Assimilation of foreigners in Germany

The first chapter of this dissertation is using data from the German SOEP panel, and I analyze the assimilation of immigrants in terms of initial wage gap and assimilation rate. The analysis consists of a basic assimilation model, a cohort model, and a source country specific model. The source country specific model allows us to distinguish assimilation rates for different groups of immigrants. I find that despite having the highest education of all immigrants, East European immigrants have the largest wage gap. Secondly individuals immigrating from former East Germany have a larger wage gap than immigrants from Italy and Turkey. For East Germans I find little evidence of assimilation. In the second chapter of this dissertation is using data from the German SOEP panel, and I analyze the assimilation for immigrants in terms of initial wage gap and assimilation rate under self-selection. This paper extends the first paper by taking employment probabilities into account during the estimation process. I find that initial wage gaps in general are larger but also relative orderings between different countries of origin are different. A negative and significant lambda leads me to believe that a self-selection problem was present and was corrected by a Heckman self-selection model applied in the analysis section of this paper

Placental syncytiotrophoblast constitutes a major barrier to vertical transmission of Listeria monocytogenes.

Listeria monocytogenes is an important cause of maternal-fetal infections and serves as a model organism to study these important but poorly understood events. L. monocytogenes can infect non-phagocytic cells by two means: direct invasion and cell-to-cell spread. The relative contribution of each method to placental infection is controversial, as is the anatomical site of invasion. Here, we report for the first time the use of first trimester placental organ cultures to quantitatively analyze L. monocytogenes infection of the human placenta. Contrary to previous reports, we found that the syncytiotrophoblast, which constitutes most of the placental surface and is bathed in maternal blood, was highly resistant to L. monocytogenes infection by either internalin-mediated invasion or cell-to-cell spread. Instead, extravillous cytotrophoblasts-which anchor the placenta in the decidua (uterine lining) and abundantly express E-cadherin-served as the primary portal of entry for L. monocytogenes from both extracellular and intracellular compartments. Subsequent bacterial dissemination to the villous stroma, where fetal capillaries are found, was hampered by further cellular and histological barriers. Our study suggests the placenta has evolved multiple mechanisms to resist pathogen infection, especially from maternal blood. These findings provide a novel explanation why almost all placental pathogens have intracellular life cycles: they may need maternal cells to reach the decidua and infect the placenta

Performance Evaluation of an Evacuated Tube Collector with a Low-Cost Diffuse Reflector

In order to increase the overall solar energy gain of evacuated tube collectors, rear‐side reflectors are used. In this way, the otherwise unused incident radiation between the tubes can be reflected back to the absorber, and the performance of the collector can be improved. In this paper, the use of a low‐cost, diffusely reflecting, trapezoidal roof covering made from a galvanized metal sheet is investigated and compared to a high‐quality, specularly reflecting plane reflector made of aluminum. For this purpose, ray‐tracing analysis and TRNSYS simulations were carried out. In the ray‐tracing analysis, the experimentally determined zero‐loss collector efficiency η0 as well as the incident angle modifiers for each reflector can be reproduced with an error lower than 7.5%. Thermal system simulations show that the performance of both reflectors is comparable. The use of the low‐cost reflector leads to an increase in annual collector output of around 30% compared to an increase with the specular reflector of around 33%. Considering a typical domestic hot water system, both reflectors enable an increase in the solar annual yield of approx. 11%

