1,190 research outputs found
Customer Trading in the Foreign Exchange Market: Empirical Evidence from an Internet Trading Platform
This paper analyzes the relationship between currency price changes and their expectations. Currency price change expectations are derived with the help of different order flow measures, from the trading behavior of investors on OANDA FXTrade, which is an internet trading platform in the foreign exchange market. We investigate whether forecasts of intra-day price changes on different sampling frequencies can be improved with the information contained in the flow of our investorsâ orders. Moreover, we verify several hypotheses on the trading behavior and the preference structure of our investors by investigating how past price changes affect future order flow.Customer Dataset, Order Flow, Price Changes, Foreign Exchange Market
A model of the anchoring effect in dichotomous choice valuation with follow-up.
This paper focuses on modelling and estimating the starting point bias in closed-ended follow-up questions, where several bids are presented successively, depending on previous answers. Although the contingent valuation literature took off in the last decade, there is only one study modelling the starting point bias. We propose a new modelling of this anchoring effect based on the assumption the first proposed bid has a direct influence on the individual's willingness-to-pay, i.e respondents modify their willingness-to-pay when presented with the first bid just before they answer the first question. Monte Carlo results support the specification of our model. An application is provided based on data from a contingent valuation study conducted concerning air quality in Strasbourg.Contingent valuation, willingness-to-pay, binary-choice, anchoring effect.
SchÀtzung ökonometrischer Modelle auf der Grundlage anonymisierter Daten
Die Anonymisierung von sensiblen Individualdaten fĂŒhrt zu einem Konflikt zwischen dem Ziel der Minimierung des Reidentifikationsrisikos und der QualitĂ€t ökonometrischer SchĂ€tzungen. Der durch Anonymisierung bedingte Verlust an Effizienz und/oder der Konsistenz eines SchĂ€tzers wirft die grundsĂ€tzliche Frage auf, inwieweit anonymisierte Individualdaten ĂŒberhaupt fĂŒr die wissenschaftliche Nutzung geeignet sind. Deshalb gehen wir in dieser Arbeit der Frage nach, welchen Einfluss Anonymisierungsverfahren auf die Eigenschaften von ökonometrischen SchĂ€tzern haben. ZunĂ€chst untersuchen wir die Auswirkungen gĂ€ngiger Anonymisierungsverfahren auf lineare ökonometrische SchĂ€tzer in endlichen Stichproben. Im zweiten Schritt untersuchen wir, inwieweit sich die Selektions-effekte durch Anonymisierung aufgrund von Data Blanking mit Hilfe von semiparametrischen Verfahren korrigieren lassen. Die quantitative Evidenz beruht auf Monte-Carlo Simulationen und einer illustrativen Anwendung fĂŒr einen Querschnitt der Kostenstrukturerhebung.Mikroaggregation, stochastische Ăberlagerung, Data Blanking, IV-SchĂ€tzung, semiparametrisches Selektionsmodell
High-Throughput Optical Assays for Assessing Drug-Induced Q-T Prolongation in Human iPS Cell-Derived Cardiomyocytes
Protection of Hepatocytes from Cytotoxic T Cell Mediated Killing by Interferon-Alpha
<p>Background: Cellular immunity plays a key role in determining the outcome of hepatitis C virus (HCV) infection, although the majority of infections become persistent. The mechanisms behind persistence are still not clear; however, the primary site of infection, the liver, may be critical. We investigated the ability of CD8+ T-cells (CTL) to recognise and kill hepatocytes under cytokine stimulation.</p>
<p>Methods/Principle Findings: Resting hepatocytes cell lines expressed low levels of MHC Class I, but remained susceptible to CTL cytotoxicity. IFN-α treatment, in vitro, markedly increased hepatocyte MHC Class I expression, however, reduced sensitivity to CTL cytotoxicity. IFN-α stimulated hepatocyte lines were still able to present antigen and induce IFN-Îł expression in interacting CTL. Resistance to killing was not due to the inhibition of the FASL/FAS- pathway, as stimulated hepatocytes were still susceptible to FAS-mediated apoptosis. In vitro stimulation with IFN-α, or the introduction of a subgenomic HCV replicon into the HepG2 line, upregulated the expression of the granzyme-B inhibitorâproteinase inhibitor 9 (PI-9). PI-9 expression was also observed in liver tissue biopsies from patients with chronic HCV infection.</p>
<p>Conclusion/Significance: IFN-α induces resistance in hepatocytes to perforin/granzyme mediate CTL killing pathways. One possible mechanism could be through the expression of the PI-9. Hindrance of CTL cytotoxicity could contribute to the chronicity of hepatic viral infections.</p>
Investment liberalisation, technology take-off and export markets entry:does foreign ownership structure matter?
