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Der Arbeitsmarkt in Deutschland erlebt einen technologisch bedingten Strukturwandel. Durch Digitalisierung werden Tätigkeiten substituierbar, Berufsbilder und dafür benötigte Qualifikationsprofile wandeln sich. Für die Arbeitskräfte resultiert daraus ein Anpassungsdruck, sich zum Erhalt ihres Humankapitals bzw. ihrer Beschäftigungsfähigkeit weiterzubilden. Fraglich ist, inwieweit die Individuen diesen Druck wahrnehmen und mit entsprechenden Weiterbildungen reagieren. Um einen Erklärungsbeitrag zum Weiterbildungsverhalten der Arbeitskräfte in Bezug auf den technologischen Wandel zu leisten, widmet sich das Promotionsvorhaben der Forschungsfrage: „Inwieweit reagieren Arbeitskräfte bezüglich ihres Weiterbildungsverhaltens auf einen sich digitalisierungsbedingt wandelnden Arbeitsmarkt?“
The use of agricultural plastic covers has become common practice for its agronomic benefits such as improving yields and crop quality, managing harvest times better, and increasing pesticide and water use efficiency. However, plastic covers are suspected of partially breaking down into smaller debris and thereby contributing to soil pollution with microplastics. A better understanding of the sources and fate of plastic debris in terrestrial systems has so far been hindered by the lack of adequate analytical techniques for the mass-based and polymer-selective quantification of plastic debris in soil. The aim of this dissertation was thus to assess, develop, and validate thermoanalytical methods for the mass-based quantification of relevant polymers in and around agricultural fields previously covered with fleeces, perforated foils, and plastic mulches. Thermogravimetry/mass spectrometry (TGA/MS) enabled direct plastic analyses of 50 mg of soil without any sample preparation. With polyethylene terephthalate (PET) as a preliminary model, the method limit of detection (LOD) was 0.7 g kg−1. But the missing chromatographic separation complicated the quantification of polymer mixtures. Therefore, a pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) method was developed that additionally exploited the selective solubility of polymers in specific solvents prior to analysis. By dissolving polyethylene (PE), polypropylene (PP), and polystyrene (PS) in a mixture of 1,2,4-trichlorobenzene and p-xylene after density separation, up to 50 g soil became amenable to routine plastic analysis. Method LODs were 0.7–3.3 mg kg−1, and the recovery of 20 mg kg−1 PE, PP, and PS from a reference loamy sand was 86–105%. In the reference silty clay, however, poor PS recoveries, potentially induced by the additional separation step, suggested a qualitative evaluation of PS. Yet, the new solvent-based Py-GC/MS method enabled a first exploratory screening of plastic-covered soil. It revealed PE, PP, and PS contents above LOD in six of eight fields (6% of all samples). In three fields, PE levels of 3–35 mg kg−1 were associated with the use of 40 μm thin perforated foils. By contrast, 50 μm PE films were not shown to induce plastic levels above LOD. PP and PS contents of 5–19 mg kg−1 were restricted to single observations in four fields and potentially originated from littering. The results suggest that the short-term use of thicker and more durable plastic covers should be preferred to limit plastic emissions and accumulation in soil. By providing mass-based information on the distribution of the three most common plastics in agricultural soil, this work may facilitate comparisons with modeling and effect data and thus contribute to a better risk assessment and regulation of plastics. However, the fate of plastic debris in the terrestrial environment remains incompletely understood and needs to be scrutinized in future, more systematic research. This should include the study of aging processes, the interaction of plastics with other organic and inorganic compounds, and the environmental impact of biodegradable plastics and nanoplastics.
In the last decades, it became evident that the world is facing an unprecedented, human-induced global biodiversity crisis with amphibians being one of the most threatened species groups. About 41% of the amphibian species are classified as endangered by the IUCN, but even in amphibian species that are listed as "least concern", population declines can be observed on a local level. With land-use change and agrochemicals (i.e. pesticides), two of the main drivers for this amphibian decline are directly linked to intensive agriculture, which is the dominant landscape type in large parts of Europe. Thus, understanding the situation of amphibians in the agricultural landscape is crucial for conservation measures. In the present thesis, I investigated the effects of viticulture on amphibian populations around Landau in der Pfalz (Germany) in terms of habitat use, pesticide exposure, biometric traits as well as genetic and age structure. From the perspective of amphibians, land-use change means usually the destruction of habitats in agricultural landscapes, which often leads to landscape fragmentation. Thus, I followed the question if also vineyards lead to the fragmentation of the landscape and if pesticides that are frequently used in viticulture have to be considered as a factor too, so if there is a chemical landscape fragmentation. Using telemetry, I could show that common toads (Bufo bufo) can be found directly in vineyards, but that they tend to avoid them as habitat. Analysing the genetic structure of common frogs (Rana temporaria) revealed that vineyards have to be considered as a barrier for amphibians. To identify if pesticides contribute to the resulting landscape fragmentation, I conducted an arena choice experiment in the laboratory in which I found evidence for an avoidance of pesticide-contaminated soil. Such an avoidance could be one of the underlying reasons for a potential chemical landscape fragmentation. By combining telemetry data with information about pesticide applications from local wine growers, I could show that a large part of the common toads is likely to come in contact with pesticides. Further, I demonstrated that the agricultural landscape, probably due to the application of pesticides, can have negative effects on the reproduction capacity of common toads. By studying palmate newts (Lissotriton helveticus) I found that adult newts from agricultural ponds are smaller than those from forest ponds. As I did not find differences in the age structure and growth, these differences might be carry-over effects from earlier life stages. While agricultural ponds might be suitable habitats for adult palmate newts, the potential carry-over effect indicates suboptimal conditions for larvae and/or juveniles. I conclude that the best management measure for sustaining amphibians in the agricultural landscape would be a heterogeneous cultural landscape with a mosaic of different habitat patches that work without or at least a reduced amount of pesticides. Green corridors between populations and different habitats would allow migrating individuals to avoid agricultural and thus pesticide-contaminated areas. This would reduce the pesticide exposure risk of amphibians, while preventing the fragmentation of the landscape and thus the isolation of populations.
