3,269 research outputs found
The measurement of angular differential cross sections at the SSL Atomic Scattering Facility
The design of the SSL Atomic Scattering Facility (ASF) located at the NASA/Marshall Space Flight Center as well as some of the initial experiments to be performed with it, are covered. The goal is to develop an apparatus capable of measuring angular differential cross sections (ADCS) for the scattering of 2 to 14 eV atomic oxygen from various gaseous targets. At present little is known about atomic oxygen scattering with kinetic energies of a few eV. This apparatus is designed to increase the understanding of collisions in this energy region. Atomic oxygen scattering processes are of vital interest to NASA because the space shuttle as well as other low earth orbit satellites will be subjected to a flux of 5 eV atomic oxygen on the ram surfaces while in orbit. The primary experiments will involve the measurements of ADCS for atomic oxygen scattering from gaseous targets (in particular, molecular nitrogen). These, as well as the related initial experiments involving thermal He scattering from N2 and O2 targets will be described
Potential increasing dominance of heterotrophy in the global ocean
Autotrophy is largely resource-limited in the modern ocean. Paleo evidence indicates this was not necessarily the case in warmer climates, and modern observations as well as standard metabolic theory suggest continued ocean warming could shift global ecology towards heterotrophy, thereby reducing autotrophic nutrient limitation. Such a shift would entail strong nutrient recycling in the upper ocean and high rates of net primary production (NPP), yet low carbon export to the deep ocean and sediments. We demonstrate transition towards such a state in the early 22nd century as a response to business-as-usual representative concentration pathway forcing (RCP8.5) in an intermediate complexity Earth system model in three configurations; with and without an explicit calcifier phytoplankton class and calcite ballast model. In all models nutrient regeneration in the near-surface becomes an increasingly important driver of primary production. The near-linear relationship between changes in NPP and global sea surface temperature (SST) found over the 21st century becomes exponential above a 2â4 global mean SST change. This transition to a more heterotrophic ocean agrees roughly with metabolic theory
Reactive Scattering Cell For Atomic Hydrogen And Deuterium
A design for a high-temperature reactive scattering cell for atomic hydrogen and atomic deuterium is described. At approximately 2700 K a dissociation of the molecular target species of over 95% has been obtained. The lifetime of 340 h of operation is sufficient for precision, long-time, differential cross-section measurements
Integration of subclassification strategies in randomised controlled clinical trials evaluating manual therapy treatment and exercise therapy for non-specific chronic low back pain: a systematic review
Background There is lack of evidence for specific treatment interventions for patients with non-specific chronic low back pain (NSCLBP) despite the substantial amount of randomised controlled clinical trials evaluating treatment outcome for this disorder. Hypothesis It has been hypothesised that this vacuum of evidence is caused by the lack of subclassification of the heterogeneous population of patients with chronic low back pain for outcome research.Methods A systematic review with a meta-analysis was undertaken to determine the integration of subclassification strategies with matched interventions in randomised controlled clinical trials evaluating manual therapy treatment and exercise therapy for NSCLBP. A structured search for relevant studies in Embase, Cinahl, Medline, PEDro and the Cochrane Trials Register database, followed by hand searching all relevant studies in English up to December 2008. Results Only 5 of 68 studies (7.4%) subclassified patients beyond applying general inclusion and exclusion criteria. In the few studies where classification and matched interventions have been used, our meta-analysis showed a statistical difference in favour of the classification-based intervention for reductions in pain (p=0.004) and disability (p=0.0005), both for short-term and long-term reduction in pain (p=0.001). Effect sizes ranged from moderate (0.43) for short term to minimal (0.14) for long term. Conclusion A better integration of subclassification strategies in NSCLBP outcome research is needed. We propose the development of explicit recommendations for the use of subclassification strategies and evaluation of targeted interventions in future research evaluating NSCLBP
Developing sexual competence? Exploring strategies for the provision of effective sexualities and relationships education
School-based sexualities and relationships education (SRE) offers one of the most promising means of improving young people's sexual health through developing 'sexual competence'. In the absence of evidence on whether the term holds the same meanings for young people and adults (e.g. teachers, researchers, policy-makers), the paper explores 'adult' notions of sexual competence as construed in research data and alluded to in UK Government guidance on SRE, then draws on empirical research with young people on factors that affect the contexts, motivations and outcomes of sexual encounters, and therefore have implications for sexual competence. These data from young people also challenge more traditional approaches to sexualities education in highlighting disjunctions between the content of school-based input and their reported sexual experience. The paper concludes by considering the implications of these insights for developing a shared notion of what SRE is trying to achieve and suggestions for recognition in the content and approaches to SRE.</p
A large multi-ethnic genome-wide association study identifies novel genetic loci for intraocular pressure.
