A Cypriot tragedy and a new identity: analysing refugee assistance programmes and their impact on cultural relationships in post-1974 Cyprus

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Coevolutionary Dynamics in a Minimal Substrate

One of the central difficulties of coevolutionary methods arises from 'intransitive superiority' - in a two-player game, for example, the fact that A beats B, and B beats C, does not exclude the possibility that C beats A. Such cyclic superiority in a coevolutionary substrate is hypothesized to cause cycles in the dynamics of the population such that it 'chases its own tail' - traveling through some part of strategy space more than once despite apparent improvement with each step. It is often difficult to know whether an application domain contains such difficulties and to verify this hypothesis in the failure of a given coevolutionary set-up. In this paper we wish to elucidate some of the issues and concepts in an abstract domain where the dynamics of coevolution can be studied simply and directly. We define three simple 'number games' that illustrate intransitive superiority and resultant oscillatory dynamics, as well as some other relevant concepts. These include the distinction between a player's perceived performance and performance with respect to an external metric, and the significance of strategies with a multi-dimensional nature. These features alone can also cause oscillatory behavior and coevolutionary failure

A Mean-field statistical theory for the nonlinear Schrodinger equation

A statistical model of self-organization in a generic class of one-dimensional nonlinear Schrodinger (NLS) equations on a bounded interval is developed. The main prediction of this model is that the statistically preferred state for such equations consists of a deterministic coherent structure coupled with fine-scale, random fluctuations, or radiation. The model is derived from equilibrium statistical mechanics by using a mean-field approximation of the conserved Hamiltonian and particle number for finite-dimensional spectral truncations of the NLS dynamics. The continuum limits of these approximated statistical equilibrium ensembles on finite-dimensional phase spaces are analyzed, holding the energy and particle number at fixed, finite values. The analysis shows that the coherent structure minimizes total energy for a given value of particle number and hence is a solution to the NLS ground state equation, and that the remaining energy resides in Gaussian fluctuations equipartitioned over wavenumbers. Some results of direct numerical integration of the NLS equation are included to validate empirically these properties of the most probable states for the statistical model. Moreover, a theoretical justification of the mean-field approximation is given, in which the approximate ensembles are shown to concentrate on the associated microcanonical ensemble in the continuum limit.Comment: 24 pages, 2 figure

The Persistence of Population III Star Formation

We present a semi-analytic model of star formation in the early universe, beginning with the first metal-free stars. By employing a completely feedback-limited star formation prescription, stars form at maximum efficiency until the self-consistently calculated feedback processes halt formation. We account for a number of feedback processes including a meta-galactic Lyman-Werner background, supernovae, photoionization, and chemical feedback. Halos are evolved combining mass accretion rates found through abundance matching with our feedback-limited star formation prescription, allowing for a variety of Population III (Pop III) initial mass functions (IMFs). We find that, for a number of models, massive Pop III star formation can continue on until at least $z \sim 20$ and potentially past $z \sim 6$ at rates of around $10^{-4}$ to $10^{-5}$ M$_\odot$ yr$^{-1}$ Mpc$^{-3}$, assuming these stars form in isolation. At this point Lyman-Werner feedback pushes the minimum halo mass for star formation above the atomic cooling threshold, cutting off the formation of massive Pop III stars. We find that, in most models, Pop II and Pop III star formation co-exist over cosmological time-scales, with the total star formation rate density and resulting radiation background strongly dominated by the former before Pop III star formation finally ends. These halos form at most $\sim 10^3$ M$_\odot$ of massive Pop III stars during this phase and typically have absolute magnitudes in the range of $M_\text{AB} = -5$ to $-10$. We also briefly discuss how future observations from telescopes such as JWST or WFIRST and 21-cm experiments may be able to constrain unknown parameters in our model such as the IMF, star formation prescription, or the physics of massive Pop III stars.Comment: 16 pages, 13 figures, submitted to MNRA

Mutualism, Parasitism, and Evolutionary Adaptation

Our investigations concern the role of symbiosis as an enabling mechanism in evolutionary adaptation. Previous work has illustrated how the formation of mutualist groups can guide genetic variation so as to enable the evolution of ultimately independent organisms that would otherwise be unobtainable. The new experiments reported here show that this effect applies not just in genetically related organisms but may also occur from symbiosis between distinct species. In addition, a new detail is revealed: when the symbiotic group members are drawn from two separate species only one of these species achieves eventual independence and the other remains parasitic. It is nonetheless the case that this second species, formerly mutualistic, was critical in enabling the independence of the first. We offer a biological example that is suggestive of the effect and discuss the implications for evolving complex organisms, natural and artificial

Same but different, but is it fair? An analysis of the use of variants of interactive computer-marked questions

Different variants of interactive computer-marked questions are used to reduce opportunities for plagiarism, and tools have been developed to indicate when variants are of significantly different difficulty. The tools include the facility index for each variant, a plot of the different scoring patterns for the variants and a probability that any difference could have occurred by chance The paper includes an example of the tools in use and identifies factors that have been found to lead to variants of different difficulty. An investigation into the impact on students’ overall scores is then described, with the conclusion that, for most modules, the effect is very small (typically ±0.5%). Factors leading to a larger effect include: a larger number of individual questions with significantly different variant difficulty; a smaller number of interactive computer-marked questions; and a higher weighting of the e-assessment component. Monitoring the behaviour of variants can lead to improvements in the quality of individual questions, better assessment design and enhanced insight into students’ misunderstandings

Lessons From Game Theory About Humanizing Next-Generation Weapons

This article draws a parallel between nuclear weapons and the next generation of military technology, autonomous systems. It outlines some legal and ethical dilemmas the latter pose, and in particular aspects of the technology that make it dehumanizing. Autonomous systems share all of these attributes with nuclear weapons. This fact should be encouraging, because the dehumanizing effects of nuclear systems have been overcome. Drawing on the evolution of nuclear strategy and the nuclear taboo, I argue that, in negotiating the legal and ethical dilemmas posed by autonomous weapons systems, the role of international law and of normative entrepreneurs will be primarily one of imagination, not regulation. The first and most important task is to create focal points in popular and elite consciousness. To this end, I make three modest suggestions for normative entrepreneurs: to take political incentives seriously, including the impossibility of abolition or non-use; to first establish simple, guiding ideas accessible to a broad population before turning to finer points of law; and to focus on interstate, rather than transnational, cooperation

Learning To Spar

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On a Good Day, You Get to Kill a Whore: Narrative Misogyny and Female Audiences in Supernatural

In this paper, I attempt to analyze the function of gender messages in media texts and the engagement of audiences with these messages. I adopt an interdisciplinary approach, applying theoretical and methodological concepts from both film studies and audience studies, in order to develop a new model through which to study media texts and fans. I apply this model to an analysis of female characters in the television program Supernatural and to self-identified female fans of Supernatural. Throughout the paper, I contend that such an interdisciplinary model is necessary for understanding media texts and audiences, and I conclude that media fans act as academics in their reading and interpretation of media texts