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The distractor-response binding effect (Frings & Rothermund, 2011; Frings, Rothermund, & Wentura, 2007; Rothermund, Wentura, & De Houwer, 2005) is based on the idea that irrelevant information will be integrated with the response to the relevant stimuli in an episodic memory trace. The immediate re-encounter of any aspect of this saved episode " be it relevant or irrelevant " can lead to retrieval of the whole episode. As a consequence, the previously executed and now retrieved response may influencing the response to the current relevant stimulus. That is, the current response may either be facilitated or be impaired by the retrieved response, depending on whether it is compatible or incompatible to the currently demanded response. Previous research on this kind of episodic retrieval focused on the influence on action control. I examined if distractor response binding also plays a role in decision making in addition to action control. To this end I adapted the distractor-to-distractor priming paradigm (Frings et al., 2007) and conducted nine experiments in which participants had to decide as fast as possible which disease a fictional patient suffered from. To infer the correct diagnosis, two cues were presented; one did not give any hint for a disease (the irrelevant cue), whereas the other did (the relevant cue). Experiments 1a to 1c showed that the distractor-response binding effect is present in deterministic decision situations. Further, experiments 2a and 2b indicate that distractor-response binding also influences decisions under uncertainty. Finally, experiments 3a to 3d were conducted to test some constraints and underlying mechanisms of the distractor-response binding effect in decision making under uncertainty. In sum, these nine experiments provide strong evidence that distractor-response binding influences decision making.
Stress related disorders increase continuously. It is not yet clear if stress also promotes breast cancer. This dissertation provides an analyses of the current state of research and focuses on the significance of pre-/postnatal stress factors and chronic stress. The derived hypotheses are empirically examined on breast cancer patients. The clinical study investigates the links between those factors and prognosis and outcome.
This thesis deals with economic aspects of employees' sickness. In addition to the classical case of sickness absence, in which an employee is completely unable to work and hence stays at home, there is the case of sickness presenteeism, in which the employee comes to work despite being sick. Accordingly, the thesis at hand covers research on both sickness states, absence and presenteeism. The first section covers sickness absence and labour market institutions. Chapter 2 presents theoretical and empirical evidence that differences in the social norm against benefit fraud, so-called benefit morale, can explain cross country diversity in the generosity of statutory sick pay entitlements between developed countries. In our political economy model, a stricter benefit morale reduces the absence rate, with counteracting effects on the politically set sick pay replacement rate. On the one hand, less absence caused by a stricter norm, makes the tax-financed insurance cheaper, leading to the usual demand side effect and hence to more generous sick pay entitlements. On the other hand, being less likely to be absent due to a stricter norm, the voters prefer a smaller fee over more insurance. We document both effects in a sample of 31 developed countries, capturing the years from 1981 to 2010. In Chapter 3 we investigate the relationship between the existence of works councils and illness-related absence and its consequences for plants. Using individual data from the German Socio-Economic Panel (SOEP), we find that the existence of a works council is positively correlated with the incidence and the annual duration of absence. Additionally, linked employer-employee data (LIAB) suggests that employers are more likely to expect personnel problems due to absence in plants with a works council. In western Germany, we find significant effects using a difference-in-differences approach, which can be causally interpreted. The second part of this thesis covers two studies on sickness presenteeism. In Chapter 4, we empirically investigate the determinants of the annual duration of sickness presenteeism using the European Working Conditions Survey (EWCS). Work autonomy, workload and tenure are positively related to the number of sickness presenteeism days, while a good working environment comes with less presenteeism. In Chapter 5 we theoretically and empirically analyze sickness absence and presenteeism behaviour with a focus on their interdependence. Specifically, we ask whether work-related factors lead to a substitutive, a complementary or no relationship between sickness absence and presenteeism. In other words, we want to know whether changes in absence and presenteeism behaviour incurred by work-related characteristics point in opposite directions (substitutive), the same direction (complementary), or whether they only affect either one of the two sickness states (no relationship). Our theoretical model shows that the relationship between sickness absence and presenteeism with regard to work-related characteristics is not necessarily of a substitutive nature. Instead, a complementary or no relationship can emerge as well. Turning to the empirical investigation, we find that only one out of 16 work-related factors, namely the supervisor status, leads to a substitutive relationship between absence and presenteeism. Few of the other determinants are complements, while the large majority is either related to sickness absence or presenteeism.
