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English prepositions take only a small proportion of the language but play a substantial role. Although prepositions are of course also frequently used in English textbooks for secondary school, students fail to incidentally acquire them and often show low achievements in using prepositions correctly. The strategy commonly employed by language instructors is teaching the multiple senses of prepositions by rote which fails to help the students to draw links between the different meanings in usage. New findings in Cognitive Linguistics (CL) suggest a different approach to teaching prepositions and thus might have a strong impact on the methodologies of foreign language teaching and learning on the aspects of meaningful learning. Based on the Theory of Domains (Langacker, 1987), the notions of image schemas (Johnson, 1987) as well as the Conceptual Metaphor Theory (Lakoff & Johnson, 1980), the present study developed a CL-inspired approach to teaching prepositions, which was compared to the traditional teaching method by an empirical study conducted in a German school setting. Referring to the participants from the higher track and the medium track, who are at different proficiency levels, the results indicate that the CL-inspired teaching approach improved students" performance significantly more than the traditional approach in all the cases for the higher track and in some cases for the medium track. Thus, these findings open up a new perspective of the CL-inspired meaningful learning approach on language teaching. In addition, the CL-inspired approach demonstrates the unification of the integrated model of text and picture comprehension (the ITPC model) in integrating the new knowledge with related prior knowledge in the cognitive structure. According to the learning procedure of the ITPC model, the image schema as visual image is first perceived through the sensory register, then is processed in the working memory by conceptual metaphor, and finally it is integrated with cognitive schemata in the long term memory. Moreover, deep-seated factors, such as transfer of mother tongue, the difficulty of teaching materials, and the influence of prior knowledge, have strong effects on the acquisition of English prepositions.
In dieser Arbeit wurde der Einfluss von nicht wässrigen Mahlflüssigkeiten auf Metall-Keramik-Pulvermischungen im Nassmahlprozess untersucht. Es wurden Al- und Cr-Al₂O₃-Pulvermischungen ausgewählt, um den Einfluss der Mahlflüssigkeiten auf die Mahlung von Metall-Keramik-Pulvermischungen mit einer duktilen (Aluminium) und einer spröden (Chrom) Metallkomponente zu untersuchen.
Assessment of bat activity in agricultural environments and the evaluation of the risk of pesticides
(2013)
Although agriculture dominates with around 50% area much of Europe- landscape, there is virtually no information on how bats use this farmed environment for foraging. Consequently, little is known about effective conservation measures to compensate potential negative effects of agrarian management practice on the food availability for bats in this habitat. Moreover, there are currently no specific regulatory requirements to include bats in European Union risk assessments for the registration of pesticides since no information about pesticide exposure on this mammal group is available. To evaluate the potential pesticide exposure of bats via ingestion of contaminated insects, information about bat presence and activity in agricultural habitats is required. In order to examine bat activity on a landscape scale it was necessary to establish a suitable survey method. Contrary to capture methods, telemetry, and direct observations, acoustic surveys of bat activity are a logistically feasible and cost-effective way of obtaining bat activity data. However, concerns regarding the methodological designs of many acoustic surveys are expressed in the scientific literature. The reasons are the failing of addressing temporal and spatial variation in bat activity patterns and the limitations of the suitability of the used acoustic detector systems. By comparing different methods and detector systems it was found that the set up of several stationary calibrated detector systems which automatically trigger the ultrasonic recording has the highest potential to produce reliable, unbiased and comparable data sets on the relative activity of bats.
By using the proposed survey method, bat diversity and activity was recorded in different crops and semi-natural habitats in southern Rhineland-Palatinate. Simultaneously, the availability of aerial prey insects was studied by using light and sticky traps. In more than 500 sampling nights about 110,000 call sequences were acoustically recorded and almost 120,000 nocturnal insects were sampled. A total of 14 bat species were recorded, among them the locally rare and critically endangered northern bat (Eptesicus nilssonii) and the barbastelle (Barbastella barbastellum), all of them also occurring over agricultural fields. The agricultural landscape of southern Palatinate is dominated by vineyards, a habitat that was shown to be of low quality for most bat species because of the demonstrated low availability of small aerial insects. By surveying bat activity and food availably in a pair-wise design on several rain water retention ponds and neighbouring vineyards it was demonstrated that aquatic insect emergence in artificial wetlands can provide an important resource subsidy for bats. The creation of artificial wetlands would be a possibility to create important foraging habitats for bats and mitigate negative effects of management practice in the agricultural landscape.
In several other agricultural crops, however, high abundances of suitable prey insects and high bat activity levels, comparable or even higher than in the nearby forests and meadows known to be used as foraging habitats were demonstrated. Especially high bat activity levels were recorded over several fruit orchards and vegetable fields where insects were also present. Both crops are known for high pesticide inputs, and, therefore, a pesticide exposure through ingestion of contaminated insects can not be excluded. To follow the current risk assessment approach for birds and mammals pesticide residues were measured on bat-specific food items in an apple orchard following insecticide applications and bat activity was recorded in parallel. The highest residue values were measured on foliage-dwelling arthropods which may results in a reproductive risk for all bat species that, even to a small extent, include this prey group in their diet. The presence of bats in agricultural landscapes that form a majority of the land area in Europe but also on a global scale leads to exposure of bats by contaminated food and depletion of their food resources by pesticide use. So far conservation efforts for bats focussed on securing hibernation sites and the creation of artificial roost sites since especially the latter were thought to be limiting population growth. However the potential pesticide effects might be also crucial for the population persistence in agricultural landscapes of bats and need to be addressed adequately, especially in risk assessment procedures for the regulation of pesticides.
Agricultural pesticides, especially insecticides, are an integral part of modern farming. However, these may often leave their target ecosystems and cause adverse effects in non- target, especially freshwater ecosystems, leading to their deterioration. In this thesis, the focus will be on Insect Growth Regulators (IGRs) that can in many ways cause disruption of the endocrine system of invertebrates. Freshwater invertebrates play important ecological, economic and medical roles, and disruption of their endocrine systems may be crucial, considering the important role hormones play in the developmental and reproductive processes in organisms. Although Endocrine Disruption Chemicals (EDCs) can affect moulting, behaviour, morphology, sexual maturity, time to first brood, egg development time, brood size (fecundity), and sex determination in invertebrates, there is currently no agreement upon how to characterize and assess endocrine disruption (ED). Current traditional ecotoxicity tests for Ecological Risk Assessment (ERA) show limitations on generating data at the population level that may be relevant for the assessment of EDCs, which effects may be sublethal, latent and persist for several generations of species (transgenerational).