Advancing theory of consumer satisfaction and word-of-mouth

Consumer satisfaction and Word-of-Mouth (WOM) are interrelated phenomena that are crucial to the successful marketing of products and services. Yet, psychological theory regarding both phenomena lacks integration, and empirical evidence on key processes, such as satisfaction formation through expectancy-disconfirmation and intra-individual WOM transmission, is heterogeneous or even missing. The present thesis addresses these issues in three studies. In the first study, a model of intra-individual WOM transmission, covering the span from the reception of WOM to the sending of WOM, was developed and experimentally tested. Results suggest that the sending of WOM is solely determined by product performance and that intra-individual WOM transmission might “become stuck” during the unclear expectancy-disconfirmation process. In order to clarify the role of expectancy-disconfirmation as a key element of intra-individual WOM transmission, expectancy-disconfirmation theories were conceptually and empirically assessed in a systematic way, in the form of a qualitative review of the respective literatures (Study 2) and a meta-analysis (Study 3). The qualitative review derives suggestions for how conceptual inconsistencies and methodological shortcomings of expectancy-disconfirmation theories can be resolved. In particular, a coherent disconfirmation typology is developed and more suitable methods for operationalizing concepts of disconfirmation are presented. The results of the meta-analysis indicate that consumers assimilate their satisfaction ratings toward their expectations and that disconfirmation and consumer satisfaction are very closely related psychological constructs. Taken together, the findings of the three studies suggest that perceived performance is the crucial antecedent to consumer satisfaction, but that expectations also matter. Furthermore, the assimilation of satisfaction ratings toward expectations is the most likely link between the reception of WOM and the sending of WOM.Die Phänomene Konsumentenzufriedenheit und Word-of-Mouth (kurz WOM, z. Dt. auch „Mundpropaganda“) sind entscheidende Einflussfaktoren auf den Markterfolg von Produkten und Dienstleistungen. Wissenschaftliche Erklärungen dieser Phänomene beruhen jedoch auf einer Vielzahl einzelner psychologischer Modelle und es fehlt eine theoretische Integration der einzelnen Modelle in eine umfassende und konsistente Gesamttheorie. Zudem ist die empirische Evidenz zu den angenommenen psychologischen Prozessen, wie z.B. dem Erwartungs-Diskonfirmations Prozess als Grundlage von Konsumentenzufriedenheit, uneinheitlich und teilweise unvollständig. Die vorliegende Dissertation greift diese Probleme in drei Studien auf. In Studie 1 wird ein Drei-Stufen Modell der intra-individuellen Übertragung von WOM entwickelt, das den psychologischen Prozess zwischen dem Empfangen von WOM und dem Senden von WOM beschreibt. In einer experimentellen Überprüfung des drei-Stufen Modells zeigte sich, dass ausschließlich die Produktqualität die Konsumentenzufriedenheit und das Senden von WOM verursacht, die Qualitätserwartungen an das Produkt hingegen keinen Einfluss auf die Konsumentenzufriedenheit haben. Dieses Ergebnis steht im Widerspruch zu der aus den Erwartungs-Diskonfirmations Theorien abgeleiteten Vorhersage und legt für sich genommen nahe, dass die intra-individuelle Übertragung von WOM im Prozess zwischen den Qualitätserwartungen und der Konsumentenzufriedenheit unterbrochen wird. Die Bedeutung der Ergebnisse aus Studie 1 für die Theorien der Erwartungs-Diskonfirmation und der intra-individuellen Übertragung von WOM sind jedoch nur schwer zu beurteilen, da in der Erwartungs-Diskonfirmations Literatur keine einheitlichen und klaren Aussagen zum konkreten Erwartungs-Diskonfirmations Prozess und zu den zu erwartenden Effekten gemacht werden. Aus diesem Grund wurden die Erwartungs-Diskonfirmations Theorien in Studie 2 und 3 konzeptionell und empirisch untersucht. In Studie 2, einem qualitativen Review, wurden Empfehlungen erarbeitet, wie konzeptionelle Widersprüche und methodische Mängel in der Erwartungs-Diskonfirmations Forschung überwunden werden können. Konkret wird eine umfassende Diskonfirmations-Typologie entwickelt, die bisherige Widersprüche zu diesem Konzept auflöst, und es werden geeignete Methoden zur Operationalisierung und Analyse des Diskonfirmations-Konzeptes vorgeschlagen. In Studie 3 wurden die Vorhersagen der Erwartungs-Diskonfirmations Theorien meta-analytisch untersucht. Die Meta-Analyse zeigte einen positiven Effekt von Qualitätserwartungen auf Konsumentenzufriedenheit, was die Vorhersagen von Assimilations-Theorien bestätigt und im Gegensatz zum Ergebnis von Studie 1 steht. Weiterhin zeigte die Meta-Analyse einen sehr starken Zusammenhang von Diskonfirmation und Konsumentenzufriedenheit, was nahe legt, dass die Konstrukte Diskonfirmation und Konsumentenzufriedenheit empirisch nicht distinkt sind. Zusammengenommen implizieren die Ergebnisse der drei Studien, dass die wahrgenommene Produkt- bzw. Dienstleistungsqualität der bedeutsamste Einflussfaktor auf Konsumentenzufriedenheit ist, aber auch Qualitätserwartungen auch eine Rolle spielen. Darüber hinaus stellt der positive Effekt von Qualitätserwartungen auf Konsumentenzufriedenheit ein mögliches Bindeglied in der intra-individuellen Übertragung von WOM dar. Schlussendlich werden Perspektiven für die zukünftige Theorieentwicklung in den Bereichen der Konsumentenzufriedenheit und des WOM diskutiert und es wird vorgeschlagen, Diskonfirmation nicht als die wahrgenommene Diskrepanz von Qualitätswahrnehmung und Qualitätserwartung, sondern als psychologischen Prozess zu konzeptualisieren

