Copper cable theft: revisiting the price–theft hypothesis

Objectives: To test the commonly espoused but little examined hypothesis that fluctuations in the price of metal are associated with changes in the volume of metal theft. Specifically, we analyze the relationship between the price of copper and the number of police recorded 'live’ copper cable thefts from the British railway network (2006 to 2012)

Evidence for enhanced learning of a socially transmitted food preference in rats interacting in large groups

Socially Transmitted Food Preferences (STFP) are typically assessed in laboratory rats by allowing a single Observer to interact with a Demonstrator fed a distinctly flavored food. Social learning is gauged by the Observer rat's subsequent preference for the Demonstrator's diet to equally palatable alternatives. This thesis tested the hypothesis that modifying the design of conventional protocols to better match the conditions that would underlie STFP in a rat's natural habitat will enhance laboratory-assessed social learning. In Experiment 1, the ability for multiple Observers interacting simultaneously with a single Demonstrator to acquire a food preference was assessed. Rats were reared for 10 weeks in enriched housing conditions and tested under conventional (CL) or group-learning (GL) approaches. The results revealed a greater tendency for GL rats to consume their respective Demonstrators' diets than CL rats. Observers tested under CL failed to display a food preference. In Experiment 1B, the influence of impoverished rearing conditions on STFP was assessed. Rats were reared under standardized housing conditions and tested using CL. Impoverished rats acquired a more robust preference when rearing conditions and learning conditions were more similar. In Experiment 2, the role of the hippocampus in the acquisition and retention of STFP under GL was assessed at 10 min following the learning phase. Rats receiving hippocampal lesions performed similarly to sham lesion rats and consumed more of the diet eaten by their respective Demonstrators. In sum, these results provide support for enhanced learning of food preferences under semi-naturalistic conditions

Temperature dependence of the resonance and low energy spin excitations in superconducting FeTe0.6_{0.6}Se0.4_{0.4}

We use inelastic neutron scattering to study the temperature dependence of the low-energy spin excitations in single crystals of superconducting FeTe$_{0.6}$Se$_{0.4}$ ($T_c=14$ K). In the low-temperature superconducting state, the imaginary part of the dynamic susceptibility at the electron and hole Fermi surfaces nesting wave vector $Q=(0.5,0.5)$, $\chi^{\prime\prime}(Q,\omega)$, has a small spin gap, a two-dimensional neutron spin resonance above the spin gap, and increases linearly with increasing $\hbar\omega$ for energies above the resonance. While the intensity of the resonance decreases like an order parameter with increasing temperature and disappears at temperature slightly above $T_c$, the energy of the mode is weakly temperature dependent and vanishes concurrently above $T_c$. This suggests that in spite of its similarities with the resonance in electron-doped superconducting BaFe$_{2-x}$(Co,Ni)$_x$As$_2$, the mode in FeTe$_{0.6}$Se$_{0.4}$ is not directly associated with the superconducting electronic gap.Comment: 7 pages, 6 figure

Directions for research practice in decolonising methodologies: Contending with paradox

The complex nature of colonisation presents with the potential for paradoxes in decolonising approaches, hence, fixed conventions and methods are discouraged. In this way, decolonising methodologies concerns interrogating dominant conventions in research that have typically excluded alternative ways of knowing from academia. This raises concern about the issue of breaking conventions, when it is potentially difficult to realise that one is depending upon them. An incremental approach to the research process and subsequent knowledge generated provides opportunity to challenge the conventions that typically dictate research praxis. In addition, fostering epistemological transformation and pluralism presents a solution to problems derived from dominant cultural assumptions and practices. My aim for this article is to extend upon the literature pertaining to decolonising methodologies, with this contribution of focusing on the research process as a means to avoid paradox in the decolonial intention. Accordingly, a process imperative that focuses on how researchers do research, over the tendency to focus on outcomes, emerges as a strategy to identify and contend with paradoxes within decolonial work. A questioning convention is posited as a means for mining the assumptions and biases of the dominant culture that would otherwise ensnare ones thinking. Consequently, research may be better liberated from oppressive colonising practices that are tacit within research and academic conventions. Narratives are provided throughout for illustrative example, and to better explore the concepts named

Nodal Landau Fermi-Liquid Quasiparticles in Overdoped La1.77_{1.77}Sr0.23_{0.23}CuO4_4

Nodal angle resolved photoemission spectra taken on overdoped La$_{1.77}$Sr$_{0.23}$CuO$_4$ are presented and analyzed. It is proven that the low-energy excitations are true Landau Fermi-liquid quasiparticles. We show that momentum and energy distribution curves can be analyzed self-consistently without quantitative knowledge of the bare band dispersion. Finally, by imposing Kramers-Kronig consistency on the self-energy $\Sigma$, insight into the quasiparticle residue is gained. We conclude by comparing our results to quasiparticle properties extracted from thermodynamic, magneto-resistance, and high-field quantum oscillation experiments on overdoped Tl$_2$Ba$_2$CuO$_{6+\delta}$.Comment: Accepted for publication in Phys. Rev.

Self-gravitating clouds of generalized Chaplygin and modified anti-Chaplygin Gases

The Chaplygin gas has been proposed as a possible dark energy, dark matter candidate. As a working fluid in a Friedmann-Robertson-Walker universe, it exhibits early behavior reminiscent of dark matter, but at later times is more akin to a cosmological constant. In any such universe, however, one can expect local perturbations to form. Here we obtain the general equations for a self-gravitating relativistic Chaplygin gas. We solve these equations and obtain the mass-radius relationship for such structures, showing that only in the phantom regime is the mass-radius relationship large enough to be a serious candidate for highly compact massive objects at the galaxy core. In addition, we study the cosmology of a modified anti-Chaplygin gas. A self-gravitating cloud of this matter is an exact solution to Einstein's equations.Comment: 16 page

Adverse cardiovascular events during treatment with pioglitazone and rosiglitazone: population based cohort study

Objective To compare the risk of acute myocardial infarction, heart failure, and death in patients with type 2 diabetes treated with rosiglitazone and pioglitazone

Spin density wave induced disordering of the vortex lattice in superconducting La2−x_{2-x}Srx_xCuO4_4

We use small angle neutron scattering to study the superconducting vortex lattice in La$_{2-x}$Sr$_x$CuO$_4$ as a function of doping and magnetic field. We show that near optimally doping the vortex lattice coordination and the superconducting coherence length $\xi$ are controlled by a van-Hove singularity crossing the Fermi level near the Brillouin zone boundary. The vortex lattice properties change dramatically as a spin-density-wave instability is approached upon underdoping. The Bragg glass paradigm provides a good description of this regime and suggests that SDW order acts as a novel source of disorder on the vortex lattice.Comment: Accepted in Phys. Rev.