) took part in a traditional practicum with live observations and face-to-face reflection and feedback with peers and experts. Pre-service teachers of the intervention groups (IG 1, IG 2, IG 3, IG 4) reflected and received feedback in highly structured text- or video-based digital environments. Intervention groups 1 (IG 1) and 2 (IG 2) participated in a text-based digital reflection and feedback environment. While IG 1 participants only received feedback from peers, IG 2 pre-service teachers also received expert feedback. Intervention groups 3 (IG 3) and 4 (IG 4) took part in a video-based digital reflection and feedback environment. IG 3 pre-service teachers only received peer feedback, whereas IG 4 participants also received expert feedback. Mixed methods were applied by generating quantitative and quantitative-qualitative data was with questionnaires, a standardized video-based test and content analysis. The studies demonstrated that classroom videos and video-based digital reflection and feedback environments can effectively enhance pre-service teachers’ professional competence. This finding can be predominantly attributed to two characteristics of the application in the digital reflection and feedback environments: (a) being able to revisit a multitude of authentic teaching situations without time pressure and (b) the degree of decomposition by deliberate, focused practice and scaffolding elements. Furthermore, expert feedback seemed to be of better quality and entailed more substantial effects than peer feedback. The results of our studies on professional vision of classroom management, beliefs about teaching and learning and feedback competence showed that expert feedback can be seen as a lens reducing and focusing classroom complexity, enabling pre-service teachers to perceive crucial teaching situations that would have otherwise gone unnoticed and to benefit from expert modelling of high-quality feedback. Consequently, video-based digital reflection and feedback environments with expert feedback can significantly improve pre-service teachers’ professional competence during teaching practicums and, thus, better prepare pre-service teachers for future classroom challenges, leading to better learning environments for school students.

In response to the globally increasing environmental, social, and economic crises, we as humanity must leave the path of business as usual and learn new ways to know, think, and act which may enable us to build a more sustainable future for all. In their role as facilitators, teachers in general are considered one, if not the most important, factor for successful learning. The implementation of education for sustainable development (ESD) across all education systems and preparing students to act as future change agents and lead the societal transformation towards sustainability also largely depends on competent and committed teachers. Correspondingly, the focus of political agendas and scientific research increasingly shifts to the effective education of educators. The different competence models that are currently being discussed in the international discourse around teacher education for sustainable development (TESD) suggest various sets of intended learning outcomes (ILOs). Yet, they usually share the assumption that teachers require ESD-related knowledge, pedagogical skills, and motivation to successfully implement ESD at the school level. In accordance with the concept of ESD-specific professional action competence (Bertschy et al., 2013), educational offers in ESD for pre-service teachers should also develop their content knowledge (CK), pedagogical content knowledge (PCK) as well as a positive attitude towards ESD. However, in the sense of a comprehensive construct, this concept has not yet been operationalized or measured. Furthermore, there is still a lack of deeper understanding as to how to best design individual courses as teaching and learning environments in TESD in order to support competence development in student teachers. Based on a dual case study, this cumulative dissertation investigates how individual ESD courses, as part of the teacher education programs at Leuphana University in Lüneburg/ Germany and Arizona State University (ASU) in Tempe/USA, actually foster students’ ESD-specific professional action competence. Furthermore, this work sheds light on the link between learning processes and outcomes, to reveal which factors actually affect the achievement of ILOs and competence development. The findings of this study indicate that both courses under investigation eventually live up to their role and increased student teachers’ competence and commitment to implement ESD in their future careers; yet, mainly due to their different thematic foci, to varying degrees. Additionally, the four Cs (personal, professional, social, and structural connections) were revealed as significant factors that support students’ learning and should be considered when planning and designing course offerings in TESD, with the goal of developing students’ knowledge, skills, and attitudes.