Der Zweck dieser Arbeit ist es, sich auf die kritischen Forschungsherausforderungen und -themen zu konzentrieren, die UI/UX-Designprinzipien umgeben, mit einem Schwerpunkt auf kulturübergreifenden Konzepten aus der Perspektive von E-Learning-Plattformen. Zu diesem Zweck betrachten wir zunächst die kulturellen Dimensionen auf der Grundlage des Hofstede-Rahmens mit dem Ziel, wichtige kulturelle Werte zu identifizieren. Als zweites Ziel der Forschung erleichtert eine Reihe von Kriterien, die so genannte Usability-Heuristik von Nielsen, die Erkennung von Usability Problemen bei der Gestaltung von Benutzeroberflächen (UI). Die Usability-Heuristiken umfassen zehn Variablen, die die Interaktion zwischen dem Benutzer und einem Produkt oder System beeinflussen. Wenn wir uns näher mit
diesen Themen befassen, werden wir in der Lage sein, eine Matrix mit Beziehungen zwischen der heuristischen Bewertung von Nielsen und dem kulturellen Rahmen von Geert Hofstede aufzudecken. Abschließend erörtern wir das mögliche Potenzial kultureller Werte zur Beeinflussung von Benutzeroberflächen für E-Learning-Plattformen. In der Tat gibt es einige Funktionen in E-Learning-Plattformen, die aufgrund der Kultur weniger diskutiert werden, obwohl sie sehr praktisch in die Plattformen integriert werden können.
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.
Menschen wünschen sich im Allgemeinen "Kontrolle" über ihre Umweltbedingungen. Dieses Bedürfnis kommt in Form von Selbstgestaltungen von Architektur und Selbstregulierungen von Stressoren zum Ausdruck. Aus diesem Grund wird das Konzept der Umweltkontrolle als zentrales Kriterium für gebaute Umwelten in allen drei Fall-Studien zu Schule (Waldorfschule Köln), Hochschule (Universität Koblenz) und Bürogebäude (Post Tower Bonn) angewendet. Im deutschen Sprachraum werden damit erstmalig in einer Monographie psychologische Untersuchungen von innovativen Gebäuden in Anlehnung an die International Building Performance Evaluation (Gebäudeleistungsevaluation) beschrieben. Der "Koblenzer Architekturfragebogen" wird als Instrument zur Beurteilung von gebauten Umwelten in drei Varianten vorgestellt. Bis zu 21 psychologische Kriterien für den Erfolg von Organisationen werden pro Studie angewandt. Ziel aller drei Studien ist unter anderem, Empfehlungen für Verbesserungen von Um- und Neubauten benennen zu können. Zwei zentrale Fragestellungen lauten daher: Unterscheidet sich in einer User-Needs Analysis eine Einschätzung des Gebäudes "zur Zeit" von der Beurteilung der "Wichtigkeit in Zukunft"? Haben Merkmale der Architektur Auswirkungen auf die Performance-Kriterien? Zu den Studien wurden drei Abbildungssätze nach dem Facettenansatz und zwei Schemata zur Beurteilung der Qualität von Schul- und Bürogebäuden entwickelt. Die in den drei Studien ermittelten Zusammenhänge der zentralen Performance-Kriterien lassen begründet annehmen, dass durch gezielte Verbesserungen wichtiger Umweltaspekte, insbesondere solcher, die Umweltkontrolle ermöglichen, das Wohlbefinden und somit die Leistung von Nutzern positiv beeinflusst werden können.
Agricultural plastic covers made from polyethylene (PE) and polypropylene (PP) provide increased yields and an improved crop quality. However, such covers are suspected of partially breaking down into smaller debris and thereby contributing to soil pollution with microplastics. To scrutinize this, we randomly sampled 240 topsoil cores (0–5 cm) from eight fields which were covered with fleeces, perforated foils, and plastic mulches for less than 2 years. Samples from the field periphery (50 m perimeter) served as a reference. Visual plastic debris > 2 mm was analyzed by Fourier transform infrared spectroscopy. Smaller, soil-associated plastic debris was dispersed from 50 g of fine soil (≤ 2 mm) using sodium hexametaphosphate solution and density-separated with saturated NaCl solution. The collected PE, PP, and polystyrene (PS) debris was selectively dissolved in a mixture of 1,2,4-trichlorobenzene and p-xylene at 150 °C and quantified by pyrolysis–gas chromatography–mass spectrometry (Py-GC/MS). We counted six PE and PS fragments > 2 mm in two out of eight fields. By contrast, Py-GC/MS detected PE, PP, and PS contents in the fine soil of six fields (6 % of all samples). In three fields, PE levels of 3–35 mg kg−1 were potentially associated with the use of thinner and less durable perforated foils (40 µm thickness). This was slightly more pronounced at field edges where the plastic covers are turned and weighed down. By contrast, 50 µm thick PE films were not shown to emit any plastic debris. PP contents of 5–10 mg kg−1 were restricted to single observations in the field centers of three sites. At one site, we found expanded PS particles > 2 mm that concurred with elevated PS levels (8–19 mg kg−1) in the fine soil. Both PP and PS were distributed indistinctly across sites so that their source remained unresolved. In addition, the extent to which plastic contents of up to 7 mg kg−1 in the field periphery of some sites were attributed to wind drift from the covered fields or from external sources needs to be investigated in future studies. Our results suggest that the short-term use of thicker and more durable plastic covers should be preferred over thinner or perforated films to limit plastic emissions and accumulation in soil.
