Explaining the Duration of Exchange-Rate Pegs

This paper is a theoretical and empirical investigation into the duration of exchange-rate pegs. The theoretical model considers a policy-maker who must trade off the economic costs of real exchange- rate misalignment against the political cost of realignment. The optimal time to spend on a peg is derived and factors that influence peg duration are identified. The predictions of the model are tested using logit analysis with a data set of exchange-rate pegs for sixteen Latin American countries and Jamaica during the 1957-1991 period. We find that the real exchange rate is a significant determinant of the likelihood of a devaluation. Structural variables, such as the openness of the economy and its geographical trade concentration, also significantly affect the likelihood of a devaluation. Finally, political events that change the political cost of realignment, such as regular and irregular executive transfers, are empirically important determinants of the likelihood of a devaluation.

Characterization of sulfotransferase proteins from Arabidopsis thaliana

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Satellite image-based generation of high frequency solar radiation time series for the assessment of solar energy systems

Solar energy is envisaged as a major pillar of the global transition to a climate-friendly energy system. Variability of solar radiation requires additional balancing measures to ensure a stable and secure energy supply. In order to analyze this issue in detail, solar radiation time series data of appropriate temporal and spatial resolution is necessary. Common weather models and satellites are only delivering solar surface irradiance with temporal resolutions of up to 15 min. Significant short-term variability in irradiances within seconds to minutes however is induced by clouds. Ground-based measurements typically used to capture this variability are costly and only sparsely available. Hence, a method to synthetically generate time series from currently available satellite imagery is of value for researchers, grid operators, and project developers. There are efforts to increase satellite resolution to 1 min, but this is not planned everywhere and will not change the spatial resolution. Therefore, the fundamental question remains if there are alternative strategies to obtain high temporal resolution observations at a pinpoint. This paper presents a method to generate 1 min resolved synthetic time series of global and direct normal irradiances for arbitrary locations. A neural network based on satellite image derived cloud structure parameters enables to classify high-frequency solar radiation variability. Combined with clear-sky radiation data, 1 min time series which reflect the typical variability characteristics of a site are reproduced. Testing and validation against ground observations (BSRN) show that the method can accurately reproduce characteristics such as frequency and ramp distributions. An application case demonstrates the usage in low-voltage grid studies

Untersuchungen zur antimikrobiellen Wirkung von Zahnpasten

Ziel dieser in vitro Studie war es, die antimikrobiellen Effekte von 22 Zahnpasten des deutschen Marktes gegenüber 8 Mikro-organismen der oralen Flora zu ermitteln. Des Weiteren wurden die Ergebnisse verglichen und versucht, Rückschlüsse auf die Bedeutung und Effektivität der Inhaltsstoffe zu ziehen. Ein abschließender Preis- Leistungsvergleich anhand der Parameter „antimikrobielle Wirkung“, „Fluoridgehalt“, „RDA-Wert“ und „Preis“ rundet die Arbeit zu einem Leitfaden für den Prophylaxe bewussten Patienten ab. Bei der Versuchs-durchführung wurde entsprechend den Richtlinien zur Prüfung und Bewertung chemischer Desinfektionsverfahren gehandelt

The role of family members in psychiatric deep brain stimulation trials:More than psychosocial support

Family members can provide crucial support to individuals participating in clinical trials. In research on the “newest frontier” of Deep Brain Stimulation (DBS)—the use of DBS for psychiatric conditions—family member support is frequently listed as a criterion for trial enrollment. Despite the significance of family members, qualitative ethics research on DBS for psychiatric conditions has focused almost exclusively on the perspectives and experiences of DBS recipients. This qualitative study is one of the first to include both DBS recipients and their family members as interview participants. Using dyadic thematic analysis—an approach that takes both the individuals and the relationship as units of analyses—this study analyzes the complex ways in which family relationships can affect DBS trial participation, and how DBS trial participation in turn influences family relationships. Based on these findings, we propose ways to improve study designs to better take family relationships into account, and better support family members in taking on the complex, essential roles that they play in DBS trials for psychiatric conditions

More Than Skin Deep: Genetics, Clinical Manifestations, and Diagnosis of Albinism

