200 research outputs found
Recognition versus Disclosure: An Investigation of the Impact on Equity Risk Using UK Operating Lease Disclosures
Get PDFThis study examines the equivalency of accounting recognition versus disclosure. OLS regression analysis is used to determine whether there is an association between equity risk and an adjustment to financial risk for off-balance sheet operating leases. Two methods of adjustment are considered: constructive capitalisation and a simple factor method. The observation of a reliably positive association suggests that UK investors/analysts view operating leases from a property rights perspective rather than an ownership perspective. This supports the argument for recognition of all lease rights and obligations 'on-balance sheet', as proposed in the recent G4+1 discussion paper ASB (1999)
The Market Value of UK Dividends From Shares With Differing Entitlements
No full textThis paper determines the market value of dividends in the UK during periods before and after 1997. Previous studies, which use the ex-dividend day method, tend to provide noisy and potentially biased measures of dividend value. We estimate the value of dividends from the prices of shares that are identical except for their dividend entitlements, and are traded concurrently (within the same hour). We argue that our estimates of dividend value are the cleanest yet available for the UK. Our evidence suggests that ex-dividend day estimates are biased downwards, but that this bias may be mitigated by the use of robust regression. Dividend values are heterogeneous and are not explained by the tax-clientele hypothesis. Copyright Blackwell Publishers Ltd, 2006.
Clinical decision aids and computed tomography coronary angiography in patients with suspected acute coronary syndrome
No full textBackground The HEART score, the T-MACS model and the GRACE score support early decision-making for acute chest pain, which could be complemented by CT coronary angiography (CTCA). However, their performance has not been directly compared. Methods In this secondary analysis of a multicentre randomised controlled trial of early CTCA in intermediate-risk patients with suspected acute coronary syndrome, C-statistics and performance metrics (using the predefined cut-offs) of clinical decision aids and CTCA, alone and then in combination, for the index hospital diagnosis of acute coronary syndrome and for 30-day coronary revascularisation were assessed in those who underwent CTCA and had complete data. Results Among 699 patients, 358 (51%) had an index hospital diagnosis of acute coronary syndrome, for which the C-statistic was higher for CTCA (0.80), followed by the T-MACS model (0.78), the HEART score (0.74) and the GRACE score (0.60). The negative predictive value was higher for the absence of coronary artery disease on CTCA (0.90) or a T-MACS estimate of <0.05 (0.83) than a HEART score of <4 (0.81) and a GRACE score of <109 (0.55). For 30-day coronary revascularisation, CTCA had the greatest C-statistic (0.80) with a negative predictive value of 0.96 and 0.92 in the absence of coronary artery disease and obstructive coronary artery disease, respectively. The combination of the T-MACS estimates and the CTCA findings was most discriminative for the index hospital diagnosis of acute coronary syndrome (C-statistic, 0.88) and predictive of 30-day coronary revascularisation (C-statistic, 0.85). No patients with a T-MACS estimate of <0.05 and normal coronary arteries had acute coronary syndrome during index hospitalisation or underwent coronary revascularisation within 30 days. Conclusions In intermediate-risk patients with suspected acute coronary syndrome, the T-MACS model combined with CTCA improved discrimination of the index hospital diagnosis of acute coronary syndrome and prediction of 30-day coronary revascularisation. Trial registration number NCT02284191.</p
Derivation and validation of a risk adjustment model for predicting seven day mortality in emergency medical admissions: mixed prospective and retrospective cohort study
Get PDFObjectives: To derive and validate a risk adjustment model for predicting seven day mortality in emergency medical admissions, to test the value of including physiology and blood parameters, and to explore the constancy of the risk associated with each model variable across a range of settings.
Design: Mixed prospective and retrospective cohort study.
Setting: Nine acute hospitals (n=3 derivation, n=9 validation) and associated ambulance services in England, Australia, and Hong Kong.
