123 research outputs found

    Packaging of a large capacity magnetic bubble domain spacecraft recorder

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    A Solid State Spacecraft Data Recorder (SSDR), based on bubble domain technology, having a storage capacity of 10 to the 8th power bits, was designed and is being tested. The recorder consists of two memory modules each having 32 cells, each cell containing sixteen 100 kilobit serial bubble memory chips. The memory modules are interconnected to a Drive and Control Unit (DCU) module containing four microprocessors, 500 integrated circuits, a RAM core memory and two PROM's. The two memory modules and DCU are housed in individual machined aluminum frames, are stacked in brick fashion and through bolted to a base plate assembly which also houses the power supply

    Preliminary design for a standard 10 sup 7 bit Solid State Memory (SSM)

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    A modular concept with three separate modules roughly separating bubble domain technology, control logic technology, and power supply technology was employed. These modules were respectively the standard memory module (SMM), the data control unit (DCU), and power supply module (PSM). The storage medium was provided by bubble domain chips organized into memory cells. These cells and the circuitry for parallel data access to the cells make up the SMM. The DCU provides a flexible serial data interface to the SMM. The PSM provides adequate power to enable one DCU and one SMM to operate simultaneously at the maximum data rate. The SSM was designed to handle asynchronous data rates from dc to 1.024 Mbs with a bit error rate less than 1 error in 10 to the eight power bits. Two versions of the SSM, a serial data memory and a dual parallel data memory were specified using the standard modules. The SSM specification includes requirements for radiation hardness, temperature and mechanical environments, dc magnetic field emission and susceptibility, electromagnetic compatibility, and reliability

    ‘Holiday Sickness’ – reported exploratory outcome of over 500 United Kingdom holidaymakers with Travellers diarrhoea

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    Aims: To ascertain any predictors of potential food poisoning pathogens and development of post-infective irritable bowel syndrome (IBS) in UK travellers. An analysis was undertaken on prospectively collected data on 527 patients reporting symptoms of suspected food poisoning between June 2012 and June 2015. Main outcome measures: Positive stool sample indicative of food poisoning pathogens and diagnosis of post-infective IBS. Results: Data on 527 patients were examined. The large majority of patients did not provide a stool sample on return from holiday (n = 430, 81.6%) as few visited a Doctor locally or in the UK. Only 18 patients (18.6%, 95% confidence interval [CI] 11.4–27.7) who provided a stool sample were positive for microbiological food poisoning pathogens. Univariate analysis indicated a significant relationship between a positive stool sample and whether the individual sought any medical assistance at the resort (odds ratio [OR] 0.24, 95% CI 0.08–0.70) and whether they took any treatment (including self-medicated), (OR 0.21, 95% CI 0.06–0.67). Of the 527 patients only 30 (5.7%, 95% CI 3.9–8.1) experienced post-infective IBS. Univariate regression indicated a significant relationship between experiencing Per Rectal (PR) bleeding and a diagnosis of post-infective IBS (OR 3.64, 95% CI 1.00–10.49). Univariate regression also indicated an increase in the risk of developing post-infective IBS with increasing duration of symptoms (OR 1.04, 95% CI 1.02–1.05). No significant relationship was found between a positive stool sample and developing post-infective IBS (P = 0.307). Conclusions: Very few patients provide a stool sample after experiencing holiday sickness abroad. Of those that do, only a small proportion have a positive stool sample indicative of a food poisoning microorganism. Around 6% of individuals were diagnosed with post-infective IBS. Those individuals with PR bleeding and symptoms persisting for longer durations were significantly more at risk of developing post-infective IBS, whilst medical aid and treatment abroad was found to reduce the odds of a positive stool sample

