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Field margins are often the only remaining habitats of various wild plant species in agricultural landscapes. However, due to their proximity to agricultural fields, the vegetation of field margins can be affected by agrochemicals applied to the crop fields. The aim of this thesis was to investigate the individual and combined effects of herbicide, insecticide and fertilizer inputs on the plant community of a field margin. Therefore, a 3-year field experiment with a randomized block design including seven treatments (H: herbicide, I: insecticide, F: fertilizer, H+I, F+I, F+H and F+H+I) and one control was conducted on a low-production meadow. Each treatment was replicated 8 times in 8 m x 8 m plots with a distance of 2 m between each plot. The fertilizer rates (25 % of the field rate) and pesticide rates (30 % of the field rate) used for the plot applications were consistent with realistic average input rates (overspray + drift) in the first meter of a field margin directly adjacent to a wheat field.
The study revealed that fertilizer and herbicide misplacements in field margins are major factors that affect the natural plant communities of these habitats. In total, 20 of the 26 abundant species on the study site were significantly affected by the fertilizer and herbicide treatment. The fertilizer promoted plants with high nutrient uptake and decreased the frequencies of small species. The herbicide caused a nearly complete disappearance of three species directly after the first application, whereas sublethal effects (e.g., phytotoxic effects and reduced seed productions of up to 100 %) were observed for the other affected species. However, if field margins are exposed to repeated agrochemical applications over several years, then such sublethal effects (particularly reproduction effects) also reduce the population size of plant species significantly, as observed in this study.
Significant herbicide-fertilizer interaction effects were also detected and could not be extrapolated from individual effects. The fertilizer and herbicide effects became stronger over time, leading to shifts in plant community compositions after three years and to a 15 % lower species diversity than in the control. The insecticide significantly affected the frequencies of two plant species (1 positively and 1 negatively). The results of the experiment suggest that a continuous annual agrochemical application on the study site would cause further plant community shifts and would likely lead to the disappearance of certain affected plants. A clear trend of increasing grass dominance at the expense of flowering herbs was detected. This finding corresponds well with monitoring data from field margins near the study site.
Although herbicide risk assessment aims to protect non-target plants in off-field habitats from adverse effects, reproduction effects and combined effects are currently not considered. Furthermore, no regulations for fertilizer applications next to field margins exist and thus, fertilizer misplacements in field margins are likely to occur and to interact with herbicide effects.
Adaptations of the current risk assessment, a development of risk mitigation measures (e.g., in-field buffers) for the application of herbicides and fertilizers, and general management measures for field margins are needed to restore and conserve plant diversity in field margins in agricultural landscapes.
This study explored the question whether greenhouse gas mitigation projects in Namibia could be initiated through local economic development programmes. In particular, research was done on whether the Clean Development Mechanism (CDM) of the Kyoto Protocol could play an essential role in the promotion of such mitigation projects.
In a first step supporting and inhibiting factors (potential for mitigation projects, business and investment climate, institutions, etc.) were discussed, which have a negative or positive influence on mitigation projects. In a second step the mind-set of climate and energy experts as well as of local economic development experts and practitioners was analysed with regard to the research questions. To this end, 229 questionnaires, 28 interviews and the output of a focus group discussion with 20 participants were evaluated. Additionally, the author conducted a real life case study to investigate the practicability of initiating greenhouse gas mitigation projects through local economic development efforts. Parallel to the development of an economic development strategy in the Namibian region of Otjozondjupa, the potential for greenhouse gas mitigation projects was explored. Based on the outcome of this investigation project ideas were developed and their potential socio-economic impact was evaluated. Promising projects were then included into the development strategy.
Due to various factors such as the complexity of CDM, low greenhouse gas emissions in Namibia, the low price of emission rights and insufficient financial means it is unlikely that CDM projects can be initiated through local economic development initiatives in Namibia. However, many stakeholders consider the idea of interlinking mitigation projects and local economic development initiatives favourably as long as such projects support the broader objectives of those initiatives. This research has shown that locally initiated mitigation projects do not contribute much to employment or income generation at the local level in Namibia. Thus, national strategic objectives should be considered, such as improving access to electricity to all strata of society or becoming less dependent on electricity imports. This requires, however, that local economic development strategies also cover the energy sector, that local governments are willing and capacitated to initiate mitigation projects, that national and local public institutions work together more closely, that national and local economic framework conditions are improved so as to attract private investments, and that the experiences and interests of the relevant stakeholders are considered throughout the project development process.