Although albinism may be considered a simple diagnosis, its clinical manifestations, which include hypopigmenta- tion of the skin, hair, and eyes and ocular abnormalities such as nystagmus and reduced visual acuity, are often subtle and initially missed. In oculocutaneous albinism, there is wide phenotypic variability, which correlates with specific mutations in genes with roles in melanin biosynthesis. Additionally, syndromic forms of albinism such as Hermansky-Pudlak syndrome, Chediak-Higashi syndrome, and Griscelli syndrome are associated with serious complications such as bleeding abnormalities, lysosomal storage defects, immunodeficient states, and progressive neurologic defects, which all can result in mortality. It is critical to confirm a suspicion of albinism and perform an appropriate workup involving molecular testing in order to establish a diagnosis. Given the various subtypes of oculocutaneous albinism and the life-threatening complications in syndromic forms of albinism, a diagnosis permits proper genetic counseling and timely implementation of necessary screenings and treatments. Recommendations regarding sun exposure and treatment of ocular abnormalities are imperative in oculocutaneous albinism, and preventive therapies should be implemented in syndromic forms. With knowledge of the differential in conjunction with the execution of simple diagnostic tests, many of these complications can be predicted and consequently ameliorated or prevented.

Cooperative WebLab in chemical engineering between France and Brazil: Validation of the methodology

A WebLab is an experiment operated remotely via Internet. Besides the strictly technical aspects of such an experiment, which may contribute to the learning of Chemical Engineering fundamentals, there is also important feedback when teams of students of two different countries are working together: the WebLab becomes an intercultural experience, enhancing the communication skills of the students. A WebLab between Universidade Federal de São Carlos (DEQ/UFSCar) and the Ecole Nationale Supérieure d’Ingénieurs en Arts Chimiques et Technologiques (ENSIACET) is presented in this work. A mass transfer experiment in a bench scale reactor (stirred and aerated) had to be studied by mixed teams, thus emulating challenges that will be common in future working environments. In order to perform the experiment, students in Brazil and in France were put into groups. The students had to make decisions about the procedure for executing the experiments. All the students were able to control the equipment, no matter where they were physically. Students communicated using video conference software. The students' and teachers' opinions of this experience were very positive. This methodology is an important contribution to the education of engineers in a world integrated by modern communication technologies

Extracellular vesicles from regenerative human cardiac cells act as potent immune modulators by priming monocytes

Background: Nano-sized vesicles, so called extracellular vesicles (EVs), from regenerative cardiac cells represent a promising new therapeutic approach to treat cardiovascular diseases. However, it is not yet sufficiently understood how cardiac-derived EVs facilitate their protective effects. Therefore, we investigated the immune modulating capabilities of EVs from human cardiac-derived adherent proliferating (CardAP) cells, which are a unique cell type with proven cardioprotective features. Results: Differential centrifugation was used to isolate EVs from conditioned medium of unstimulated or cytokinestimulated (IFNγ, TNFα, IL-1β) CardAP cells. The derived EVs exhibited typical EV-enriched proteins, such as tetraspanins, and diameters mostly of exosomes (< 100 nm). The cytokine stimulation caused CardAP cells to release smaller EVs with a lower integrin ß1 surface expression, while the concentration between both CardAP-EV variants was unaffected. An exposure of either CardAP-EV variant to unstimulated human peripheral blood mononuclear cells (PBMCs) did not induce any T cell proliferation, which indicates a general low immunogenicity. In order to evaluate immune modulating properties, PBMC cultures were stimulated with either Phytohemagglutin or anti-CD3. The treatment of those PBMC cultures with either CardAP-EV variant led to a significant reduction of T cell proliferation, pro-inflammatory cytokine release (IFNγ, TNFα) and increased levels of active TGFβ. Further investigations identified CD14+ cells as major recipient cell subset of CardAP–EVs. This interaction caused a significant lower surface expression of HLA-DR, CD86, and increased expression levels of CD206 and PD-L1. Additionally, EV-primed CD14+ cells released significantly more IL-1RA. Notably, CardAP-EVs failed to modulate anti-CD3 triggered T cell proliferation and pro-inflammatory cytokine release in monocultures of purified CD3+ T cells. Subsequently, the immunosuppressive feature of CardAPEVs was restored when anti-CD3 stimulated purified CD3+ T cells were co-cultured with EV-primed CD14+ cells. Beside attenuated T cell proliferation, those cultures also exhibited a significant increased proportion of regulatory T cells. Conclusions: CardAP-EVs have useful characteristics that could contribute to enhanced regeneration in damaged cardiac tissue by limiting unwanted inflammatory processes. It was shown that the priming of CD14+ immune cells by CardAP-EVs towards a regulatory type is an essential step to attenuate significantly T cell proliferation and proinflammatory cytokine release in vitro