Eine Ursache des Insektenrückgangs ist die Abnahme der für Arthropoden wichtigen Lebensräume. Der kleinstrukturierte Obstanbau als Dauerkultur mit vielfältigen Strukturen (Bäume, Grünland, offener Boden) kann als Refugium wirken. Gerade Dauerkulturen, welche über viele Jahre bestehen bleiben, können einen großen ökologischen Wert für Insekten und Spinnentiere darstellen, wenn die negativen Einflüsse der Bewirtschaftung durch gezielte Maßnahmen minimiert werden. Im Gegensatz zu den gut untersuchten Streuobstwiesen liegen bisher nur wenige oder ungenaue Daten über die Arthropodenfauna in Erwerbsobstanlagen vor. Ziele dieser Arbeit sind eine genauere Erfassung der Arthropodenfauna in Erwerbsobstanlagen, Benennung der Einflussfaktoren und Erarbeitung einer indikatorgestützten Bewertungsmethode mit Entwicklung von Maßnahmen zur Förderung der Biodiversität. Es wurde eine intensive Erfassung der Insekten und Spinnentiere auf Basis von Individuenzahlen, Verteilung der Tiere auf Großgruppen, Artenzahlen der Käfer (inkl. Rote Liste) und Wanzen, deren Diversität und der sie beeinflussenden Faktoren auf vier Erwerbsobstflächen und einer Streuobstwiese als Referenzfläche in der Gemeinde Zornheim (Rheinland-Pfalz) untersucht. Mittels des erarbeiteten Bewertungsbogens wurden die Auswirkungen der fünf Faktorenkomplexe: Sonderstrukturen, Anlagenstruktur, Beschattung, Mahdregime und Einsatz von Pflanzenschutzmitteln auf die Arthropodenfauna erhoben und die auf der Fläche zu erwartende Biodiversität ermittelt. Die visuelle Darstellung der Einflussfaktoren mit Netzdiagrammen zeigt biodiversitätsbeeinträchtigende Faktoren und ermöglicht so Empfehlungen zur Aufwertung der Biodiversität. Die Bewertungsmethode kann nach Verifizierung im Rahmen von erfolgsorientierten Agrarumwelt- und Klimamaßnahmen (AUKM), zur Anerkennung von Kompensationsmaßnahmen (z.B. PIK) und zur Ermittlung des ökologischen Wertes (Ökosystemdienstleistung) von Obstanlagen genutzt werden. In modifizierter Form könnte es ebenfalls im Bereich der Flächenbewertung in Landschafts- und Bauleitplanung eingesetzt werden.
Agricultural intensification is leading to a severe decline in farmland biodiversity worldwide. The resulting landscape simplification through the expansion of monocultures and removal of non-crop habitats has a major impact on arthropod communities in agricultural landscapes. While arable fields are often highly disturbed and ephemeral habitats that are unsuitable for many species, non-crop habitats in agroecosystems can provide important refugia. The creation of non-crop habitats through agri-environmental schemes (AES) in intensive agricultural landscapes, such as the ‘Maifeld’ region in western Germany, is intended to mitigate the negative effects of agricultural intensification, although the effectiveness of these measures for nature conservation is still controversial. Therefore, this work focuses on the taxonomic and functional diversity of beetles (Coleoptera) and spiders (Araneida), being important providers of ecosystem services, between wheat fields and different non-crop habitats, namely grassy field margins adjacent to wheat and oilseed rape fields, small- and large-scale set-aside areas sown with wildflowers, and permanent grassland fallows. Arthropods were collected between 2019 and 2020 using pitfall traps and suction sampling. Land-use type influenced beetle and spider diversity in the study area, with significantly higher values in grassland fallows than wheat fields. Surprisingly, species diversity differed little among all non-crop habitats, but all harboured distinct species assemblages. In particular, large long-term grassland fallows showed the largest within-group variation of beetle and spider assemblages and represented important habitats, especially for habitat specialists and threatened species, likely due to their variable soil moisture and complex habitat structure. In contrast, the homogeneous arthropod assemblages of wheat fields exhibited lower trait richness and were dominated by a few predatory species adapted to such disturbed, man-made habitats. Interestingly, all conservation measures complemented each other in that they contributed in different ways to supporting beetles and spiders in agricultural landscapes. Even small-scale non-crop habitats and existing habitat boundaries in an agricultural matrix appear to be valuable habitats for farmland arthropods by enhancing taxonomic diversity. Field margins and small wildflower-sown patches can link isolated non-crop habitats and contribute to a heterogeneous agricultural landscape. Consequently, a combination of various small- and large-scale greening measures leads to increased compositional and configurational landscape heterogeneity, resulting in improved beetle and spider diversity. Considering the ongoing loss of farmland biodiversity worldwide, agri-environmental schemes should be promoted in the future, as they are particularly important for arthropod conservation in intensive agricultural landscapes such as the Maifeld region.