It is therefore the primary objective of this thesis to use a test method to investigate adverse effects of EDCs on endpoints concerning development and reproduction in freshwater invertebrates. The full life-cycle test over two generations that includes all sensitive life stages of C. riparius (a sexual reproductive organism) allows an assessment of its reproduction and should be suitable for the investigation of long-term toxicity of EDCs in freshwater invertebrates. C. riparius is appropriate for this purpose because of its short life cycle that enables the assessment of functional endpoints of the organism over several generations. Moreover, the chironomid life cycle consists of a complete metamorphosis controlled by a well-known endocrine mechanism and the endocrine system of insects has been most investigated in great detail among invertebrates. Hence, the full life-cycle test with C. riparius provides an approach to assess functional endpoints (e.g. reproduction, sex ratio) that are population-relevant as a useful amendment to the ERA of EDCs. In the laboratory, C. riparius was exposed to environmentally-relevant concentrations of the selected IGRs in either spiked water or spiked sediment scenario over two subsequent generations.
The results reported in this thesis revealed significant effects of the IGRs on the development and the reproduction of C. riparius with the second (F1) generation showing greater sensitivity. These findings indicated for the first time the suitability of multigenerational testing for various groups of EDCs and strongly suggested considering the full life-cycle of C. riparius as an appropriate test method for a better assessment of EDCs in the freshwater environment. In conclusion, this thesis helps to detect additional information that can be extrapolated at population level and, thus, might contribute to better protection of freshwater ecosystems against the risks of Endocrine Disrupting Chemicals (EDCs.) It may furthermore contribute to changes in the ERA process that are necessary for a real implementation of the new European chemical legislation, REACH (Registration, Evaluation Authorization and Restriction of Chemicals). Finally, significant interactions between temperature, chemical exposure and generation were reported for the first time and, may help predict impacts that may occur in the future, in the field, under predicted climate change scenarios.
This dissertation investigates the usage of theorem provers in automated question answering (QA). QA systems attempt to compute correct answers for questions phrased in a natural language. Commonly they utilize a multitude of methods from computational linguistics and knowledge representation to process the questions and to obtain the answers from extensive knowledge bases. These methods are often syntax-based, and they cannot derive implicit knowledge. Automated theorem provers (ATP) on the other hand can compute logical derivations with millions of inference steps. By integrating a prover into a QA system this reasoning strength could be harnessed to deduce new knowledge from the facts in the knowledge base and thereby improve the QA capabilities. This involves challenges in that the contrary approaches of QA and automated reasoning must be combined: QA methods normally aim for speed and robustness to obtain useful results even from incomplete of faulty data, whereas ATP systems employ logical calculi to derive unambiguous and rigorous proofs. The latter approach is difficult to reconcile with the quantity and the quality of the knowledge bases in QA. The dissertation describes modifications to ATP systems in order to overcome these obstacles. The central example is the theorem prover E-KRHyper which was developed by the author at the Universität Koblenz-Landau. As part of the research work for this dissertation E-KRHyper was embedded into a framework of components for natural language processing, information retrieval and knowledge representation, together forming the QA system LogAnswer.
Also presented are additional extensions to the prover implementation and the underlying calculi which go beyond enhancing the reasoning strength of QA systems by giving access to external knowledge sources like web services. These allow the prover to fill gaps in the knowledge during the derivation, or to use external ontologies in other ways, for example for abductive reasoning. While the modifications and extensions detailed in the dissertation are a direct result of adapting an ATP system to QA, some of them can be useful for automated reasoning in general. Evaluation results from experiments and competition participations demonstrate the effectiveness of the methods under discussion.
The conservation of groundwater ecosystems requires an assessment and evaluation scheme that shows the state of the ecosystem. Consequently, faunal and microbial criteria are required for groundwater monitoring, in addition to physico-chemical analyses. To proof the adequacy of the application of groundwater organisms for the biological assessment of groundwater quality, an extensive sampling collection of various groundwater systems was accomplished between 2002 and 2009 in Germany. Key aspects were the examination of the indicator potential of groundwater communities towards surface-groundwater interactions and anthropogenic impacts, as well as the analysis of stygofaunal distribution patterns, as a base and reference for a faunal assessment scheme of groundwater systems. The sampling design considered local, regional, and biogeographic conditions. To test the indicator potential of groundwater organisms on a local and regional scale, groundwater systems in Nordrhein-Westfalen (NRW) and Baden-Württemberg (BW) were examined. The faunal and microbial data from unconsolidated aquifers (Erftgebiet, NRW) show the sensitivity of groundwater organisms against land use effects, e.g. extensive agriculture. Data analyses revealed positive correlations of organic material (estimated amount of detritus, TOC) and nitrate with faunal abundance, species richness, diversity and the proportions of stygoxene species. Moreover, the bacterial abundance and diversity in the groundwater of the Erftgebiet was high compared to oligotrophic groundwater systems, indicating an effect of surface influence due to agricultural land use. The groundwater colonization in the Alb-Donau-Kreis (BW) was analyzed for regional effects (landscape, type of aquifer, hydrogeology) and local effects (comparing single wells). The results show that the fauna reflects the strength of the hydrological exchange on different spatial scales. Furthermore, the fauna reflects the interaction of regional and local conditions. Accordingly, the diversity and abundance of groundwater organisms was influenced by the high connectivity of the karst and unconsolidated alluvial aquifers, the type of land use, covering layers of soil, the age of groundwater, and the sampling depths. In general, faunal and microbial data of the Alb-Donau-Kreis are characteristic for oligotrophic, oligoalimonic groundwaters. The large scale analyses of stygofaunal distribution patterns revealed significant biogeographical differences of the communities. These community patterns of the groundwater fauna do not coincide with existing classification schemes defined for surface landscapes or freshwater systems. The largest differences between faunal surface and subsurface distribution patterns were found between the groundwater of northern and southern Germany and the foothills of the central mountain ranges - all of them regions shaped by the last ice ages.
In accordance with the faunal data assessed in groundwater, four different stygoregions were defined that are populated by distinct faunal assemblages. These are 1) the "Northern lowlands", 2) the "Central mountain ranges", 3) the "South-western mountain ranges", and 4) the "Southern mountain ranges and northern alps". The study corroborates that stygofaunal and microbial communities are an adequate tool for the qualitative assessment and monitoring of groundwater ecosystems. The best indicators to detect anthropogenic impacts on groundwater ecosystems are the faunal diversity, abundance, the proportions of stygobitic (obligate groundwater species) and stygoxene species (species not obligate for groundwater), and the bacterial abundance. The development of an ecologically based groundwater assessment and management, is crucial for the conservation of our groundwater ecosystems and thus, healthy drinking water. The defintion of "stygoregions" is an important base for the development of an assessment and reference scheme for groundwater ecosystems. The assessment of the ecological state of groundwater systems must be conducted on local scale, because the strength of the local hydrological influence determines the amount of food and oxygen as well as stygoxene animals within the aquifer, and thus shapes the local groundwater communities. Nevertheless, information of the biogeographic and regional conditions is needed as a reference for the type of species and abundances that potentially can occur in certain groundwater systems.
