352 research outputs found

    Controlling for transactions bias in regional house price indices

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    Transactions bias arises when properties that trade are not a random sample of the total housing stock. Price indices are susceptible because they are typically based on transactions data. Existing approaches to this problem rely on Heckman-type correction methods, where a probit regression is used to capture the differences between properties that sell and those that do not sell in a given period. However, this approach can only be applied where there is reliable data on the whole housing stock. In many countries—the UK included—no such data exist and there is little prospect of correcting for transactions bias in any of the regularly updated mainstream house price indices. Thispaper suggests a possible alternative approach, using information at postcode sector level and Fractional Probit Regression to correct for transactions bias in hedonic price indices based on one and a half million house sales from 1996 to 2004, distributed across 1200 postcode sectors in the South East of England

    Evolution of the electronic structure with size in II-VI semiconductor nanocrystals

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    In order to provide a quantitatively accurate description of the band gap variation with sizes in various II-VI semiconductor nanocrystals, we make use of the recently reported tight-binding parametrization of the corresponding bulk systems. Using the same tight-binding scheme and parameters, we calculate the electronic structure of II-VI nanocrystals in real space with sizes ranging between 5 and 80 {\AA} in diameter. A comparison with available experimental results from the literature shows an excellent agreement over the entire range of sizes.Comment: 17 pages, 4 figures, accepted in Phys. Rev.

    An evaluation of thoron (and radon) equilibrium factorclose towalls based on long-term measurements in dwellings

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    Thoron gas and its progeny behave quite differently in room environments, owing to the difference in their half-lives; therefore, it is important to measure simultaneously gas and progeny concentrations to estimate the time-integrated equilibrium factor. Furthermore, thoron concentration strongly depends on the distance from the source, i.e. generally walls in indoor environments. In the present work, therefore, the measurements of both thoron and radon gas and their progeny concentrations were consistently carried out close to the walls, in 43 dwellings located in the Sokobanja municipality, Serbia. Three different types of instruments have been used in the present survey to measure the time-integrated thoron and radon gas and their progeny concentrations simultaneously. The equilibrium factor for thoron measured ‘close to the wall’, FW Tn, ranged from 0.001 to 0.077 with a geometric mean (GM) [geometric standard deviation (GSD)] of 0.006 (2.2), whereas the equilibrium factor for radon, FRn, ranged from 0.06 to 0.95 with a GM (GSD) of 0.23 (2.0)

    Systematic Two-Hybrid and Comparative Proteomic Analyses Reveal Novel Yeast Pre-mRNA Splicing Factors Connected to Prp19

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    Prp19 is the founding member of the NineTeen Complex, or NTC, which is a spliceosomal subcomplex essential for spliceosome activation. To define Prp19 connectivity and dynamic protein interactions within the spliceosome, we systematically queried the Saccharomyces cerevisiae proteome for Prp19 WD40 domain interaction partners by two-hybrid analysis. We report that in addition to S. cerevisiae Cwc2, the splicing factor Prp17 binds directly to the Prp19 WD40 domain in a 1∶1 ratio. Prp17 binds simultaneously with Cwc2 indicating that it is part of the core NTC complex. We also find that the previously uncharacterized protein Urn1 (Dre4 in Schizosaccharomyces pombe) directly interacts with Prp19, and that Dre4 is conditionally required for pre-mRNA splicing in S. pombe. S. pombe Dre4 and S. cerevisiae Urn1 co-purify U2, U5, and U6 snRNAs and multiple splicing factors, and dre4Δ and urn1Δ strains display numerous negative genetic interactions with known splicing mutants. The S. pombe Prp19-containing Dre4 complex co-purifies three previously uncharacterized proteins that participate in pre-mRNA splicing, likely before spliceosome activation. Our multi-faceted approach has revealed new low abundance splicing factors connected to NTC function, provides evidence for distinct Prp19 containing complexes, and underscores the role of the Prp19 WD40 domain as a splicing scaffold

    Earnings smoothing and CEO cash bonus compensation: The role of mandatory derivatives disclosure policy

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    © 2018 Macmillan Publishers Ltd., part of Springer Nature. Motivated by intense controversy over mandatory derivative instruments disclosure required by the Statement of Financial Accounting Standard No. 133 (SFAS 133), this study is to examine whether the sensitivity of CEOs compensation to earnings smoothing changes following the adoption of SFAS 133. Moreover, the study investigates whether the sensitivity of CEOs compensation to earnings smoothing after the implementation of SFAS 133 varies with the level of market volatility. Using the correlation between the changes in discretionary accruals and the changes in pre-discretionary income as a measure of earnings smoothing and dollar value of a bonus earned by the CEOs during the year as a measure of CEOs compensation, the empirical evidence reveals that while earnings smoothing and CEOs compensation are positively related, the positive relation is stronger after the adoption of SFAS 133. The study also finds that the positive association between earnings smoothing and CEOs compensation after the adoption of SFAS 133 is larger when the market volatility is higher. This study provides direct evidence on the impact of the adoption of SFAS 133 on the sensitivity of CEO compensation to earnings smoothing and sheds light on current literature on the effects of accounting regulations, earnings smoothing, and compensation plan. Moreover, this study helps standard setters to better understand the trade-off between transparency and compensation plans

    Dopamine Beta Hydroxylase Genotype Identifies Individuals Less Susceptible to Bias in Computer-Assisted Decision Making

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    Computerized aiding systems can assist human decision makers in complex tasks but can impair performance when they provide incorrect advice that humans erroneously follow, a phenomenon known as “automation bias.” The extent to which people exhibit automation bias varies significantly and may reflect inter-individual variation in the capacity of working memory and the efficiency of executive function, both of which are highly heritable and under dopaminergic and noradrenergic control in prefrontal cortex. The dopamine beta hydroxylase (DBH) gene is thought to regulate the differential availability of dopamine and norepinephrine in prefrontal cortex. We therefore examined decision-making performance under imperfect computer aiding in 100 participants performing a simulated command and control task. Based on two single nucleotide polymorphism (SNPs) of the DBH gene, −1041 C/T (rs1611115) and 444 G/A (rs1108580), participants were divided into groups of low and high DBH enzyme activity, where low enzyme activity is associated with greater dopamine relative to norepinephrine levels in cortex. Compared to those in the high DBH enzyme activity group, individuals in the low DBH enzyme activity group were more accurate and speedier in their decisions when incorrect advice was given and verified automation recommendations more frequently. These results indicate that a gene that regulates relative prefrontal cortex dopamine availability, DBH, can identify those individuals who are less susceptible to bias in using computerized decision-aiding systems
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