202 research outputs found

    The effect of a scanning flat fold mirror on a CMB B-mode experiment

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    We investigate the possibility of using a flat-fold beam steering mirror for a CMB B-mode experiment. An aluminium flat-fold mirror is found to add ∼\sim0.075% polarization, which varies in a scan synchronous way. Time-domain simulations of a realistic scanning pattern are performed, and the effect on the power-spectrum illustrated and a possible method of correction applied.Comment: 8 pages, 5 figures. Accepted for publication in Rev Sci Ins

    A Demonstration of Spectral and Spatial Interferometry at THz Frequencies

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    A laboratory prototype spectral/spatial interferometer has been constructed to demonstrate the feasibility of the double Fourier technique at Far Infrared (FIR) wavelengths (0.15 - 1 THz). It is planned to use this demonstrator to investigate and validate important design features and data processing methods for future astronomical FIR interferometer instruments. In building this prototype we have had to address several key technologies to provide an end-end system demonstration of this double Fourier interferometer. We report on the first results taken when viewing single slit and double slit sources at the focus of a large collimator used to simulate real sources at infinity. The performance of the prototype instrument for these specific field geometries is analyzed to compare with the observed interferometric fringes and to demonstrate image reconstruction capabilities.Comment: Accepted for publication in Applied Optic

    Confident, Credible but Lonely – Outcomes Following Postgraduate Interprofessional Education in Rehabilitation

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    Background: Interprofessional education aims to enhance health service delivery. This study examined whether health professionals changed their clinical practice after completing a postgraduate interprofessional qualification in rehabilitation. Methods & Findings: All graduates of postgraduate qualifications in rehabilitation at University of Otago were invited to complete a questionnaire. Thirteen participants were purposively selected for further in-depth interviews. Questionnaire data were summarized using descriptive statistics. Qualitative responses from questionnaires and interview transcripts were explored using thematic analysis. The survey response rate was 24% (77/315 students). Postgraduate study was reported to have had a positive impact on professional attitudes and commitment to learning (81%), to enhance interdisciplinary collaboration (79%), and to promote change in service delivery (40%). Themes identified from questionnaire responses were: 1) increased confidence, 2) enhanced credibility, and 3) widened view of rehabilitation. Analysis of the interviews identified three contrasting themes: 1) isolation hampers momentum, 2) managers and clinical leaders do not value postgraduate qualifications, 3) implementing change required postgraduate study plus persistence. Conclusions: Educators and employers of health professionals should be aware of the benefits of postgraduate interprofessional education for health professionals and healthcare delivery. Employers should recognize and value these benefits and support health professionals to apply new skills in their clinical practice

    Detection of a CMB decrement towards a cluster of mJy radiosources

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    We present the results of radio, optical and near-infrared observations of the field of TOC J0233.3+3021, a cluster of milliJansky radiosources from the TexOx Cluster survey. In an observation of this field with the Ryle Telescope (RT) at 15 GHz, we measure a decrement in the cosmic microwave background (CMB) of −675±95μ-675 \pm 95 \muJy on the RT's ≈\approx 0.65 kλ\lambda baseline. Using optical and infrared imaging with the McDonald 2.7-m Smith Reflector, Calar Alto 3.5-m telescope and UKIRT, we identify the host galaxies of five of the radiosources and measure magnitudes of R≈24R \approx 24, J≈20J \approx 20, K≈18K \approx 18. The CMB decrement is consistent with the Sunyaev-Zel'dovich (SZ) effect of a massive cluster of galaxies, which if modelled as a spherical King profile of core radius θC=20′′\theta_C = 20^{\prime\prime} has a central temperature decrement of 900μ900 \muK. The magnitudes and colours of the galaxies are consistent with those of old ellipticals at z∼1z \sim 1. We therefore conclude that TOC J0233.3+3021 is a massive, high redshift cluster. These observations add to the growing evidence for a significant population of massive clusters at high redshift, and demonstrate the effectiveness of combining searches for AGN `signposts' to clusters with the redshift-independence of the SZ effect.Comment: Six pages; accepted for publication in MNRAS. Version with full-resolution UV plot available from http://www.mrao.cam.ac.uk/~garret/MB185.p

    "The daily grunt": middle class bias and vested interests in the 'Getting in Early' and 'Why Can't They Read?' reports.

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    It is a long-standing and commonly held belief in the UK and elsewhere that the use of elite forms of language reflects superior intellect and education. Expert opinion from sociolinguistics, however, contends that such a view is the result of middle-class bias and cannot be scientifically justified. In the 1960s and 1970s,such luminaries as Labov (1969) and Trudgill (1975) were at pains to point out to educationalists, with some success, that this 'deficit 'view of working-class children's communicative competence is not a helpful one. However, a close reading of recent think-tank reports and policy papers on language and literacy teaching in schools reveals that the linguistic deficit hypothesis has resurfaced and is likely to influence present-day educational policy and practice. In this paper I examine in detail the findings, claims and recommendations of the reports and I argue that they are biased, poorly researched and reflect the vested interests of certain specialist groups, such as speech and language therapists and companies who sell literacy materials to schools. I further argue that we need to, once again, inject the debate with the social dimensions of educational failure, and we need to move away from the pathologisation of working-class children's language patterns

    Mapping of the SZ effect in the cluster Cl 0016+16 with the Ryle Telescope

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    We have mapped the high-redshift (z = 0.546) cluster Cl 0016+16 with the Ryle Telescope at 15 GHz. The Sunyaev-Zel'dovich decrement is clearly detected, and resolved. We combine our data with an X-ray image from ROSAT, and a gas temperature from ASCA to estimate the Hubble Constant H0 = 69 +21/-16 km/s/Mpc for an Omega_M=1.0 cosmology or H0 = 84 +25/-19 km/s/Mpc for Omega_M=0.3 and Omega_Lambda=0.7.Comment: 10 pages, 2 tables, 6 figures Submitted to MNRA

    Software systems for operation, control, and monitoring of the EBEX instrument

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    We present the hardware and software systems implementing autonomous operation, distributed real-time monitoring, and control for the EBEX instrument. EBEX is a NASA-funded balloon-borne microwave polarimeter designed for a 14 day Antarctic flight that circumnavigates the pole. To meet its science goals the EBEX instrument autonomously executes several tasks in parallel: it collects attitude data and maintains pointing control in order to adhere to an observing schedule; tunes and operates up to 1920 TES bolometers and 120 SQUID amplifiers controlled by as many as 30 embedded computers; coordinates and dispatches jobs across an onboard computer network to manage this detector readout system; logs over 3~GiB/hour of science and housekeeping data to an onboard disk storage array; responds to a variety of commands and exogenous events; and downlinks multiple heterogeneous data streams representing a selected subset of the total logged data. Most of the systems implementing these functions have been tested during a recent engineering flight of the payload, and have proven to meet the target requirements. The EBEX ground segment couples uplink and downlink hardware to a client-server software stack, enabling real-time monitoring and command responsibility to be distributed across the public internet or other standard computer networks. Using the emerging dirfile standard as a uniform intermediate data format, a variety of front end programs provide access to different components and views of the downlinked data products. This distributed architecture was demonstrated operating across multiple widely dispersed sites prior to and during the EBEX engineering flight.Comment: 11 pages, to appear in Proceedings of SPIE Astronomical Telescopes and Instrumentation 2010; adjusted metadata for arXiv submissio
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