Chapter 2: Using data from the German Socio-Economic Panel, this study examines the relation-ship between immigrant residential segregation and immigrants" satisfaction with the neighbor-hood. The estimates show that immigrants living in segregated areas are less satisfied with the neighborhood. This is consistent with the hypothesis that housing discrimination rather than self-selection plays an important role in immigrant residential segregation. Our result holds true even when controlling for other influences such as household income and quality of the dwelling. It also holds true in fixed effects estimates that account for unobserved time-invariant influences. Chapter 3: Using survey data from the German Socio-Economic Panel, this study shows that immigrants living in segregated residential areas are more likely to report discrimination because of their ethnic background. This applies to both segregated areas where most neighbors are immigrants from the same country of origin as the surveyed person and segregated areas where most neighbors are immigrants from other countries of origin. The results suggest that housing discrimination rather than self-selection plays an important role in immigrant residential segregation. Chapter 4: Using data from the German Socio-Economic Panel (SOEP) and administrative data from 1996 to 2009, I investigate the question whether or not right-wing extremism of German residents is affected by the ethnic concentration of foreigners living in the same residential area. My results show a positive but insignificant relationship between ethnic concentration at the county level and the probability of extreme right-wing voting behavior for West Germany. However, due to potential endogeneity issues, I additionally instrument the share of foreigners in a county with the share of foreigners in each federal state (following an approach of Dustmann/Preston 2001). I find evidence for the interethnic contact theory, predicting a negative relationship between foreign-ers" share and right-wing voting. Moreover, I analyze the moderating role of education and the influence of cultural traits on this relationship. Chapter 5: Using data from the Socio-Economic Panel from 1998 to 2009 and administrative data on regional ethnic diversity, I show that ethnic diversity inhibits significantly people- political interest and participation in political organizations in West Germany. People seem to isolate themselves from political participation if exposed to more ethnic diversity which is particularly relevant with respect to the ongoing integration process of the European Union and the increasing transfer of legislative power from the national to European level. The results are robust if an instrumental variable strategy suggested by Dustmann and Preston (2001) is used to take into account that ethnic diversity measured on a local spatial level could be endogenous due to residential sorting. Interestingly, participation in non-political organizations is positively affected by ethnic diversity if selection bias is corrected for.
Every day we are exposed to a large set of appetitive food cues, mostly of high caloric, high carbohydrate content. Environmental factors like food cue exposition can impact eating behavior, by triggering anticipatory endocrinal responses and reinforcing the reward value of food. Additionally, it has been shown that eating behavior is largely influence by neuroendocrine factors. Energy homeostasis is of great importance for survival in all animal species. It is challenged under the state of food deprivation which is considered to be a metabolic stressor. Interestingly, the systems regulating stress and food intake share neural circuits. Adrenal glucocorticoids, as cortisol, and the pancreatic hormone insulin have been shown to be crucial to maintain catabolic and anabolic balance. Cortisol and insulin can cross the blood-brain barrier and interact with receptors distributed throughout the brain, influencing appetite and eating behavior. At the same time, these hormones have an important impact on the stress response. The aim of the current work is to broaden the knowledge on reward related food cue processing. With that purpose, we studied how food cue processing is influenced by food deprivation in women (in different phases of the menstrual cycle) and men. Furthermore, we investigated the impact of the stress/metabolic hormones, insulin and cortisol, at neural sites important for energy metabolism and in the processing of visual food cues. The Chapter I of this thesis details the underlying mechanisms of the startle response and its application in the investigation of food cue processing. Moreover, it describes the effects of food deprivation and of the stress-metabolic hormones insulin and cortisol in reward related processing of food cues. It explains the rationale for the studies presented in Chapter II-IV and describes their main findings. A general discussion of the results and recommendations for future research is given. In the study described in Chapter II, startle methodology was used to study the impact of food deprivation in the processing of reward related food cues. Women in different phases of the menstrual cycle and men were studied, in order to address potential effects of sex and menstrual cycle. All participants were studied either satiated or food deprived. Food deprivation provoked enhanced acoustic startle (ASR) response during foreground presentation of visual food cues. Sex and menstrual cycle did not influence this effect. The startle pattern towards food cues during fasting can be explained by a frustrative nonreward effect (FNR), driven by the impossibility to consume the exposed food. In Chapter III, a study is described, which was carried out to explore the central effects of insulin and cortisol, using continuous arterial spin labeling to map cerebral blood flow patterns. Following standardized periods of fasting, male participants received either intranasal insulin, oral cortisol, both, or placebo. Intranasal insulin increased resting regional cerebral blood flow in the putamen and insular cortex, structures that are involved in the regulation of eating behavior. Neither cortisol nor interaction effects were found. These results demonstrate that insulin exerts an action in metabolic centers during resting state, which is not affected by glucocorticoids. The study described in Chapter IV uses a similar pharmacological manipulation as the one presented in Chapter III, while assessing processing of reward related food cues through the startle paradigm validated in Chapter II. A sample of men was studied during short-term food deprivation. Considering the importance of both cortisol and insulin in glucose metabolism, food pictures were divided by glycemic index. Cortisol administration enhanced ASR during foreground presentation of "high glycemic" food pictures. This result suggests that cortisol provokes an increase in reward value of high glycemic food cues, which is congruent with previous research on stress and food consumption. This thesis gives support to the FNR hypothesis towards food cues during states of deprivation. Furthermore, it highlights the potential effects of stress related hormones in metabolism-connected neuronal structures, and in the reward related mechanisms of food cue processing. In a society marked by increased food exposure and availability, alongside with increased stress, it is important to better understand the impact of food exposition and its interaction with relevant hormones. This thesis contributes to the knowledge in this field. More research in this direction is needed.
