The paper studies Bayesian games which are extended by adding pre-play communication. Let G be a Bayesian game with full support and with three or more players. The main result is that if players can send private messages to each other and make public announcements then every communication equilibrium outcome, q, that is rational (i.e., involves probabilities that are rational numbers) can be implemented in a sequential equilibrium of a cheap talk extension of G, provided that the following condition is satisfied: There exists a Bayesian Nash equilibrium s in G such that for each type ti of each player i the expected payoff of ti in q is larger than the expected payoff of ti in s. Journal of Economic Literature classification number: C7. Key words: communication, Bayesian games, sequential equilibrium.
Communication in Repeated Games with Costly Monitoring
with Michael Kahneman
We study repeated games with discounting where perfect monitoring is possible, but costly. It is shown that if players can make public announcements, then every payo. vector which is an interior point in the set of feasible and individually rational payo.s can be implemented in a sequential equilibrium of the repeated game when the discount factor is high enough. Thus, e.ciency can be approximated even when the cost of monitoring is high, provided that the discount factor is high enough. Key words: Repeated games, costly monitoring, Communication.
Global analyses of RNA expression levels are useful for classifying genes and overall phenotypes. Often these classification problems are linked, and one wants to find "marker genes" that are differentially expressed in particular sets of "conditions." We have developed a method that simultaneously clusters genes and conditions, finding distinctive "checkerboard" patterns in matrices of gene expression data, if they exist. In a cancer context, these checkerboards correspond to genes that are markedly up- or downregulated in patients with particular types of tumors. Our method, spectral biclustering, is based on the observation that checkerboard structures in matrices of expression data can be found in eigenvectors corresponding to characteristic expression patterns across genes or conditions. In addition, these eigenvectors can be readily identified by commonly used linear algebra approaches, in particular the singular value decomposition (SVD), coupled with closely integrated normalization steps. We present a number of variants of the approach, depending on whether the normalization over genes and conditions is done independently or in a coupled fashion. We then apply spectral biclustering to a selection of publicly available cancer expression data sets, and examine the degree to which the approach is able to identify checkerboard structures. Furthermore, we compare the performance of our biclustering methods against a number of reasonable benchmarks (e.g., direct application of SVD or normalized cuts to raw data).
Collision induced spectra allow a characterization of the rate of change of the dipolar asymmetry of the electronic charge distribution. We compute such spectra using classical trajectories but include essential quantal corrections. These corrections are necessary to satisfy the sum rules to leading order in Planck's constant. A corrected computation using classical dynamics for the motion during the collision results when the spectrum is computed from the dipole velocity rather than from the dipole itself. The resulting spectrum is then an asymmetric function of frequency. The Laplace distribution is discussed as a convenient representation of the asymmetric spectrum over both the negative and positive frequency axis. For the emission spectrum the frequency distribution corresponds to the Planck equation with a radiation temperature that is equal to the mean deformation energy of the electronic charge distribution. Therefore, collision induced emission provides a thermometer for the electronic deformation during the collision. (C) 2003 American Institute of Physics.
Information regarding the stresses and strains in the canine femur during various activities is important for veterinary orthopaedic surgeons, engineers designing implants for dogs, and researchers of human orthopaedics who use dogs as models. Nevertheless, such information is currently unavailable. The objective of this study is to determine the stress and strain distribution in the canine femur during mid-stance, for two loading scenarios. Three-dimensional finite element models of the canine femur were created. Two loading cases were considered: the hip joint reaction force alone, and the hip joint reaction force with all muscle forces acting on the femur. Force directions and magnitudes were obtained from the literature. Analyses were performed with NASTRAN for Windows(R) software. When all muscle forces were considered, stresses and strains were significantly reduced, peak compressive stresses were found to occur in the medial diaphysis, and peak tensile stresses occurred in the lateral diaphysis. While the canine femur seems to be, loaded primarily in bending when only the hip joint reaction force is considered, the bending moment is significantly decreased when all muscle forces are considered as well. Further in vivo and in vitro experiments are needed to validate the results of the calculations described in this paper. It is expected that future studies will be carried out, in which the stress and strain distributions in femora with different types of implants and stems will be compared to those in the normal femur. (C) 2003 IPEM. Published by Elsevier Science Ltd. All rights reserved.
