The Spectral Energy Distribution of Powerful Starburst Galaxies I : Modelling the Radio Continuum

This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society. © 2018 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.We have acquired radio-continuum data between 70MHz and 48 GHz for a sample of 19 southern starburst galaxies at moderate redshifts (0.067 < z < 0.227) with the aim of separating synchrotron and free-free emission components. Using a Bayesian framework, we find the radio continuum is rarely characterized well by a single power law, instead often exhibiting lowfrequency turnovers below 500 MHz, steepening at mid to high frequencies, and a flattening at high frequencies where free-free emission begins to dominate over the synchrotron emission. These higher order curvature components may be attributed to free-free absorption across multiple regions of star formation with varying optical depths. The decomposed synchrotron and free-free emission components in our sample of galaxies form strong correlations with the total-infrared bolometric luminosities. Finally, we find that without accounting for free-free absorption with turnovers between 90 and 500MHz the radio continuum at low frequency (v < 200 MHz) could be overestimated by upwards of a factor of 12 if a simple power-law extrapolation is used from higher frequencies. The mean synchrotron spectral index of our sample is constrained to be α = -1.06, which is steeper than the canonical value of -0.8 for normal galaxies. We suggest this may be caused by an intrinsically steeper cosmic ray distribution.Peer reviewe

The Spectral Energy Distribution of Powerful Starburst Galaxies I: Modelling the Radio Continuum

We have acquired radio continuum data between 70\,MHz and 48\,GHz for a sample of 19 southern starburst galaxies at moderate redshifts ($0.067 < z < 0.227$) with the aim of separating synchrotron and free-free emission components. Using a Bayesian framework we find the radio continuum is rarely characterised well by a single power law, instead often exhibiting low frequency turnovers below 500\,MHz, steepening at mid-to-high frequencies, and a flattening at high frequencies where free-free emission begins to dominate over the synchrotron emission. These higher order curvature components may be attributed to free-free absorption across multiple regions of star formation with varying optical depths. The decomposed synchrotron and free-free emission components in our sample of galaxies form strong correlations with the total-infrared bolometric luminosities. Finally, we find that without accounting for free-free absorption with turnovers between 90 to 500\,MHz the radio-continuum at low frequency ($\nu < 200$\,MHz) could be overestimated by upwards of a factor of twelve if a simple power law extrapolation is used from higher frequencies. The mean synchrotron spectral index of our sample is constrained to be $\alpha=-1.06$, which is steeper then the canonical value of $-0.8$ for normal galaxies. We suggest this may be caused by an intrinsically steeper cosmic ray distribution

Appropriate disclosure of a diagnosis of dementia : identifying the key behaviours of 'best practice'

Background: Despite growing evidence that many people with dementia want to know their diagnosis, there is wide variation in attitudes of professionals towards disclosure. The disclosure of the diagnosis of dementia is increasingly recognised as being a process rather than a one-off behaviour. However, the different behaviours that contribute to this process have not been comprehensively defined. No intervention studies to improve diagnostic disclosure in dementia have been reported to date. As part of a larger study to develop an intervention to promote appropriate disclosure, we sought to identify important disclosure behaviours and explore whether supplementing a literature review with other methods would result in the identification of new behaviours. Methods: To identify a comprehensive list of behaviours in disclosure we conducted a literature review, interviewed people with dementia and informal carers, and used a consensus process involving health and social care professionals. Content analysis of the full list of behaviours was carried out. Results: Interviews were conducted with four people with dementia and six informal carers. Eight health and social care professionals took part in the consensus panel. From the interviews, consensus panel and literature review 220 behaviours were elicited, with 109 behaviours over-lapping. The interviews and consensus panel elicited 27 behaviours supplementary to the review. Those from the interviews appeared to be self-evident but highlighted deficiencies in current practice and from the panel focused largely on balancing the needs of people with dementia and family members. Behaviours were grouped into eight categories: preparing for disclosure; integrating family members; exploring the patient's perspective; disclosing the diagnosis; responding to patient reactions; focusing on quality of life and well-being; planning for the future; and communicating effectively. Conclusion: This exercise has highlighted the complexity of the process of disclosing a diagnosis of dementia in an appropriate manner. It confirms that many of the behaviours identified in the literature (often based on professional opinion rather than empirical evidence) also resonate with people with dementia and informal carers. The presence of contradictory behaviours emphasises the need to tailor the process of disclosure to individual patients and carers. Our combined methods may be relevant to other efforts to identify and define complex clinical practices for further study.This project is funded by UK Medical Research Council, Grant reference number G0300999

