Effect of Uncertainty about Others' Rationality in Experimental Asset Markets: An Experimental Analysis

We investigate the extent to which price deviations from fundamental values in an experimental asset market are due to the uncertainty of subjects regarding others' rationality. We do so by comparing the price forecasts submitted by subjects in two market environments: (a) all six traders are human subjects (6H), and (b) one human subject interacts with five profit-maximizing computer traders who assume all the traders are also maximizing profit (1H5C). The subjects are told explicitly about the behavioral assumption of the computer traders (in both 6H and 1H5C) as well as which environment they are in. Results from our experiments show that there is no significant difference between the distributions of the initial deviations of the forecast prices from the fundamental values in the two markets. However, as subjects learn by observing the realized prices, the magnitude of deviations becomes significantly smaller in 1H5C than in 6H markets. We also conduct additional experiments where subjects who have experienced the 1H5C market interact with five inexperienced subjects. The price forecasts initially submitted by the experienced subjects follow the fundamental value despite the fact that the subjects are explicitly told that the five other traders in the market are inexperienced subjects. These findings do not support the hypothesis that uncertainty about others' rationality plays a major role in causing substantial deviation of forecast prices from the fundamental values in these asset market experiments

Learning Games

This paper proposes a model of learning about a game. Players initially have littleknowledge about the game. Through playing the identical game repeatedly, eachplayer not only learns which action to choose but also constructs his personal viewon the game. The model is studied using a hybrid payoff matrix of the prisoner’sdilemma and coordination games. Results of computer simulations show (1) when allthe players are slow in learning the game, they have only a partial understanding ofthe game, but may enjoy higher payoffs than the cases with full or no understandingof the game; (2) when one of the players is quick in learning the game, he obtains ahigher payoff than the others. However, all of them can receive lower payoffs than thecase where all the players are slow learners

Inraoperative and Histological Visualization of Disrupted Vulnerable Plaques following Diagnostic Angiography of Moderate Carotid Stenosis

Background. Digital subtraction angiography (DSA) remains an important tool for diagnosis of carotid stenosis but is associated with risk for periprocedural complications. This is the first report of direct intraoperative and histolopathologic visualization of DSA-related carotid plaque disruption. Case. A 64-year-old man diagnosed to have a 60% right carotid stenosis received diagnostic DSA for therapeutic decision-making. He developed transient left hand numbness and weakness immediately after the procedure. Intraoperative imaging during carotid endarterectomy revealed a fragile plaque with sharp surface laceration and intraplaque hemorrhage at the bifurcation. Microscopy of the specimen demonstrated a large atheromatous plaque with fibrous hypertrophy and intraplaque hemorrhage filled with recent hemorrhagic debris. Conclusion. The visualized carotid lesion was more serious than expected, warning the danger of embolization or occlusion associated with the catheter maneuvers. Thus the highest level of practitioner training and technical expertise that ensures precise assessment of plaque characteristics should be encouraged

Multiscale element mapping of buried structures by ptychographic x-ray diffraction microscopy using anomalous scattering

We propose an element mapping technique of nano-meso-microscale structures buried within large and/or thick objects by ptychographic x-ray diffraction microscopy using anomalous scattering. We performed quantitative imagings of both the electron density and Au element of Au/Ag nanoparticles at the pixel resolution of better than 10 nm in a field of view larger than 5 × 5 μm2 by directly phasing ptychographic coherent diffraction patterns acquired at two x-ray energies below the Au L3 edge. This method provides us with multiscale structural and elemental information for understanding the element/property relationship linking nanoscale structures to macroscopic functional properties in material and biological systems. © 2011 American Institute of Physics.Yukio Takahashi, Akihiro Suzuki, Nobuyuki Zettsu, Yoshiki Kohmura, Kazuto Yamauchi, and Tetsuya Ishikawa, "Multiscale element mapping of buried structures by ptychographic x-ray diffraction microscopy using anomalous scattering", Appl. Phys. Lett. 99(13), 131905 (2011) https://doi.org/10.1063/1.3644396

Phase Diagram of Pressure-Induced Superconductivity in EuFe2As2 Probed by High-Pressure Resistivity up to 3.2 GPa

We have constructed a pressure$-$temperature ($P-T$) phase diagram of $P$-induced superconductivity in EuFe$_2$As$_2$ single crystals, via resistivity ($\rho$) measurements up to 3.2 GPa. As hydrostatic pressure is applied, an antiferromagnetic (AF) transition attributed to the FeAs layers at $T_\mathrm{0}$ shifts to lower temperatures, and the corresponding resistive anomaly becomes undetectable for $P$ $\ge$ 2.5 GPa. This suggests that the critical pressure $P_\mathrm{c}$ where $T_\mathrm{0}$ becomes zero is about 2.5 GPa. We have found that the AF order of the Eu$^{2+}$ moments survives up to 3.2 GPa without significant changes in the AF ordering temperature $T_\mathrm{N}$. The superconducting (SC) ground state with a sharp transition to zero resistivity at $T_\mathrm{c}$ $\sim$ 30 K, indicative of bulk superconductivity, emerges in a pressure range from $P_\mathrm{c}$ $\sim$ 2.5 GPa to $\sim$ 3.0 GPa. At pressures close to but outside the SC phase, the $\rho(T)$ curve shows a partial SC transition (i.e., zero resistivity is not attained) followed by a reentrant-like hump at approximately $T_\mathrm{N}$ with decreasing temperature. When nonhydrostatic pressure with a uniaxial-like strain component is applied using a solid pressure medium, the partial superconductivity is continuously observed in a wide pressure range from 1.1 GPa to 3.2 GPa.Comment: 7 pages, 6 figures, accepted for publication in Physical Review B, selected as "Editors' Suggestion

KL-6 concentration in pulmonary epithelial lining fluid is a useful prognostic indicator in patients with acute respiratory distress syndrome

<p>Abstract</p> <p>Background</p> <p>KL-6 is a mucin-like glycoprotein expressed on the surface of alveolar type II cells. Elevated concentrations of KL-6 in serum and epithelial lining fluid (ELF) in patients with acute respiratory distress syndrome (ARDS) have been previously reported; however, kinetics and prognostic significance of KL-6 have not been extensively studied. This study was conducted to clarify these points in ARDS patients.</p> <p>Methods</p> <p>Thirty-two patients with ARDS who received mechanical ventilation under intubation were studied for 28 days. ELF and blood were obtained from each patient at multiple time points after the diagnosis of ARDS. ELF was collected using a bronchoscopic microsampling procedure, and ELF and serum KL-6 concentrations were measured.</p> <p>Results</p> <p>KL-6 levels in ELF on days 0 to 3 after ARDS diagnosis were significantly higher in nonsurvivors than in survivors, and thereafter, there was no difference in concentrations between the two groups. Serum KL-6 levels did not show statistically significant differences between nonsurvivors and survivors at any time point. When the highest KL-6 levels in ELF and serum sample from each patient were examined, KL-6 levels in both ELF and serum were significantly higher in nonsurvivors than in survivors. The optimal cut-off values were set at 3453 U/mL for ELF and 530 U/mL for serum by receiver operating characteristic (ROC) curve analyses. Patients with KL-6 concentrations in ELF higher than 3453 U/mL or serum concentrations higher than 530 U/mL had significantly lower survival rates up to 90 days after ARDS diagnosis.</p> <p>Conclusions</p> <p>ELF and serum KL-6 concentrations were found to be good indicators of clinical outcome in ARDS patients. Particularly, KL-6 levels in ELF measured during the early period after the diagnosis were useful for predicting prognosis in ARDS patients.</p