29 research outputs found

    MIPAS detection of cloud and aerosol particle occurrence in the UTLS with comparison to HIRDLS and CALIOP

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    Satellite infrared emission instruments require efficient systems that can separate and flag observations which are affected by clouds and aerosols. This paper investigates the identification of cloud and aerosols from infrared, limb sounding spectra that were recorded by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), a high spectral resolution Fourier transform spectrometer on the European Space Agency's (ESA) ENVISAT (Now inoperative since April 2012 due to loss of contact). Specifically, the performance of an existing cloud and aerosol particle detection method is simulated with a radiative transfer model in order to establish, for the first time, confident detection limits for particle presence in the atmosphere from MIPAS data. The newly established thresholds improve confidence in the ability to detect particle injection events, plume transport in the upper troposphere and lower stratosphere (UTLS) and better characterise cloud distributions utilising MIPAS spectra. The method also provides a fast front-end detection system for the MIPClouds processor; a processor designed for the retrieval of macro- and microphysical cloud properties from the MIPAS data. <br><br> It is shown that across much of the stratosphere, the threshold for the standard cloud index in band A is 5.0 although threshold values of over 6.0 occur in restricted regimes. Polar regions show a surprising degree of uncertainty at altitudes above 20 km, potentially due to changing stratospheric trace gas concentrations in polar vortex conditions and poor signal-to-noise due to cold atmospheric temperatures. The optimised thresholds of this study can be used for much of the time, but time/composition-dependent thresholds are recommended for MIPAS data for the strongly perturbed polar stratosphere. In the UT, a threshold of 5.0 applies at 12 km and above but decreases rapidly at lower altitudes. The new thresholds are shown to allow much more sensitive detection of particle distributions in the UTLS, with extinction detection limits above 13 km often better than 10<sup>−4</sup> km<sup>−1</sup>, with values approaching 10<sup>−5</sup> km<sup>−1</sup> in some cases. <br><br> Comparisons of the new MIPAS results with cloud data from HIRDLS and CALIOP, outside of the poles, establish a good agreement in distributions (cloud and aerosol top heights and occurrence frequencies) with an offset between MIPAS and the other instruments of 0.5 km to 1 km between 12 km and 20 km, consistent with vertical oversampling of extended cloud layers within the MIPAS field of view. We conclude that infrared limb sounders provide a very consistent picture of particles in the UTLS, allowing detection limits which are consistent with the lidar observations. Investigations of MIPAS data for the Mount Kasatochi volcanic eruption on the Aleutian Islands and the Black Saturday fires in Australia are used to exemplify how useful MIPAS limb sounding data were for monitoring aerosol injections into the UTLS. It is shown that the new thresholds allowed such events to be much more effectively derived from MIPAS with detection limits for these case studies of 1 × 10<sup>−5</sup> km<sup>−1</sup> at a wavelength of 12 μm

    Educational supervision and the impact of workplace-based assessments: a survey of psychiatry trainees and their supervisors

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    <p>Abstract</p> <p>Background</p> <p>Educational supervision (ES) is considered to be an essential component of basic specialist training in psychiatry in the UK. However, previous studies have indicated variation in its provision, and uncertainty about structure and content. Workplace-based assessments (WPBAs) were introduced in 2007 as part of major postgraduate medical training reform. Placing considerable time demands on trainees and supervisors alike, the extent to which WPBAs should utilise ES time has not been specified. As ES and WPBAs have discrete (although complementary) functions, there is the potential for this increased emphasis on assessment to displace other educational needs.</p> <p>Methods</p> <p>All junior doctors and their educational supervisors in one UK psychiatry training scheme were surveyed both before and after the introduction of WPBAs. Frequency and duration of ES were established, and structure, content and process were ascertained. Opinions on usefulness and responsibility were sought. The usage of ES for WPBAs was also assessed.</p> <p>Results</p> <p>The response rate of 70% showed general agreement between trainees and supervisors, but some significant discrepancies. Around 60% reported 1 hour of ES taking place weekly or 3 times per month. Most agreed that responsibility for ES should be shared equally between trainees and supervisors, and ES was largely seen as useful. Around 50% of trainees and supervisors used 25–50% of ES time for WPBAs, and this did not appear to affect the usefulness of ES or the range of issues covered.</p> <p>Conclusion</p> <p>ES continues to be an important component of psychiatric training. However, using ES for WPBAs introduces the potential for tension between trainees' education and their assessment by emphasising certain training issues at the expense of others. The impact of reduced training time, WPBAs and uncertainties over ES structure and content should be monitored to ensure that its benefits are maximised by remaining tailored to individual trainees' needs.</p

    A measurement-based verification framework for UK greenhouse gas emissions: an overview of the Greenhouse gAs Uk and Global Emissions (GAUGE) project