The search for scientific literature in scientific information systems is a discipline at the intersection between information retrieval and digital libraries. Recent user studies show two typical weaknesses of the classical IR model: ranking of retrieved and maybe relevant documents and the language problem during the query formulation phase. At the same time traditional retrieval systems that rely primarily on textual document and query features are stagnating for years, as it could be observed in IR evaluation campaigns such as TREC or CLEF. Therefore alternative approaches to surpass these two problem fields are needed. Two different search support systems are presented in this work and evaluated with a lab evaluation using the IR test collection GIRT and iSearch with 150 and 65 topics, respectively. These two systems are (1) a query expansion that is based on the analysis of co-occurrences of document attributes and (2) a ranking mechanism that applies informetric analysis of the productivity of information producers in the information production process. Both systems were compared to a baseline system using the Solr search engine. Both methods showed positive effects when applying additional document attributes like author names, ISSN codes and controlled terms. The query expansion showed an improvement in precision (bpref +12%) and in recall (R +22%).
he alternative ranking methods were able to compete with the baseline for author names and ISSN codes and were able to beat the baseline by using controlled terms (MAP +14%). A clear negative influence was seen when using entities like publishers or locations. Both methods were able to generate a substantially different sorting of the result set, measured using Kendall. So, additional to the improved relevance in the result list, the user can get a new and different view on the document set. Query expansion using author names, ISSN codes and thesaurus terms showed great potential that lies within the rich metadata sets of digital library systems. The proposed ranking methods could outperform standard relevance ranking methods after they were filtered by the existence of a so-called power law. This showed that the proposed ranking methods cannot be used universally in any case but require specific frequency distributions in the metadata. A connection between the underlying informetric laws of Bradford, Lotka and Zipf is made clear. The evaluated methods were implemented as interactive search supporting systems that can be used in an interactive prototype and the social science digital library system Sowiport. Besides that, the methods are adaptable to other systems and environments using a free software framework and a web API.
Die vorliegende Doktorarbeit verfolgt das Ziel, die Bevölkerungsentwicklung im Westerwaldkreis im Zeitraum von 1974 bis 2008 auf Kreis-, Verbandsgemeinde- und Gemeindeebene detailliert zu untersuchen und im Rahmen eines Handlungskonzeptes für ausgewählte Gemeinden geeignete Maßnahmen zur konkreten Gestaltung des Demographischen Wandels aufzuzeigen. Dies geschieht zunächst anhand einer umfassenden Analyse der Bevölkerungsdaten. Dazu zählt eine Einteilung des Untersuchungszeitraums in spezielle Phasen der Bevölkerungsentwicklung, welche durch die jährlichen Veränderungsraten des Bevölkerungsstandes des Westerwaldkreises charakterisiert werden. Anschließend wird ausführlicher auf wichtige Kennzahlen der Bevölkerungsentwicklung aus den Bereichen der natürlichen Bevölkerungsbewegung, der Bevölkerungsstruktur und der Wanderungen eingegangen mit der Intention, einerseits detaillierte Ergebnisse hervorzubringen, die im Rahmen bisheriger Untersuchungen nicht vorliegen und andererseits Grundlagen für die Ursachenforschung zu schaffen, die der Analyse der Bevölkerungsdaten folgt. Für diese Ursachenforschung werden fünf Gemeinden exemplarisch ausgewählt, die eine besonders positive bzw. negative Bevölkerungsentwicklung im Untersuchungszeitraum aufweisen. Integrale Bestandteile dieser Ursachenforschung sind, neben einer ausführlichen Darstellung der Bevölkerungsentwicklung der Gemeinden, Experteninterviews und eigene humangeographische Beobachtungen. Des Weiteren wird speziell für die drei ausgewählten Gemeinden mit negativer Bevölkerungsentwicklung eine Online-Umfrage unter Jugendlichen durchgeführt, um weitere Ursachen herauszufinden und erste zentrale Ansatzpunkte für das abschließende Handlungskonzept zu finden. Dieses Konzept verfolgt primär die Intention, den Demographischen Wandel in den drei Gemeinden in der Art und Weise zukünftig zu gestalten, dass seine negativen Folgen vermieden bzw. zumindest abgemildert werden. Dazu ist es notwendig, auf die spezifischen Situationen vor Ort einzugehen und die praktische Umsetzbarkeit möglicher Handlungsempfehlungen zu berücksichtigen, damit das Konzept Eingang in die kommunalpolitische Planung findet und somit nicht nur einen Beitrag zur bevölkerungsgeographischen Forschung darstellt, sondern auch einen Nutzen für die kommunale Handlungspraxis stiftet.
Worldwide one third to one half of the freshwater crayfish species are threatened with population decline or extinction. Besides habitat deterioration, pollution, and other man-made environmental changes, invasive species and pathogens are major threats to the survival of European crayfish species. Freshwater crayfish are the largest freshwater invertebrates and strongly influence the structure of food webs. The disappearance of crayfish from a water body may change the food web and could have dramatic consequences for an ecosystem.rnOne goal in modern species conservation strategies is the conservation of genetic diversity, since genetic diversity is an advantage for the long-term survival of a species. The main aim of my thesis was to reveal the genetic structure and to identify genetic hotspots of the endangered noble crayfish (Astacus astacus) throughout Europe (part 1 of my thesis). Since the most significant threat to biodiversity of European crayfish species is the crayfish plague pathogen Aphanomyces astaci I studied new aspects in the distribution of A. astaci (part two of my thesis). The results serve as a basis for future conservation programs for freshwater crayfish. In the first part of my thesis I conducted a phylogeographic analysis of noble crayfish using mitochondrial DNA and nuclear microsatellite data. With these methods I aimed to identify its genetic hotspots and to reconstruct the recolonization history of central Europe by this species. I detected high genetic diversities in southestern Europe indicating that noble crayfish outlasted the cold climate phases during the Pleistocene in this region (Appendix 1). Because of the high genetic diversity found there, southeastern Europe is of particular importance for the conservation of noble crayfish. The mitochondrial DNA analysis points to a bifurcated colonization process from the eastern Black Sea basin to a) the North Sea and to b) the Baltic Sea basin (Appendix 2). A second independent refugium that was localized on the Western Balkans did not contribute to the colonization of central Europe. Furthermore, I found that the natural genetic structure is dissolved, probably due to the high human impact on the distribution of noble crayfish (e.g. artificial translocation). In the second part of this thesis using real-time PCR I identified calico crayfish (Orconectes immunis) as the fourth North American crayfish species to be carrier of the agent of the crayfish plague (Appendix 3). Furthermore I detected the crayfish plague pathogen in American spiny-cheek crayfish (Orconectes limosus) and native narrow-clawed crayfish (Astacus leptodactylus) in the lower Danube in Romania (Appendix 4). The distribution of infected spiny-cheek crayfish poses a threat to the native biodiversity in southeastern Europe and shows the high invasion potential of this crayfish species. Moreover, I found that even the native narrow-clawed crayfish in the Danube Delta, about 970 km downstream of the current invasion front of American crayfish, is a carrier of A. astaci (Appendix 5). This finding is of high importance, as the native species do not seem to suffer from the infection. In Appendix 6 I elucidate demonstrate that the absence of the crayfish plague agent is the most likely explanation for the coexistence of populations of European and American crayfish in central Europe. In my thesis I show that the common assumption that all North American crayfish are carrier of A. astaci and that all native crayfish species die when infected with A. astaci does not hold true. The studies presented in my thesis reveal new aspects that are crucial for native crayfish conservation: 1) The genetic diversity of noble crayfish is highest in southeastern Europe where noble crayfish outlasted the last glacial maximum in at least two different refugia. 2) Not all American crayfish populations are carrier of A. astaci and 3) not all Europen crayish populations die shortly after being infected with the crayfish plague pathogen.rnTo conserve native crayfish species and their (genetic) diversity in the long term, further introductions of American crayfish into European waters must be avoided. However, the introduction will only decrease if the commercial trade with non-indigenous crayfish species is prohibited.