A Spaetzle-like role for Nerve Growth Factor β in vertebrate immunity to Staphylococcus aureus

Many key components of innate immunity to infection are shared between Drosophila and humans. However, the fly Toll ligand Spaetzle is not thought to have a vertebrate equivalent. We have found that the structurally related cystine-knot protein, nerve growth factor β (NGFβ), plays an unexpected Spaetzle-like role in immunity to Staphylococcus aureus infection in chordates. Deleterious mutations of either human NGFβ or its high-affinity receptor tropomyosin-related kinase receptor A (TRKA) were associated with severe S. aureus infections. NGFβ was released by macrophages in response to S. aureus exoproteins through activation of the NOD-like receptors NLRP3 and NLRC4 and enhanced phagocytosis and superoxide-dependent killing, stimulated proinflammatory cytokine production, and promoted calcium-dependent neutrophil recruitment. TrkA knockdown in zebrafish increased susceptibility to S. aureus infection, confirming an evolutionarily conserved role for NGFβ-TRKA signaling in pathogen-specific host immunity

Functional drug screening reveals anticonvulsants as enhancers of mTOR-independent autophagic killing of Mycobacterium tuberculosis through inositol depletion.

Mycobacterium tuberculosis (MTB) remains a major challenge to global health made worse by the spread of multidrug resistance. We therefore examined whether stimulating intracellular killing of mycobacteria through pharmacological enhancement of macroautophagy might provide a novel therapeutic strategy. Despite the resistance of MTB to killing by basal autophagy, cell-based screening of FDA-approved drugs revealed two anticonvulsants, carbamazepine and valproic acid, that were able to stimulate autophagic killing of intracellular M. tuberculosis within primary human macrophages at concentrations achievable in humans. Using a zebrafish model, we show that carbamazepine can stimulate autophagy in vivo and enhance clearance of M. marinum, while in mice infected with a highly virulent multidrug-resistant MTB strain, carbamazepine treatment reduced bacterial burden, improved lung pathology and stimulated adaptive immunity. We show that carbamazepine induces antimicrobial autophagy through a novel, evolutionarily conserved, mTOR-independent pathway controlled by cellular depletion of myo-inositol. While strain-specific differences in susceptibility to in vivo carbamazepine treatment may exist, autophagy enhancement by repurposed drugs provides an easily implementable potential therapy for the treatment of multidrug-resistant mycobacterial infection

Heat pipe collectors with overheating prevention in a cost-optimized system concept: Monitoring of system performance and stagnation loads under real conditions

Heat pipe collectors can significantly reduce stagnation loads in solar thermal systems due to their thermophysical properties. The paper experimentally investigates a novel system concept based on both evacuated tube collectors and flat-plate collectors with overheating prevention. Due to the resulting temperature limitation in the collector, the use of polymeric pipes as well as a significantly downsized expansion volume is possible. We implemented this concept in five demonstration plants and monitored their behavior over more than one year of operation. Both domestic hot water systems and combi-systems with space heating support in residential and office buildings are under consideration. The measured collector performance in all the systems matches the theoretical collector efficiency curve with a maximum deviation of five percentage points. Depending on the individual system configurations, the specific annual yield ranges between 174 kWh/m² and 445 kWh/m². During stagnation, we report a maximum temperature between 105 °C and 127 °C. In comparison to state-of-the-art systems, the maximum temperature in the solar circuit is 80–100 K lower and evaporation does not occur. The approach leads to reductions in investment costs of up to 16% and can significantly decrease the annual maintenance effort. Assuming a system lifetime of 25 years, we estimate a cost reduction of up to 22% in Levelized Cost of Heat (LCoH) compared to common system configurations

A Spaetzle-like role for nerve growth factor beta in vertebrate immunity to Staphylococcus aureus

Many key components of innate immunity to infection are shared between Drosophila and humans. However, the fly Toll ligand Spaetzle is not thought to have a vertebrate equivalent. We have found that the structurally related cystine-knot protein, nerve growth factor β (NGFβ), plays an unexpected Spaetzle-like role in immunity to Staphylococcus aureus infection in chordates. Deleterious mutations of either human NGFβ or its high-affinity receptor tropomyosin-related kinase receptor A (TRKA) were associated with severe S. aureus infections. NGFβ was released by macrophages in response to S. aureus exoproteins through activation of the NOD-like receptors NLRP3 and NLRC4 and enhanced phagocytosis and superoxide-dependent killing, stimulated proinflammatory cytokine production, and promoted calcium-dependent neutrophil recruitment. TrkA knockdown in zebrafish increased susceptibility to S. aureus infection, confirming an evolutionarily conserved role for NGFβ-TRKA signaling in pathogen-specific host immunity