Simulation of oscillopsia in virtual reality

Purpose: Nystagmus is characterised by involuntary eye movement. A proportion of those with nystagmus experience the world constantly in motion as their eyes move: a symptom known as oscillopsia. Individuals with oscillopsia can be incapacitated and often feel neglected due to limited treatment options. Effective communication of the condition is challenging and no tools to aid communication exist. This paper describes a virtual reality (VR) application that recreates the effects of oscillopsia, enabling others to appreciate the condition. Methods: Eye tracking data was incorporated into a VR oscillopsia simulator and released as a smartphone app – “Nystagmus Oscillopsia Sim VR”. When a smartphone is used in conjunction with a Google Cardboard headset, it presents an erratic image consistent with oscillopsia. The oscillopsia simulation was appraised by six participants for its representativeness. These individuals have nystagmus and had previously experienced oscillopsia but were not currently symptomatic; they were therefore uniquely placed to judge the app. The participants filled in a questionnaire to record impressions and the usefulness of the app. Results: The published app has been downloaded ~3700 times (28/02/2018) and received positive feedback from the nystagmus community. The validation study questionnaire scored the accuracy of the simulation an average of 7.8/10 while its ability to aid communication received 9.2/10. Conclusion: The evidence indicates that the simulation can effectively recreate the sensation of oscillopsia and facilitate effective communication of the symptoms associated with the condition. This has implications for communication of other visual conditions

Revisiting ENSO and IOD Contributions to Australian Precipitation

Tropical modes of variability, such as El Niño–Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD), exert a strong influence on the interannual variability of Australian precipitation. Nevertheless, commonly used indices of ENSO and IOD variability display significant co-variability that prevents a robust quantification of the independent contribution of each mode to precipitation anomalies. This co-variability issue is often addressed by statistically removing ENSO or IOD variability from the precipitation field before calculating teleconnection patterns. However, by performing a suite of coupled and uncoupled modeling experiments in which either ENSO or IOD variability is physically removed, we show that ENSO-only-driven precipitation patterns computed by statistically removing the IOD influence significantly underestimate the impact of ENSO on Australian precipitation variability. Inspired by this, we propose a conceptual model that allows one to effectively separate the contribution of each mode to Australian precipitation variability

A joint role for forced and internally-driven variability in the decadal modulation of global warming

Despite the observed monotonic increase in greenhouse-gas concentrations, global mean temperature displays important decadal fluctuations typically attributed to both external forcing and internal variability. Here, we provide a robust quantification of the relative contributions of anthropogenic, natural, and internally-driven decadal variability of global mean sea surface temperature (GMSST) by using a unique dataset consisting of 30-member large initial-condition ensembles with five Earth System Models (ESM-LE). We present evidence that a large fraction (~29–53%) of the simulated decadal-scale variance in individual timeseries of GMSST over 1950–2010 is externally forced and largely linked to the representation of volcanic aerosols. Comparison with the future (2010–2070) period suggests that external forcing provides a source of additional decadal-scale variability in the historical period. Given the unpredictable nature of future volcanic aerosol forcing, it is suggested that a large portion of decadal GMSST variability might not be predictable

Using scenarios to explore UK upland futures

Uplands around the world are facing significant social, economic and environmental changes, and decision-makers need to better understand what the future may hold if they are to adapt and maintain upland goods and services. This paper draws together all major research comprising eight studies that have used scenarios to describe possible futures for UK uplands. The paper evaluates which scenarios are perceived by stakeholders to be most likely and desirable, and assesses the benefits and drawbacks of the scenario methods used in UK uplands to date. Stakeholders agreed that the most desirable and likely scenario would be a continuation of hill farming (albeit at reduced levels) based on cross-compliance with environmental measures. The least desirable scenario is a withdrawal of government financial support for hill farming. Although this was deemed by stakeholders to be the least likely scenario, the loss of government support warrants close attention due to its potential implications for the local economy. Stakeholders noted that the environmental implications of this scenario are much less clear-cut. As such, there is an urgent need to understand the full implications of this scenario, so that upland stakeholders can adequately prepare, and policy-makers can better evaluate the likely implications of different policy options. The paper concludes that in future, upland scenario research needs to: (1) better integrate in-depth and representative participation from stakeholders during both scenario development and evaluation; and (2) make more effective use of visualisation techniques and simulation models

Methane dissociation on Pt(111): Searching for a specific reaction parameter density functional

Theoretical Chemistr

Chapter 12 - Long-term climate change: Projections, commitments and irreversibility