Die Wirbelsäule als tragende Säule des menschlichen Körpers ist bei vielen Bewegungsabläufen hohen Belastungen ausgesetzt. Fehl- und Überbelastungen rufen dabei oft dauerhafte Schädigungen hervor. Daher ist es von Interesse, die innerhalb der Wirbelsäule auftretenden Belastungen zu bestimmen. Eine moderne und zuverlässige Methode zur Belastungsbestimmung ist der Aufbau eines Berechnungsmodells.
In der vorliegenden Arbeit wurde ein Mehr-Körper-System (MKS) Modell der Lendenwirbelsäule erstellt. Mit Hilfe des Modells können sowohl die übertragenen Kräfte und Momente in allen inneren Strukturen berechnet als auch die Kinematik des Bewegungsablaufs simuliert werden. Die Grundstruktur des Modells bilden die als Starrkörper angenommenen knöchernen Strukturen der fünf Lendenwirbel L1 bis L5, des Os Sacrums und des Os iliums, die über die Segmentierung eines CT-Datensatzes des Abgusses der Wirbeloberflächen eines durchschnittlich großen Europäers gewonnen wurden. Die elastischen Elemente der Wirbelsäule wurden unter Berücksichtigung ihrer physikalischen Eigenschaften in das Modell implementiert. Grundlage für die Modellierung der Zwischenwirbelscheiben waren dabei eigens durchgeführte experimentelle Messungen. Das charakteristische Kraft-Deformations-Verhalten der Ligamente wurde der Literatur entnommen.
Die Umsetzung im Computermodell berücksichtigt neben dem physikalischen Verhalten eines einzelnen Ligamentes zusätzlich durch einen Gewichtungsfaktor das Zusammenspiel aller Ligamente im komplex aufgebauten Ligamentapparat. Die Facettengelenke wurden durch Kontaktmodellierung in den Knorpelschichten realisiert. Daneben wurde ein Modell eines Implantatsystems entwickelt, das zur dynamischen Stabilisierung der Lendenwirbelsäule genutzt wird. Die Validierung der erstellten Modelle erfolgte über den Vergleich mit In-Vitro erhobenen Daten. Betrachtet wurden neben der intakten Wirbelsäule zudem degenerative Schädigungen der Zwischenwirbelscheibe und deren operative Versorgung durch Nukleotomie und dynamische Stabilisierung. Die Ergebnisse der Simulationen zeigen dabei eine sehr gute Näherung an die experimentell ermittelten Messwerte. Durch Anwendung der Computermodelle konnten die Auswirkungen verschiedener operativer Eingriffe, wie Interlaminotomie, Hemilaminektomie und Laminektomie auf die unterschiedlichen Strukturen der Lendenwirbelsäule berechnet werden. Ein weiteres Anwendungsgebiet lag in der Untersuchung des momentanen Drehzentrums. Neben der Bestimmung der Drehpunktbahn bei intakter Wirbelsäule konnten die Effekte einer degenerativ geschädigten und operativ versorgten Zwischenwirbelscheibe auf den Verlauf des momentanen Drehzentrums berechnet und simuliert werden.
The polysaccharide hydration phenomenon is nowadays the subject of intense research. The interaction of native and modified polysaccharides and polysaccharides-based bioconjugates with water has an important influence on their functional behaviour. Notwithstanding that the hydration phenomenon has been studied for decades, there is still a lack of awareness about the influence of hydration water on the polysaccharide´s structure and consequences for industrial or medicinal applications. The hydration of polysaccharides is often described by the existence of water layers differing in their physical properties depending on the distance from the polysaccharide. Using the differential scanning calorimetry (DSC) such water layers were categorized according their properties upon cooling in hyaluronan (HYA, sodium salt of ß-1,4-linked units of ß-1,3-linked D-glucuronic acid and N-acetyl-D-glucosamine), a model polysaccharide in the present work. The amount of non-freezing water, i.e. water in close proximity of HYA chain which does not freeze et all, was determined around 0.74gH2O/gHYA for HYA with molecular weight from 100 to 740kDa and 0.84gH2O/gHYA for molecular weight of 1390kDa. The amount of freezing-bound water, the water pool which is affected by presence of HYA but freezes, was determined in the range from 0.74 to 2gH2O/gHYA. Above this value only non-freezing and bulk water are present since melting enthalpy measured above this concentration reached the same value as for pure water. Since this approach suffers from several experimental problems, a new approach, based on the evaporation enthalpy determination, was suggested. The analysis of the evaporation enthalpies revealed an additional process associated with apparent energy release taking part below the water content of 0.34gH2O/gHYA. Existence of this phenomenon was observed also for protonated form of HYA. The existence of energy compensating process was confirmed with the Kissinger-Akahira-Sunose method which allowed determination of actual water evaporation/desorption enthalpies in all stages of the evaporation process. In fact, the apparent evaporation enthalpy value increased until water content of 0.34gH2O/gHYA, and then dropped down to lower values which were, still higher than the value of the pure water evaporation enthalpy. By the use of time domain nuclear magnetic resonance (TD-NMR) technique it was revealed that this phenomenon is the plasticisation of HYA.
Further, it was revealed that the non-freezing water determined by the use of DSC consists of two water fractions, i.e. 15% of water structurally integrated, interacting directly with polar sites, and 85% of water structurally restricted, embedded in-between the HYA chains. The occurrence of plasticisation concentration close to equilibrium moisture content provided the possibility to influence the HYA physical structure during the drying. In this way three samples of native HYA, dried under various conditions were prepared and their physical properties were analyzed. The samples differed in kinetics of rehydration, plasticisation concentration, glass transitions, and morphology. The properties of water pool were studied in solutions of 10"25mg HYA/mL as well. The fast filed cycling (FFC) NMR relaxometry showed the existence of three water fractions which correlation times spanned from 10"6 to 10"10 seconds, progressively decreasing in dependency on its distance from HYA chain. The formation of a weak and transient intramolecular water bridge between HYA chains was observed. It was shown that, unlike the inorganic electrolytes, polyelectrolytes hydration is a dynamic process which reflects not only the technique used for the analysis, experimental conditions but also the conformation of the polysaccharide and its "thermal" and "hydration" history.
