Homo Æqualis: A Cross-Society Experimental Analysis of Three Bargaining Games

Data from three bargaining games-the Dictator Game, the Ultimatum Game, and the Third-Party Punishment Game-played in 15 societies are presented. The societies range from US undergraduates to Amazonian, Arctic, and African hunter-gatherers. Behaviour within the games varies markedly across societies. The paper investigates whether this behavioural diversity can be explained solely by variations in inequality aversion. Combining a single parameter utility function with the notion of subgame perfection generates a number of testable predictions. While most of these are supported, there are some telling divergences between theory and data: uncertainty and preferences relating to acts of vengeance may have influenced play in the Ultimatum and Third-Party Punishment Games; and a few subjects used the games as an opportunity to engage in costly signalling.

The PHENIX Experiment at RHIC

The physics emphases of the PHENIX collaboration and the design and current status of the PHENIX detector are discussed. The plan of the collaboration for making the most effective use of the available luminosity in the first years of RHIC operation is also presented.Comment: 5 pages, 1 figure. Further details of the PHENIX physics program available at http://www.rhic.bnl.gov/phenix

Flexural behavior of model sea ice in a centrifuge

An experimental program was devised for the production of saline ice sheets in a centrifuge and the determination of flexural strength and elastic modulaus of this ice through in situ cantilever beam testing. A cold box, in which dry ice acted as a heat sink, was used for this purpose. The ice beams were produced by lowering a heated brass frame through the ice cover. The load and beam deflections were recorded furing indentation. The results of this analysis showed that inertial acceleration did not affect the flexural strength of the thin ice sheets required for this type of simulation. The data obtained were consistent with previously published strength values for thicker ice. The effective modulus showed a dependency on brine volume and inertial acceleration. The values obtained are substantially lower than those from conventional 1g tests and increase with the level of inertial acceleration. This is attributed to the confining stress.Peer reviewed: YesNRC publication: Ye

Mechanical testing of floating ice sheets

A cold box was designed for the in situ determination of the flexural strength and modulus of floating ice sheets. It consists of an aluminum casing which houses an insulated water basin and a dry ice compartment suspended above the water surface. Cantilever beams were produced by lowering a heated brass frame into the ice. Load and displacement transducers were mounted at one end of a horizontal support, with a counterweight of equal mass at the other end. Multiple tests were conducted by sequentially lowering, raising and rotating this system about a central pivot. Inertial acceleration had no appreciable effect on the modulus of elasticity and the strength of freshwater ice.Mr. Jones was affiliated with the National Research Council of Canada, Institute for Marine Dynamics when he authored this article.M. Jones \ue9tait affili\ue9 avec le Conseil national de recherches du Canada, Institut de la dynamique marine lorsqu\u2019il a r\ue9dig\ue9 cet article.Peer reviewed: YesNRC publication: Ye

Physical properties of columnar ice grown in a centrifuge

This paper investigates the physical properties of floating ice covers produced at normal gravity (1g) and at an inertial acceleration equivalent to 50 times gravity (50g), from water with different salt concentrations. The experiments were conducted in a dry-ice cold box. No significant difference in grain size was observed in the ice produced at 1g and 50g. Salinity profiles and bulk ice density varied with the level of inertial acceleration.Mr. Jones was affiliated with the National Research Council of Canada, Institute for Marine Dynamics when he authored this article.M. Jones \ue9tait affili\ue9 avec le Conseil national de recherches du Canada, Institut de la dynamique marine lorsqu\u2019il a r\ue9dig\ue9 cet article.Peer reviewed: YesNRC publication: Ye

Safety and Efficacy of Arterial Closure Devices Following Antegrade Femoral Access: A Case–Control Study

Purpose: Vascular closure device (VCD) use following antegrade femoral access may present unique challenges relative to retrograde access. We retrospectively compared safety and efficacy of these devices between antegrade and retrograde patient cohorts undergoing percutaneous intervention. Materials and Methods: Over a 5-year period, a consecutive series of 107 limbs in 84 patients underwent VCD arteriotomy closure following percutaneous revascularization using an antegrade approach (VCD-A). Device deployment success rates, time to ambulation, and complication rates were compared to a contemporaneous control group of 401 limbs in 305 patients who underwent closure following retrograde access (VCD-R) during revascularization or embolization procedures. Results: Closure was attempted in VCD-A using 53 StarClose, 35 Perclose, and 19 Angio-Seal devices. Hemostasis (without supplemental manual compression) was achieved in 86/107 (80.4%) limbs. Closure was attempted in VCD-R using 215 StarClose, 119 Perclose, and 67 Angio-Seal devices with hemostasis in 357/401 (89.0%) limbs. Device deployment failure occurred in 7/107 (6.5%) of VCD-A and 20/401 (5.0%) of VCD-R ( P = .52), independent of specific device type. Femoral pseudoaneurysm developed in 1/107 and 1/401 of VCD-A and VCD-R ( P = .31), and minor hematoma developed in 3/107 and 8/401 of the VCD-A and VCD-R ( P = .61). Mean time to ambulation was 204.1 minutes in VCD-A and 204.8 minutes in VCD-R ( P = .97). Conclusion: Antegrade femoral closure was associated with high rates of technical success and low complications, similar to retrograde closure. Time to ambulation was the same in both groups despite higher heparin doses in the antegrade patients. </jats:sec