The origin of the spacetime metric: Bell's `Lorentzian pedagogy' and its significance in general relativity

The purpose of this paper is to evaluate the `Lorentzian pedagogy' defended by J.S. Bell in his essay ``How to teach special relativity'', and to explore its consistency with Einstein's thinking from 1905 to 1952. Some remarks are also made in this context on Weyl's philosophy of relativity and his 1918 gauge theory. Finally, it is argued that the Lorentzian pedagogy - which stresses the important connection between kinematics and dynamics - clarifies the role of rods and clocks in general relativity.Comment: To be published in ``Physics Meets Philosophy at the Planck Length'', C. Callender and N. Huggett (eds.), Cambridge University Press (1999). 22 pages, no figures, LaTeX, uses harvard.sty; 3 references added, typos corrected and minor changes to conten

Localization to delocalization transition in a driven nonlinear cavity array

We study nonlinear cavity arrays where the particle relaxation rate in each cavity increases with the excitation number. We show that coherent parametric inputs can drive such arrays into states with commensurate filling that form non-equilibrium analogs of Mott insulating states. We explore the boundaries of the Mott insulating phase and the transition to a delocalized phase with spontaneous first order coherence. While sharing many similarities with the Mott insulator to superfluid transition in equilibrium, the phase-diagrams we find also show marked differences. Particularly the off diagonal order does not become long range since the influence of dephasing processes increases with increasing tunneling rates.Comment: 7 pages, 8 figure

Systematic review and meta-analysis of optimal P2Y₁₂ blockade in dual antiplatelet therapy for patients with diabetes with acute coronary syndrome

Background: Patients with diabetes are at increased risk of acute coronary syndromes (ACS) and their mortality and morbidity outcomes are significantly worse following ACS events, independent of other comorbidities. This systematic review sought to establish the optimum management strategy with focus on P2Y₁₂ blockade in patients with diabetes with ACS. Methods: MEDLINE (1946 to present) and EMBASE (1974 to present) databases, abstracts from major cardiology conferences and previously published systematic reviews were searched to June 2014. Relevant randomised control trials with clinical outcomes for P2Y₁₂ inhibitors in adult patients with diabetes with ACS were scrutinised independently by 2 authors with applicable data was extracted for primary composite end point of cardiovascular death, myocardial infarction (MI) and stroke; enabling calculation of relative risks with 95% CI with subsequent direct and indirect comparison. Results: Four studies studied clopidogrel in patients with diabetes, with two (3122 patients) having primary outcome data showing superiority of clopidogrel against placebo with RR0.84 (95% CI 0.72–0.99). Irrespective of management strategy, the newer agents prasugrel (2 studies) and ticagrelor (1 study) had a lower primary event rate compared with clopidogrel; RR 0.80 (95% CI 0.66 to 0.97) and RR 0.89 (95% CI 0.77 to 1.02), respectively. When ticagrelor was indirectly compared with prasugrel, there was a trend to an improved primary outcome with prasugrel (RR 1.11 (95% CI 0.94 to 1.31)) particularly in those managed with percutaneous coronary intervention (PCI) (RR 1.23 (95% CI 0.95 to 1.59)). Prasugrel demonstrated a statistical superiority with prevention of further MI with RR 1.48 (95% CI 1.11 to 1.97). This was not at the expense of increased major thrombolysis in MI (TIMI) bleeding rates RR 0.94 (95% CI 0.59 to 1.51). Conclusions: This meta-analysis shows the addition of a P2Y₁₂ inhibitor is superior to placebo, with a trend favouring the use of prasugrel in patients with diabetes with ACS, particularly those undergoing PCI

Charged Schrodinger Black Holes

We construct charged and rotating asymptotically Schrodinger black hole solutions of IIB supergravity. We begin by obtaining a closed-form expression for the null Melvin twist of a broad class of type IIB backgrounds, including solutions of minimal five-dimensional gauged supergravity, and identify the resulting five-dimensional effective action. We use these results to demonstrate that the near-horizon physics and thermodynamics of asymptotically Schrodinger black holes obtained in this way are essentially inherited from their AdS progenitors, and verify that they admit zero-temperature extremal limits with AdS_2 near-horizon geometries. Notably, the AdS_2 radius is parametrically larger than that of the asymptotic Schrodinger space.Comment: 22 pages, LaTe

The Material Light: Exploring The Relationship Between Contained and Container

Many buildings around us use the same ubiquitous boundary materials that fall short in directly influencing the disposition of the space it defines. There are many different opportunities to explore myriad material compositions to present the ambient qualities of space in a manner the puts the constructed boundary to the task to acclimatize the interior it envelopes. This thesis will explore a series of material compositions, with a focus on natural light, and how the articulation of the spatial boundary can bring out the strong qualities of daylight for visually sensitive activities. With this exploration, I will examine ways to define the contained ambient daylight through the nuances of the material boundary itself, developing and testing the possibilities made possible by careful material selection and composition. By exploring these different material assemblages, it will contribute to the boundary – space dialog, expanding the possibilities with careful experimentation using state-of-the-art tools and techniques. It also brings an increased awareness of how building materials can contribute to the intensive shaping of interior environments without the use of high-grade energy sources

The clinical applications of cardiogoniometry in cardiovascular disease

Cardiogoniometry (CGM) is a method of 3-dimensional electrocardiographic assessment which has primarily been investigated to evaluate its role in diagnosing patients with suspected coronary artery disease (CAD). Previous work has suggested it has considerable diagnostic ability at identifying patients with both stable CAD and those with acute coronary syndrome (ACS). However, previous studies which investigated the diagnostic performance of CGM in stable CAD did not use robust measures to accurately identify patients with physiologically significant coronary ischaemia. Furthermore, although the ability of CGM to identify specific lesions in stable CAD has been evaluated, to the best of our knowledge no research has been performed to assess the ability of CGM to detect the site of the culprit lesion in patients with non-ST elevation myocardial infarction. The first two studies of this thesis aim to address these two questions about the role of CGM in patients with CAD.Cardiac resynchronisation therapy (CRT) is a treatment used in patients with heart failure and left bundle branch block which attempts to restore synchronous contraction of the ventricles by pacing both the left and right ventricle together. Unfortunately, 25% of patients do not gain a clinical benefit from CRT, such patients are classed as ‘non-responders’. Many methods have been proposed to optimise CRT for ‘non-responders’, however, no specific optimisation method has yet been identified which significantly improves the long term benefit of CRT in non-responders. The detailed spatial and temporal information on cardiac electrical activity that CGM provides suggests that CGM may have a role in the optimisation of CRT. The aim of the third study in this thesis is to evaluate whether CGM can detect changes to CRT pacing settings, in view of developing a method of CRT optimisation using CGM