Usability experts conduct user studies to identify existing usability problems. An established method is to record gaze behavior with an eye-tracker. These studies require a lot of effort to evaluate the results. Automated recognition of good and bad usability in recorded user data can support usability experts in eye tracking evaluation and reduce the effort. The objective of that bachelor thesis is to identify suitable eye-tracking metrics that correlate with the quality of usability. For this purpose, the central research question is answered: Which eye-tracking metrics correlate with the quality of a web form’s operation? To answer the research question, a quantitative A/B-user-study with eye-tracking was conducted and recorded the
gaze behavior of 30 subjects while filling out the web form. The web form was designed, that each web form page was available as a good and bad variant according to known usability guidelines. The results confirm a significant correlation between the eye-tracking-metric "number of visits to an
AOI" and the quality of the operation of a web form. The eye-tracking-metrics
"number of fixations within an AOI" and "duration of fixations within an AOI" also correlate with the quality of usability. No correlation could be confirmed for the "time of the first fixation within an AOI".
Enterprise Collaboration Systems (ECS) werden zunehmend als Kernkomponenten des digitalen Arbeitsplatzes in Unternehmen eingesetzt, die mit der Implementierung dieser neuen Softwaregattung jeweils unterschiedliche Ziele für die innerbetriebliche Zusammenarbeit verfolgen. Diese Ziele werden in der Praxis oftmals nicht eindeutig genug formuliert. Der Einsatz von traditionellen Controlling-Kennzahlen mit dem Schwerpunkt auf Termineinhaltung und Kosten sind zudem ungeeignet, um die Realisierung des individuellen Nutzens von ECS zu messen. Diese Forschungsarbeit beschreibt die Entwicklung und Anwendung des Benefits Scorecards for Collaboration Platforms in Enterprises (SCoPE) Frameworks, das als ein Rahmenwerk für die kennzahlengestützte Nutzenmessung von ECS dient und an dem Goal-Question-Metrics-Approach der NASA sowie der Balance Scorecard von Kaplan & Norton angelehnt ist. Die Ergebnisse tragen zu einem breiteren Verständnis der kennzahlenbasierten Nutzenanalyse für ECS in Organisationen bei. Das Benefits-SCoPE-Framework wurde in enger Zusammenarbeit mit Experten aus 16 Anwenderunternehmen im Rahmen der Initiative IndustryConnect entwickelt. In einem design-orientierten Ansatz wurde ein ausgewählter Methodenmix angewandt, inklusive Experteninterview, Fokusgruppe, Workshop und Card Sorting. Der von Anwenderunternehmen erwartete Nutzen des ECS wird in spezifische, durch Kennzahlen beantwortbare Fragestellungen umformuliert und fragmentiert. Insgesamt konnten so 313 nutzenorientierte Fragen von drei Anwenderunternehmen identifiziert werden. Die durchgeführte Kategorisierung der Fragen verdeutlicht zum einen das gemeinsame Verständnis der Unternehmen hinsichtlich der entscheidenden Faktoren für die Nutzenrealisierung von ECS und zum anderen die Nutzen-ziele, die die Unternehmen durch den Einsatz des ECS anvisieren. Die Entwicklung und Erhebung von Kennzahlen zur quantitativen Beantwortung von ausgewählten Fragestellungen wird mit funktions-fähigen Prototypen auf einer operativen Kollaborationsplattform demonstriert, die seit mehr als sieben Jahren im Einsatz ist und mehr als 5.000 registrierte Benutzer aufweist. Die Kennzahlenentwicklung, die Auswahl der Datenerhebungsmethode, die Durchführung der Messung sowie die Interpretation der Messergebnisse werden im Framework durch die Verwendung von Benefits Scorecards unterstützt. Die individuelle Orchestrierung mehrerer Benefits Scorecards repräsentiert die Struktur eines Ordnungssystems zur ECS-Nutzenanalyse in Anwenderunternehmen und verdeutlicht das Vorgehen zur Erhebung der äquivalenten Daten.
The growing numbers of breeding rooks (Corvus frugilegus) in the city of Landau (Rhineland- Palatinate, Germany) increase the potential for conflict between rooks and humans, which is mainly associated with noise and faeces. Therefore, the aim of this work is a better understanding of the breeding tree selection of the rook in order to develop options for action and management in the future.
Part I of this thesis provides general background information on the rook and includes mapping of the rookeries in the Anterior Palatinate and South Palatinate including Landau in the year 2020. That mapping revealed that the number of rural colonies has decreased, while the number of urban colonies has increased in the study area in the last few years. In line with current literature, tree species and tree size were important criteria for breeding tree selection. However, the mapping showed that additional factors must be important as well.
Therefore, as rooks seem to often breed along traffic axes, Part II of this thesis examines how temperature, artificial light and noise, which are all linked to traffic axes, affect the breeding tree selection of the rook in the city of Landau. The following three hypotheses are developed: (1) manually selected breeding trees (Bm) have a warmer microclimate than manually selected non-breeding trees (Nm) or randomly selected non-breeding trees (Nr), (2) Bm are exposed to a higher light level than Nm or Nr and (3) Bm are exposed to a higher noise level than Nm or Nr. To test these hypotheses, 15 Bm, 13 Nm and 16 Nr are investigated.
The results show that Bm were exposed to more noise than both types of non-breeding trees (μBm, noise = 36.52481 dB, μNm, noise = 31.27229 dB, μNr, noise = 29.17417 dB) where the difference between Bm and Nr was significant. In addition, there was a tendency for Bm to be exposed to less light (μBm, light = 0.356 lx) than Nm (μNm, light = 0.4107692 lx) and significantly less light than Nr (μNr, light = 1.995 lx), while temperature did not differ between the groups (μBm, temp = 16.90549 °C, μNm, temp = 16.93118 °C, μNr, temp = 17.28639 °C).