Participants: Adults with medical emergencies (n=5644 derivation, n=13 762 validation) who were alive and not in cardiac arrest when attended by an ambulance and either were admitted to hospital or died in the ambulance or emergency department.
Interventions: Data were either collected prospectively or retrospectively from routine sources and extraction from ambulance and emergency department records.
Main outcome measure: Mortality up to seven days after hospital admission.
Results: In the derivation phase, age, ICD-10 code, active malignancy, Glasgow coma score, respiratory rate, peripheral oxygen saturation, temperature, white cell count, and potassium and urea concentrations were independent predictors of seven day mortality. A model based on age and ICD-10 code alone had a C statistic of 0.80 (95% confidence interval 0.78 to 0.83), which increased to 0.81 (0.79 to 0.84) with the addition of active malignancy. This was markedly improved only when physiological variables (C statistic 0.87, 0.85 to 0.89), blood variables (0.87, 0.84 to 0.89), or both (0.90, 0.88 to 0.92) were added. In the validation phase, the models with physiology variables (physiology model) and all variables (full model) were tested in nine hospitals. Overall, the C statistics ranged across centres from 0.80 to 0.91 for the physiology model and from 0.83 to 0.93 for the full model. The rank order of hospitals based on adjusted mortality differed markedly from the rank order based on crude mortality. ICD-10 code, Glasgow coma score, respiratory rate, systolic blood pressure, oxygen saturation, haemoglobin concentration, white cell count, and potassium, urea, creatinine, and glucose concentrations all had statistically significant interactions with hospital.
Conclusion: A risk adjustment model for emergency medical admissions based on age, ICD-10 code, active malignancy, and routinely recorded physiological and blood variables can provide excellent discriminant value for seven day mortality across a range of settings. Using risk adjustment markedly changed hospitals’ rankings. However, evidence was found that the association between key model variables and mortality were not constant.published_or_final_versionThe DAVROS (Development And Validation of Risk-adjusted Outcomes for Systems of emergency care) Research Team includes the Project Management Group (Steve Goodacre, Richard Wilson, Neil Shephard, Jon Nicholl, Martina Santarelli, Jim Wardrope); the principal investigators (Alison Walker (Yorkshire Ambulance Service), Anne Spaight (East Midlands Ambulance Service), Julian Humphrey (Barnsley District General Hospital), Simon McCormick (Rotherham District General Hospital), Anne-Maree Kelly (Western Hospital, Footscray, Victoria), Tim Rainer (Chinese University of Hong Kong), Tim Coats (Leicester Royal Infirmary), Vikki Holloway (Northampton General Hospital), Will Townend (Hull Royal Infirmary), Steve Crane (York District General Hospital)); and the Steering Committee (Fiona Lecky, Mark Gilthorpe, Enid Hirst, Rosemary Harper)
Theoretical studies of the historical development of the accounting discipline: a review and evidence
Get PDFMany existing studies of the development of accounting thought have either been atheoretical or have adopted Kuhn's model of scientific growth. The limitations of this 35-year-old model are discussed. Four different general neo-Kuhnian models of scholarly knowledge development are reviewed and compared with reference to an analytical matrix. The models are found to be mutually consistent, with each focusing on a different aspect of development. A composite model is proposed. Based on a hand-crafted database, author co-citation analysis is used to map empirically the entire literature structure of the accounting discipline during two consecutive time periods, 1972–81 and 1982–90. The changing structure of the accounting literature is interpreted using the proposed composite model of scholarly knowledge development
Quadrupole moments of odd-A <sup>53−63</sup>Mn: Onset of collectivity towards N = 40