Before and after its accession to the WTO in 2001, China has undergone a far-reaching investment liberalisation. As part of this, existing restrictions on foreign ownership structure and mandatory export and technology transfer requirements imposed on foreign firms have been lifted in a number of industries. Against this background we identify the causal effects of foreign acquisitions on export market entry and technology take-off and evaluate whether the level of foreign ownership plays a role in stimulating these changes. Using doubly robust propensity score reweighted bivariate probit regressions to control for the selection bias associated with firm level foreign acquisition incidences, we uncover strong but heterogeneous positive effects on export activity for all types of foreign ownership structure. We also find that minority foreign owned acquisition targets experience higher likelihood of R&D, providing evidence that joint ventures can contribute positively to China's "science and technology take-off"
Differential binding of autoantibodies to MOG isoforms in inflammatory demyelinating diseases
Objective: To analyze serum immunoglobulin G (IgG) antibodies to major isoforms of myelin oligodendrocyte glycoprotein (MOG-alpha 1-3 and beta 1-3) in patients with inflammatory demyelinating diseases. Methods: Retrospective case-control study using 378 serum samples from patients with multiple sclerosis (MS), patients with non-MS demyelinating disease, and healthy controls with MOG alpha-1-IgG positive (n = 202) or negative serostatus (n = 176). Samples were analyzed for their reactivity to human, mouse, and rat MOG isoforms with and without mutations in the extracellular MOG Ig domain (MOG-ecIgD), soluble MOG-ecIgD, and myelin from multiple species using live cell-based, tissue immunofluorescence assays and ELISA. Results: The strongest IgG reactivities were directed against the longest MOG isoforms alpha-1 (the currently used standard test for MOG-IgG) and beta-1, whereas the other isoforms were less frequently recognized. Using principal component analysis, we identified 3 different binding patterns associated with non-MS disease: (1) isolated reactivity to MOG-alpha-1/beta-1 (n = 73), (2) binding to MOG-alpha-1/beta-1 and at least one other alpha, but no beta isoform (n = 64), and (3) reactivity to all 6 MOG isoforms (n = 65). The remaining samples were negative (n = 176) for MOG-IgG. These MOG isoform binding patterns were associated with a non-MS demyelinating disease, but there were no differences in clinical phenotypes or disease course. The 3 MOG isoform patterns had distinct immunologic characteristics such as differential binding to soluble MOG-ecIgD, sensitivity to MOG mutations, and binding to human MOG in ELISA. Conclusions: The novel finding of differential MOG isoform binding patterns could inform future studies on the refinement of MOG-IgG assays and the pathophysiologic role of MOG-IgG
Linguistic validation of the Spanish version of the National Cancer Instituteâs Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE)
Purpose: The U.S. NCIâs PRO-CTCAE is a library of self-report items for assessing symptomatic adverse events in cancer clinical trials from the patient perspective. The aim of this study was to translate and linguistically validate a Spanish version. Methods: PRO-CTCAEâs 124 items were translated from English into Spanish using multiple forward and back translations. Native Spanish speakers undergoing cancer treatment were enrolled at six cancer treatment sites. Participants each completed approximately 50 items and were then interviewed using cognitive probes. The interviews were analyzed at the item level by linguistic themes, and responses were examined for evidence of equivalence to English. Items for which â„20 % of participants experienced difficulties were reviewed, and phrasing was revised and then retested in subsequent interviews. Items where <20 % of respondents experienced difficulties were also reviewed and were considered for rephrasing and retesting. Results: One hundred nine participants from diverse Spanish-speaking countries were enrolled (77 in Round 1 and 32 in Round 2). A majority of items were well comprehended in Round 1. Two items presented difficulties in â„20 % of participants and were revised/retested without further difficulties. Two items presented difficulties in <20 %, and when retested exhibited no further difficulties. Two items presented difficulties in <20 %, but were not revised due to lack of alternatives. Sixteen items presented difficulties in â€12 % and were not revised because difficulties were minor. Conclusions: The Spanish PRO-CTCAE has been developed and refined for use in Spanish-speaking populations, with high levels of comprehension and equivalence to the English PRO-CTCAE. Trial registration: ClinicalTrials.gov:NCT0143624
- âŠ