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    We describe the motivation, design, and execution of the Greenhouse gAs Uk and Global Emissions (GAUGE) project. The overarching scientific objective of GAUGE was to use atmospheric data to estimate the magnitude, distribution, and uncertainty of the UK greenhouse gas (GHG, defined here as CO₂, CH₄, and N₂O) budget, 2013–2015. To address this objective, we established a multi-year and interlinked measurement and data analysis programme, building on an established tall-tower GHG measurement network. The calibrated measurement network comprises ground-based, airborne, ship-borne, balloon-borne, and space-borne GHG sensors. Our choice of measurement technologies and measurement locations reflects the heterogeneity of UK GHG sources, which range from small point sources such as landfills to large, diffuse sources such as agriculture. Atmospheric mole fraction data collected at the tall towers and on the ships provide information on sub-continental fluxes, representing the backbone to the GAUGE network. Additional spatial and temporal details of GHG fluxes over East Anglia were inferred from data collected by a regional network. Data collected during aircraft flights were used to study the transport of GHGs on local and regional scales. We purposely integrated new sensor and platform technologies into the GAUGE network, allowing us to lay the foundations of a strengthened UK capability to verify national GHG emissions beyond the project lifetime. For example, current satellites provide sparse and seasonally uneven sampling over the UK mainly because of its geographical size and cloud cover. This situation will improve with new and future satellite instruments, e.g. measurements of CH₄ from the TROPOspheric Monitoring Instrument (TROPOMI) aboard Sentinel-5P. We use global, nested, and regional atmospheric transport models and inverse methods to infer geographically resolved CO₂ and CH₄ fluxes. This multi-model approach allows us to study model spread in a posteriori flux estimates. These models are used to determine the relative importance of different measurements to infer the UK GHG budget. Attributing observed GHG variations to specific sources is a major challenge. Within a UK-wide spatial context we used two approaches: (1) Δ¹⁴CO₂ and other relevant isotopologues (e.g. δ¹³CCH₄) from collected air samples to quantify the contribution from fossil fuel combustion and other sources, and (2) geographical separation of individual sources, e.g. agriculture, using a high-density measurement network. Neither of these represents a definitive approach, but they will provide invaluable information about GHG source attribution when they are adopted as part of a more comprehensive, long-term national GHG measurement programme. We also conducted a number of case studies, including an instrumented landfill experiment that provided a test bed for new technologies and flux estimation methods. We anticipate that results from the GAUGE project will help inform other countries on how to use atmospheric data to quantify their nationally determined contributions to the Paris Agreement

    Prevalence of Neck Pain due to Prolonged Cycling in Young Adults: A Survey Study

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    Neck pain is a common complaint among non-professional cyclists. Poor posture, overuse, and injury are all factors that contribute to neck pain in cyclists. However, there are several ways to prevent and treat neck pain, including maintaining good posture, stretching, and physical therapy. By taking these steps, non-professional cyclists can continue to enjoy the benefits of cycling without experiencing neck pain.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

    Mental Health of Migrant Elders — The Islington Study

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    Background In the UK, 6% of those aged 65 years and over were born abroad, most of whom now live in inner-city areas. It has been suggested that ethnic elders are particularly vulnerable to mental illness. Aims To compare the prevalence of dementia and depression in older migrants with those born in the UK. Method A cross-sectional community study of 1085 people aged 65 years or older in an inner-London borough. Results Compared with those born in the UK, the prevalence of dementia was raised in African-Carib beans (17.3%, relative risk=1.72, CI=1.06-2.81) and lower for the Irish-born (3.6%, relative risk=0.36,CI=0.17-0.87). All those of African-Caribbean country of birth were significantly younger (P=0.000) but no more likely to be taking antihypertensive drugs. They were no more likely to report having cardiovascular problems but had increased rates of diabetes (P < 0.0000). The overall prevalence of depression was 18.3% (95% CI=16.1-20.7). The highest prevalence rate was found among those born in Greece and Turkey (27.2%, CI=17.9-39.6). Migration per se does not appear to be a risk for depression and dementia in this population. Conclusions The excess of dementia may be of vascular aetiology. There is the potential for primary or secondary prevention

    Accessibility of health and social services to immigrant elders: The Islington Study

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    Background Numbers of immigrant elders are increasing and it is unclear whether they can access services. Aims To examine service utilisation of older immigrants compared with their UK-born counterparts and relate it to health difficulties. Method Cross-sectional study in inner London measuring service use, mental health and disability. Results A total of 1085 people aged greater than or equal to65 years were interviewed. Independent predictors of contact with a general practitioner included being born in Cyprus, Cypriots were the only immigrant population to report significantly more somatic symptoms than those born in the UK (P=0.005). Africans and Caribbeans used day care and other social services most frequently. Conclusions Immigrants could access services. Africans and Caribbeans appear to have poorer physical health and thus have greater contact with services, Cypriots who experience depression may present with prominent somatic symptoms. This is likely to be due to a different idiom of distress
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