41 research outputs found

    Competition between Pressure and Gravity Confinement in Lyman-Alpha Forest Observations

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    A break in the distribution function of Lyα\alpha clouds (at a typical redshift of 2.52.5) has been reported by Petitjean et al. (1993). This feature is what would be expected from a transition between pressure confinement and gravity confinement (as predicted in Charlton, Salpeter, and Hogan (1993)). The column density at which the feature occurs has been used to determine the external confining pressure, 10cm3K\sim 10 {\rm cm}^{-3} {\rm K}, which could be due to a hot, intergalactic medium. For models that provide a good fit to the data, the contribution of the gas in clouds to Ω\Omega is small. The specific shape of the distribution function at the transition (predicted by models to have a non-monotonic slope) can serve as a diagnostic of the distribution of dark matter around Lyα\alpha forest clouds, and the present data already eliminate certain models.Comment: 10 pages plain TeX, 2 figures available upon request, submitted to ApJ Letters, PSU-jc-

    The Lung Screen Uptake Trial (LSUT): protocol for a randomised controlled demonstration lung cancer screening pilot testing a targeted invitation strategy for high risk and ‘hard-to-reach’ patients

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    Background Participation in low-dose CT (LDCT) lung cancer screening offered in the trial context has been poor, especially among smokers from socioeconomically deprived backgrounds; a group for whom the risk-benefit ratio is improved due to their high risk of lung cancer. Attracting high risk participants is essential to the success and equity of any future screening programme. This study will investigate whether the observed low and biased uptake of screening can be improved using a targeted invitation strategy. Methods/design A randomised controlled trial design will be used to test whether targeted invitation materials are effective at improving engagement with an offer of lung cancer screening for high risk candidates. Two thousand patients aged 60–75 and recorded as a smoker within the last five years by their GP, will be identified from primary care records and individually randomised to receive either intervention invitation materials (which take a targeted, stepped and low burden approach to information provision prior to the appointment) or control invitation materials. The primary outcome is uptake of a nurse-led ‘lung health check’ hospital appointment, during which patients will be offered a spirometry test, an exhaled carbon monoxide (CO) reading, and an LDCT if eligible. Initial data on demographics (i.e. age, sex, ethnicity, deprivation score) and smoking status will be collected in primary care and analysed to explore differences between attenders and non-attenders with respect to invitation group. Those who attend the lung health check will have further data on smoking collected during their appointment (including pack-year history, nicotine dependence and confidence to quit). Secondary outcomes will include willingness to be screened, uptake of LDCT and measures of informed decision-making to ensure the latter is not compromised by either invitation strategy. Discussion If effective at improving informed uptake of screening and reducing bias in participation, this invitation strategy could be adopted by local screening pilots or a national programme. Trial registration This study was registered with the ISRCTN (International Standard Registered Clinical/soCial sTudy Number : ISRCTN21774741) on the 23rd September 2015 and the NIH ClinicalTrials.gov database (NCT0255810) on the 22nd September 2015

    Measures of satisfaction with care during labour and birth: a comparative review

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    Background Satisfaction is the one of the most frequently reported outcome measures for quality of care. Assessment of satisfaction with maternity services is crucial, and psychometrically sound measures are needed if this is to inform health practices. This paper comparatively reviews current measures of satisfaction with care during labour and birth. Methods A review of the literature was conducted. Studies were located through computerised databases and hand searching references of identified articles and reviews. Inclusion criteria were that the questionnaire was a multi-item scale of satisfaction with care during labour and birth, and some form of psychometric information (either information about questionnaire construction, or reliability, or validity) had to be reported. Results Nine questionnaires of satisfaction with care during labour and birth were identified. Instruments varied in psychometric properties and dimensions. Most described questionnaire construction and tested some form of reliability and validity. Measures were generally not based on the main theoretical models of satisfaction and varied in scope and application to different types of samples (e.g. satisfaction following caesarean section). For an in-depth measure of satisfaction with intrapartum care, the Intrapartal-Specific Quality from the Patient’s Perspective questionnaire (QPP-I) is recommended. Brief measures with good reliability and validity are provided by the Six Simple Questions (SSQ) or Perceptions of Care Adjective Checklist (PCACL-R). Conclusions Despite the interest in measures of satisfaction there are only a small number of validated measures of satisfaction with care during labour and birth. It is important that brief, reliable and valid measures are available for use in general and specific populations in order to assist research and inform practice

    Outsourcing as a strategy for driving transformation

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    CONTROL: GETTING IT AND KEEPING IT IN BUSINESS PROCESS OUTSOURCING

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    Proposals to outsource corporate functions often meet with resistance because of control issues and concerns about proprietary information. But proponents of outsourcing are quick to note that many of these reservations dwell on perceptions and apprehensions, rather than on the track record of outsourced projects. In fact, veterans of successful arrangements observe that outsourcing frees up valuable management time and thus enables an enhanced form of control. 2003 Morgan Stanley.
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