This work is mainly concerned with multiple goals as indicators of stable as well as situation-specific motivation. During school lessons, pupils strive for competence-oriented goals as well as goals which target psychological well-being. The goal to enlarge one- competence and to acquire deeper knowledge (mastery goal), to attain normative competence (performance approach goal) as well as the goal to avoid the demonstration of lack ofrncompetence (performance avoidance goal) belong to the category of academic goals. The category of well-being goals includes the goal to avoid hard work (work avoidance goal) as well as the aim to interact socially with relevant peers (affiliation goal).
It is still unclear, however, if goals are best defined as fluctuating state or stable trait variables. Here, both aspects of goals are conceptualized differentially and their connection is explored in two studies based on a longitudinal design. Another question that is raised here is concerned with the explanation of state-goal-genesis. Different motivational theories serve as the basis for the development of a new framework model, which explores the genesis of state goal-components due to trait goal-components, situational appraisals and their interaction. In the literature, three effect models between appraisals and trait goals regarding the state goals are identified: a) appraisals and trait goals might predict state goals additively (additive effect), b) trait goals might influence the state goals mediated by the appraisals (reactive effect), or c) the trait goals may have differential effects on the state goals for low or high values of the appraisals (interaction effect). Moreover, assumptions on proximal consequences of state-goals are made within the framework model.
Study 1 comprised of two samples (N = 197 and N = 297). Both multiple goal factors as well as their state- and trait-components were validated empirically in a longitudinal design. State goal measures proved to be sensitive to situational influences and to be differentially valid compared to trait goal measures. Study 2 primarily dealt with the explanationrnof the genesis of state goals in actual learning situations. The basic assumptions of the framework model as well as the three effect models were explored systematically in a longitudinal design (N = 542). As expected, competence oriented goals correlated with adaptive indicators of learning processes (e.g., flow), while the well-being goals did not. The additive effect hypothesis was confirmed while the reactive effect hypothesis was rejected. With the help of latent moderator models, some interaction effects were identified which showed that trait goals were differentially predictive for state goals depending on the level of situational appraisals.
Diffusion imaging captures the movement of water molecules in tissue by applying varying gradient fields in a magnetic resonance imaging (MRI)-based setting. It poses a crucial contribution to in vivo examinations of neuronal connections: The local diffusion profile enables inference of the position and orientation of fiber pathways. Diffusion imaging is a significant technique for fundamental neuroscience, in which pathways connecting cortical activation zones are examined, and for neurosurgical planning, where fiber reconstructions are considered as intervention related risk structures.
Diffusion tensor imaging (DTI) is currently applied in clinical environments in order to model the MRI signal due to its fast acquisition and reconstruction time. However, the inability of DTI to model complex intra-voxel diffusion distributions gave rise to an advanced reconstruction scheme which is known as high angular resolution diffusion imaging (HARDI). HARDI received increasing interest in neuroscience due to its potential to provide a more accurate view of pathway configurations in the human brain.
In order to fully exploit the advantages of HARDI over DTI, advanced fiber reconstructions and visualizations are required. This work presents novel approaches contributing to current research in the field of diffusion image processing and visualization. Diffusion classification, tractography, and visualizations approaches were designed to enable a meaningful exploration of neuronal connections as well as their constitution. Furthermore, an interactive neurosurgical planning tool with consideration of neuronal pathways was developed.
The research results in this work provide an enhanced and task-related insight into neuronal connections for neuroscientists as well as neurosurgeons and contribute to the implementation of HARDI in clinical environments.