It was demonstrated that some native polysaccharide structures can be easily modified by manipulation of preparation conditions, giving fractions with specific physicochemical properties without necessity of any chemical modification.
Früher wurden in Museen den Besuchern meist gesicherte Wissensbestände präsentiert. Heute ist das vielfach anders: Nicht nur fraglos geltendes Wissen, sondern auch der Prozess dorthin wird aufgezeigt. Die dargebotene Information ist teilweise nicht mehr konsistent und widerspruchsfrei sondern konfligierend. Wie aber reagieren die Besucher auf konfligierende Information? Wie unterstützen ihre persönlichen Vorrausetzungen eine differenziertere Betrachtung? Wie können Museen " obwohl ihre Information doch freiwillig, selbstbestimmt, ohne Zwang und Pression rezipiert wird - die Informationsverarbeitung ihrer Besucher durch eine bestimmte räumliche Informationsanordnung beeinflussen? Diese Fragen wurden mittels vier Feldstudien vor Ort untersucht:
Studie 1 charakterisiert Museumsbesucher durch Persönlichkeitsprofile, die aus den für die Verarbeitung konfligierender Information als relevant betrachteten Personenmerkmalen (epistemologischen Überzeugungen, Ambiguitätstoleranz, Selbstwirksamkeitsannahmen) erstellt sind.
Studie 2 untersucht den Einfluss dieser Personenmerkmale und des situationalen Interesses auf die Tendenz zur Konfliktverarbeitung, ohne Fähigkeiten und Fassungskraft des Besuchers zu berücksichtigen.
Studie 3 überprüft die Effekte von situationalem Interesse, epistemologischen Überzeugungen, Ambiguitätstoleranz und Selbstwirksamkeitsannahmen auf die Konfliktverarbeitungsleistung.
In Studie 4 wird schließlich die Wirkung räumlich naher Informationspräsentation untersucht.
Museumsbesucher können durch die Persönlichkeitsprofile "selbstzweifelnd skeptisch", "selbstbewusst vertrauensvoll" und "stabilitätsgläubig" charakterisiert werden. Eine überwältigende Mehrheit zeigt die Bereitschaft, Konflikte wahrzunehmen und ein großer Teil ist darüber hinaus bereit, konfligierende Informationen auf tieferer Ebene zu verarbeiten. Eine räumlich nahe (thematisch kontinuierliche) Präsentation unterstützt die Tendenz, tief zu verarbeiten. Etwa drei Viertel der Besucher konnten erkennen, wann konfligierende Information logisch widersprüchlich ist und konnten überzufällig gut bei konsistenter und konfligierender Information Kohärenz bilden. Positive Selbstwirksamkeitsannahmen unterstützen vermittelt über hohes situationales Interesse die Tendenz, Information tiefer zu verarbeiten und steigern die Fähigkeit, Kohärenz zu bilden. Reifere epistemologische Überzeugungen der Dimension "Sicherheit" und "Veränderlichkeit" fördern Kohärenzbildung.
Structure of soil organic matter (SOM) is a hot topic of discussion among scientific community for several decades. The mostly discussed models, among many, are polymer model and supramolecular model. While the former considers SOM as macromolecules consisting of amorphous and crystalline domains, the latter explains SOM as a physicochemical entity dominated by weak hydrophobic and H-bond interactions in the secondary level, which holds individual molecules of primary structure together. The weak forces in secondary level impart characteristic mobility of SOM. Very important consequence of this multidimensional formulation is that physicochemical structure plays a crucial role in most biogeochemical functions of SOM, apart from the chemical composition. Recently introduced concept of cation and water molecule mediated bridges between OM molecular segments (CaB and WaMB, respectively) evolved from physicochemical understanding of SOM structure. Even though several indirect evidences were produced for CaB and WaMB during last years, no clear-cut understanding of these processes has been achieved yet. Experimental difficulty due to overlapping effects of equally important CaB-governing parameters such a pH and competing cations raises huge challenge in investigating CaB-related influences. This thesis, therefore, aims to validate an experimental set-up for inducing CaB within OM structures and assessing it from various chemical and physicochemical aspects.
The method involved removal of omnipresent cations and adjustment of pH before cation addition. This helped to separate pH effects and cation effects. Based on results obtained on two different types of organic matter, it can be deduced that multivalent cations can cross-link SOM, given that functional group density of the SOM material is enough for the functional groups to be arranged in sufficient spatial proximity to each other. Physicochemical structural reorganisation during aging causes formation of more and/or stronger CaB and WaMB. As for inducing CaB directly after cation treatment, cationic size and valency were found determinant also for aging effect. A strongly cross-linked system in the beginning is less vulnerable to structural changes and undergoes aging with lower intensity, than an initially weakly cross-linked system. Responsible for the structural changes is, the inherent mobility of SOM within its physicochemical assemblage. Thus the information on structural requirement of CaB and its consequences on OM matrix rigidity will help to obtain insight into the physicochemical SOM structure. Additionally, organic matter quality (assessed by thermal analysis) and pore structure of SOM formed in a set of artificial soils showed that mineral materials are important for the chemical nature of SOM molecules, but not for the physical structure of organo-mineral associations, at least after several months of SOM development.
Furthermore, nanothermal analysis using atomic force microscopy (AFM-nTA) was implemented in soils for the first time to reveal nanoscale thermal properties and their spatial distribution in nano- and micrometer scales. This helped to identify physicochemical processes, such as disruption of WaMB, in low-organic soils, in which bulk methods fail due to their low sensitivity. Further, various types of materials constituting in soils were distinguished with high resolution by advanced application of the method, in combination with other AFM parameters. Attempts were done to identify various materials, with the usage of defined test materials. Above all, the method is potent to reveal microspatial heterogeneity on sample surfaces, which could help understanding process-relevant hotspots, for example.
This thesis thus contributes to the scientific understanding on physicochemical structural dynamics via cross-linking by cations and via nanoscale thermal properties. Direct investigation on CaB demonstrated here will potentially help making a big leap in knowledge about the interaction. The observed aging effects add well to the understanding of supramolecular consideration of SOM. By introducing nanothermal analysis to the field of soil science, it is made possible to face the problem of heterogeneity and spatial distribution of thermal characteristics. Another important achievement of AFM-nTA is that it can be used to detect physicochemical processes, which are of low intensity.
The amount of information on the Web is constantly increasing and also there is a wide variety of information available such as news, encyclopedia articles, statistics, survey data, stock information, events, bibliographies etc. The information is characterized by heterogeneity in aspects such as information type, modality, structure, granularity, quality and by its distributed nature. The two primary techniques by which users on the Web are looking for information are (1) using Web search engines and (2) browsing the links between information. The dominant mode of information presentation is mainly static in the form of text, images and graphics. Interactive visualizations offer a number of advantages for the presentation and exploration of heterogeneous information on the Web: (1) They provide different representations for different, very large and complex types of information and (2) large amounts of data can be explored interactively using their attributes and thus can support and expand the cognition process of the user. So far, interactive visualizations are still not an integral part in the search process of the Web. The technical standards and interaction paradigms to make interactive visualization usable by the mass are introduced only slowly through standardatization organizations. This work examines how interactive visualizations can be used for the linking and search process of heterogeneous information on the Web. Based on principles in the areas of information retrieval (IR), information visualization and information processing, a model is created, which extends the existing structural models of information visualization with two new processes: (1) linking of information in visualizations and (2) searching, browsing and filtering based on glyphs. The Vizgr toolkit implements the developed model in a web application. In four different application scenarios, aspects of the model will be instantiated and are evaluated in user tests or examined by examples.
