302 research outputs found

    Risk attitude, beliefs, and information in a corruption game: An experimental analysis

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    For our experiment on corruption we designed a coordination game to model the influence of risk attitudes, beliefs, and information on behavioral choices and determined the equilibria. We observed that the participants' risk attitudes failed to explain their choices between corrupt and non-corrupt behavior. Instead, beliefs appeared to be a better predictor of whether or not they would opt for the corrupt alternative. Furthermore, varying the quantity of information available to players (modeled by changing the degree of uncertainty) provided additional insight into the players' propensity to engage in corrupt behavior. The experimental results show that a higher degree of uncertainty in the informational setting reduces corruption. --Corruption,game theory,experiment,risk attitude,beliefs

    Threshold effects in charm hadroproduction.

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    We describe calculations of cc production to next-to-next-to-leading order (NNLO) and next-to-next-to-leading logarithm (NNLL) near threshold in pp and −p interactions. We study the relevance of these calculations for existing cc total cross section data by examining their sensitivity to partonic threshold kinematics, their convergence properties and scale dependence

    Collapse of Coherent Large Scale Flow in Strongly Turbulent Liquid Metal Convection

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    The large-scale flow structure and the turbulent transfer of heat and momentum are directly measured in highly turbulent liquid metal convection experiments for Rayleigh numbers varied between 4×1054 \times 10^5 and 5×109\leq 5 \times 10^9 and Prandtl numbers of 0.025  Pr  0.0330.025~\leq~Pr~\leq ~0.033. Our measurements are performed in two cylindrical samples of aspect ratios Γ=\Gamma = diameter/height =0.5= 0.5 and 1 filled with the eutectic alloy GaInSn. The reconstruction of the three-dimensional flow pattern by 17 ultrasound Doppler velocimetry sensors detecting the velocity profiles along their beamlines in different planes reveals a clear breakdown of coherence of the large-scale circulation for Γ=0.5\Gamma = 0.5. As a consequence, the scaling laws for heat and momentum transfer inherit a dependence on the aspect ratio. We show that this breakdown of coherence is accompanied with a reduction of the Reynolds number ReRe. The scaling exponent β\beta of the power law NuRaβNu\propto Ra^{\beta} crosses \FIN{eventually} over from β=0.221\beta=0.221 to 0.124 when the liquid metal flow at Γ=0.5\Gamma=0.5 reaches Ra2×108Ra\gtrsim 2\times 10^8 and the coherent large-scale flow is completely collapsed.Comment: 4 pages, 5 figures, 1 supplementary with 1 figure and 4 tables, 1 movi

    Otto Warburg and his contributions to the screw pine family (Pandanaceae)

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    Otto Warburg (1859–1938) had a great interest in tropical botany. He travelled in South-East Asia and the South Pacific between 1885 and 1889 and brought back a considerable collection of plant specimens from this expedition later donated to the Royal Botanical Museum in Berlin. Warburg published the first comprehensive monograph on the family Pandanaceae in 1900 in the third issue of Das Pflanzenreich established and edited by Adolf Engler (1844–1930). The aim of this article is to clarify the taxonomy, nomenclature and typification of Warburg's contributions to the Pandanaceae. Considerable parts of Warburg's original material was destroyed in Berlin during World War II but duplicates survived, shared by Engler and Warburg with Ugolino Martelli (1860–1934). Martelli was an expert on the family and he assembled a precious herbarium of Pandanaceae that was later donated to the Museo di Storia Naturale dell'Università degli Studi di Firenze. Warburg published 86 new names in Pandanaceae between 1898 and 1909 (five new sections, 69 new species, five new varieties, two new combinations and five replacement names). A complete review of the material extant in B and FI led to the conclusion that 38 names needed a nomenclatural act: 34 lectotypes, three neotypes and one epitype are designated here. Twenty new synonyms are also proposed. One Freycinetia name and six Pandanus names are considered as incertae sedis. A total of 21 names published by Warburg are accepted: 11 in Freycinetia and ten in Pandanus. In addition, four names published in Pandanus by Warburg serve as the basionyms of accepted names in the genus Benstonea

    Interpretable Anomaly Detection in Echocardiograms with Dynamic Variational Trajectory Models

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    We propose a novel anomaly detection method for echocardiogram videos. The introduced method takes advantage of the periodic nature of the heart cycle to learn three variants of a variational latent trajectory model (TVAE). While the first two variants (TVAE-C and TVAE-R) model strict periodic movements of the heart, the third (TVAE-S) is more general and allows shifts in the spatial representation throughout the video. All models are trained on the healthy samples of a novel in-house dataset of infant echocardiogram videos consisting of multiple chamber views to learn a normative prior of the healthy population. During inference, maximum a posteriori (MAP) based anomaly detection is performed to detect out-of-distribution samples in our dataset. The proposed method reliably identifies severe congenital heart defects, such as Ebstein's Anomaly or Shone-complex. Moreover, it achieves superior performance over MAP-based anomaly detection with standard variational autoencoders when detecting pulmonary hypertension and right ventricular dilation. Finally, we demonstrate that the proposed method enables interpretable explanations of its output through heatmaps highlighting the regions corresponding to anomalous heart structures.Comment: accepted at IMLH workshop ICML 202
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