Die Studie befasst sich mit der Bildungsaspiration, der Wertevermittlung und -tradierung iranischstämmiger Familien in Deutschland. Ziel ist es, zu ermitteln, worauf die familiäre Bildungsaspiration zurückzuführen ist. Im Fokus der Fallstudie stehen drei Familien, die nach der Islamischen Revolution von 1979 aus ihrem Herkunftsland nach Deutschland immigriert sind. Es handelt sich um eine zweigenerationenperspektivische Befragung innerhalb einer Familie. Dies bedeutet, dass innerhalb einer Familie Einzelinterviews mit jeweils einer Person aus der Eltern- und Kindergeneration durchgeführt wurden. So werden gemeinsam erlebte Situationen, wie z.B. Flucht oder Teilhabe am deutschen Bildungssystem, oder Begriffe, wie z.B. Bildung oder Bildungserfolg, aus der jeweiligen Perspektive geschildert bzw. definiert. Darüber hinaus geben die Befragten Auskünfte über die Großelterngeneration, sodass das gesamte Datenmaterial Angaben über drei Generationen umfasst. Dieser qualitativen Exploration geht eine bundesweite Befragung voraus an der 70 Personen iranischer Herkunft teilnahmen. Weiterhin zeichnet sich die Arbeit durch einen ressourcenorientierten Forschungsansatz aus. Die erhobenen Daten geben Antwort auf die zentralen Fragen:
Auf welche Ursachen lässt sich Bildungsaspiration von immigrierten, iranischstämmigen Familien in Deutschland zurückführen?
Welche Rolle spielen die Sprachen des Herkunfts- und Einwanderungslandes in der Wertetradierung? In der Studie werden die individuellen Bildungsgeschichten der Befragten in den wissenschaftlichen Diskurs zur Bildungsaspiration, Bildungs-, Migrations- und Mehrsprachigkeitsforschung eingefügt. Hierbei wird ein interdisziplinäres und somit multiperspektivisches Theoriekonstrukt zugrunde gelegt, welches sich durch einen geschichts-, länder- und generationsübergreifenden Forschungsansatz auszeichnet. Ein zentrales Ergebnis ist, dass ein Verständnis für geschichtliche Entwicklungen im Herkunftsland erforderlich ist, um das Bildungsverhalten im iranischstämmigen Familienkontext nachzuvollziehen. Erst durch Kontextualisierung von individuellen und gesellschaftlichen Dimensionen kann nachvollzogen werden, warum im Falle dieser Minderheitengruppe geringes ökonomisches Kapital, das infolge von beruflichen Brüchen der Eltern nach ihrer Flucht im Einwanderungsland entstanden ist, keine negativen Auswirkungen auf die Entwicklung des kulturellen Kapitals der Folgegenerationen hat. Folglich zeigt die Studie, dass im Falle der interviewten Familien gängige Erklärungsmodelle, wie die Korrelation vom geringem ökonomischen Kapital und geringem kulturellen Kapital, nicht zutreffen. Vielmehr wird kulturelles Kapital von Generation zu Generation tradiert. Ein weiteres Ergebnis der Studie ist das erarbeitete Dreiebenen-Modell. Es umfasst geschichtlich-gesellschaftliche, politische sowie familiäre Entwicklungen und Einstellungen auf der Mikro-, Meso- und Makroebene. Damit ist eine Grundlage geschaffen, um das Tradierungsverhalten anderer Zuwanderungsgruppen zu erklären.
This study examined whether positive resource change and two types of baseline stressors would influence general life satisfaction and satisfaction with health at the end of treatment in mothers attending an inpatient rehabilitation or preventive program for mothers, fathers and children. Parenting self-efficacy was included as an indicator of resources while baseline distress was operationalized in terms of parenting-related stressors and depressive symptoms, respectively. Drawing on Hobfoll- conservation of resources theory, it was hypothesized that resource change and baseline stressors would interact in their effect on satisfaction measures at the end of the preventive/rehabilitation program: resource gains were expected to influence satisfaction more strongly in patients who reported higher stress levels at baseline (as compared to patients with lower baseline distress; primary research question). Hypotheses were tested using a sample of N=1724 female prevention and rehabilitation patients by means of structural equation modeling including latent interactions. Results showed that parenting-related stressors were negatively associated with general satisfaction as well as satisfaction with health while resource gains had a small positive effect on satisfaction. There was, however, no significant interaction of parenting-related stressors and positive resource change. When depressive symptoms were included as a measure of baseline distress, they were negatively associated with both facets of satisfaction. In these models, there were only small positive associations of resource gains and satisfaction measures. Again, no interaction effects were found. Additional analyses that comprised both stressor types as predictors showed that the effects of depressive symptoms on satisfaction were more pronounced than the influence of parenting-related stressors; the effects of resource gains were small to negligible. In addition, it was examined whether problem-oriented coping strategies mediated the influence of positive resource change on general life satisfaction and satisfaction with health, respectively (secondary research question). Correlations between coping, resource change and satisfaction were low or not significant. Given this lack of direct associations between the relevant variables, no further path analytic testing was performed; the hypothesized mediating role of problem-oriented coping could thus not be confirmed. All in all, study results show that contrary to the hypotheses derived from conservation of resources theory, the effects of positive resource change and distress indicators on patients" life satisfaction and satisfaction with health were not interdependent.
