CO2 laser waveguiding in proton implanted GaAs

Surface layers capable of supporting optical modes at 10.6 microns have been produced in n-type GaAs wafers through 300 keV proton implantation. The dominant mechanism for this effect appears to be free carrier compensation. Characterization of the implanted layers by analysis of infrared reflectivity spectra and synchronous coupling at 10.6 microns produced results in good agreement with elementary models. These results of sample characterization by infrared reflectivity and by CO2 laser waveguiding as implanted are presented and evaluated

An exploration of social and economic outcome and associated health-related quality of life after critical illness in general intensive care unit survivors: a 12-month follow-up study.

INTRODUCTION: The socio-economic impact of critical illnesses on patients and their families in Europe has yet to be determined. The aim of this exploratory study was to estimate changes in family circumstances, social and economic stability, care requirements and access to health services for patients during their first 12 months after ICU discharge. METHODS: Multi-center questionnaire-based study of survivors of critical illness at 6 and 12 months after ICU discharge. RESULTS: Data for 293 consenting patients who spent greater than 48 hours in one of 22 UK ICUs were obtained at 6 and 12 months post-ICU discharge. There was little evidence of a change in accommodation or relationship status between pre-admission and 12 months following discharge from an ICU. A negative impact on family income was reported by 33% of all patients at 6 months and 28% at 12 months. There was nearly a 50% reduction in the number of patients who reported employment as their sole source of income at 12 months (19% to 11%) compared with pre-admission. One quarter of patients reported themselves in need of care assistance at 6 months and 22% at 12 months. The majority of care was provided by family members (80% and 78%, respectively), for half of whom there was a negative impact on employment. Amongst all patients receiving care, 26% reported requiring greater than 50 hours a week. Following discharge, 79% of patients reported attending their primary care physician and 44% had seen a community nurse. Mobility problems nearly doubled between pre-admission and 6 months (32% to 64%). Furthermore, 73% reported moderate or severe pain at 12 months and 44% remained significantly anxious or depressed. CONCLUSIONS: Survivors of critical illness in the UK face a negative impact on employment and commonly have a care requirement after discharge from hospital. This has a corresponding negative impact on family income. The majority of the care required is provided by family members. This effect was apparent by 6 months and had not materially improved by 12 months. This exploratory study has identified the potential for a significant socio-economic burden following critical illness

'HeART of Stroke (HoS)', a community-based Arts for Health group intervention to support self-confidence and psychological well-being following a stroke: protocol for a randomised controlled feasibility study

Introduction Over 152 000 people in the UK have strokes annually and a third experience residual disability. Low mood also affects a third of stroke survivors; yet psychological support is poor. While Arts for Health interventions have been shown to improve well-being in people with mild-to-moderate depression post-stroke, their role in helping people regain sense of self, well-being and confidence has yet to be evaluated. The main aim of this study is to explore the feasibility of conducting a pragmatic multicentre randomised controlled trial to assess the effectiveness and cost-effectiveness of an Arts for Health group intervention (‘HeART of Stroke’ (HoS)) for stroke survivors. HoS is a 10-session artist-facilitated group intervention held in the community over 14 weeks. It offers a non-judgemental, supportive environment for people to explore sense of self, potentially enhancing well-being and confidence. Methods and analysis Sixty-four people, up to 2 years post-stroke, recruited via secondary care research staff or community stroke/rehabilitation teams in two UK centres will be randomised to either HoS plus usual care or usual care only. Self-reported outcomes, measured at baseline and approximately 5 months postrandomisation, will include stroke-related, well-being, mood, self-esteem, quality of life and process measures. Analyses will focus on estimating key feasibility parameters (eg, rates of recruitment, retention, intervention attendance). We will develop outcome and resource use data collection methods to inform an effectiveness and cost-effectiveness analysis in the future trial. Interviews, with a sample of participants, will explore the acceptability of the intervention and study processes, as well as experiences of the HoS group. Ethics and dissemination National Health Service (NHS), Research and Development and University ethical approvals have been obtained. Two peer-reviewed journal publications are planned plus one service user led publication. Findings will be disseminated at key national conferences, local stakeholder events and via institutional websites.This paper presents independent research funded by the National Institute for Health Research (NIHR) under its Research for Patient Benefit (RfPB) Programme (Grant Reference Number PB-PG-0212-27054)

NMR shim coil design utilising a rapid spherical harmonic calculation method

A rapid spherical harmonic calculation method is used for the design of Nuclear Magnetic Resonance shim coils. The aim is to design each shim such that it generates a field described purely by a single spherical harmonic. By applying simulated annealing techniques, coil arrangements are produced through the optimal positioning of current-carrying circular arc conductors of rectangular cross-section. This involves minimizing the undesirable harmonies in relation to a target harmonic. The design method is flexible enough to be applied for the production of coil arrangements that generate fields consisting significantly of either zonal or tesseral harmonics. Results are presented for several coil designs which generate tesseral harmonics of degree one