This study shows for the first time that rooks prefer trees which are exposed to low light levels and high noise levels, i.e. more intense traffic noise, for breeding. It can only be speculated that the cause of this is lower enemy pressure at such sites. The fact that temperature does not seem to have any influence on breeding tree selection may be due to only small temperature differences at nest height, which might be compensated by breeding behaviour. Consequently, in the long term one management approach could be to divert traffic from inner-city areas, especially schools and hospitals, to bypasses. If tree genera suitable for rooks, such as plane trees, are planted along the bypasses, those sites could provide suitable alternative habitats to inner-city breeding locations, which become less attractive for breeding due to noise reduction. In the short term in addition to locally implemented repellent measures the most effective approach is to strengthen rook acceptance among the population. However, further research is needed to verify the results of this thesis and to gain further insights into rook breeding site selection in order to develop effective management measures.
Objectives: Crayfish plague disease, caused by the oomycete pathogen Aphanomyces astaci represents one of the greatest risks for the biodiversity of the freshwater crayfish. This data article covers the de novo transcriptome assembly and annotation data of the noble crayfish and the marbled crayfish challenged with Ap. astaci. Following the controlled infection experiment (Francesconi et al. in Front Ecol Evol, 2021, https://doi.org/10.3389/fevo.2021.647037), we conducted a differential gene expression analysis described in (Boštjančić et al. in BMC Genom, 2022, https://doi.org/10.1186/s12864-022-08571-z) Data description: In total, 25 noble crayfish and 30 marbled crayfish were selected. Hepatopancreas tissue was isolated, followed by RNA sequencing using the Illumina NovaSeq 6000 platform. Raw data was checked for quality with FastQC, adapter and quality trimming were conducted using Trimmomatic followed by de novo assembly with Trinity. Assembly quality was assessed with BUSCO, at 93.30% and 93.98% completeness for the noble crayfish and the marbled crayfish, respectively. Transcripts were annotated using the Dammit! pipeline and assigned to KEGG pathways. Respective transcriptome and raw datasets may be reused as the reference transcriptome assemblies for future expression studies.
To render the surface of a material capable of withstanding mechanical and electrochemical loads, and to perform well in service, the deposition of a thin film or coating is a solution. In this project, such a thin film deposition is carried out. The coating material chosen is titanium nitride (TiN) which is a ceramic material known to possess a high hardness (>10 GPa) as well as good corrosion resistance. The method of deposition selected is high power impulse magnetron sputtering (HiPIMS) that results in coatings with high quality and enhanced properties. Sputtering is a physical process that represents the removal or dislodgment of surface atoms by energetic particle bombardment. The term magnetron indicates that a magnetic field is utilized to increase the efficiency of the sputtering process. In HiPIMS, a high power is applied in pulses of low duty cycles to a cathode that is sputtered and that consists of the coating material. As result of the high power, the ionization of the sputtered material takes place giving the possibility to control these species with electric and magnetic field allowing thereby the improvement and tuning of coating properties. However, the drawback of HiPIMS is a low deposition rate.
In this project, it is demonstrated first that it is possible to deposit TiN coating using HiPIMS with an optimized deposition rate, by varying the magnetic field strength. It was found that low magnetic field strength (here 22mT) results in a deposition rate similar to that of conventional magnetron sputtering in which the average power is applied continuously, called also direct current magnetron sputtering (dcMS). The high deposition rate at low magnetic field strength was attributed to a reduction in the back attraction probability of the sputtered species. The magnetic field strength did not show noticeable influence on the mechanical properties. The proposed explanation was that the considered peak current density interval 1.22-1.72 A∙cm-2 does not exhibit dramatic changes in the plasma dynamics.
In a second part, using the optimized deposition rate, the optimized chemical composition of TiN was determined. It was shown that the chemical composition of TiN does not significantly influence the corrosion performance but impacts considerably the mechanical properties. It was also shown that the corrosion resistance of the coatings deposited using HiPIMS was higher than that of the coatings deposited using dcMS.
The third study was the effect of annealing post deposition on the properties of TiN coating deposited using HiPIMS. The hardness of the coatings showed a maximum at 400°C reaching 24.8 GPa. Above 400°C however, a lowering of the hardness was measured and was due to the oxidation of TiN which led to the formation of TiN-TiO2 composites with lower mechanical properties.
The coating microscopic properties such as crystal orientation, residual stresses, average grain size were determined from X-ray diffraction data and the roughness was measured using atomic force microscopy. These properties were found to vary with the magnetic field strength, the chemical composition as well as the annealing temperature.
Die Ukraine sieht seit dem Euromaidan im Jahr 2014 ihre Zukunft in einer stabilen Veran-kerung im westlichen Wertesystem. Für die EU ist die Ukraine ein priority partner und damit von besonderem Gewicht. Deshalb lag es folgerichtig im Interesse der EU, die Ukra-ine nach Kräften auf diesem Weg zu unterstützen.
Die wissenschaftliche Forschung zur EU-Demokratieförderung konzentrierte sich bis-her im Wesentlichen auf Staaten mit konkreter EU-Beitrittsperspektive. Sie kam zu dem Ergebnis, dass der Erfolg der Demokratieförderung maßgeblich von der Konditionierung eines EU-Beitritts getragen war. Damit konnte dieser Erfolg der EU als dominanter Träger der Demokratieförderung zugeordnet werden.
