16,635 research outputs found

    Signal-to-Noise Eigenmode Analysis of the Two-Year COBE Maps

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    To test a theory of cosmic microwave background fluctuations, it is natural to expand an anisotropy map in an uncorrelated basis of linear combinations of pixel amplitudes --- statistically-independent for both the noise and the signal. These S/NS/N-eigenmodes are indispensible for rapid Bayesian analyses of anisotropy experiments, applied here to the recently-released two-year COBE {\it dmr} maps and the {\it firs} map. A 2-parameter model with an overall band-power and a spectral tilt Ī½Ī”T\nu_{\Delta T} describes well inflation-based theories. The band-powers for {\it all} the {\it dmr} 53,90,3153,90,31 aa+bb GHz and {\it firs} 170 GHz maps agree, {(1.1Ā±0.1)Ɨ10āˆ’5}1/2\{(1.1\pm 0.1)\times 10^{-5}\}^{1/2}, and are largely independent of tilt and degree of (sharp) S/NS/N-filtering. Further, after optimal S/NS/N-filtering, the {\it dmr} maps reveal the same tilt-independent large scale features and correlation function. The unfiltered {\it dmr} 5353 aa+bb index Ī½Ī”T+1\nu_{\Delta T}+1 is 1.4Ā±0.41.4\pm 0.4; increasing the S/NS/N-filtering gives a broad region at (1.0--1.2)Ā±\pm0.5, a jump to (1.4--1.6)Ā±\pm0.5, then a drop to 0.8, the higher values clearly seen to be driven by S/NS/N-power spectrum data points that do not fit single-tilt models. These indices are nicely compatible with inflation values (āˆ¼\sim0.8--1.2), but not overwhelmingly so.Comment: submitted to Phys.Rev.Letters, 4 pages, uuencoded compressed PostScript; also bdmr2.ps.Z, via anonymous ftp to ftp.cita.utoronto.ca, cd to /pub/dick/yukawa; CITA-94-2

    Shuttle program: OFT ascent/descent ancillary data requirements document

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    Requirements are presented for the ascent/descent (A/D) navigation and attitude-dependent ancillary data products to be generated for the space shuttle orbiter in support of the orbital flight test (OFT) flight test requirements, MPAD guidance and navigation performance assessment, and the mission evaluation team. The A/D ancillary data support for OFT mission evaluation activities is confined to providing postflight position, velocity, attitude, and associated navigation and attitude derived parameters for the Orbiter over particular flight phases and time intervals

    Smoking and intention to quit in deprived areas of Glasgow: is it related to housing improvements and neighbourhood regeneration because of improved mental health?

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    Background: People living in areas of multiple deprivation are more likely to smoke and less likely to quit smoking. This study examines the effect on smoking and intention to quit smoking for those who have experienced housing improvements (HI) in deprived areas of Glasgow, UK, and investigates whether such effects can be explained by improved mental health. Methods: Quasi-experimental, 2-year longitudinal study, comparing residentsā€™ smoking and intention to quit smoking for HI group (n=545) with non-HI group (n=517), adjusting for baseline (2006) sociodemographic factors and smoking status. SF-12 mental health scores were used to assess mental health, along with self-reported experience of, and General Practitioner (GP) consultations for, anxiety and depression in the last 12 months. Results: There was no relationship between smoking and HI, adjusting for baseline rates (OR=0.97, 95% CI 0.57 to 1.67, p=0.918). We found an association between intention to quit and HI, which remained significant after adjusting for sociodemographics and previous intention to quit (OR 2.16, 95% CI 1.12 to 4.16, p=0.022). We found no consistent evidence that this association was attenuated by improvement in our three mental health measures. Conclusions: Providing residents in disadvantaged areas with better housing may prompt them to consider quitting smoking. However, few people actually quit, indicating that residential improvements or changes to the physical environment may not be sufficient drivers of personal behavioural change. It would make sense to link health services to housing regeneration projects to support changes in health behaviours at a time when environmental change appears to make behavioural change more likely
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