Road safety education for older drivers : evaluation of a classroom-based training initiative

Around the world, a growing proportion of drivers are aged 70 or over. Although accident rates for older drivers are lower than for young or novice drivers, increased frailty and slowed reactions mean that older drivers are at higher risk of death or serious injury when involved in a road collision. The objectives of this study were to: (a) identify driving knowledge and self-regulatory strategies among a group of older drivers with a view to planning future on-road training; (b) measure driver self-assessments of ability and confidence before and after classroom training delivered by driving instructors; (c) evaluate the utility and acceptability of training courses for older drivers using questionnaires and focus groups; d) examine the characteristics of course participants. 142 drivers aged ≥75 completed a two-hour classroom-based driving course and took part in the evaluation: 94 aged 75–79, 48 aged ≥80, 68% male. Main reasons for taking part were to update knowledge, improve driving and check they were safe to drive. Results showed that females were more likely than males to avoid driving in difficult conditions (at night, in bad weather, unfamiliar roads). More drivers aged 75–79 said they did not restrict their driving (52, 57%) compared to drivers aged ≥80 (19, 43%). Pre-course, males rated their driving confidence and ability significantly higher than females. Post-course, self-ratings of confidence and ability were unchanged for 76 (60%) drivers. However, two-thirds reported improved knowledge and 80% said they would change their driving behaviour as a result of the course. Focus group results suggest that competent drivers are more likely to attend educational courses than unsafe drivers. This study provides preliminary evidence that classroom-based training can initiate behaviour change among older drivers. Future research will examine the effectiveness of on-road training in this age group

Transfer of autocollimator calibration for use with scanning gantry profilometers for accurate determination of surface slope and curvature of state of the art x ray mirrors

X ray optics, desired for beamlines at free electron laser and diffraction limited storage ring x ray light sources, must have almost perfect surfaces, capable of delivering light to experiments without significant degradation of brightness and coherence. To accurately characterize such optics at an optical metrology lab, two basic types of surface slope profilometers are used the long trace profilers LTPs and nanometer optical measuring NOM like angular deflectometers, based on electronic autocollimator AC ELCOMAT 3000. The inherent systematic errors of the instrument s optical sensors set the principle limit to their measuring performance. Where autocollimator of a NOM like profiler may be calibrated at a unique dedicated facility, this is for a particular configuration of distance, aperture size, and angular range that does not always match the exact use in a scanning measurement with the profiler. Here we discuss the developed methodology, experimental set up, and numerical methods of transferring the calibration of one reference AC to the scanning AC of the Optical Surface Measuring System OSMS , recently brought to operation at the ALS Xray Optics Laboratory. We show that precision calibration of the OSMS performed in three steps, allows us to provide high confidence and accuracy low spatial frequency metrology and not print into measurements the inherent systematic error of tool in use. With the examples of the OSMS measurements with a state of the art x ray aspherical mirror, available from one of the most advanced vendors of X ray optics, we demonstrate the high efficacy of the developed calibration procedure. The results of our work are important for obtaining high reliability data, needed for sophisticated numerical simulations of beamline performance and optimization of beamline usage of the optics. This work was supported by the U. S. Department of Energy under contract number DE AC02 05CH1123

Homeless population

The aim was to derive and analyze a model for numbers of homeless and non-homeless people in a borough, in particular to see how these figures might be affected by different policies regarding housing various categories of people. Most attention was focused on steady populations although the stability of these and possible timescales of dynamic problems were also discussed. The main outcome of this brief study is the identification of the key role played by the constant k_1 - the constant which fixes the speed at which the homeless are rehoused in permanent council property. Reducing this constant, i.e. making the system "fairer" with less priority to accommodating homeless families, appears to have little effect on the sizes of other categories on the waiting list but there is a marked increase in the number of households in temporary accommodation. The model, indicated by the size of its longest time-scale, should be modified to allow for births etc. It could be varied by allowing people to remove themselves from the register or by allowing the rates at which registered and unregistered people become homeless to differ, but these modifications are unlikely to substantially change the main result. The inclusion of movement from the homeless to the general population would have the effect of limiting the numbers in temporary accommodation. However, it is thought this effect is very small so a great reduction in k_1 would be needed for this flow to become significant

It Must be Awful for Them: Perspective and Task Context Affects Ratings for Health Conditions

When survey respondents rate the quality of life (QoL) associated with a health condition, they must not only evaluate the health condition itself, but must also interpret the meaning of the rating scale in order to assign a specific value. The way that respondents approach this task depends on subjective interpretations, resulting in inconsistent results across populations and tasks. In particular, patients and non-patients often give very different ratings to health conditions, a discrepancy that raises questions about the objectivity of either groups\u27 evaluations. In this study, we found that the perspective of the raters (i.e., their own current health relative to the health conditions they rated) influences the way they distinguish between different health states that vary in severity. Consistent with prospect theory, a mild and a severe lung disease scenario were rated quite differently by lung disease patients whose own health falls between the two scenarios, whereas healthy non-patients, whose own health was better than both scenarios, rated the two scenarios as much more similar. In addition, we found that the context of the rating task influences the way participants distinguish between mild and severe scenarios. Both patients and non-patients gave less distinct ratings to the two scenarios when each were presented in isolation than when they were presented alongside other scenarios that provided contextual information about the possible range of severity for lung disease. These results raise continuing concerns about the reliability and validity of subjective QoL ratings, as these ratings are highly sensitive to differences between respondent groups and the particulars of the rating task