Das erste Kapitel "ECOWAS" capability and potential to overcome constraints to growth and poverty reduction of its member states" diskutiert die Analyse wirtschaftlicher und sozialer Barrieren für ökonomisches Wachstum " eine der Hauptelemente für Entwicklungs- und Armutsreduktionsstrategien in Entwicklungsländern. Die Form der länderspezifischen Analyse von Wachstumsbarrieren wurde nach dem Scheitern der auf alle Länder generalisierten Entwicklungsstrategie des Washington Consensus insbesondere durch den Ansatz der "Growth Diagnostics" der Harvard Professoren Hausman, Rodrik und Velasco eingeführt. Es zeigt sich jedoch, dass bisher der Fokus rein auf den länderspezifischen Analysen bzw. Strategieentwicklungen liegt. Diese Arbeit erweiterte die Diskussion auf die regionale Ebene, indem es beispielhaft an der Economic Community of West African States (ECOWAS) die länderspezifischen Wachstumsbarrieren mit den regionalen Wachstumsbarrieren vergleicht. Dies erfolgt mittels einer Darstellung der in Studien und Strategien bereits identifizierten, länderspezifischen Wachstumsbarrieren in den jeweiligen Ländern sowie mit der Auswertung der regionalen Strategien der ECOWAS. Dazu wird ermittelt, inwieweit auf der regionalen Ebene auch messbare Ergebnisse bei der Bekämpfung von Wachstumsbarrieren erzielt werden. Es zeigt sich, dass ,trotz der wirtschaftlichen und sozialen Diversität der Region, die ECOWAS den Großteil der in den Ländern identifizierten Wachstumsbarrieren ebenfalls auflistet und darüber hinaus sogar mit messbaren Ergebnissen dazu beiträgt, Veränderungen des Status Quo zu erreichen. Die Erweiterung des Ansatzes der Growth Diagnostics auf die regionale Ebene sowie die Erweiterung um das vergleichende Element von länderspezifischen und regionalen Wachstumsbarrieren zeigen sich als praktikabler Weg, Entwicklungsstrategien auf regionaler Ebene zu prüfen und subsidiär weiterzuentwickeln. Das zweite Kapitel "Simplifying evaluation of potential causalities in development projects using Qualitative Comparative Analysis (QCA)" diskutiert die Methode der qualitativen komperativen Analyse (QCA) als Evaluierungsmethodik für Projekte der Entwicklungszusammenarbeit. Hierbei stehen die adäquate Messung sowie die verständliche Darstellung der Wirkung von Entwicklungszusammenarbeit im Vordergrund. Dies ist ein Beitrag zu der intensiv geführten Diskussion, wie Wirkung von Hilfe in Entwicklungsländern gemessen und daraus für weitere Projekte gelernt werden kann. Mit der beispielhaften Anwendung der QCA auf einen Datensatz der deutschen Entwicklungszusammenarbeit im Senegal wird erstmalig diese Methode für die Entwicklungszusammenarbeit in der Praxis angewandt. Der Fokus liegt dabei auf der Überprüfung von bestimmten Programmtheorien, d.h. der Annahme bestimmter Zusammenhänge zwischen eingesetzten Mitteln, äußeren Umständen und den Projektergebnissen bei der Implementierung von Projekten. Während solche Programmtheorien in dem Großteil der Projektskizzen der deutschen Entwicklungszusammenarbeit enthalten sind, werden die wenigsten dieser Programmtheorien geprüft. Diese Arbeit zeigt QCA als eine effiziente Methode für diese Überprüfung. Eine eindeutige Bestätigung oder Falsifizierung dieser Theorien ist mittels dieser Methodik möglich. Dazu können die Ergebnisse bei den beiden einfacheren Formen der QCA, der crisp-set sowie der multi-value QCA, leicht nachvollziehbar vermittelt werden. Des Weiteren zeigt die Arbeit, dass QCA ebenfalls die Weiterentwicklung einer Programmtheorie ermöglicht, allerdings ist diese Weiterentwicklung nur begrenzt effizient und stark von den vorliegenden Daten sowie der Datenstruktur abhängig. Die Arbeit zeigt somit das Potential der QCA insbesondere für den Test von Programmtheorien auf und stellt die praktische Anwendung für mögliche Replizierung beispielhaft dar. Das dritte und letzte Kapitel der Doktorarbeit "The regional trade dynamics of Turkey: a panel data gravity model" analysiert den türkischen Handel, um die Veränderungen der letzten Jahrzehnte aufzuzeigen und daran zu diskutieren, inwieweit sich die Türkei als aufstrebendes Schwellenland von den bestehenden Handelsstrukturen loslöst. Diese Arbeit ist ein Beitrag zur Diskussion der sich Verschiebenden Machtkonstellationen durch das wirtschaftliche Aufholen der Schwellenländer. Bei der Türkei ist diese Diskussion zusätzlich interessant, da die Frage, ob die Türkei sich von der westlichen Welt, Nordamerika und Europa, abwendet, berücksichtigt wird. Mittels Dummy-Variablen für verschiedene Regionen in einem Gravitätsmodell werden die türkischen Handelsdaten zuerst insgesamt und nach Sektoren analysiert und die Veränderungen über verschieden Perioden des türkischen Außenhandels betrachtet. Es zeigt sich, dass in den türkischen Handelsbeziehungen eine Regionalisierung und eine Diversifizierung der Handelspartner stattfinden. Allerdings geht dies nicht mit einer Abkehr von westlichen Handelspartnern einher.
