Models of OH Maser Variations in U Her

Arecibo spectra of the mainline OH maser emission from U Her over more than a decade show variations of the OH emission over these time scales. These observations are combined with high spatial resolution VLBA maps to investigate the causes of the variations in the velocities of the maser components. Global properties of the dust shell, such as accelerations, variations in the pump and shell-wide magnetic field changes are examined as possibilities, and eliminated. A possible solution to the problem involving plasma turbulence and the local magnetic field is introduced, and the relevant time scales of the turbulence are calculated. The turbulent velocity field yields time scales of the turbulence are calculated. The turbulent velocity field yields time scales that are too long (of order centuries), while the turbulent magnetic field produces variations on appropriate time scales of a few years. A line-of-sight model of the turbulence is developed and investigated. The complete exploration of this solution requires extensive theoretical and observational work. Possible avenues of investigation of the plasma turbulence model are presented.Comment: 23 pages, 17 figures, ApJ: accepted Sept, 199

Dust Grains and the Luminosity of Circumnuclear Water Masers in Active Galaxies

In previous calculations for the luminosities of 22 GHz water masers, the pumping is reduced and ultimately quenched with increasing depth into the gas because of trapping of the infrared (approximately equals 30-150 micrometers), spectral line radiation of the water molecule. When the absorption (and reemission) of infrared radiation by dust grains is included, we demonstrate that the pumping is no longer quenched but remains constant with increasing optical depth. A temperature difference between the grains and the gas is required. Such conditions are expected to occur, for example, in the circumnuclear masing environments created by X-rays in active galaxies. Here, the calculated 22 GHz maser luminosities are increased by more than an order of magnitude. Application to the well-studied, circumnuclear masing disk in the galaxy NGC 4258 yields a maser luminosity near that inferred from observations if the observed X-ray flux is assumed to be incident onto only the inner surface of the disk

Tunable dipolar magnetism in high-spin molecular clusters

We report on the Fe17 high-spin molecular cluster and show that this system is an exemplification of nanostructured dipolar magnetism. Each Fe17 molecule, with spin S=35/2 and axial anisotropy as small as D=-0.02K, is the magnetic unit that can be chemically arranged in different packing crystals whilst preserving both spin ground-state and anisotropy. For every configuration, molecular spins are correlated only by dipolar interactions. The ensuing interplay between dipolar energy and anisotropy gives rise to macroscopic behaviors ranging from superparamagnetism to long-range magnetic order at temperatures below 1K.Comment: Replaced with version accepted for publication in Physical Review Letter

Legal determinants of external finance revisited : the inverse relationship between investor protection and societal well-being

This paper investigates relationships between corporate governance traditions and quality of life as measured by a number of widely reported indicators. It provides an empirical analysis of indicators of societal health in developed economies using a classification based on legal traditions. Arguably the most widely cited work in the corporate governance literature has been the collection of papers by La Porta et al. which has shown, inter alia, statistically significant relationships between legal traditions and various proxies for investor protection. We show statistically significant relationships between legal traditions and various proxies for societal health. Our comparative evidence suggests that the interests of investors may not be congruent with the interests of wider society, and that the criteria for judging the effectiveness of approaches to corporate governance should not be restricted to financial metrics

Critical Error Frequency and the Impact of Training with Inhalers Commonly used for Maintenance Treatment in Chronic Obstructive Pulmonary Disease

Introduction: Training in correct inhaler use, ideally in person or by video demonstration, can minimize errors but is rarely provided in clinics. This open-label, low-intervention study evaluated critical error rates with dry-powder inhalers (DPIs), before and after training, in patients with chronic obstructive pulmonary disease. Methods: Patients prescribed an inhaled corticosteroid (ICS)/long-acting β2-agonist (LABA) (ELLIPTA, Turbuhaler, or DISKUS), long-acting muscarinic antagonist (LAMA)/LABA (ELLIPTA or Breezhaler), or LAMA-only DPI (ELLIPTA, HandiHaler, or Breezhaler) were enrolled. Critical errors were assessed before training (Visit 1 [V1]; primary endpoint) and 6 weeks thereafter (Visit 2 [V2]; secondary endpoint). Logistic regression models were used to calculate odds ratios (ORs) for between-group comparisons. Results: The intent-to-treat population comprised 450 patients. At V1, fewer patients made ≥ 1 critical error with ELLIPTA (10%) versus other ICS/LABA DPIs (Turbuhaler: 40%, OR 4.66, P=0.005; DISKUS: 26%, OR 2.48, P=0.114) and other LAMA or LAMA/LABA DPIs (HandiHaler: 34%, OR 3.50, P=0.026; Breezhaler: 33%, OR 3.94, P=0.012). Critical error rates with the primary ICS/LABA DPI were not significantly different between ELLIPTA ICS/LABA (10%) and ICS/LABA plus LAMA groups (12– 25%). Critical errors with the primary ICS/LABA DPI occurred less frequently with ELLIPTA ICS/LABA with or without LAMA (11%) versus Turbuhaler ICS/LABA with or without LAMA (39%, OR 3.99, P< 0.001) and DISKUS ICS/LABA with or without LAMA (26%, OR 2.18, P=0.069). Simulating single-inhaler versus multiple-inhaler triple therapy, critical error rates were lower with ELLIPTA fluticasone furoate/vilanterol (FF/VI; 10%) versus ELLIPTA FF/VI plus LAMA (22%), considering errors with either DPI (OR 2.50, P=0.108). At V2, critical error rates decreased for all DPIs/groups, reaching zero only for ELLIPTA. Between-group comparisons were similar to V1. Conclusion: Fewer patients made critical errors with ELLIPTA versus other ICS/LABA, and LAMA or LAMA/LABA DPIs. The effect of “verbal” training highlights its importance for reducing critical errors with common DPIs