Das Lernen und Verstehen dynamischer Sachverhalte kann sowohl anhand von statischen Bildern als auch von Animationen erfolgen. Da die bisher vorliegenden Befunde keine eindeutige Überlegenheit der einen oder der anderen Repräsentationsform erkennen lassen, sind differenziertere Wirkungsanalysen erforderlich. Grundannahme der vorliegenden Dissertation war, dass beide Darstellungsformen unterschiedlich gut für den Aufbau dynamischer mentaler Modelle einerseits und den Aufbau dynamischer perzeptueller Repräsentationen andererseits geeignet sind. Es wurde erstens angenommen, dass dynamische mentale Modelle keine kontinuierlichen mentalen Simulationen ermöglichen, sondern aus einer Sequenz von diskreten prototypischen Prozess-Zuständen (sog. "key states") bestehen und deshalb besser anhand statischer Bilder dieser "key states" als anhand einer Animation konstruiert werden können. Zweitens wurde angenommen, dass perzeptuelle Repräsentationen dynamischer Sachverhalte aus dynamischen Schemata bestehen, die besser anhand einer Animation als anhand von statischen Bildern gebildet werden können. Als Indikator für die Qualität mentaler Modelle wurden Inferenzaufgaben verwendet, bei denen durch Manipulation dieser Modelle neue Informationen zu erschließen sind. Als Indikator für die Qualität dynamischer perzeptueller Repräsentationen wurden Leistungen bei der Kategorisierung von Bewegungsabläufen verwendet. Die erste Annahme wurde am Beispiel der synaptischen Informationsübertragung (nach einer Vorpilot- und Pilotstudie) in einer ersten Hauptstudie mit 61 Probanden überprüft.
Die Ergebnisse weisen darauf hin, dass die Hypothese eher bei Probanden mit höherem Vorwissen als bei solchen mit niedrigerem Vorwissen zutrifft. Die zweite Annahme wurde am Beispiel des Erkennens der Gangart von Pferden (nach einer Pilotstudie) in einer zweiten Hauptstudie mit 52 Probanden überprüft. Die Ergebnisse zeigten durchwegs Unterschiede in der erwarteten Richtung, die jedoch nicht oder nur marginal signifikant sind. Allerdings führten die Animationen zu einer hochsignifikant geringeren kognitiven Belastung als statische Bilder. Darüber hinaus zeigten sich signifikante Interaktionen mit den räumlichen Fähigkeiten: Probanden mit geringeren Fähigkeiten profitieren bei der Kategorisierung von Bewegungsabläufen bedeutsam mehr von Animationen als von statischen Bildern.
Kapitel 1 führt - unter Berücksichtigung gesamtgesellschaftlicher Tendenzen im Hinblick auf verschiedene Lebensformen - zunächst in das Thema ein. Auf Basis der Tatsache geringer Scheidungsraten von Managerehen werden unterschiedliche Annahmen formuliert, die für die Ehestabilität dieser Paare eine Rolle spielen könnten.
Im Weiteren werden hier wesentliche Fragestellungen zum Thema der vorliegenden Arbeit und deren Zielsetzung begründet. Kapitel 2 fasst den aktuellen Forschungsstand zusammen. Bisherige Untersuchungsergebnisse zum Themenfeld Manager und deren Ehen sowie auch der Ehestabilitätsforschung werden hier vorgestellt und auf ihre Relevanz hin befragt. Ziel ist es, bereits gewonnene Ergebnisse nach ihrer Bedeutung für diese Arbeit zu bewerten und entsprechende Fragestellungen daraus abzuleiten. Kapitel 3 setzt sich mit theoretischen Ansätzen zur Erklärung von Ehestabilität auseinander. Vor dem Hintergrund verschiedener Handlungsmodelle stellt sich die Frage, ob die Stabilität von Managerehen das Ergebnis von wertorientiertem, zweckorientiertem oder gar traditionalem Handeln ist. Insbesondere werden hier der kultursoziologische Ansatz von Schreiber und die Rational Choice Theorie von Esser als maßgebliche theoretische Grundlage für den Leitfaden und die Auswertung des empirischen Materials vorgestellt und erläutert. Im Anschluss daran erklärt Kapitel 4 die Voraussetzungen und den Ablauf der Erhebung der Daten und beschreibt die Paare des vorliegenden Samples. Als Methode der Befragung wurde das Leitfadeninterview gewählt, welches begründet und von seiner Konzeption wie auch seinen Inhalten her beschrieben wird. Die Erläuterung zur Durchführung der Interviews und zur Methode der Analyse der Gespräche bilden den Abschluss dieses Kapitels. Kapitel 5 führt sodann in das vorliegende empirische Material ein. Es dient der Beschreibung der interviewten Paare in der Darstellungsform von insgesamt zehn Paarportraits. Ziel hierbei ist zum einen, die Beziehungswelt der Paare abzubilden, zum anderen zu zeigen, dass es bei allen Befragten prägnant wiederkehrende Strukturelemente innerhalb der Beziehung gibt. Diese geben einen ersten Hinweis auf die besonderen Stabilitätsfaktoren von Managerehen. Das folgende Kapitel 6 fasst die Erfolgsfaktoren ehelicher Stabilität der befragten Paare zusammen. Es kann aufzeigen, wie die Faktoren Heiratsmotivation, Rollenverteilung, Paarinteraktion, Statussymbole, soziales Umfeld, Beziehungswünsche und -visionen von den Paaren beschrieben werden und welche Rolle sie im Hinblick auf die Ehestabilität der Paare spielen. Hier wird deutlich dass es bei den Aussagen der Befragten große Strukturähnlichkeiten gibt, die es erlauben von einem Sondertypus "stabile Ehe" zu sprechen. In einer zusammenfassenden Beschreibung wird herausgestellt, welche Merkmale diesen besonderen Typus kennzeichnen und was ihn letztendlich charakterisiert. Managerehepaare leben in einer erfolgreichen Lebensform zusammen. Sie stellen einen Sondertypus unter den bisher bekannten Lebensformen dar. Das Schlusskapitel 7 fasst die Ergebnisse dieser Arbeit zusammen und pointiert sie in der Konstruktion einer managerspezifischen Lebensform, für die der Name LTA (Living Together Apart)20 gewählt wurde.
