Genetically modified plants have been grown commercially for about 25 years. Bt plants, which contain genes from the bacterium Bacillus thuringiensis (Bt) and produce Cry proteins, are used particularly frequently. Risk assessment has long focused on the terrestrial environment. Only since the publication of Rosi-Marshall et al. in 2007 potential effects on the aquatic environment came into focus. The first part of this dissertation analyse the existing literature on lower-tier effect studies and fate studies examining the effects of GM plants on the aquatic environment. Potential effects on aquatic organisms are apparent. Some studies also demonstrate the entry of GM plant material into the aquatic environment and the leaching of toxins into the water. The second part of the dissertation investigate the effects of Cry1Ab toxin on two species of caddisfly larvae (Chaetopterryx spec., Sericostoma spec.). Trichopterans are phylogenetically closely related to lepidopterans, which are often the target organisms of Cry toxins. In order to be able to create several concentrations, a new spiking method was used in which dissolved Cry1Ab toxin was applied on leaves of black alder (Alnus glutinosa). Effects were particularly evident at sublethal endpoints. The lipid content of Chaetopteryx spec. larvae was lower after twelve weeks with increasing Cry1Ab concentration. The reduction in lipid content may indicate an increase in energy requirements for repair mechanisms. Sericostoma spec. showed a slowdown in larval development at the highest Cry1Ab concentration after six weeks, which could lead to later emergence and thus effects on the food chain. In the third part of the dissertation, the assessment of impacts of GM crops on the aquatic environment was investigated using higher-tier studies. Since higher-tier studies are already common with pesticides, these were compared to the higher-tier studies already conducted with GM crops. It is found that there is no standardization of higher-tier studies with GM crops, which is necessary for quality assurance and comparability of studies. In addition, there are great difficulties in establishing different test concentrations, which is necessary for the investigation of a dose-response relationship. Overall, it is clear that there are still significant knowledge gaps of the effects of GM plants on the aquatic environment. Further studies are essential for a comprehensive and meaningful risk assessment.

Manmade dams have been constructed from centuries for multiple purposes, and in the past decades they have been constructed in a fast pace, with the hotspot in tropical and subtropical regions. However, studies that explore hydrodynamics in these areas are scarce and biased to the rich literature available for temperate regions. Lakes and reservoirs have the same controlling mechanisms for physical processes and primary production, hence, analyses that were initially conceptualized for lakes are frequently applied for reservoirs. Nevertheless, longitudinal gradients in reservoirs challenges the application of these approaches. Degradation of water quality in reservoirs is a major concern, and it is expected to be aggravated with climate change. Therefore, studies that explore mechanisms controlling water quality are essential for the maintenance of these systems, especially in tropical and subtropical regions. The aim of this thesis is to comprehend the role of hydrodynamic processes in the fate of nutrients in reservoirs and its implications on water quality, in a subtropical region. With focus on the relevance of different density current patterns. For that, analyses combining field measurements and numerical simulations were performed in a medium to small size subtropical drinking water reservoir for a complete seasonal cycle. Measurements were conducted combining several approaches: traditional sampling, sensors in high temporal and spatial resolution, and remote sensing. Besides, hydrodynamic models were set up and calibrated to reproduce observations, and to simulate scenarios that assisted on the analysis. Results showed that different flow paths of density currents did not influence on phytoplankton dynamics. At the regions where the main nutrient supply was the river inflow (upstream), the density currents did not vary, the euphotic zone usually covered the entire depth, and vertical mixing was observed on a daily basis, turning the flow path of the density currents irrelevant. At downstream regions, the remobilization of nutrients in the sediment was the main source for primary production. Even though density currents had a seasonal pattern in the downstream region, thermal stratification conditions were the driver for variations in chlorophyll-a concentrations, with peaks after vertical mixing. This mechanism had in its favor the frequent anoxic conditions in the hypolimnion that enhanced the dissolution of reactive phosphorus from the sediment. Anoxic conditions were easily reached because the sediment in the downstream area was rich in organic matter. Phytoplankton produced in the upstream area was transported by the density currents, and for this reason, large concentrations of chl-a was observed below the euphotic zone. Further, the extensive measurements of temperature, and flow velocities, together with the hydrodynamic models, provided insights about the hydrodynamics of reservoirs. For instance, that the relevant processes occurred along the longitudinal, and mixing conditions varied along it. The relevance of inflow conditions regarding the presence of structures such as forebays and pre-dams, and the degree of stream shading in the catchment was assessed. And turbulence and internal waves had different features than the documented for high latitudes. Those findings can assist on the management of reservoirs, based on the comprehension of the physical processes.

Generation Z strömt derzeit mit neuen Wertvorstellungen und hohen Ansprüchen in die Arbeitswelt ein, was Führungskräfte vor eine große Herausforderung stellt. Um sich im Fachkräftemangel zu behaupten, die jungen Talente zu rekrutieren sowie langfristig an das Unternehmen zu binden, müssen Unternehmen, insbesondere Führungskräfte die Erwartungen und Anforderungen der Generation Z kennen und diesen gerecht werden. Während die Erwartungen und Anforderungen der Vorgängergenerationen bereits analysiert wurden, sind die der jungen Generation Z unbekannt. Um die Erwartungen und Anforderungen der Generation Z an Führungskräfte und deren Verhaltensweisen zu identifizieren, wurde eine qualitative Forschungsmethode angewandt, indem fünf Experteninterviews mit Studierenden aus der Generation Z geführt wurden. Diese wurden anschließend mithilfe einer qualitativen Inhaltsanalyse anhand von Kategorien ausgewertet. Die junge Generation stellt hohe Erwartungen an Führungskräfte sowie deren Verhalten ihnen gegenüber. So fordern sie nicht nur klare Vorgaben hinsichtlich der an sie gestellten Erwartungen, sondern zeigen auch das Bedürfnis nach regelmäßigem Austausch und Feedbackgesprächen mit ihrem Leader. Führung sollte für Generation Z immer auf Augenhöhe stattfinden, geprägt von einer offenen Kommunikation sowie einem wertschätzenden Umgang. Zudem sollte die Führungskraft als Ansprechpartner bei Problemen und Fragen für die Generation Z zur Seite stehen. Die dargestellten Ergebnisse der Arbeit leisten einen wichtigen Beitrag für Wissenschaftler im Forschungsfeld Generationsmanagement und helfen zudem Entscheidungsträgern im Personalmanagement die Anforderungen und Erwartungen der jungen Generation Z zu erfüllen. Somit profitieren sie nicht nur im Recruiting davon, sondern können die jungen Talente möglicherweise langfristig an das Unternehmen binden.

Satzung über die Wahl der Doktorandenvertretung der Universität Koblenz Teil-Grundordnung zum Qualitätssicherungssystem der Rheinland-Pfälzischen Technischen Universität Kaiserslautern-Landau

The Coronavirus Pandemic has influenced the lives of many people. We analyzed the effects of physical activity and stress on students’ motivation during the Pandemic. Participants were 254 university students who reported their academic motivation, physical activity, general stress, the Coronavirus Pandemic strain, and their Coronavirus stress. Women reported higher levels of Coronavirus stress, general stress, and motivation. The Coronavirus stress was predicted by the strain of the Coronavirus Pandemic but not by physical activity. General stress and gender predicted mastery goals, and performance goals were predicted by general stress. Physical activity was not related to students’ motivation during the Pandemic. Higher levels of general stress were associated with higher academic motivation. Negative emotions like stress could have enhanced students’ motivation during uncertain times of the Pandemic. Moreover, a moderate stress level could be favorable for academic dedication and achievement.