The MWA GLEAM 4Jy Sample; a new large, bright radio source sample at 151 MHz

C.A. Jackson, T.M.O. Franzen, N. Seymour, S.V. White, Tara Murphy, E.M. Sadler, J.R. Callingham, R.W. Hunstead, J. Hughes, J.V. Wall, M.E. Bell, K.S. Dwarakanath, B.Q. For, B.M. Gaensler, P.J. Hancock, L, Hindson, N. Hurley-Walker, M. Johnston-Hollitt, A.D. Kapinska, E. Lenc, B. McKinley, J. Morgan, A.R. Offringa, P. Procopio, L. Staveley-Smith, R.B. Wayth, C. Wu, Q. Zheng, ‘The MWA GLEAM 4Jy Sample; a new large, bright radio source sample at 151 MHz’, paper presented at The Many Facests of Extragalactiv Radio Surveys: Towards New Scientific Challenges, Bologna, Italy, 20-23 October, 2015.This paper outlines how the new GaLactic and Extragalactic All-sky MWA Survey (GLEAM, Wayth et al. 2015), observed by the Murchison Widefield Array covering the frequency range 72 - 231 MHz, allows identification of a new large, complete, sample of more than 2000 bright extragalactic radio sources selected at 151 MHz. With a flux density limit of 4 Jy this sample is significantly larger than the canonical fully-complete sample, 3CRR (Laing, Riley & Longair 1983). In analysing this small bright subset of the GLEAM survey we are also providing a first user check of the GLEAM catalogue ahead of its public release (Hurley-Walker et al. in prep). Whilst significant work remains to fully characterise our new bright source sample, in time it will provide important constraints to evolutionary behaviour, across a wide redshift and intrinsic radio power range, as well as being highly complementary to results from targeted, small area surveys.Non peer reviewe

Limits of noise and confusion in the MWA GLEAM year 1 survey

T.M.O. Franzen, C.A. Jackson, J.R. Callingham, R.D. Ekers, P.J. Hancock, N. Hurley-Walker, J. Morgan, N. Seymour, R.B. Wayth, S.V. White, M.E. Bell, K.S. Dwarakanath, B.Q. For, B.M. Gaensler, L. Hindson, M. Johnston-Hollitt, A.D. Kapinska, E. Lenc, B. McKinley, A.R. Offringa, P. Procopio, L. Staveley-Smith, C. Wu, Q. Zheng, ‘Limits of noise and confusion in the MWA GLEAM year 1 survey’, paper presented at the The Many Facests of Extragalactiv Radio Surveys: Towards New Scientific Challenges, Bologna, Italy, 20-23 October, 2015.The GaLactic and Extragalactic All-sky MWA survey (GLEAM) is a new relatively low resolution, contiguous 72-231 MHz survey of the entire sky south of declination +25 deg. In this paper, we outline one approach to determine the relative contribution of system noise, classical confusion and sidelobe confusion in GLEAM images. An understanding of the noise and confusion properties of GLEAM is essential if we are to fully exploit GLEAM data and improve the design of future low-frequency surveys. Our early results indicate that sidelobe confusion dominates over the entire frequency range, implying that enhancements in data processing have the potential to further reduce the noise.Non peer reviewedFinal Accepted Versio

Generating forms of media capital inside and outside a field: the strange case of David Cameron in the UK political field