Get PDFThe spectroscopic quadrupole moments of the odd–even Mn isotopes between N=28N=28 and N=38N=38 have been measured using bunched-beam collinear laser spectroscopy at ISOLDE, CERN. In order to increase sensitivity to the quadrupole interaction, the measurements have been done using a transition in the ion rather than in the atom, with the additional advantage of better spectroscopic efficiency. Since the chosen transition is from a metastable state, optical pumping in ISOLDE's cooler and buncher (ISCOOL) was used to populate this state. The extracted quadrupole moments are compared to large-scale shell model predictions using three effective interactions, GXPF1A, LNPS and modified A3DA. The inclusion of both the 1νg9/2 and 2νd5/2 orbitals in the model space is shown to be necessary to reproduce the observed increase in the quadrupole deformation from N=36 onwards. Specifically, the inclusion of the 2νd5/2 orbital induces an increase in neutron and proton excitations across the reduced gaps at N=40 and Z=28, leading to an increase in deformation above N=36
The electron capture in Ho experiment – ECHo
Get PDFNeutrinos, and in particular their tiny but non-vanishing masses, can be considered one of the doors towards physics beyond the Standard Model. Precision measurements of the kinematics of weak interactions, in particular of theH β-decay and theHo electron capture (EC), represent the only model independent approach to determine the absolute scale of neutrino masses. The electron capture inHo experiment, ECHo, is designed to reach sub-eV sensitivity on the electron neutrino mass by means of the analysis of the calorimetrically measured electron capture spectrum of the nuclideHo. The maximum energy available for this decay, about 2.8 keV, constrains the type of detectors that can be used. Arrays of low temperature metallic magnetic calorimeters (MMCs) are being developed to measure theHo EC spectrum with energy resolution below 3 eV FWHM and with a time resolution below 1 μs. To achieve the sub-eV sensitivity on the electron neutrino mass, together with the detector optimization, the availability of large ultra-pureHo samples, the identification and suppression of background sources as well as the precise parametrization of theHo EC spectrum are of utmost importance. The high-energy resolutionHo spectra measured with the first MMC prototypes with ion-implantedHo set the basis for the ECHo experiment. We describe the conceptual design of ECHo and motivate the strategies we have adopted to carry on the present medium scale experiment, ECHo-1K. In this experiment, the use of 1 kBqHo will allow to reach a neutrino mass sensitivity below 10 eV/c. We then discuss how the results being achieved in ECHo-1k will guide the design of the next stage of the ECHo experiment, ECHo-1M, where a source of the order of 1 MBqHo embedded in large MMCs arrays will allow to reach sub-eV sensitivity on the electron neutrino mass
Target and Ion Source Development for Better Beams in the ARIEL Era
No full textAny ISOL facility pushing the boundaries of nuclear physics must be able to provide cutting-edge ion beams to its users - beams of isotopes far from stability, with few contaminants, that may be difficult to extract from an ISOL target. The development of these pure, exotic beams must be supported by continuing research and development on targets and ion sources. In the ARIEL era, new target/ion source geometries and operational modes will provide new opportunities which can only be exploited with time for development. To prioritize this, TRIUMF proposes to build a dedicated test stand for target and ion source research which will model the critical features of the new ARIEL target stations. This stand will provide a testing ground for methods of increasing efficiency and selectivity, such as investigations of new surface ion source [1, 2] and Forced Electron Beam Induced Arc Discharge (FEBIAD) ion source [3, 2] designs. In addition, this will provide a development environment for new beams, either from new target materials, or through techniques such as extracting molecular beams. In order to maximize the gain from these investigations in on-line operation, the ion optical properties of the final beam will be investigated concurrently
Material development towards a solid 100 kW electron-gamma converter for TRIUMF-ARIEL
No full textA series of irradiation tests have been performed at TRIUMF to investigate different material pairings to act as high-power electron-to-gamma converter for the ARIEL Electron Target East (AETE). The bulk of the converter body will be made out of an aluminum alloy with a sub-millimeter high-Z metal layer bonded to the surface facing the incoming electron beam. This contribution presents the approach chosen to select the optimal material for the high-Z layer, describes the tests performed and shows result which led to the successful selection of a specific tantalum-aluminum pairing as the future ARIEL converter material
- …
