15 research outputs found
Gender and microinsurance
insurance; microfinance; risk; coping strategies; social security; poverty; gender analysis;
Dividing the Pie
We examine the consequences of transparency in an experimentalmultiple-dealer market with asymmetrically informed dealers. Fiveprofessional securities traders make a market for a single security.In each trading round, one of the dealers (the "insider") is told thesecurity's true value. We vary both pre-trade and post-tradetransparency by changing the way quote and trade information ispublished. The insider's profits are greatest when price efficiency islowest. Price efficiency, in turn, is reduced by pre-tradetransparency and increased by posttrade transparency. Marketliquidity, measured by dealers' bid-ask spreads, is improved bypre-trade transparency and reduced by post-trade transparency.financial markets;information asymmetry;market microstructure;experimental economics
Dividing the Pie
We examine the consequences of transparency in an experimental
multiple-dealer market with asymmetrically informed dealers. Five
professional securities traders make a market for a single security.
In each trading round, one of the dealers (the "insider") is told the
security's true value. We vary both pre-trade and post-trade
transparency by changing the way quote and trade information is
published. The insider's profits are greatest when price efficiency is
lowest. Price efficiency, in turn, is reduced by pre-trade
transparency and increased by posttrade transparency. Market
liquidity, measured by dealers' bid-ask spreads, is improved by
pre-trade transparency and reduced by post-trade transparency
Price Discovery on Foreign Exchange Markets with Differentially Informed Traders
This paper uses Reuters exchange rate data to investigate the contributions to the price discovery process by individual banks in the foreign exchange market. We propose multivariate time series models as well as models in tick time to study the dynamic relations between the quotes of individual banks. We investigate the hypothesis that German banks are price leaders in the deutschmark/dollar market. Our empirical results suggest an important but not exclusive role for German banks in the price discovery process. There is also a group of banks, German and non-German, that lags behind the market and does not contribute to the price discovery process. In contrast to Peiers~(1997) we do not find evidence for stronger price leadership of Deutsche bank on days with suspected Bundesbank interventions in the foreign exchange market
A comparative study of image retargeting
Example of retargeting the butterfly image shown in Figure 2 to half its size. In this study we evaluate 8 different image retargeting methods, asking users to compare their results and examine what qualities in retargeted images mattered to them. We also correlate the users ’ preferences with automatic image similarity measures. Our findings provide insights on the retargeting problem, and present a clear benchmark for future research in the field. The numerous works on media retargeting call for a methodological approach for evaluating retargeting results. We present the first comprehensive perceptual study and analysis of image retargeting. First, we create a benchmark of images and conduct a large scale user study to compare a representative number of state-of-the-art retargeting methods. Second, we present analysis of the users ’ responses, where we find that humans in general agree on the evaluation of the results and show that some retargeting methods are consistently more favorable than others. Third, we examine whether computational image distance metrics can predict human retargeting perception. We show that current measures used in this context are not necessarily consistent with human rankings, and demonstrate that better results can be achieved using image features that were not previously considered for this task. We also reveal specific qualities in retargeted media that are more important for viewers. The importance of our work lies in promoting better measures to assess and guide retargeting algorithms in the future. The full benchmark we collected, including all images, retargeted results, and the collected user data, are available to the research community for further investigation a
Genome of the Netherlands population-specific imputations identify an ABCA6 variant associated with cholesterol levels
van Leeuwen EM, Karssen LC, Deelen J, et al. Genome of the Netherlands population-specific imputations identify an ABCA6 variant associated with cholesterol levels. Nature Communications. 2015;6(1): 6065
Integrated clinical and omics approach to rare diseases : Novel genes and oligogenic inheritance in holoprosencephaly
Holoprosencephaly is a pathology of forebrain development characterized by high phenotypic heterogeneity. The disease presents with various clinical manifestations at the cerebral or facial levels. Several genes have been implicated in holoprosencephaly but its genetic basis remains unclear: different transmission patterns have been described including autosomal dominant, recessive and digenic inheritance. Conventional molecular testing approaches result in a very low diagnostic yield and most cases remain unsolved. In our study, we address the possibility that genetically unsolved cases of holoprosencephaly present an oligogenic origin and result from combined inherited mutations in several genes. Twenty-six unrelated families, for whom no genetic cause of holoprosencephaly could be identified in clinical settings [whole exome sequencing and comparative genomic hybridization (CGH)-array analyses], were reanalysed under the hypothesis of oligogenic inheritance. Standard variant analysis was improved with a gene prioritization strategy based on clinical ontologies and gene co-expression networks. Clinical phenotyping and exploration of cross-species similarities were further performed on a family-by-family basis. Statistical validation was performed on 248 ancestrally similar control trios provided by the Genome of the Netherlands project and on 574 ancestrally matched controls provided by the French Exome Project. Variants of clinical interest were identified in 180 genes significantly associated with key pathways of forebrain development including sonic hedgehog (SHH) and primary cilia. Oligogenic events were observed in 10 families and involved both known and novel holoprosencephaly genes including recurrently mutated FAT1, NDST1, COL2A1 and SCUBE2. The incidence of oligogenic combinations was significantly higher in holoprosencephaly patients compared to two control populations (P < 10 -9). We also show that depending on the affected genes, patients present with particular clinical features. This study reports novel disease genes and supports oligogenicity as clinically relevant model in holoprosencephaly. It also highlights key roles of SHH signalling and primary cilia in forebrain development. We hypothesize that distinction between different clinical manifestations of holoprosencephaly lies in the degree of overall functional impact on SHH signalling. Finally, we underline that integrating clinical phenotyping in genetic studies is a powerful tool to specify the clinical relevance of certain mutations