Chris Cannings: A Life in Games

Chris Cannings was one of the pioneers of evolutionary game theory. His early work was inspired by the formulations of John Maynard Smith, Geoff Parker and Geoff Price; Chris recognized the need for a strong mathematical foundation both to validate stated results and to give a basis for extensions of the models. He was responsible for fundamental results on matrix games, as well as much of the theory of the important war of attrition game, patterns of evolutionarily stable strategies, multiplayer games and games on networks. In this paper we describe his work, key insights and their influence on research by others in this increasingly important field. Chris made substantial contributions to other areas such as population genetics and segregation analysis, but it was to games that he always returned. This review is written by three of his students from different stages of his career

A radio survey of supersoft, persistent and transient X-ray sources in the Magellanic Clouds

We present a radio survey of X-ray sources in the Large and Small Magellanic clouds with the Australia Telescope Compact Array at 6.3 and 3.5 cm. Specifically, we have observed the fields of five LMC and two SMC supersoft X-ray sources, the X-ray binaries LMC X-1, X-2, X-3 & X-4, the X-ray transient Nova SMC 1992, and the soft gamma-ray repeater SGR 0525-66. None of the targets are detected as point sources at their catalogued positions. In particular, the proposed supersoft jet source RXJ 0513-69 is not detected, placing constraints on its radio luminosity compared to Galactic jet sources. Limits on emission from the black hole candidate systems LMC X-1 and X-3 are consistent with the radio behaviour of persistent Galactic black hole X-ray binaries, and a previous possible radio detection of LMC X-1 is found to almost certainly be due to nearby field sources. The SNR N49 in the field of SGR 0525-66 is mapped at higher resolution than previously, but there is still no evidence for any enhanced emission or disruption of the SNR at the location of the X-ray source.Comment: 5 pages, LaTeX. Accepted for publication in MNRA

Enhanced deviant responses in patterned relative to random sound sequences

The brain draws on knowledge of statistical structure in the environment to facilitate detection of new events. Understanding the nature of this representation is a key challenge in sensory neuroscience. Specifically, it is unknown whether real-time perception of rapidly-unfolding sensory signals is driven by a coarse or detailed representation of the proximal stimulus history. We recorded electroencephalography brain responses to frequency outliers in regularly-patterned (REG) versus random (RAND) tone-pip sequences which were generated anew on each trial. REG and RAND sequences were matched in frequency content and span, only differing in the specific order of the tone-pips. Stimuli were very rapid, limiting conscious reasoning in favour of automatic processing of regularity. Listeners were naïve and performed an incidental visual task. Outliers within REG evoked a larger response than matched outliers in RAND. These effects arose rapidly (within 80 msec) and were underpinned by distinct sources from those classically associated with frequency-based deviance detection. These findings are consistent with the notion that the brain continually maintains a detailed representation of ongoing sensory input and that this representation shapes the processing of incoming information. Predominantly auditory-cortical sources code for frequency deviance whilst frontal sources are associated with tracking more complex sequence structure

The dimensionality, antecedents and consequences of union commitment : a study of a civil service union.

vii, 102 leaves : ill. ; 28 cm.Includes abstract.Includes bibliographical references (leaves 93-99).The study explores the dimensionality, antecedents and consequences of union commitment using a 13-item version of the Gordon, Philpot, Thomas & Spiller (1980) Union Commitment Scale. Data were gathered through a survey of members of a civil service union in eastern Canada (n = 914). The study replicates the findings of Kelloway and Catano (1990) and as such supports the construct validity of a three oblique factor structure of the Union Commitment Scale comprising Loyalty to the Union, Willingness to Work for the Union and Responsibility to the Union. A proposed model of antecedent and outcome variables of union commitment was supported. In testing the antecedent component of the model, union related variables emerged as better predictors of union commitment than either demographic or work related variables. Through further analysis, sex of the respondent emerged as a moderator in this relationship. Additionally, the data supported an outcome component in that union commitment acted as a useful predictor for strike propensity, willingness to undertake militant action and instrumentality in the form of union participation

Nonadiabatic Dynamics of Ultracold Fermions in Optical Superlattices

We study the time-dependent dynamical properties of two-component ultracold fermions in a one-dimensional optical superlattice by applying the adaptive time-dependent density matrix renormalization group to a repulsive Hubbard model with an alternating superlattice potential. We clarify how the time evolution of local quantities occurs when the superlattice potential is suddenly changed to a normal one. For a Mott-type insulating state at quarter filling, the time evolution exhibits a profile similar to that expected for bosonic atoms, where correlation effects are less important. On the other hand, for a band-type insulating state at half filling, the strong repulsive interaction induces an unusual pairing of fermions, resulting in some striking properties in time evolution, such as a paired fermion co-tunneling process and the suppression of local spin moments. We further address the effect of a confining potential, which causes spatial confinement of the paired fermions.Comment: 4 pages, 5 figure