This chapter assesses long-term projections of climate change for the end of the 21st century and beyond, where the forced signal depends on the scenario and is typically larger than the internal variability of the climate system. Changes are expressed with respect to a baseline period of 1986-2005, unless otherwise stated

Lattice Dynamics and Thermal Equation of State of Platinum

Platinum is widely used as a pressure calibration standard. However, the established thermal EOS has uncertainties, especially in the high $P$-$T$ range. We use density functional theory to calculate the thermal equation of state of platinum, up to 550 GPa and 5000 K. The static lattice energy is computed by using the LAPW method, with LDA, PBE, and the recently proposed WC functional. The electronic thermal free energy is evaluated using the Mermin functional. The vibrational part is computed within the quasi-harmonic approximation using density functional perturbation theory and pseudopotentials. Special attention is paid to the influence of the electronic temperature to the phonon frequencies. We find that in overall LDA results agree best with the experiments. Based on the DFT calculations and the established experimental data, we develop a consistent thermal EOS of platinum as a reference for pressure calibration.Comment: 24pages, 13 giure

Microstructure development of BiFeO3-PbTiO3 films deposited by pulsed laser deposition on platinum substrates

BiFeO3-PbTiO3 films around the morphotropic phase boundary were deposited by pulsed laser deposition on polycrystalline Pt/TiOx/SiO2/Si substrates. X-ray analysis confirms that 0.6BiFeO3-0.4PbTiO3 films are (0 0 1) tetragonal preferentially orientated due to lattice matching with the underlying substrate. The misfit strain at the substrate-film interface is relieved by a ∼19% orientation transformation from (0 0 1) to (1 0 0) due to the lattice mismatch at the substrate-film interface and the difference in thermal expansion coefficients of the substrate and deposited film. 0.7BiFeO3-0. 3PbTiO3 films are mixed-phase rhombohedral-tetragonal with (0 0 1)/(1 1 1) preferential orientation due to the lattice match to the (1 1 1) and (1 0 0) of the underlying platinum as well as to being close to the morphotropic phase boundary. Inconsistent structural and electrical properties in reported BiFeO3-PbTiO3 films are explained in terms of film morphology and diffusion of bismuth into platinum. Films below ∼220 nm thickness produce short circuits due to a Volmer-Weber growth mechanism which results in physical defects within the films. Films above this critical thickness also produce variable electrical properties due to diffusion of bismuth into the underlying platinum electrode which has been confirmed by energy dispersive X-ray spectroscopy

Academic freedom in Europe: time for a Magna Charta?

This paper is a preliminary attempt to establish a working definition of academic freedom for the European Union states. The paper details why such a definition is required for the European Union and then examines some of the difficulties of defining academic freedom. By drawing upon experience of the legal difficulties beset by the concept in the USA and building on previous analyses of constitutional and legislative protection for academic freedom, and of legal regulations concerning institutional governance and academic tenure, a working definition of academic freedom is then derived. The resultant definition which, it is suggested, could form the basis for a European Magna Charta Libertatis Academicae, goes beyond traditional discussions of academic freedom by specifying not only the rights inherent in the concept but also its accompanying duties, necessary limitations and safeguards. The paper concludes with proposals for how the definition might be tested and carried forward

Trends in Austral jet position in ensembles of high- and low-top CMIP5 models

Trends in the position of the DJF Austral jet have been analysed for multi-model ensemble simulations of a subset of high- and low-top models for the periods 1960-2000, 2000-2050, and 2050-2098 under the CMIP5 historical, RCP4.5, and RCP8.5 scenarios. Comparison with ERA-Interim, CFSR and the NCEP/NCAR reanalysis shows that the DJF and annual mean jet positions in CMIP5 models are equatorward of reanalyses for the 1979-2006 mean. Under the RCP8.5 scenario, the mean jet position in the high-top models moves 3 degrees poleward of its 1860-1900 position by 2098, compared to just over 2 degrees for the low-top models. Changes in jet position are linked to changes in the meridional temperature gradient. Compared to low-top models, the high-top models predict greater warming in the tropical upper troposphere due to increased greenhouse gases for all periods considered: up to 0.28 K/decade more in the period 2050-2098 under the RCP8.5 scenario. Larger polar lower-stratospheric cooling is seen in high-top models: -1.64 K/decade compared to -1.40 K/decade in the period 1960-2000, mainly in response to ozone depletion, and -0.41 K/decade compared to -0.12 K/decade in the period 2050-2098, mainly in response to increases in greenhouse gases. Analysis suggests that there may be a linear relationship between the trend in jet position and meridional temperature gradient, even under strong forcing. There were no clear indications of an approach to a geometric limit on the absolute magnitude of the poleward shift by 2100