The presence of pharmaceutical drugs and their by-products as environmental organic contaminants in a variety of eco-systems and their potential environmental impacts is a well-known aspect and has been raised in recent years. Studying the transformation of pharmaceutical drugs in the aquatic system is very important as it can lead to the formation of many new transformation products (TPs) that can have different properties (e.g. more mobile, toxic or present at higher concentrations) and this can enable them to reach the environmental compartments not affected by their parent compounds. Yet, many of the pharmaceutical drugs are not well regulated or controlled and they can cause a lot of adverse ecological and/or human health effects. In addition, impact of the continuous change in the environmental conditions such as pH, temperature and initial concentration on the transformation behaviour of pharmaceuticals is overlooked in many researches although it is of high interest. Psychotropic drugs are among the pharmaceuticals which their potential hazards including environmental fate and behaviour is still not well understood compared to other drugs such as antibiotics. Psychotropic drugs are highly used, and their worldwide consumption has been increasing nowadays especially in developed countries such as Europe and the United States. Furthermore, they are highly found in different environmental compartments and can cause a lot of toxicological problems. Trimipramine (TMP), Desipramine (DMI) and Chlorprothixene (CPTX) are three psychotropic drugs with closely related chemical structures and they are selected to be studied in this thesis as they are among the worldwide commonly prescribed psychotropic drugs and data available on their environmental fate (e.g., degradation or transformation and fate of the TPs) is lacking in the environmental researches. To investigate the ecological impact of the pharmaceuticals on water organisms and to study their fate in the aquatic system, laboratory biodegradation and photodegradation tests are recommended. The use of LC-MS/MS analysis with the combination of photolysis and biodegradation tests to identify the formed TPs and to study the biodegradability and the persistence of the TPs is a helpful new insight into the environmental behaviour of contaminants and their TPs. Different environmental conditions can affect the fate of pharmaceuticals in the environment, therefore answering the question how different variables such as temperature, pH and initial concentration could affect the degradation pattern of pharmaceuticals can provide valuable information regarding their environmental fate. Toxicity assessments of contaminants and their TPs using in-silico software based on quantitative structure activity relationship (QSAR) models can be a good choice especially in case of TPs because the TPs are mostly not available commercially and II are usually only formed in low concentrations within complex matrices so that isolation and purification are very difficult. Accordingly, 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 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). TMP, DMI and CPTX were found to be not readily biodegradable in Closed Bottle test (CBT), and in Manometric Respiratory test (MRT). They did not show any significant elimination or mineralization within 128 minutes of irradiation using a xenon Lamp. In UV-photodegradation samples, LC-MS/MS results showed elimination of the three psychotropic drugs with corresponding comparatively lower degrees of mineralization indicating formation of abundant photo-TPs. From the UV-photolysis tests, which were carried out under different environmental conditions, it can be concluded that the degradation rates of TMP, DMI and CPTX decreased when their initial concentrations increased. pH affected the photodegradation behaviour of TMP, DMI and CPTX with different pattern depending on many factors such as solubility, molar absorption coefficient (ɛ), ionisation form and chemical structure. Temperature elevation showed non-significant effect on the photodegradation performance of DMI and CPTX, while showed an enhanced effect on the photodegradation performance of TMP. This could be because the molecules of DMP and CPTX can reach the sufficient energy required for degradation at low temperature. While TMP`s molecules still require some more energy to undergo degradation and temperature helps them to reach easily these required activation energy. Elucidating the TPs and studying the degradation pathways for TMP, DMI and CPTX during UV irradiation indicated that hydroxylation is the most abundant pathway followed by oxidation and isomerization. De-chlorination pathway was observed during the UV-transformation of CPTX. III Deamination and loss of the aliphatic side chain were observed only during the UV-transformation of TMP, while not observed during DMI and CPTX transformation. This indicates that the bond between the amino- group and the aliphatic side chain in DMI and CPTX can be more resistant to photodegradation compared to the same bond in TMP. This could be due to the presence of extra methyl groups in TMP molecule which can decrease the previously mentioned bond strength. Biodegradation tests performed for photodegradation mixtures, which contain the psychotropic drugs and their TPs, showed low biodegradation results. Despite that, elimination of some TPs was observed in the LC-MS/MS analysis at the end of these biodegradation tests. This indicates the probability of biodegradation ability for some TPs and this ability was hindered by the predominant effect of other non-biodegradable compounds. In-silico predictions showed that for many endpoints, photo-transformation might lead to an increased toxicity in humans and to water organisms compared with the parent compound. 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.