Diese Studie leistet einen Beitrag zur Weiterentwicklung der Nachrichtenwerttheorie. Hierzu wird das Konzept der Fotonachrichtenfaktoren zunächst theoretisch aufgearbeitet und seine Plausibilität anhand verschiedener Teilbereiche der Journalismusforschung dargelegt. Darauf aufbauend wird es im Rahmen einer Inhaltsanalyse eingesetzt, die die Prüfung des erweiterten Modells der Nachrichtenwerttheorie ermöglicht. Dieses Modell geht von einem gemeinsamen Einfluss der textbasierten Nachrichtenfaktoren und der Fotonachrichtenfaktoren auf den Nachrichtenwert bzw. die journalistische Beachtung eines Beitrags aus. Ergänzend werden die Fotonachrichtenfaktoren zur Bildung von Fototypen herangezogen. Die Analysen werden am Beispiel der Kriegs- und Krisenberichterstattung deutscher Tageszeitungen durchgeführt. Dieser Themenbereich des Journalismus genießt viel Aufmerksamkeit sowohl bei Medienrezipienten als auch bei Kommunikationswissenschaftlern. Die Ergebnisse der Studie unterstützen die Grundidee der Fotonachrichtenfaktoren: Sie können, ähnlich wie die textbasierten Nachrichtenfaktoren, zu übergeordneten Bündeln zusammengefasst werden. Diese Bündel zeigen Einflüsse auf die formale Gestaltung der Fotos und können gemeinsam mit den Textnachrichtenfaktoren teilweise die journalistische Beachtung des Artikels erklären. Darüber hinaus ist die gewählte Operationalisierung der Fotonachrichtenfaktoren geeignet, Fototypen bzw. zentrale Motive der visuellen Kriegsberichterstattung deutscher Tageszeitungen zu identifizieren. Die Ergebnisse dieser Studie liefern Ausgangspunkte für weitere Fragestellungen zum Zusammenwirken der Text- und Fotonachrichtenfaktoren, der Anwendung der Zwei-Komponenten-Theorie und der Wirkung von typischen Bildmotiven.
The availability of digital cameras and the possibility to take photos at no cost lead to an increasing amount of digital photos online and on private computers. The pure amount of data makes approaches that support users in the administration of the photo necessary. As the automatic understanding of photo content is still an unsolved task, metadata is needed for supporting administrative tasks like search or photo work such as the generation of photo books. Meta-information textually describes the depicted scene or consists of information on how good or interesting a photo is.
In this thesis, an approach for creating meta-information without additional effort for the user is investigated. Eye tracking data is used to measure the human visual attention. This attention is analyzed with the objective of information creation in the form of metadata. The gaze paths of users working with photos are recorded, for example, while they are searching for photos or while they are just viewing photo collections.
Eye tracking hardware is developing fast within the last years. Because of falling prices for sensor hardware such as cameras and more competition on the eye tracker market, the prices are falling, and the usability is increasing. It can be assumed that eye tracking technology can soon be used in everyday devices such as laptops or mobile phones. The exploitation of data, recorded in the background while the user is performing daily tasks with photos, has great potential to generate information without additional effort for the users.
The first part of this work deals with the labeling of image region by means of gaze data for describing the depicted scenes in detail. Labeling takes place by assigning object names to specific photo regions. In total, three experiments were conducted for investigating the quality of these assignments in different contexts. In the first experiment, users decided whether a given object can be seen on a photo by pressing a button. In the second study, participants searched for specific photos in an image search application. In the third experiment, gaze data was collected from users playing a game with the task to classify photos regarding given categories. The results of the experiments showed that gaze-based region labeling outperforms baseline approaches in various contexts. In the second part, most important photos in a collection of photos are identified by means of visual attention for the creation of individual photo selections. Users freely viewed photos of a collection without any specific instruction on what to fixate, while their gaze paths were recorded. By comparing gaze-based and baseline photo selections to manually created selections, the worth of eye tracking data in the identification of important photos is shown. In the analysis of the data, the characteristics of gaze data has to be considered, for example, inaccurate and ambiguous data. The aggregation of gaze data, collected from several users, is one suggested approach for dealing with this kind of data.