Studies on the toxicity of chemical mixtures find that components at levels below no-observed-effect concentrations (NOECs) may cause toxicity resulting from the combined effects of mixed chemicals. However, chemical risk assessment frequently focuses on individual chemical substances, although most living organisms are substantially exposed to chemical mixtures rather than single substances. The concepts of additive toxicity, concentration addition (CA), and independent action (IA) models are often applied to predict the mixture toxicity of similarly and dissimilarly acting chemicals, respectively. However, living organisms and the environment may be exposed to both types of chemicals at the same time and location. In addition, experimental acquisition of toxicity data for every conceivable mixture is unfeasible since the number of chemical combinations is extremely large. Therefore, an integrated model to predict mixture toxicity on the basis of single mixture components having various modes of toxic action (MoAs) needs to be developed. The objectives of the present study were to analyze the challenges in predicting mixture toxicity in the environment, and to develop integrated models that overcome the limitations of the existing prediction models for estimating the toxicity of non-interactive mixtures through computational models. For these goals, four sub-topics were generated in this study. Firstly, applicable domains and limitations of existing integrated models were analyzed and grouped into three kinds of categories in this study. There are current approaches used to assess mixture toxicity; however, there is a need for a new research concept to overcome challenges associated with such approaches, which recent studies have addressed. These approaches are discussed with particular emphasis on those studies involved in computational approaches to predict the toxicity of chemical mixtures based on the toxicological data of individual chemicals. Secondly, through a case study and a computational simulation, it was found that the Key Critical Component (KCC) and Composite Reciprocal (CR) methods (as described in the European Union (EU) draft technical guidance notes for calculating the Predicted No Effect Concentration (PNEC) and Derived No Effect Level (DNEL) of mixtures) could derive significantly different results. As the third and fourth sub-topics of this study, the following two integrated addition models were developed and successfully applied to overcome the inherent limitations of the CA and IA models, which could be theoretically used for either similarly or dissimilarly acting chemicals: i) a Partial Least Squares-Based Integrated Addition Model (PLS-IAM), and, ii) a Quantitative Structure-Activity Relationship-Based Two-Stage Prediction (QSAR-TSP) model. In this study, it was shown that the PLS-IAM might be useful to estimate mixture toxicity when the toxicity data of similar mixtures having the same compositions were available. In the case of the QSAR-TSP model, it showed the potential to overcome the critical limitation of the conventional TSP model, which requires knowledge of the MoAs for all chemicals. Therefore, this study presented good potential for the advanced integrated models (e.g., PLS-IAM and QSAR-TSP), while considering various non-interactive constituents that have different MoAs in order to increase the reliance of conventional models and simplify the procedure for risk assessment of mixtures.
Galerucinae, Latreille 1802 is the second largest subgroup of chrysomelidae. 1837 Chervrolat described the taxon Ootheca, which has originally only one listed species. Nearly 200 years all galerucinae with a "compact" bodyshape, a broad pronotum, a convex dorsum , short antennae and short legs were assigned to Ootheca. When I started a revision of Ootheca, this taxon included 38 species. Comparing morphological characters of the exoskeleton combined with the depiction/description of characteristic structures of the male genitalia allowed a detailed description of the genus Ootheca and its species. After the revision 9 valid species remained in Ootheca, 4 are described to be new, 13 species were transferred to other valid described genera and 10 species remained, because of a lack of unambiguous assignment. The examination of the median lobe additionally enables me to describe three sister taxa: Oothecoides (6 species), Ootibia (5 species ) und Oosagitta (6 species).
Die Dissertation "Schreibprozesse in der Wikipedia" untersucht auf Basis einer linguistischen Textanalyse individuelle und gemeinschaftliche Schreibhandlungen in der Wikipedia. An Beispiel ausgewählter Artikel werden Artikelinitiationen, Handlungsmuster beim Er- und Überarbeiten der Texte, Prozesse des Planens, Gliederns und Bewertens sowie Kontroversen, Edit Wars und Vandalismus als grundlegende Aspekte des Schreibens in gemeinschaftlichen Online-Kontexten betrachtet. Dabei erscheinen vor allem Kontroversen als ein in der Schreibforschung bisher vernachlässigter Einflussfaktor, der nicht nur Auswirkungen auf die Schreibprozesse in der Wikipedia, sondern auch auf die gesamte Abbildung, Genese und vor allem Aushandlung von Wissen hat.
Tagging systems are intriguing dynamic systems, in which users collaboratively index resources with the so-called tags. In order to leverage the full potential of tagging systems, it is important to understand the relationship between the micro-level behavior of the individual users and the macro-level properties of the whole tagging system. In this thesis, we present the Epistemic Dynamic Model, which tries to bridge this gap between the micro-level behavior and the macro-level properties by developing a theory of tagging systems. The model is based on the assumption that the combined influence of the shared background knowledge of the users and the imitation of tag recommendations are sufficient for explaining the emergence of the tag frequency distribution and the vocabulary growth in tagging systems. Both macro-level properties of tagging systems are closely related to the emergence of the shared community vocabulary. rnrnWith the help of the Epistemic Dynamic Model, we show that the general shape of the tag frequency distribution and of the vocabulary growth have their origin in the shared background knowledge of the users. Tag recommendations can then be used for selectively influencing this general shape. In this thesis, we especially concentrate on studying the influence of recommending a set of popular tags. Recommending popular tags adds a feedback mechanism between the vocabularies of individual users that increases the inter-indexer consistency of the tag assignments. How does this influence the indexing quality in a tagging system? For this purpose, we investigate a methodology for measuring the inter-resource consistency of tag assignments. The inter-resource consistency is an indicator of the indexing quality, which positively correlates with the precision and recall of query results. It measures the degree to which the tag vectors of indexed resources reflect how the users perceive the similarity between resources. We argue with our model, and show it with a user experiment, that recommending popular tags decreases the inter-resource consistency in a tagging system. Furthermore, we show that recommending the user his/her previously used tags helps to increase the inter-resource consistency. Our measure of the inter-resource consistency complements existing measures for the evaluation and comparison of tag recommendation algorithms, moving the focus to evaluating their influence on the indexing quality.
Chemical plant protection is an essential element in integrated pest management and hence, in current crop production. The use of Plant Protection Products (PPPs) potentially involves ecological risk. This risk has to be characterised, assessed and managed.
For the coming years, an increasing need for agricultural products is expected. At the same time, preserving our natural resources and biodiversity per se is of equally fundamental importance. The relationship of our economic success and cultural progress to protecting the environment has been made plain in the Ecosystem Service concept. These distinct 'services' provide the foundation for defining ecological protection goals (Specific Protection Goals, SPGs) which can serve in the development of methods for ecological risk characterisation, assessment and management.
Ecological risk management (RM) of PPPs is a comprehensive process that includes different aspects and levels. RM is an implicit part of tiered risk assessment (RA) schemes and scenarios, yet RM also explicitly occurs as risk mitigation measures. At higher decision levels, RM takes further risks, besides ecological risk, into account (e.g., economic). Therefore, ecological risk characterisation can include RM (mitigation measures) and can be part of higher level RM decision-making in a broader Ecosystem Service context.