Mit dem Fokus auf Staaten ohne EU-Beitrittsperspektive entfällt diese Konditionie-rung. Auch weitere Akteure traten bei der Demokratieförderung hinzu, und die Wirksam-keit der Demokratieförderung kann nicht mehr der EU direkt zugeordnet werden. Es ent-stand also eine Forschungslücke, in welcher Weise jetzt die Wirksamkeit der EU-Demokratieförderung analysiert werden kann. Die vorliegende Studie greift diese For-schungslücke auf.
Zunächst wird analysiert, welcher Demokratiestatus der Ukraine und welche Defizite sich für den Untersuchungszeitraum ermitteln lassen. Im Anschluss erfolgt die Analyse der EU-Demokratieförderung auf der Grundlage einer eigens dafür entworfenen Definition von kohärenter Strategie, die eine statische und eine dynamische Dimension abbildet.
Die statische Dimension geht der Frage nach, ob die Zielsetzungen und Vorhaben der EU-Demokratieförderung auf die Demokratiedefizite zugeschnitten waren. Die dynami-sche Dimension des Transformationsprozesses beschäftigt sich mit der Frage, ob das jewei-lige Vorgehen den Prinzipien aus sozialkonstruktivistischer Perspektive folgte. Mit dieser sozialkonstruktivistischen Perspektive wird ein Weg aufgezeigt, wie man ohne eine EU-Beitritts-Konditionierung die Transformation demokratischer Werte und Normen erfolg-reich ausgestalten kann.
Das Ergebnis ist, dass die EU-Strategie der Demokratieförderung zwar mit ihren Ziel-setzungen und Vorhaben auf die Demokratiedefizite der Ukraine ausgerichtet war, aber auch, dass das Vorgehen in einem Fall nicht den Prinzipien aus sozialkonstruktivistischer Perspektive entsprach. Diesem Vorgehen lag keine kohärente EU-Strategie zugrunde.
Die Analyse auf der Ebene der Strategie lässt der EU-Demokratieförderung keine di-rekte Wirkung zuweisen, da auch andere Akteure eine Wirkung entfalten. Auf der Ebene eines konkreten Reformprojekts konnte dann der Nachweis geführt werden, dass die De-zen-tralisierungsreform direkt der EU zugeordnet werden kann, das Vorgehen den Prinzi-pien aus sozialkonstruktivistischer Perspektive folgt und eine positive Wirkung entfaltet.
Begünstigt wurde dieser Erfolg, da er sich auf demokratische Werte und Normen ab-stützen konnte, die in überdurchschnittlicher Ausprägung bereits vorhanden waren. Dar-über hinaus wurde aufgezeigt, dass dieses Projekt eine breit gefächerte potenzielle Wirkung auf den Reformprozess in Richtung Demokratie entfaltet.
Die Dissertation wurde am 14. Dezember 2021 abgeschlossen und an der Universität Koblenz-Landau eingereicht. Im Nachgang bietet ein „Postskript“ mit Datum September 2022 unter Berücksichtigung aktueller Entwicklungen eine Perspektive für weiterführende Forschungsfragen.
Die Arbeit stellt eine Systematisierung der wissenschaftsphilosophischen Gedanken der klassischen Pragmatisten (Charles S. Peirce, William James, John Dewey) dar.
Deren Erfahrungstheorie sowie die Bestimmung des Verhältnisses von Theorie und Praxis bilden die Grundlage einer holistischen Wissenschaftsphilosophie.
Die exemplarische Anwendung auf klassische wissenschaftstheoretische Fragestellungen zeigt die Aktualität des Ansatzes.
Diet-related effects of antimicrobials in aquatic decomposer-shredder and periphyton-grazer systems
(2022)
Leaf-associated microbial decomposers as well as periphyton serve as important food sources for detritivorous and herbivorous macroinvertebrates (shredders and grazers) in streams. Shredders and grazers, in turn, provide not only collectors with food but also serve as prey for predators. Therefore, decomposer-shredder and periphyton-grazer systems (here summarized as freshwater biofilm-consumer systems) are highly important for the energy and nutrient supply in heterotrophic and autotrophic stream food webs. However, both systems can be affected by chemical stressors, amongst which antimicrobials (e.g., antibiotics, fungicides and algaecides) are of particular concern. Antimicrobials can impair shredders and grazers not only via waterborne exposure (waterborne effect pathway) but also through dietary exposure and microorganism-mediated alterations in the food quality of their diet (dietary effect pathway). Even though the relevance of the latter pathway received more attention in recent years, little is known about the mechanisms that are responsible for the observed effects in shredders and grazers. Therefore, the first objective of this thesis was to broaden the knowledge of indirect antimicrobial effects in a model shredder and grazer via the dietary pathway. Moreover, although freshwater biofilm-consumer systems are most likely exposed to antimicrobial mixtures comprised of different stressor groups, virtually nothing is known of these mixture effects in both systems. Therefore, the second objective was to assess and predict diet-related antimicrobial mixture effects in a model freshwater biofilm-consumer system. During this thesis, positive diet-related effects of a model antibiotic on the energy processing and physiology of the shredder Gammarus fossarum were observed. They were probably triggered by shifts in the leaf-associated microbial community in favor of aquatic fungi that increased the food quality of leaves for the shredder. Contrary to that, a model fungicide induced negative effects on the energy processing of G. fossarum via the dietary pathway, which can be explained by negative impacts on the microbial decomposition efficiency leading to a reduced food quality of leaf litter for gammarids. For diet-related antimicrobial effects in periphyton-grazer systems, a model algaecide altered the periphyton community composition by increasing nutritious and palatable algae. This resulted in an enhanced consumption and physiological fitness of the grazer Physella acuta. Finally, it was shown that complex horizontal interactions among leaf-associated microorganisms are involved, making diet-related antimicrobial mixture effects in the shredder G. fossarum difficult to predict. Thus, this thesis provides new insights into indirect diet-related effects of antimicrobials on shredders and grazers as well as demonstrates uncertainties of antimicrobial mixture effect predictions for freshwater biofilm-consumer systems. Moreover, the findings in this thesis are not only informative for regulatory authorities, as indirect effects and effects of mixtures across chemical classes are not considered in the environmental risk assessment of chemical substances, but also stimulate future research to close knowledge gaps identified during this work.