The results of the performed experiments show the value of gaze data as source of information. It allows to benefit from human abilities where algorithms still have problems to perform satisfyingly.
German politicians have identified a need for greater citizen involvement in decision-making than in the past, as confirmed by a recent German parliamentarians study ("DEUPAS"). As in other forms of social interactions, the Internet provides significant potential to serve as the digital interface between citizens and decision-makers: in the recent past, dedicated electronic participation ("e-participation") platforms (e.g. dedicated websites) have been provided by politicians and governments in an attempt to gather citizens" feedback and comment on a particular issue or subject. Some of these have been successful, but a large proportion of them are grossly under-used " often only small numbers of citizens use them. Over the same time period, enthusiasm of Society for social networks has increased and is now commonplace. Many citizens use social networks such as Facebook and Twitter for all kinds of purposes, and in some cases to discuss political issues.
Social networks are therefore obviously attractive to politicians " from local government to federal agencies, politicians have integrated social media into their daily work. However, there is a significant challenge regarding the usefulness of social networks. The problem is the continuous increase in digital information: social networks contain vast amounts of information, and it is impossible for a human to manually filter the relevant information from the irrelevant (so-called "information overload"). Even using the search tools provided by social networks, it is still a huge task for a human to determine meanings and themes from the multitude of search results. New technologies and concepts have been proposed to provide summaries of masses of information through lexical analysis of social media messages, and therefore they promise an easy and quick overview of the information.
This thesis examines the relevance of these analyses" results, for the use in everyday political life, with the emphasis on the social networks Facebook and Twitter as data sources. Here we make use of the WeGov Toolbox and its analysis components that were developed during the EU project WeGov. The assessment has been performed in consultation with actual policy-makers from different levels of German government: policy-makers from the German Federal Parliament, the State Parliament North Rhine-Westphalia, the State Chancellery of the Saarland and the cities of Cologne and Kempten all took part in the study. Our method was to execute the analyses on data collected from Facebook and Twitter, and present the results to the policy-makers, who would then evaluate them using a mixture of qualitative methods.
The responses of the participants have provided us with some useful conclusions:
1) None of the participants believe that e-participation is possible in this way. But participants confirm that "citizen-friendliness" can be supported by this approach.
2) The most likely users for the summarisation tools are those who have experience with social networks, but are not "power users". The reason being is that "power users" already knew the relevant information provided by analysis tools. But without any experiences for social networks it is hard to interpret the analysis results the right way.
3) The evaluation has considered geographical aspects, and related this to e.g. a politician- constituency as a local area of social networks. Comparing the rural to the urban areas, it is shown that the amount of relevant political information in the rural areas is low. While the proportion of publicly available information in urban areas is relatively high, the proportion in the rural areas is much lower.
The findings that result from the engagement with policy-makers will be systematically surveyed and validated within this thesis.
Mathematical Modelling of GIS Tailored GUI Design with the Application of Spatial Fuzzy Logic
(2014)
This PhD thesis is situated within the framework of the Research-Group Learning and Neurosciences (ReGLaN)-Health and Logistics project. The goal of this project is the optimisation of health service delivery in the rural areas of South Africa. Cooperation takes place between ReGLaN-Health and Logistics and the South African Council for Scientific and Industrial Research (CSIR) Meraka Institute, with Prof Dr Dr Marlien Herselman of Pretoria, South Africa, as the central contact person. This thesis deals with the mathematical modelling of Geographic Information System (GIS)-tailoredrnGraphical User Interface (GUI) design with the application of spatial fuzzy logic. This thesis considers the mathematical visualisation of risk and resource maps for epidemiological issues using GIS and adaptive GUI design for an Open Source (OS) application for digital devices. The intention ofrnthis thesis is to provide spatial decision support tailored to different user groups. In order for the GUI elements to be evaluated and initialised, empirical teaching-learning-research on dealing with geomedia and GUI elements was conducted.