Community wealth building in an age of just transitions: exploring civil society approaches to net zero and future research synergies

Community Wealth Building (CWB) is a burgeoning international policy agenda for local economic development that seeks to enhance democratic ownership, retain the benefits of local economic activity and empower place-based economies and workers. Parallel to this, in the context of net zero transitions, there has been increasing interest in approaches to enhancing civil society and community ownership over local energy provision. However, in academic and practitioner debates, there has been very little interaction between these two strands of thinking and action on the need for radical change in current energy provision, particularly as part of a wider transformative change away from dominant neoliberal economic thinking, policies and structures. In this Perspective, we explore the various ways in which synergies exist between CWB and energy transitions by considering two civil society approaches to transitions; namely, the Thousand Flowers transition pathway and research in Grassroots Innovations. We examine how community energy could be strengthened through CWB, by showing how the ideas within these two approaches respond to the five core principles of CWB. Promising future directions for research and practice are identified, including linking up CWB and just transitions strategies, a renewed focus on local financial innovation and the growing role of anchor institutions in supporting net zero transitions, particularly where CWB supports economic democracy transformations in new net zero economies

Severe symptomatic aortic stenosis: medical therapy and transcatheter aortic valve implantation (TAVI)—a real-world retrospective cohort analysis of outcomes and cost-effectiveness using national data

Objectives: Determine the real-world difference between 2 groups of patients with severe aortic stenosis and similar baseline comorbidities: surgical turn down (STD) patients, who were managed medically prior to the availability of transcatheter aortic valve implantation (TAVI) following formal surgical outpatient assessment, and patients managed with a TAVI implant. Design: Retrospective cohort study from real-world data. Setting: Electronic patient letters were searched for patients with a diagnosis of severe aortic stenosis and a formal outpatient STD prior to the availability of TAVI (1999–2009). The second group comprised the first 90 cases of TAVI in South Wales (2009 onwards). 2 years prior to and 5 years following TAVI/STD were assessed. Patient data were pseudoanonymised, using the Secure Anonymized Information Linkage (SAIL) databank, and extracted from Office National Statistics (ONS), PatientEpisode Database for Wales (PEDW) and general practitioner databases. Population: 90 patients who had undergone TAVI in South Wales, and 65 STD patients who were medically managed. Main outcome measures: Survival, hospital admission frequency and length of stay, primary care visits, and cost-effectiveness. Results: TAVI patients were significantly older (81.8 vs 79.2), more likely to be male (59.1% vs 49.3%), baseline comorbidities were balanced. Mortality in TAVI versus STD was 28% vs 70% at 1000 days follow-up. There were significantly more hospital admissions per year in the TAVI group prior to TAVI/STD (1.5 (IQR 1.0– 2.4) vs 1.0 IQR (0.5–1.5)). Post TAVI/STD, the TAVI group had significantly lower hospital admissions (0.3 (IQR 0.0–1.0) vs 1.2 (IQR 0.7–3.0)) and lengths of stay (0.4 (IQR 0.0–13.8) vs 11.0 (IQR 2.5–28.5), p<0.05). The incremental cost-effectiveness ratio (ICER) for TAVI was £10 533 per quality-adjusted life year (QALY). Conclusions: TAVI patients were more likely to survive and avoid hospital admissions compared with the medically managed STD group. The ICER for TAVI was £10 533 per QALY, making it a cost-effective procedure

A physical interpretation of the jet-like X-ray emission from supernova remnant W49B

In the framework of the study of supernova remnants and their complex interaction with the interstellar medium and the circumstellar material, we focus on the galactic supernova remnant W49B. Its morphology exhibits an X-ray bright elongated nebula, terminated on its eastern end by a sharp perpendicular structure aligned with the radio shell. The X-ray spectrum of W49B is characterized by strong K emission lines from Si, S, Ar, Ca, and Fe. There is a variation of the temperature in the remnant with the highest temperature found in the eastern side and the lowest one in the western side. The analysis of the recent observations of W49B indicates that the remnant may be the result of an asymmetric bipolar explosion where the ejecta are collimated along a jet-like structure and the eastern jet is hotter and more Fe-rich than the western one. Another possible scenario associates the X-ray emission with a spherical explosion where parts of the ejecta are interacting with a dense belt of ambient material. To overcome this ambiguity we present new results of the analysis of an XMM-Newton observation and we perform estimates of the mass and energy of the remnant. We conclude that the scenario of an anisotropic jet-like explosion explains quite naturally our observation results, but the association of W49B with a hypernova and a gamma-ray burst, although still possible, is not directly supported by any evidence.Comment: 7 pages, 5 figures, accepted for publication in Advances in Space Researc