Electron transfer processes at tungsten oxide films prepd. by the sol-gel method were investigated and characterized by scanning electrochem. microscopy (SECM) and cyclic voltammetry. The feedback mode of the SECM was used for studying the localization and mechanism of the heterogeneous charge transfer at tungsten oxide thin films, which were deposited on conducting, i.e., tin oxide, and insulating substrates. Investigating the feedback current as a function of the mediator concn., thickness of the tungsten oxide film and the nature and concn. of the electrolyte, allow detn. of the rate limiting step and cond. of the film. [on SciFinder(R)]
The adsorption of thiols on different metal surfaces has been studied using potentiometric measurements. The adsorption is a complex process that comprises a few steps. The first involves neg. charge transfer to the electrode surface as evidenced by a sharp neg. shift of the open circuit potential (ocp). The charge that is accumulated on the electrode surface is discharged through a redn. process that involves either water or oxygen redn. The rate of the discharging process depends strongly on the overpotential of the electrode material for water redn., the medium, and to some extent, on addnl. functional groups that the thiol bears. A detailed general mechanism that is in agreement with our findings is proposed and discussed. [on SciFinder(R)]
Human HT2-19 cells with a conditional cdk1 mutation stop dividing upon cdk1 inactivation and undergo multiple rounds of endoreplication. We show herein that major cell cycle events remain synchronized in these endoreplicating cells. DNA replication alternates with gap phases and cell cycle-specific cyclin E expression is maintained. Centrosomes duplicate in synchrony with chromosome replication, giving rise to polyploid cells with multiple centrosomes. Centrosome migration, a typical prophase event, also takes place in endoreplicating cells. The timing of these events is unaffected by cdk1 inactivation compared with normally dividing cells. Nuclear lamina breakdown, in contrast, previously shown to be dependent on cdk1, does not take place in endoreplicating HT2-19 cells. Moreover, breakdown of all other major components of the nuclear lamina, like the inner nuclear membrane proteins and nuclear pore complexes, seems also to depend on cdk1. Interestingly, the APC/C ubiquitin ligase is activated in these endoreplicating cells by fzr but not by fzy. The oscillations of interphase events are thus independent of cdk1 and of mitosis but may depend on APC/Cfzr activity.
A semiclassical cellular method is proposed. Signals generated by semiclassical techniques generally deteriorate over time as trajectories become chaotic. One approach to remedy this problem has been to have each trajectory weighted by an entire cell of nearby trajectories (Filinov transform). But even in this approach the exponential part of the propagator typically becomes large and positive over time. Here the cellularization (Filinov) parameter is subject to constraints which make it time dependent and trajectory dependent. It also depends on dimensionality, so it ends up as a matrix. Physically, the Filinov transform is done differently in different directions associated with the stability matrix for the phase-essentially a more confined integration in directions where the matrix diverges and a wider integration in other directions. This squelches the contribution from any part of a trajectory that becomes excessively chaotic. A trajectory-dependent cellurized frozen Gaussian is applied here within the Herman-Kluk semiclassical approach. It is tested by looking at a single-particle three-dimensional problem, He attached to a rigid immovable naphtalene, where it is shown to be more accurate than the original HK approach, without the divergence of the correlation function common in the usual cellular dynamics (HK) formulation, and is able to separate a low-lying excited state from the ground state. (C) 2003 American Institute of Physics.
Measuring the wavelength dependence of photodissociation transition amplitudes to crossing electronic states is discussed with reference to extracting time domain information. Outwards from the crossing the system evolves on one or the other state as ascertained from the electronic state of the products. One can therefore measure the phase difference for the motion on the two potentials accumulated between the Franck-Condon region and the crossing point. A computational example, the photodissociation of HI and DI, is provided. The interference varies rapidly with wavelength and provides considerable leverage for determination of ultra-short time differences. The interference exhibits a significant isotope effect. (C) 2003 Elsevier Science B.V. All rights reserved.
O. Tirosh-Becker. 2003. “The Use of Rabbinic Sources in Karaite Writings.” In Karaite Judaism: A Guide to its History and Literary Sources, HOS Series Vol. 73, edited by M. Polliack, Pp. 319-338. Leiden: Brill Academic Publishers.