The aim of this thesis is to contribute to improved quantification of ecological risk as a basis for RA and RM. The initial general objective had been entitled as "… to estimate the spatial and temporal extent of exposure and effects…" and was found to be closely related to forthcoming SPGs with their defined 'Risk Dimension'.
An initial exploration of the regulatory framework of ecological RA and RM of PPPs and their use, carried out in the present thesis, emphasised the value of risk characterisation at landscape-scale. The landscape-scale provides the necessary and sufficient context, including abiotic and biotic processes, their interaction at different scales, as well as human activities. In particular, spatially (and temporally) explicit landscape-scale risk characterisation and RA can provide a direct basis for PPP-specific or generic RM. From the general need for tiered landscape-scale context in risk characterisation, specific requirements relevant to a landscape-scale model were developed in the present thesis, guided by the key objective of improved ecological risk quantification. In principle, for an adverse effect (Impact) to happen requires a sensitive species and life stage to co-occur with a significant exposure extent in space and time. Therefore, the quantification of the Probability of an Impact occurring is the basic requirement of the model. In a landscape-scale context, this means assessing the spatiotemporal distribution of species sensitivity and their potential exposure to the chemical.
The core functionality of the model should reflect the main problem structures in ecological risk characterisation, RA and RM, with particular relationship to SPGs, while being adaptable to specific RA problems. This resulted in the development of a modelling framework (Xplicit-Framework), realised in the present thesis. The Xplicit-Framework provides the core functionality for spatiotemporally explicit and probabilistic risk characterisation, together with interfaces to external models and services which are linked to the framework using specific adaptors (Associated-Models, e.g., exposure, eFate and effect models, or geodata services). From the Xplicit-Framework, and using Associated-Models, specific models are derived, adapted to RA problems (Xplicit-Models).
Xplicit-Models are capable of propagating variability (and uncertainty) of real-world agricultural and environmental conditions to exposure and effects using Monte Carlo methods and, hence, to introduce landscape-scale context to risk characterisation. Scale-dependencies play a key role in landscape-scale processes and were taken into account, e.g., in defining and sampling Probability Density Functions (PDFs). Likewise, evaluation of model outcome for risk characterisation is done at ecologically meaningful scales.
Xplicit-Models can be designed to explicitly address risk dimensions of SPGs. Their definition depends on the RA problem and tier. Thus, the Xplicit approach allows for stepwise introduction of landscape-scale context (factors and processes), e.g., starting at the definitions of current standard RA (lower-tier) levels by centring on a specific PPP use, while introducing real-world landscape factors driving risk. With its generic and modular design, the Xplicit-Framework can also be employed by taking an ecological entity-centric perspective. As the predictive power of landscape-scale risk characterisation increases, it is possible that Xplicit-Models become part of an explicit Ecosystem Services-oriented RM (e.g., cost/benefit level).
Die vorliegende Arbeit wurde verfasst, um Einflüsse und Zusammenhänge von Mitarbeiterzufriedenheit auf Burnout zu erforschen. Zudem wurde der Frage nachgegangen, inwieweit organisationsbedingte Variablen beim Zusammenhang von Mitarbeiterzufriedenheit und Burnout bei Flugbegleitern eine Rolle spielen. Hierfür wurde die Airline-Branche, genau genommen das Kabinenpersonal als Repräsentant, verwendet und eine umfangreiche Arbeitsplatzanalyse durchgeführt.
Zur Erfassung der vielfältigen Dimensionen der Mitarbeiterzufriedenheit diente der Fragebogen zur Erfassung der Mitarbeiterzufriedenheit (FEMAZU), sowie für die Facetten von Burnout die Burnout-Screening-Skalen (BOSS) "Beruf" und "körperliche Beschwerden". Die organisationsbedingten Variablen wurden im Zuge einer Gruppendiskussion erhoben und zu entsprechenden Statements ausformuliert, um für den Fragebogen verwendet werden zu können. Dieser wurde im nach der Erstellung durch einen Pretest praktisch validiert. Die Online-Erhebung erfolgte anhand 420 Flugbegleitern im deutschsprachigen Raum.rnZu der quantitativen Erhebung wurde eine qualitative Methode angewandt, um detaillierter Informationen bezüglich der Komplexität in Entstehung und Verlauf der Krankheitsgeschichte von Burnout zu bekommen und Hinweise für die Einwirkung organisationsbedingter Variablen zu erhalten.
Entsprechend der repräsentativen Stichprobe in der vorliegenden Arbeit konnte ein starker Zusammenhang von Mitarbeiterzufriedenheit auf die verschiedenen Facetten von Burnout erwiesen sowie überwiegend signifikante Ergebnisse verzeichnet werden. Als wesentliche Einflussvariablen konnten individuelle Ziele, Arbeitsbedingungen, Aufgabenfeld, Empowerment, Commitment, Emotionsregulation und Work-Life-Balance identifiziert werden. Bedingt durch die ohnehin sehr speziellen Arbeitsbedingungen im Berufsleben der Flugbegleiter sollten die Airlines bei ihren Mitarbeitern auf eine ausgeglichene Work-Life-Balance achten. Die Ergebnisse zeigten hierfür deutliche Zusammenhänge mit Mitarbeiterzufriedenheit und Burnout. Um entsprechende ausfallsbedingten Kosten vorzubeugen, wurde in der vorliegenden Arbeit eine Handlungsempfehlung gegeben. Durch die hohe Flexibilitätsanforderung in der Tätigkeit des Kabinenpersonals sowie den zahlreichen physiologischen Einflüssen wie beispielsweise Lärm, Jetlag, Schichtdienst oder Zeitverschiebungen ist es für Unternehmen, die auf langfristige Mitarbeiter setzen besonders wichtig, an dieser Stelle häufigen und langen krankheitsbedingten Fehlzeiten vorzubeugen. Eine höhere Planstabilität, ein größerer Einfluss auf die Plangestaltung und ausreichend Ruhezeit würde beispielsweise der Vereinbarkeit von Beruf und Privat entgegen kommen.
Andere in der Literatur als bedeutend eruierten Variablen, wie bspw. die Arbeitsplatzsicherheit und der Zivilstand, zeigten keine oder nur eine sehr geringe Signifikanz. Abschließend wurden Faktoren, welche einen Einfluss auf das Ergebnis haben könnten, ausführlich erläutert und diskutiert sowie eine Empfehlung für die Praxis und zukünftige wissenschaftliche Untersuchungen abgeleitet. Insbesondere der Forschungsausblick zeigt, dass der Zusammenhang der Dimensionen Mitarbeiterzufriedenheit und Burnout, welche anhand der Stichprobe der Flugbegleiter in dieser Arbeit erhoben wurde, noch umfassende Erforschungen erfordert, um hier vor allem für die Wirtschaft Verbesserungen und entsprechende Kostenreduktion bewirken zu können. Sowohl für die Wirtschaft als auch die Wissenschaft wäre eine engere Zusammenarbeit wünschenswert und gewinnbringend.