Examining the Seyfert - Starburst Connection with Arcsecond Resolution Radio Continuum Observations

We compare the arcsecond-scale circumnuclear radio continuum properties between five Seyfert and five starburst galaxies, concentrating on the search for any structures that could imply a spatial or causal connection between the nuclear activity and a circumnuclear starburst ring. No evidence is found in the radio emission for a link between the triggering or feeding of nuclear activity and the properties of circumnuclear star formation. Conversely, there is no clear evidence of nuclear outflows or jets triggering activity in the circumnuclear rings of star formation. Interestingly, the difference in the angle between the apparent orientation of the most elongated radio emission and the orientation of the major axis of the galaxy is on average larger in Seyferts than in starburst galaxies, and Seyferts appear to have a larger physical size scale of the circumnuclear radio continuum emission. The concentration, asymmetry, and clumpiness parameters of radio continuum emission in Seyferts and starbursts are comparable, as are the radial profiles of radio continuum and near-infrared line emission. The circumnuclear star formation and supernova rates do not depend on the level of nuclear activity. The radio emission usually traces the near-infrared Br-gamma and H2 1-0 S(1) line emission on large spatial scales, but locally their distributions are different, most likely because of the effects of varying local magnetic fields and dust absorption and scattering.Comment: 21 pages, 10 figures. Accepted for publication in the Astronomical Journa

Modelling Conformational Flexibility in a Spectrally Addressable Molecular Multi-Qubit Model System

Dipolar coupled multi-spin systems have the potential to be used as molecular qubits. Herein we report the synthesis of a molecular multi-qubit model system with three individually addressable, weakly interacting, spin (Formula presented.) centres of differing g-values. We use pulsed Electron Paramagnetic Resonance (EPR) techniques to characterise and separately address the individual electron spin qubits; CuII, Cr7Ni ring and a nitroxide, to determine the strength of the inter-qubit dipolar interaction. Orientation selective Relaxation-Induced Dipolar Modulation Enhancement (os-RIDME) detecting across the CuII spectrum revealed a strongly correlated CuII-Cr7Ni ring relationship; detecting on the nitroxide resonance measured both the nitroxide and CuII or nitroxide and Cr7Ni ring correlations, with switchability of the interaction based on differing relaxation dynamics, indicating a handle for implementing EPR-based quantum information processing (QIP) algorithms

Increased SK3 expression in DM1 lens cells leads to impaired growth through a greater calcium-induced fragility

Although cataract is a characteristic feature of myotonic dystrophy type 1 (DM1), little is known of the underlying mechanisms. We generated four lens epithelial cell lines derived from DM1 cataracts and two from age-matched, non-DM cataracts. Small-pool PCR revealed typical large triplet repeat expansions in the DM1 cells. Furthermore, real-time PCR analysis showed reduced SIX5 expression and increased expression of the Ca2+-activated K+ channel SK3 in the DM1 cells. These cells also exhibited longer population doubling times which did not arise through reduced proliferation, but rather increased cell death as shown by increased release of lactate dehydrogenase (LDH). Using 86Rb+ as a tracer for K+, we found no difference in the resting K+ influx or efflux kinetics. In all cases, the ouabain sensitive component of the influx contributed ~50% of the total. However, stimulating internal Ca2+ by exposure to ionomycin not only caused greater stimulation of K+ (86Rb) efflux in the DM1 cells but also induced a higher rate of cell death (LDH assay). Since both the hyper-stimulation of K+ efflux and cell death were reduced by the highly specific SK inhibitor apamin, we suggest that increased expression of SK3 has a critical role in the increased Ca2+-induced fragility in DM1 cells. The present data, therefore, both help explain the lower epithelial cell density previously observed in DM1 cataracts and provide general insights into mechanisms underlying the fragility of other DM1-affected tissues

A radio study of the superwind galaxy NGC1482

We present multifrequency radio continuum as well as HI observations of the superwind galaxy NGC1482, with both the GMRT and the VLA. This galaxy has a remarkable hourglass-shaped optical emission line outflow as well as bi-polar soft X-ray bubbles on opposite sides of the galactic disk. The low-frequency, lower-resolution radio observations show a smooth structure. From the non-thermal emission, we estimate the available energy in supernovae, and examine whether this would be adequate to drive the observed superwind outflow. The high-frequency, high-resolution radio images of the central starburst region located at the base of the superwind bi-cone shows one prominent peak and more extended emission with substructure. This image has been compared with the infrared, optical red-continuum, H_alpha, and, soft and hard X-ray images from Chandra. The peak of infrared emission is the only feature which is coincident with the prominent radio peak, and possibly defines the centre of the galaxy. The HI observations with the GMRT show two blobs of emission on opposite sides of the central region. These are rotating about the centre of the galaxy and are located at ~2.4 kpc from it. In addition, these observations also reveal a multicomponent HI-absorption profile against the central region of the radio source, with a total width of ~250 km/s. The extreme blue- and red-shifted absorption components are at 1688 and 1942 km/s respectively, while the peak absorption is at 1836 km/s. This is consistent with the heliocentric systemic velocity of 1850+/-20 km/s, estimated from a variety of observations. We discuss possible implications of these results.Comment: 11 pages, 10 figures, 4 tables, accepted for publication in MNRA