A Public Dilemma: Cooperation with Large Stakes and a Large Audience

We analyze a large-stakes prisoner's dilemma game played on a TV show. Players cooperate 40% of the time, demonstrating that social preferences are important; however, cooperation is significantly below the 50% threshold that is required for inequity aversion to sustain cooperation. Women cooperate significantly more than men, while players who have "earned" more of the stake cooperate less. A player's promise to cooperate is also a good predictor of his decision. Surprisingly, a player's probability of cooperation is unrelated to the opponent's characteristics or promise. We argue that inequity aversion alone cannot adequately explain these results; reputational concerns in a public setting might be more important.

Beauty and the Sources of Discrimination

We analyze discrimination against less attractive people on a TV game show with high stakes. The game has a rich structure that allows us to disentangle the relationship between attractiveness and the determinants of a player’s earnings. Unattractive players perform no worse than attractive ones, and are equally cooperative in the prisoner’s dilemma stage of the game. Nevertheless, they are substantially more likely to be eliminated by their peers, even though this is costly. We investigate third party perceptions of discrimination by asking subjects to predict elimination decisions. Subjects implicitly assign a role for attractiveness but underestimate its magnitude

Is Beauty only Skin-deep? Disentangling the Beauty Premium on a Game Show

This paper analyzes behavior on a TV game show where players’ monetary payoffs depend upon an array of factors, including ability in answering questions, perceived cooperativeness and the willingness of other players to choose them. We find a substantial beauty premium and are able to disentangle contributing factors. Attractive players perform no differently than less attractive ones, on every dimension. They also exhibit and engender the same degree of cooperativeness. Nevertheless, attractive players are substantially less likely to be eliminated by their peers. Our results suggest a consumption value basis for the beauty premium

A Public Dilemma: Cooperation with Large Stakes and a Large Audience

We analyze a large-stakes prisoner's dilemma game played on a TV show. Players cooperate 40% of the time, demonstrating that social preferences are important; however, cooperation is significantly below the 50% threshold that is required for inequity aversion to sustain cooperation. Women cooperate significantly more than men, while players who have "earned" more of the stake cooperate less. A player's promise to cooperate is also a good predictor of his decision. Surprisingly, a player's probability of cooperation is unrelated to the opponent's characteristics or promise. We argue that inequity aversion alone cannot adequately explain these results; reputational concerns in a public setting might be more important

Physics Reach of High-Energy and High-Statistics IceCube Atmospheric Neutrino Data

This paper investigates the physics reach of the IceCube neutrino detector when it will have collected a data set of order one million atmospheric neutrinos with energies in the 0.1 \sim 10^4 TeV range. The paper consists of three parts. We first demonstrate how to simulate the detector performance using relatively simple analytic methods. Because of the high energies of the neutrinos, their oscillations, propagation in the Earth and regeneration due to \tau decay must be treated in a coherent way. We set up the formalism to do this and discuss the implications. In a final section we apply the methods developed to evaluate the potential of IceCube to study new physics beyond neutrino oscillations. Not surprisingly, because of the increased energy and statistics over present experiments, existing bounds on violations of the equivalence principle and of Lorentz invariance can be improved by over two orders of magnitude. The methods developed can be readily applied to other non-conventional physics associated with neutrinos.Comment: 21 pages, 7 figures, Revtex

A novel mutation in SACS gene in a family from southern Italy

A form of autosomal recessive spastic ataxia (ARSACS) has been described in the Charlevoix and Saguenay regions of Quebec. So far a frameshift and a nonsense mutation have been identified in the SACS gene. The authors report a new mutation (1859insC), leading to a frameshift with a premature termination of the gene product sacsin, in two sisters from consanguineous parents. The phenotype is similar to previously described patients with ARSACS

Time-dependent quantum transport with superconducting leads: a discrete basis Kohn-Sham formulation and propagation scheme

In this work we put forward an exact one-particle framework to study nano-scale Josephson junctions out of equilibrium and propose a propagation scheme to calculate the time-dependent current in response to an external applied bias. Using a discrete basis set and Peierls phases for the electromagnetic field we prove that the current and pairing densities in a superconducting system of interacting electrons can be reproduced in a non-interacting Kohn-Sham (KS) system under the influence of different Peierls phases {\em and} of a pairing field. An extended Keldysh formalism for the non-equilibrium Nambu-Green's function (NEGF) is then introduced to calculate the short- and long-time response of the KS system. The equivalence between the NEGF approach and a combination of the static and time-dependent Bogoliubov-deGennes (BdG) equations is shown. For systems consisting of a finite region coupled to ${\cal N}$ superconducting semi-infinite leads we numerically solve the static BdG equations with a generalized wave-guide approach and their time-dependent version with an embedded Crank-Nicholson scheme. To demonstrate the feasibility of the propagation scheme we study two paradigmatic models, the single-level quantum dot and a tight-binding chain, under dc, ac and pulse biases. We provide a time-dependent picture of single and multiple Andreev reflections, show that Andreev bound states can be exploited to generate a zero-bias ac current of tunable frequency, and find a long-living resonant effect induced by microwave irradiation of appropriate frequency.Comment: 20 pages, 9 figures, published versio

Exploring the spectroscopic diversity of type Ia supernovae with DRACULA: a machine learning approach

The existence of multiple subclasses of type Ia supernovae (SNeIa) has been the subject of great debate in the last decade. One major challenge inevitably met when trying to infer the existence of one or more subclasses is the time consuming, and subjective, process of subclass definition. In this work, we show how machine learning tools facilitate identification of subtypes of SNeIa through the establishment of a hierarchical group structure in the continuous space of spectral diversity formed by these objects. Using Deep Learning, we were capable of performing such identification in a 4 dimensional feature space (+1 for time evolution), while the standard Principal Component Analysis barely achieves similar results using 15 principal components. This is evidence that the progenitor system and the explosion mechanism can be described by a small number of initial physical parameters. As a proof of concept, we show that our results are in close agreement with a previously suggested classification scheme and that our proposed method can grasp the main spectral features behind the definition of such subtypes. This allows the confirmation of the velocity of lines as a first order effect in the determination of SNIa subtypes, followed by 91bg-like events. Given the expected data deluge in the forthcoming years, our proposed approach is essential to allow a quick and statistically coherent identification of SNeIa subtypes (and outliers). All tools used in this work were made publicly available in the Python package Dimensionality Reduction And Clustering for Unsupervised Learning in Astronomy (DRACULA) and can be found within COINtoolbox (https://github.com/COINtoolbox/DRACULA).Comment: 16 pages, 12 figures, accepted for publication in MNRA