Elevated intraocular pressure (IOP) is a major risk factor for glaucoma, a leading cause of blindness. IOP heritability has been estimated to up to 67%, and to date only 11 IOP loci have been reported, accounting for 1.5% of IOP variability. Here, we conduct a genome-wide association study of IOP in 69,756 untreated individuals of European, Latino, Asian, and African ancestry. Multiple longitudinal IOP measurements were collected through electronic health records and, in total, 356,987 measurements were included. We identify 47 genome-wide significant IOP-associated loci (Pâ<â5âĂâ10-8); of the 40 novel loci, 14 replicate at Bonferroni significance in an external genome-wide association study analysis of 37,930 individuals of European and Asian descent. We further examine their effect on the risk of glaucoma within our discovery sample. Using longitudinal IOP measurements from electronic health records improves our power to identify new variants, which together explain 3.7% of IOP variation
Producing the docile body: analysing Local Area Under-performance Inspection (LAUI)
Sir Michael Wilshaw, the head of the Office for Standards in Education (OfSTED), declared a 'new wave' of Local Area Under-performance Inspections (LAUI) of schools 'denying children the standard of education they deserve'. This paper examines how the threat of LAUI played out over three mathematics lessons taught by a teacher in her first year in the profession. A Foucauldian approach is mobilised with regard to disciplinary power and 'docile bodies'. The paper argues that, in the case in point, LAUI was a tool mediating performative conditions and, ultimately, the docile body. The paper will be of concern to policy sociologists, teachers, school leaders, and those interested in school inspection
Under-representation of males in the early years: the challenges leaders face
This article investigates why there appears to be an under-representation of males in comparison to their female colleagues in the Early Years (EY) sector, and the perception of male teachers progressing more quickly to leadership positions when they do enter this context. Using case studies of final year male students on an Initial Teacher Training (ITT) undergraduate degree course at one university, we attempt to analyse data on male under-representation in Early Years against contemporary theories of identity, power and leadership. Questionnaires and interviews were conducted with the male sample group and male senior leaders in primary schools to gain an overview as to the leadership support they needed and provided. Our tentative findings suggested that male trainees are happy to work in an Early Years context and take leadership positions, but the challenge for leaders is that male trainees require strong leadership mentoring processes to help overcome perceived contextual barriers
Electron Capture at Very Small Scattering Angles from Atomic Hydrogen by 25-125-keV Protons
Differential cross sections for electron capture in collisions between protons and hydrogen atoms have been experimentally determined for incident proton energies of 25, 60, and 125 keV in the center-of-mass scattering-angle range of 0-3 mrad. The experimental results compare more favorably with the results of both a multistate and a two-state calculation than with the results of a continuum distorted-wave-approximation calculation. There is no evidence of a Jackson-Schiff-type minimum
The stigmatisation of people with chronic back pain
This study responded to the need for better theoretical understanding of experiences that shape the beliefs, attitudes and needs of chronic back patients attending pain clinics. The aim was explore and conceptualise the experiences of people of working age who seek help from pain clinics for chronic back pain. Methods. This was a qualitative study, based on an interpretative phenomenological approach (IPA). During in-depth interviews in their homes, participants were invited to 'tell their story' from the time their pain began. Participants were twelve male and six female patients, aged between 28 and 62 years, diagnosed as having chronic benign back pain. All had recently attended one of two pain clinics as new referrals. The interview transcripts were analysed thematically. Findings. Stigmatisation emerged as a key theme from the narrative accounts of participants. The findings expose subtle as well as overt stigmatising responses by family, friends, health professionals and the general public which appeared to have a profound effect on the perceptions, self esteem and behaviours of those interviewed. Conclusions. The findings suggest that patients with chronic back pain feel stigmatised by the time they attend pain clinics and this may affect their attitudes and behaviours towards those offering professional help. Theories of chronic pain need to accommodate these responses, while pain management programmes need to address the realities and practicalities of dealing with stigma in everyday life
- âŠ