As societies become more ‘mediated’ so the elevation of public figures is increasingly linked to their ability to generate a positive public profile through the mass media. Politicians, artists, film stars, authors and others each gain professional status, in part, based on how consumer-citizens actively respond to media representations of themselves. The linking of media to individual celebrity and symbolic power is now implicit in much writing. Individuals succeed because of their personal charisma (Weber, 1948) and an innate ability to present a media personality that directly engages with large publics (Ankersmit, 1997; Horton and Wohl, 1993; Pels, 2003; Street, 2003). Alternatively, one’s symbolic image is primarily manufactured by promotional professionals (Boorstin, 1962; Evans, 2005; Franklin, 2004; Hall Jamieson, 1996; Lilleker and LeesMarshment, 2006) and parts of themedia industry itself (Evans and Hesmondhalgh, 2005; Turner, 2004). However one’s public image develops, media exposure then bestows a ‘primary definer’ status on those placed in positions of power thus drawing additional media coverage (Bennett, 1990; Champagne, 2005; Hall et al., 1978, Herman and Chomsky, 2002)

Lumazine Synthase Protein Nanoparticle-Gd(III)-DOTA Conjugate as a T1 contrast agent for high-field MRI

With the applications of magnetic resonance imaging (MRI) at higher magnetic fields increasing, there is demand for MRI contrast agents with improved relaxivity at higher magnetic fields. Macromolecule-based contrast agents, such as protein-based ones, are known to yield significantly higher r(1) relaxivity at low fields, but tend to lose this merit when used as T-1 contrast agents (r(1)/r(2) = 0.5 similar to 1), with their r(1) decreasing and r(2) increasing as magnetic field strength increases. Here, we developed and characterized an in vivo applicable magnetic resonance (MR) positive contrast agent by conjugating Gd(III)-chelating agent complexes to lumazine synthase isolated from Aquifex aeolicus (AaLS). The r(1) relaxivity of Gd(III)-DOTA-AaLS-R108C was 16.49 mM(-1)s(-1) and its r(1)/r(2) ratio was 0.52 at the magnetic field strength of 7 T. The results of 3D MR angiography demonstrated the feasibility of vasculature imaging within 2 h of intravenous injection of the agent and a significant reduction in T-1 values were observed in the tumor region 7 h post-injection in the SCC-7 flank tumor model. Our findings suggest that Gd(III)-DOTA-AaLS-R108C could serve as a potential theranostic nanoplatform at high magnetic field strength.open0

Spintronics: Fundamentals and applications

Spintronics, or spin electronics, involves the study of active control and manipulation of spin degrees of freedom in solid-state systems. This article reviews the current status of this subject, including both recent advances and well-established results. The primary focus is on the basic physical principles underlying the generation of carrier spin polarization, spin dynamics, and spin-polarized transport in semiconductors and metals. Spin transport differs from charge transport in that spin is a nonconserved quantity in solids due to spin-orbit and hyperfine coupling. The authors discuss in detail spin decoherence mechanisms in metals and semiconductors. Various theories of spin injection and spin-polarized transport are applied to hybrid structures relevant to spin-based devices and fundamental studies of materials properties. Experimental work is reviewed with the emphasis on projected applications, in which external electric and magnetic fields and illumination by light will be used to control spin and charge dynamics to create new functionalities not feasible or ineffective with conventional electronics.Comment: invited review, 36 figures, 900+ references; minor stylistic changes from the published versio

D* Production in Deep Inelastic Scattering at HERA

This paper presents measurements of D^{*\pm} production in deep inelastic scattering from collisions between 27.5 GeV positrons and 820 GeV protons. The data have been taken with the ZEUS detector at HERA. The decay channel $D^{*+}\to (D^0 \to K^- \pi^+) \pi^+$ (+ c.c.) has been used in the study. The $e^+p$ cross section for inclusive D^{*\pm} production with $5<Q^2<100 GeV^2$ and $y<0.7$ is 5.3 \pms 1.0 \pms 0.8 nb in the kinematic region {$1.3<p_T(D^{*\pm})<9.0$ GeV and $| \eta(D^{*\pm}) |<1.5$}. Differential cross sections as functions of p_T(D^{*\pm}), $\eta(D^{*\pm}), W$ and $Q^2$ are compared with next-to-leading order QCD calculations based on the photon-gluon fusion production mechanism. After an extrapolation of the cross section to the full kinematic region in p_T(D^{*\pm}) and $\eta$(D^{*\pm}), the charm contribution $F_2^{c\bar{c}}(x,Q^2)$ to the proton structure function is determined for Bjorken $x$ between 2 $\cdot$ 10$^{-4}$ and 5 $\cdot$ 10$^{-3}$.Comment: 17 pages including 4 figure