The influence of affect on vocal parameters has been well investigated in speech portrayed by actors, but little is known about affect expression in more natural or authentic speech behavior. This is partly due to the difficulty of generating speech samples that represent authentic expression of speaker affect. The present work investigates the influence of speaker affect on the vocal fundamental frequency (F0) in comparatively authentic speech samples. Three well-documented psychophysiological research methods were applied for the induction of affective states in German native speakers in order to obtain speech samples with authentic affect expression: the Cold Pressor Test (CPT), the Stroop Color-Word Test (SCWT) and the presentation of slides from the International Affective Pictures System (IAPS). The here reported results show that the influence of affect on F0 is differentially modulated by psychophysiological processes as well as socio-cultural influences. They also indicate that this approach may be useful for future research and further to gain a deeper understanding of authentic vocal affect expression. Moreover, F0 may constitute an additional non-invasive, easy to obtain measure for the established psychophysiological research methodology.
Evaluation of desalination techniques for treating the brackish water of Olushandja sub-basin
(2014)
The groundwater of Olushandja sub-basin as part of Cuvelai basin in central-northern Namibia is saline with TDS content varying between 4,000ppm to 90,000ppm. Based on climatic conditions, this region can be classified as a semi-arid to arid region with an annual rainfall during summer time varying between 200mm to 500mm. The mean annual evaporation potential is about 2,800mm, which is much higher than the annual rainfall. The southern block of this sub-basin is of low population density. It has not been covered by the supply networks for electricity and water. Therefore, the inhabitants are forced to use the untreated groundwater from the hand-dug wells for their daily purposes. This groundwater is not safe for human consumption and therefore needs to be desalinated for that purpose. The goal of this thesis has been to select a suitable desalination technology for that region. The technology to be selected is from those which use renewable energy sources, which have capacity of production from 10m3 to 100m3 per day, which are simple and robust against existing harsh environmental conditions and have already been implemented successfully in some place. Based on these criteria, the technologies which emerged from the literature are: multistage flashing (MSF), multi effect distillation (MED), multi effect humidification (MEH), membrane distillation (MD), reverse osmosis (RO) and electro dialysis reversed (ED). Out of these technologies, RO & ED are based on membrane techniques and MSF, MED & MEH use thermal processes whereas MD technology uses a hybrid process of thermal and membrane techniques for desalinating the water. For evaluation of technical performance, environmental sustainability and financial feasibility of the above mentioned desalination techniques, the following criteria have been used: gained output ratio, recovery rate, pretreatment requirements, sensitivity to feed water quality, post treatment, operating temperature, operating pressure, scaling and fouling potential, corrosion susceptibility, brine disposal, prime energy requirement, mechanical and electrical power output, heat energy, running costs and water generation costs. The data regarding the performance standards of the successfully implemented desalination techniques have been obtained from the literature of performance benchmarks. The Utility Value Analysis Tool of the Rafter-Group of Multi-Criteria Analysis (MCA) has been used for measuring the performance score of a technology. To perform the utility analysis, an evaluation matrix has to be constructed through the following procedures: selection of the decision options (or assessment groups), identification of the evaluation criteria, measurement of performance and transformation of the units. Then the criteria under the objective groups are assigned a level of importance for determining their weights.To perform the sensitivity analysis the level of importance of a criterion is changed by giving more weight or rate to the assessment group of interest (or study). Within the assessment group of interests, the best performing desalination technology has been selected according to