Large eddy simulation of plume dispersion behind an aircraft in the take-off phase

The aim of this paper is to provide an investigation, using large eddy simulation, into plume dispersion behind an aircraft in co-flowing take-off conditions. Validation studies of the computational model were presented by Aloysius and Wrobel (Environ Model Softw 24:929–937, 2009) and a study of the flow and dispersion properties of a double-engine aircraft jetwas presented by Aloysius et al. EEC/SEE/2007/001,EUROCONTROLExperimentalCentre, http://www.eurocontrol.int/eec/gallery/content/public/document/eec/report/2007/ 032_ALAQS_comparison_of_CFD_and_Lagrangian_dispersion_methods.pdf), in which only the engine was modelled. In this paper, the complete geometry of a Boeing 737 is modelled and investigated. The currentwork represents a contribution towards a better understanding of the source dynamics behind an airplane jet engine during the take-off and landing phases. The information provided from these simulations will be useful for future improvements of existing dispersion models

Anarchic hand with abnormal agency following right inferior parietal lobe damage: a case report

Anarchic hand syndrome (AHS) is characterized by goal-directed movements performed without volitional control (agency). Different AHS subtypes have been identified; however, few studies have examined the posterior subtype. We report a case of AHS following right-hemisphere parietal damage, with left-sided somatosensory and proprioceptive impairment. Agency was examined for nonanarchic (volitional) movements performed using the anarchic hand. The patient experienced abnormal agency for movements whether motor intention and visual feedback were congruent or incongruent, but not when intention was absent (passive movement). Findings suggest a general disturbance of veridical motor awareness and agency in this case of parietal AHS

The use of the SF-36 questionnaire in adult survivors of childhood cancer: evaluation of data quality, score reliability, and scaling assumptions

BACKGROUND: The SF-36 has been used in a number of previous studies that have investigated the health status of childhood cancer survivors, but it never has been evaluated regarding data quality, scaling assumptions, and reliability in this population. As health status among childhood cancer survivors is being increasingly investigated, it is important that the measurement instruments are reliable, validated and appropriate for use in this population. The aim of this paper was to determine whether the SF-36 questionnaire is a valid and reliable instrument in assessing self-perceived health status of adult survivors of childhood cancer. METHODS: We examined the SF-36 to see how it performed with respect to (1) data completeness, (2) distribution of the scale scores, (3) item-internal consistency, (4) item-discriminant validity, (5) internal consistency, and (6) scaling assumptions. For this investigation we used SF-36 data from a population-based study of 10,189 adult survivors of childhood cancer. RESULTS: Overall, missing values ranged per item from 0.5 to 2.9 percent. Ceiling effects were found to be highest in the role limitation-physical (76.7%) and role limitation-emotional (76.5%) scales. All correlations between items and their hypothesised scales exceeded the suggested standard of 0.40 for satisfactory item-consistency. Across all scales, the Cronbach's alpha coefficient of reliability was found to be higher than the suggested value of 0.70. Consistent across all cancer groups, the physical health related scale scores correlated strongly with the Physical Component Summary (PCS) scale scores and weakly with the Mental Component Summary (MCS) scale scores. Also, the mental health and role limitation-emotional scales correlated strongly with the MCS scale score and weakly with the PCS scale score. Moderate to strong correlations with both summary scores were found for the general health perception, energy/vitality, and social functioning scales. CONCLUSION: The findings presented in this paper provide support for the validity and reliability of the SF-36 when used in long-term survivors of childhood cancer. These findings should encourage other researchers and health care practitioners to use the SF-36 when assessing health status in this population, although it should be recognised that ceiling effects can occur

Monitoring of Biodiesel Transesterification Process Using Impedance Measurement

Transesterification is commonly used to produce biodiesel from methylester. In order to control the conversion process it is often useful to employ process monitoring and in particular monitor the mass transfer processes that limit the initial reaction rates. Such monitoring of the initial phase of reaction may provide opportunity for process optimization. Previous work has identified many methods to monitor reaction progress. This paper proposes the use of a simple method which is able to provide information regarding the progress of mass transfer and chemical reaction during biodiesel production. The process uses impedance measurement. The experimentally determined impedance results clearly show the two important phases of the transesterification reaction, a mass transfer control phase followed by a kinetically controlled phase

On the zero-temperature limit of Gibbs states

We exhibit Lipschitz (and hence H\"older) potentials on the full shift $\{0,1\}^{\mathbb{N}}$ such that the associated Gibbs measures fail to converge as the temperature goes to zero. Thus there are "exponentially decaying" interactions on the configuration space $\{0,1\}^{\mathbb Z}$ for which the zero-temperature limit of the associated Gibbs measures does not exist. In higher dimension, namely on the configuration space $\{0,1\}^{\mathbb{Z}^{d}}$, $d\geq3$, we show that this non-convergence behavior can occur for finite-range interactions, that is, for locally constant potentials.Comment: The statement of Theorem 1.2 is more accurate and some new comment follow i