Abstract zum Print-Buch: Walden, R. (2008). Architekturpsychologie: Schule, Hochschule und Bürogebäude der Zukunft. Lengerich: Pabst Science Publishers. Menschen wünschen sich im Allgemeinen „Kontrolle“ über ihre Umweltbedingungen (vgl. Flammer, 1990; Burger, 1992). Dieses Bedürfnis kommt in Form von Selbstgestaltungen von Architektur und Selbstregulierungen von Stressoren zum Ausdruck. Aus diesem Grund wird das Konzept der Umweltkontrolle als zentrales Kriterium für gebaute Umwelten in allen drei Fall-Studien zu Schule, Hochschule und Büro angewendet. Die Erhebung smethoden Programming (nutzerorientierte Programmentwicklung), User-Needs Analysis (Nutzer-Bedarfs-Analyse) und Post-Occupancy Evaluation werden im Hinblick auf ihren Stellenwert für die Building Performance Evaluation (Gebäudeleistungsevaluation) (Preiser & Schramm, 1997; 2005) erläutert. Der „Koblenzer Architekturfragebogen“ wird als Instrument zur Beurteilung von gebauten Umwelten in drei Varianten vorgestellt. Es werden zu den drei Studien jeweils ausgewählte Ergebnisse zu zwei verschiedenen Umweltbereichen berichtet.
Auswirkungen von Architektur auf Performance von Nutzern (vgl. BOSTI-Studien, 1984, 2001) werden im empirischen Teil in drei Studien zu innovativen Gebäuden (Waldorfschule in Köln, Universität in Koblenz, Post Tower in Bonn) ermittelt. Performance wird gemessen anhand von 1) Lern- und Arbeitsleistungen, 2) Wohlbefinden und 3) Umweltkontrolle sowie 4) Sozialverhalten im Fall der Schulstudie und mit der Hilfe von 16 (Bürogebäude) bzw. 21 (Universität) psychologischen Kriterien für den Erfolg von Organisationen. Ziel aller drei Studien ist unter anderem, das theoretische Konzept „Umweltkontrolle“ zu überprüfen und Empfehlungen für Verbesserungen von Um- bzw. Neubauten benennen zu können. Zwei zentrale Frages tellungen lauten daher: Unterscheidet sich in einer User-Needs Analysis eine Einschätzung des Gebäudes „zur Zeit“ von der Beurteilung der „Wichtigkeit in Zukunft“? Haben Merkmale der Architektur Auswirkungen auf die Performance-Kriterien?
Zu den Studien wurden drei Abbildungssätze nach dem Facettenansatz (Borg, 1996) und zwei Schemata zur Beurteilung der Qualität von Schul- und Bürogebäuden entwickelt. Aus den Schemata wurden zur Schule 139 Fragen für 26 Lehrer und 86 Fragen für 122 Schüler gewonnen, zur Hochschule 203 Fragen für 147 Studierende und 28 Dozenten sowie zu dem Bürogebäude 254 Fragen für 56 studentische Beurteiler. Einzelne Merkmale von Gebäuden wurden anhand einer Skala von +2 ☺☺ („zur Zeit“ sehr gut bzw. sehr wichtig „in Zukunft“) bis –2 // („zur Zeit“ sehr schlecht bzw. sehr unwichtig „in Zukunft“) bewertet. Die drei Performance-Hauptkriterien, insbesondere zu der Einschätzung der „Wichtigkeit in Zukunft“, korrelieren in der Regel in allen drei Studien substanziell und hoch signifikant miteinander, so dass erwartet werden kann, dass eine höhere Ei nschätzung von Umweltkontrolle durch die Nutzer
zu mehr Wohlbefinden führt und über beide Va riablen auch die Beurteilungen von Lern- und Arbeitsleistungen „in Zukunft“ gesteigert werden können. Nach den Ergebnissen der drei Studien wünschen si ch die Nutzer bzw. Beurteiler beispielsweise in allen drei Umwelten Rückzugsmöglichkeiten, in der Schule in Form von Schülerbüros, Nischen und Sitzgruppen im Klassenzimmer, in der Universität in Form von geschützten Bänken im Außenbereich und Arbeitstischen zum Beispiel in der Cafeteria und im Bürogebäude durch weniger Transparenz im Kombibüro und damit weniger Einsicht aller Tätigkeiten durch Vorgesetzte und Kollegen. Die in den drei Studien ermittelten Zusammenhänge der zentralen Perfor mance-Kriterien lassen begründet annehmen, dass durch gezielte Verbesserungen wichtiger Umweltaspekte, insbesondere solcher, die Umweltkontrolle ermöglichen, das Wohlbefinden und somit die Leistung von Nutzern positiv beeinflusst werden kann.
The presented study was motivated by the dynamic phenomena observed in basic catalytic surface reactions, especially by bi- and tristability, and the interactions between these stable states. In this regard, three reaction-diffusion models were developed and examined using bifurcation theory and numerical simulations.