the outcome of the sensitivity analysis. The important conclusions of this study are the identification of the capabilities of thermal and membrane based small scale desalination technologies and their applicability based on site specific needs. The sensitivity analysis indicates that the MED technology is the most environmental friendly technology that uses minimum energy and produces least concentrated brine for disposal. The ED technology has emerged to be technically suitable, but it is only applicable when source water has less than 12.000 ppm salt content. The MSF process has favorable thermal efficiency and it is insensitive to feed water quality. Its major drawbacks are energy needs and post treatment requirements that affected its net score. The MD and MSF process have scored the lowest for the technical and economic assessment groups and are concluded not to be suitable for Olushandja sub-basin. The MEH process is cheaper and technically more appropriate than the MED in the two assessment groups. Based on the above mentioned evaluations, this study concluded that Olushandja sub-basin needs more data collection on the geological profile, distinctive identification of aquifers and evidence on the interaction between the aquifers. From the best available data obtained, it could not be established with certainty where the highest level of salinity can be found in the profile, or how the geological profile is layered. More data on ground water quality for spatial overview of the trends and pattern of the sub-basin will be useful in drawing better conclusion on the specific desalination technology needed which is suitable for a specified village or living space.
This dissertation includes three research articles on the portfolio risks of private investors. In the first article, we analyze a large data set of private banking portfolios in Switzerland of a major bank with the unique feature that parts of the portfolios were managed by the bank, and parts were advisory portfolios. To correct the heterogeneity of individual investors, we apply a mixture model and a cluster analysis. Our results suggest that there is indeed a substantial group of advised individual investors that outperform the bank managed portfolios, at least after fees. However, a simple passive strategy that invests in the MSCI World and a risk-free asset significantly outperforms both the better advisory and the bank managed portfolios. The new regulation of the EU for financial products (UCITS IV) prescribes Value at Risk (VaR) as the benchmark for assessing the risk of structured products. The second article discusses the limitations of this approach and shows that, in theory, the expected return of structured products can be unbounded while the VaR requirement for the lowest risk class can still be satisfied. Real-life examples of large returns within the lowest risk class are then provided. The results demonstrate that the new regulation could lead to new seemingly safe products that hide large risks. Behavioral investors who choose products based only on their official risk classes and their expected returns will, therefore, invest into suboptimal products. To overcome these limitations, we suggest a new risk-return measure for financial products based on the martingale measure that could erase such loopholes. Under the mean-VaR framework, the third article discusses the impacts of the underlying's first four moments on the structured product. By expanding the expected return and the VaR of a structured product with its underlying moments, it is possible to investigate each moment's impact on them, simultaneously. Results are tested by Monte Carlo simulation and historical simulation. The findings show that for the majority of structured products, underlyings with large positive skewness are preferred. The preferences for variance and for kurtosis are ambiguous.
The presented research aims at providing a first empirical investigation on lexical structure in Chinese with appropriate quantitative methods. The research objects contain individual properties of words (part of speech, polyfunctionality, polysemy, word length), the relationships between properties (part of speech and polyfunctionality, polyfunctionality and polysemy, polysemy and word length) and the lexical structure composed by those properties. Some extant hypotheses in QL, such as distributions of polysemy and the relationship between word length and polysemy, are tested on the data of Chinese, which enrich the applicability of the laws with a language not tested yet. Several original hypotheses such as the distribution of polyfunctionality and the relationship between polyfunctionality and polysemy are set up and inspected.