Imprints of dark energy on cosmic structure formation: II) Non-Universality of the halo mass function

The universality of the halo mass function is investigated in the context of dark energy cosmologies. This widely used approximation assumes that the mass function can be expressed as a function of the matter density omega_m and the rms linear density fluctuation sigma only, with no explicit dependence on the properties of dark energy or redshift. In order to test this hypothesis we run a series of 15 high-resolution N-body simulations for different cosmological models. These consists of three LCDM cosmologies best fitting WMAP-1, 3 and 5 years data, and three toy-models characterized by a Ratra-Peebles quintessence potential with different slopes and amounts of dark energy density. These toy models have very different evolutionary histories at the background and linear level, but share the same sigma8 value. For each of these models we measure the mass function from catalogues of halos identified in the simulations using the Friend-of-Friend (FoF) algorithm. We find redshift dependent deviations from a universal behaviour, well above numerical uncertainties and of non-stochastic origin, which are correlated with the linear growth factor of the investigated cosmologies. Using the spherical collapse as guidance, we show that such deviations are caused by the cosmology dependence of the non-linear collapse and virialization process. For practical applications, we provide a fitting formula of the mass function accurate to 5 percents over the all range of investigated cosmologies. We also derive an empirical relation between the FoF linking parameter and the virial overdensity which can account for most of the deviations from an exact universal behavior. Overall these results suggest that the halo mass function contains unique cosmological information since it carries a fossil record of the past cosmic evolution.Comment: 21 pages, 19 figures, 5 tables, published in MNRAS. Paper I: arXiv:0903.549

Through Thick and Thin: Kinematic and Chemical Components in the Solar Neighbourhood

We search for the existence of chemically-distinct stellar components in the solar neighbourhood using published data. Extending earlier work, we show that when the abundances of Fe, alpha elements, and the r-process element Eu are considered, stars separate neatly into two groups that delineate the traditional thin and thick disk of the Milky Way. The group akin to the thin disk is traced by stars with [Fe/H]>-0.7 and alpha/Fe<0.2. The thick disk-like group overlaps the thin disk in [Fe/H] but has higher abundances of alpha elements and Eu. Stars in the range -1.5<[Fe/H]<-0.7 with low [alpha/Fe] ratios, however, seem to belong to a separate, dynamically-cold, non-rotating component that we associate with tidal debris. The kinematically-hot stellar halo dominates the sample for [Fe/H]<-1.5. These results suggest that it may be possible to define the main dynamical components of the solar neighbourhood using only their chemistry, an approach with a number of interesting consequences. The kinematics of thin disk stars is then independent of metallicity: their average rotation speed remains roughly constant in the range -0.7<[Fe/H]<+0.4, a result that argues against radial migration having played a substantial role in the evolution of the thin disk. The velocity dispersion of stars assigned to the thin disk is also independent of [Fe/H], implying that the familiar increase in velocity dispersion with decreasing metallicity is the result of the increased prevalence of the thick disk at lower metallicities, rather than of the sustained operation of a dynamical heating mechanism. The substantial overlap in [Fe/H] and, probably, stellar age, of the various components might affect other reported trends in the properties of stars in the solar neighbourhood.Comment: 8 pages, 5 figures, some clarifications after referee report. Conclusions unchange

A multi-wavelength study of Supernova Remnants in six nearby galaxies. I: Detection of new X-ray selected Supernova Remnants with Chandra

We present results from a study of the Supernova Remnant (SNR) population in a sample of six nearby galaxies (NGC 2403, NGC 3077, NGC 4214, NGC 4449, NGC 4395 and NGC 5204) based on Chandra archival data. We have detected 244 discrete X-ray sources down to a limiting flux of 10^{-15} erg/s. We identify 37 X-ray selected thermal SNRs based on their X-ray colors or spectra, 30 of which are new discoveries. In many cases the X-ray classification is confirmed based on counterparts with SNRs identified in other wavelengths. Three of the galaxies in our sample (NGC 4214, NGC 4395 and NGC 5204) are studied for the first time, resulting in the discovery of 13 thermal SNRs. We discuss the properties (luminosity, temperature, density) of the X-ray detected SNRs in the galaxies of our sample in order to address their dependence on their environment. We find that X-ray selected SNRs in irregular galaxies appear to be more luminous than those in spirals. We attribute this to the lower metalicities and therefore more massive progenitor stars of irregular galaxies or the higher local densities of the ISM. We also discuss the X-ray selected SNR populations in the context of the Star Formation Rate of their host galaxies. A comparison of the numbers of observed luminous X-ray selected SNRs with those expected based on the luminosity functions of X-ray SNRs in the MCs and M33 suggest different luminosity distributions between the SNRs in spiral and irregular galaxies with the latter tending to have flatter distributions.Comment: 56 pages, 14 figures, 26 tables. Accepted for publication in Ap