A first model was designed to extend the bistable CO oxidation on Ir(111) to include hydrogen and its oxidation. The differential equation system was analyzed within the framework of bifurcation theory, revealing three branches of stable solutions.
One state is characterized by high formation rates (upper rate state, UR), while the other two branches display low formation rates (lower rate (LR) \& very low rate (VLR) states).
The overlapping branches form the shape of a `swallowtail', the curve of saddle-node bifurcations forming two cusps. Increasing the temperature leads to a subsequent unfolding and hence decreases the system complexity.
A series of numerical simulations representing possible experiments was conducted to illustrate the experimental accessibility (or the lack) of said states. Relaxation experiments show partially long decay times. Quasistatic scanning illustrates the existence of all three states within the tristable regime and their respective conversion once crossing a fold.
A first attempt regarding the state dominance in reaction-diffusion fronts was done. While UR seems to dominate in 1D, a 2D time-evolution shows that LR invades the interphase between UR and VLR.
Subsequently, a generic monospecies mock model was used for the comprehensive study of reaction-diffusion fronts. A quintic polynomial as reaction term was chosen, derived by the sixth-order potential associated with the `butterfly bifurcation'. This ensures up to three stable solutions($u_{0}$,$u_{1}$,$u_{2}$), depending on the four-dimensional parameter space.
The model was explored extensively, identifying regions with similar behaviors.
A term for the front velocity connecting two stable states was derived, depending only on the relative difference of the states' potential wells.
Equipotential curves were found, where the front velocity vanishes of a given front. Numerical simulations on a two-dimensional, finite disk using a triangulated mesh supported these findings.
Additionally, the front-splitting instability was observed for certain parameters. The front solution $u_{02}$ becomes unstable and divides into $u_{01}$ and $u_{12}$, exhibiting different front velocities. A good estimate for the limit of the front splitting region was given and tested using time evolutions.
Finally, the established mock model was modified from continuous to discrete space, utilizing a simple domain in 1D and three different lattices in 2D (square, hexagonal, triangular).
For low diffusivities or large distances between coupling nodes, fronts can become pinned, if the parameters are within range of the equipotential lines. This phenomenon is known as propagation failure and its extent in parameter space was explored in 1D. In 2D, an estimate was given for remarkable front orientations respective to the lattice using a pseudo-2D approximation. Near the pinning region, front velocities differ significantly from the continuous expectation as the shape of the curve potential becomes significant. Factors that decide the size and shape of the pinning regions are the coupling strength, the lattice, the front orientation relative to the lattice, and the front itself. The bifurcation diagram shows a snaking curve in the pinning region, each alternating branch representing a stable or unstable frozen front solution. Numerical simulations supported the observations concerning propagation failure and lattice dependence.
Furthermore, the influence of front orientation on the front velocity was explored in greater detail, showing that fronts with certain lattice-dependent orientations are more or less prone to propagation failure. This leads to the possibility of pattern formation, reflecting the lattice geometry. An attempt to quantify the front movement depending on angular front orientation has shown reasonable results and good agreement with the pseudo-2D approach.
Invasive species play increasing roles worldwide. Invasions are considered successful when species establish and spread in their exotic range. Subsequently, dispersal is a major determinant of species’ range dynamics. Mermessus trilobatus, native to North America, has rapidly spread in Europe via aerial dispersal. Here we investigated the interplay of ecological and evolutionary processes behind its colonisation success.
First, we examined two possible ecological mechanisms. Similar to other invasive invertebrates, the colonisation success of Mermessus trilobatus might be related to human-induced habitat disturbance. Opposite to this expectation, our results showed that densities of Mermessus trilobatus decreased with soil disturbance in grasslands suggesting that its invasion success was not connected to a ruderal strategy. Further, invasive species often escape the ecological pressures from novel enemies in their exotic ranges. Unexpectedly, invasive Mermessus trilobatus was more sensitive to a native predator than native Erigone dentipalpis during our predator susceptibility trials. This indicates that the relation between the invasive spider and its native predator is dominated by prey naïveté rather than enemy release.
The remaining three chapters of the thesis investigated the dispersal behaviour of this invasive species. Hitherto, studies of passive aerial dispersal used wind as the primary dispersal-initiating factor despite a recent demonstration of the effects of the atmospheric electric fields on spiders’ pre-dispersal behaviour. During our experiments, only the wind facilitated the flight, although electric fields induced pre-dispersal behaviour in spiders. Consequently, studies around passive aerial dispersal should control electric fields but use wind as a stimulating factor.
Rapidly expanding species might be disproportionately distributed in their exotic range, with an accumulation of dispersive genotypes at the leading edge of their range. Such imbalanced spatial segregation is possible when the dispersal behaviour of expanding species is heritable. Our results showed that the dispersal traits of Mermessus trilobatus were heritable through both parents and for both sexes with recessive inheritance of high dispersal ability in this species.
Following the heritability experiments, we documented an accelerated spread of Mermessus trilobatus in Europe and tested whether dispersal, reproduction or competing ability was at the source of this pattern. Our results showed that the accumulation of more mobile but not reproductive or competitive genotypes at the expansion front of this invasive species gave rise to an accelerated range expansion by more than 1350 km in under 45 years.
Invasive Mermessus trilobatus is inferior to native sympatric species with respect to competing ability (Eichenberger et al., 2009), disturbance tolerance and predation pressure. Nevertheless, the species successfully established in its exotic range and spread by accelerating its expansion rate. Rapid reproduction that balances the high ecological pressures might be the other potential mechanism behind its colonisation success in Europe and deserves further investigation.