Whole-brain patterns of 1H-magnetic resonance spectroscopy imaging in Alzheimer's disease and dementia with Lewy bodies

Acknowledgements We thank Craig Lambert for his help in processing the MRS data. The study was funded by the Sir Jules Thorn Charitable Trust (grant ref: 05/JTA) and was supported by the National Institute for Health Research (NIHR) Newcastle Biomedical Research Centre and the Biomedical Research Unit in Lewy Body Dementia based at Newcastle upon Tyne Hospitals National Health Service (NHS) Foundation Trust and Newcastle University and the NIHR Biomedical Research Centre and Biomedical Research Unit in Dementia based at Cambridge University Hospitals NHS Foundation Trust and the University of Cambridge.Peer reviewedPublisher PD

Superconductivity in Heavy Alkaline-Earths Intercalated Graphites

We report the discovery of superconductivity below 1.65(6) K in Sr-intercalated graphite SrC6, by susceptibility and specific heat (Cp) measurements. In comparison with CaC6, we found that the anisotropy of the upper critical fields for SrC6 is much reduced. The Cp anomaly at Tc is smaller than the BCS prediction indicating an anisotropic superconducting gap for SrC6 similar to CaC6. The significantly lower Tc of SrC6 as compared to CaC6 can be understood in terms of "negative" pressure effects, which decreases the electron-phonon coupling for both in-plane intercalant and the out-of-plane C phonon modes. We observed no superconductivity for BaC6 down to 0.3 K.Comment: 4 pages, 4 figures, submitted to Phys. Rev. Let

A universal GRB photon energy-peak luminosity relation

The energetics and emission mechanism of GRBs are not well understood. Here we demonstrate that the instantaneous peak flux or equivalent isotropic peak luminosity, L_iso ergs s^-1, rather than the integrated fluence or equivalent isotropic energy, E_iso ergs, underpins the known high-energy correlations. Using new spectral/temporal parameters calculated for 101 bursts with redshifts from BATSE, BeppoSAX, HETE-II and Swift we describe a parameter space which characterises the apparently diverse properties of the prompt emission. We show that a source frame characteristic-photon-energy/peak luminosity ratio, K_z, can be constructed which is constant within a factor of 2 for all bursts whatever their duration, spectrum, luminosity and the instrumentation used to detect them. The new parameterization embodies the Amati relation but indicates that some correlation between E_peak and E_iso follows as a direct mathematical inference from the Band function and that a simple transformation of E_iso to L_iso yields a universal high energy correlation for GRBs. The existence of K_z indicates that the mechanism responsible for the prompt emission from all GRBs is probably predominantly thermal.Comment: Submitted to Ap

Implementing a Business Process Management System Using ADEPT: A Real-World Case Study

This article describes how the agent-based design of ADEPT (advanced decision environment for processed tasks) and implementation philosophy was used to prototype a business process management system for a real-world application. The application illustrated is based on the British Telecom (BT) business process of providing a quote to a customer for installing a network to deliver a specified type of telecommunication service. Particular emphasis is placed upon the techniques developed for specifying services, allowing heterogeneous information models to interoperate, allowing rich and flexible interagent negotiation to occur, and on the issues related to interfacing agent-based systems and humans. This article builds upon the companion article (Applied Artificial Intelligence Vol.14, no 2, pgs. 145-189) that provides details of the rationale and design of the ADEPT technology deployed in this application

Very High Modulation Efficiency of Ultralow Threshold Current Single Quantum Well InGaAs Lasers

A record high current modulation efficiency of 5 GHz/[sqrt](mA) has been demonstrated in an ultralow threshold strained layer single quantum well InGaAs laser

Calculating energy derivatives for quantum chemistry on a quantum computer

Modeling chemical reactions and complicated molecular systems has been proposed as the `killer application' of a future quantum computer. Accurate calculations of derivatives of molecular eigenenergies are essential towards this end, allowing for geometry optimization, transition state searches, predictions of the response to an applied electric or magnetic field, and molecular dynamics simulations. In this work, we survey methods to calculate energy derivatives, and present two new methods: one based on quantum phase estimation, the other on a low-order response approximation. We calculate asymptotic error bounds and approximate computational scalings for the methods presented. Implementing these methods, we perform the world's first geometry optimization on an experimental quantum processor, estimating the equilibrium bond length of the dihydrogen molecule to within 0.014 Angstrom of the full configuration interaction value. Within the same experiment, we estimate the polarizability of the H2 molecule, finding agreement at the equilibrium bond length to within 0.06 a.u. (2% relative error).Comment: 19 pages, 1 page supplemental, 7 figures. v2 - tidied up and added example to appendice

Time-reversal and super-resolving phase measurements

We demonstrate phase super-resolution in the absence of entangled states. The key insight is to use the inherent time-reversal symmetry of quantum mechanics: our theory shows that it is possible to \emph{measure}, as opposed to prepare, entangled states. Our approach is robust, requiring only photons that exhibit classical interference: we experimentally demonstrate high-visibility phase super-resolution with three, four, and six photons using a standard laser and photon counters. Our six-photon experiment demonstrates the best phase super-resolution yet reported with high visibility and resolution.Comment: 4 pages, 3 figure

The Distance to Nova V959 Mon from VLA Imaging

Determining reliable distances to classical novae is a challenging but crucial step in deriving their ejected masses and explosion energetics. Here we combine radio expansion measurements from the Karl G. Jansky Very Large Array with velocities derived from optical spectra to estimate an expansion parallax for nova V959 Mon, the first nova discovered through its gamma-ray emission. We spatially resolve the nova at frequencies of 4.5-36.5 GHz in nine different imaging epochs. The first five epochs cover the expansion of the ejecta from 2012 October to 2013 January, while the final four epochs span 2014 February to 2014 May. These observations correspond to days 126 through 199 and days 615 through 703 after the first detection of the nova. The images clearly show a non-spherical ejecta geometry. Utilizing ejecta velocities derived from 3D modelling of optical spectroscopy, the radio expansion implies a distance between 0.9 +/- 0.2 and 2.2 +/- 0.4 kpc, with a most probable distance of 1.4 +/- 0.4 kpc. This distance implies a gamma-ray luminosity much less than the prototype gamma-ray-detected nova, V407 Cyg, possibly due to the lack of a red giant companion in the V959 Mon system. V959 Mon also has a much lower gamma-ray luminosity than other classical novae detected in gamma-rays to date, indicating a range of at least a factor of 10 in the gamma-ray luminosities for these explosions.Comment: 11 pages, 8 figures, 3 tables, submitted to ApJ 2015-01-21, under revie