Tropical forests worldwide support high biodiversity and contribute to the sustenance of local people’s livelihoods. However, the conservation and sustainability of these forests are threatened by land-use changes and a rapidly increasing human population. In this dissertation, I focused on the effects of land-use change on forest biodiversity in the rural landscapes of southwestern Ethiopia, against a backdrop of human population growth. These landscapes are being progressively degraded, encroached and fragmented as a result of different pressures, including the intensification of coffee production, farmland expansion, urbanization and a growing rural population. Understanding the drivers of biodiversity loss and the responses of biodiversity to such pressures is fundamental to direct conservation efforts in these tropical forests. This dissertation aimed to characterize biodiversity patterns in the moist Afromontane forests of southwestern Ethiopia and to examine how biodiversity patterns are affected by land-use and land-use changes (mediated by coffee management intensity, landscape attributes and housing development) in a context of a rapidly growing rural population. To achieve this goal, I take an interdisciplinary approach where, first, I examined the effects of coffee management intensity on diversity patterns of woody plants and birds, spanning a gradient of site-level disturbance from nearly undisturbed forest interior to highly managed shade coffee forests. Results showed that specialized species of woody plants (forest specialists) and birds (forest specialists, insectivores and frugivores) were affected by coffee management intensity. The richness of forest specialist trees and the richness and/or abundance of insectivores, frugivores and forest specialist birds decrease with increasing levels of disturbance. Second, I investigated the effects of landscape context on woody plants, birds and mammals. Community composition and specialist species of woody plants and birds were sensitive to landscape context, where woody plants responded positively to gradients of edge-interior and birds to gradients of edge-interior and forest cover. Further results showed that a diverse mammal community, with 26 species, occurs at the forest edge of shade coffee forests and that the leopard, an apex predator in the region depended on large areas of natural forest. A closer examination of leopard activity patterns revealed a shift in the diel activity as a response to human disturbance inside the forest, further highlighting the importance of natural undisturbed forests for leopards in the region. Together, these findings demonstrate the value of low managed shade coffee forests for biodiversity, and importantly, emphasize the irreplaceable value of undisturbed natural forests for biodiversity. Third, I investigated the effects of prospective rural population growth (mediated by housing development) on the forest mammal community. Here, population growth was projected to negatively influence several mammal species, including the leopard. Housing development that encroached the forest entailed worse outcomes for biodiversity than a combination of prioritized development in already developed areas and coffee forest protection. Fourth, to understand the motivations behind high human fertility rates in the region, I examined the determinants of women fertility preferences, including their perceptions on social and biophysical stressors affecting local livelihoods such as food insecurity and environmental degradation. Fertility preferences were influenced by underlying social norms and mindsets, a perceived utilitarian value of children and male dominance within the household, and were only marginally affected by perceptions of social and biophysical stressors. Results further indicated a mismatch between the global discourse on the population-environment-food nexus and local perceptions of this issue by women. My findings suggest the need for new deliberative and culturally sensitive approaches that engage with pervasive social norms to slow down population growth. Overall, this dissertation demonstrates the key value of moist Afromontane forests in southwestern Ethiopia for biodiversity conservation. It indicates the need to promote coffee management practices that reduce forest degradation and highlights that high priority should be given to the conservation of undisturbed natural forests. It also suggests the need to integrate conservation goals with housing development in landscape planning. A promising approach to achieve the above conservation priorities would be the creation of a Biosphere Reserve and to promote the ecological connectivity between the larger forest remnants in the region. Finally, this dissertation demonstrates the importance of placed-based holistic approaches in conservation that consider both proximate and distal drivers of forest biodiversity decline.    

The aim of this paper is to determine how a carbon footprint label for grocery products can be designed to facilitate a sustainable consumption behaviour. Therefore, a mixed-method approach was used consisting out of a review of relevant literature and an explorative quantitative survey with n = 158 participants. It was found that consumers generally have a positive attitude towards carbon labelling, but they lack understanding of the term, its underlying concepts and the emissions caused by grocery products. In regard to the design criteria of a carbon label, labels with a coloured scale are preferred most by consumers. Also, the mechanisms of consumer behaviour imply that not all parts of the behaviour are visible and controllable for individuals themselves. The concluding concept proposal summarises important criteria of a carbon labelling system that has the goal to educate consumers and facilitate a lower carbon consumption behaviour, such as a simple visual design, the use of a colour scale, a design enabling a comparison, the provision of a link to further information, the public enforcement of the system and overall uniformity.