    Mock data sets for the Eboss and DESI Lyman-α\alpha forest surveys

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    {We present a publicly-available code to generate mock Lyman-α\alpha (\lya) forest data sets. The code is based on the Fluctuating Gunn-Peterson Approximation (FGPA) applied to Gaussian random fields and on the use of fast Fourier transforms (FFT). The output includes spectra of lya transmitted flux fraction, FF, a quasar catalog, and a catalog of high-column-density systems. While these three elements have realistic correlations, additional code is then used to generate realistic quasar spectra, to add absorption by high-column-density systems and metals, and to simulate instrumental effects. Redshift space distortions (RSD) are implemented by including the large-scale velocity-gradient field in the FGPA resulting in a correlation function of FF that can be accurately predicted. One hundred realizations have been produced over the 14,000 deg2^2 Dark Energy Spectroscopy Instrument (DESI) survey footprint with 100 quasars per deg2^{2}, and they are being used for the Extended Baryon Oscillation Survey (eBOSS) and DESI surveys. The analysis of these realizations shows that the correlation of FF follows the prediction within the accuracy of eBOSS survey. The most time-consuming part of the production occurs before application of the FGPA, and the existing pre-FGPA forests can be used to easily produce new mock sets with modified redshift-dependent bias parameters or observational conditions.Comment: to be submitted ot JCA

    Colorectal cancer screening awareness among physicians in Greece

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    BACKGROUND: Data comparison between SEER and EUROCARE database provided evidence that colorectal cancer survival in USA is higher than in European countries. Since adjustment for stage at diagnosis markedly reduces the survival differences, a screening bias was hypothesized. Considering the important role of primary care in screening activities, the purpose of the study was to investigate the colorectal cancer screening awareness among Hellenic physicians. METHODS: 211 primary care physicians were surveyed by mean of a self-reported prescription-habits questionnaire. Both physicians' colorectal cancer screening behaviors and colorectal cancer screening recommendations during usual check-up visits were analyzed. RESULTS: Only 50% of physicians were found to recommend screening for colorectal cancer during usual check-up visits, and only 25% prescribed cost-effective procedures. The percentage of physicians recommending stool occult blood test and sigmoidoscopy was 24% and 4% respectively. Only 48% and 23% of physicians recognized a cancer screening value for stool occult blood test and sigmoidoscopy. Colorectal screening recommendations were statistically lower among physicians aged 30 or less (p = 0.012). No differences were found when gender, level and type of specialization were analyzed, even though specialists in general practice showed a trend for better prescription (p = 0.054). CONCLUSION: Contemporary recommendations for colorectal cancer screening are not followed by implementation in primary care setting. Education on presymptomatic control and screening practice monitoring are required if primary care is to make a major impact on colorectal cancer mortality

    Lynch syndrome: barriers to and facilitators of screening and disease management

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    Background Lynch syndrome is a hereditary cancer with confirmed carriers at high risk for colorectal (CRC) and extracolonic cancers. The purpose of the current study was to develop a greater understanding of the factors influencing decisions about disease management post-genetic testing. Methods The study used a grounded theory approach to data collection and analysis as part of a multiphase project examining the psychosocial and behavioral impact of predictive DNA testing for Lynch syndrome. Individual and small group interviews were conducted with individuals from 10 families with the MSH2 intron 5 splice site mutation or exon 8 deletion. The data from confirmed carriers (n = 23) were subjected to re-analysis to identify key barriers to and/or facilitators of screening and disease management. Results Thematic analysis identified personal, health care provider and health care system factors as dominant barriers to and/or facilitators of managing Lynch syndrome. Person-centered factors reflect risk perceptions and decision-making, and enduring screening/disease management. The perceived knowledge and clinical management skills of health care providers also influenced participation in recommended protocols. The health care system barriers/facilitators are defined in terms of continuity of care and coordination of services among providers. Conclusions Individuals with Lynch syndrome often encounter multiple barriers to and facilitators of disease management that go beyond the individual to the provider and health care system levels. The current organization and implementation of health care services are inadequate. A coordinated system of local services capable of providing integrated, efficient health care and follow-up, populated by providers with knowledge of hereditary cancer, is necessary to maintain optimal health

    Completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: Cosmological implications from two decades of spectroscopic surveys at the Apache Point Observatory

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    We present the cosmological implications from final measurements of clustering using galaxies, quasars, and Ly α forests from the completed Sloan Digital Sky Survey (SDSS) lineage of experiments in large-scale structure. These experiments, composed of data from SDSS, SDSS-II, BOSS, and eBOSS, offer independent measurements of baryon acoustic oscillation (BAO) measurements of angular-diameter distances and Hubble distances relative to the sound horizon, r_{d}, from eight different samples and six measurements of the growth rate parameter, fσ_{8}, from redshift-space distortions (RSD). This composite sample is the most constraining of its kind and allows us to perform a comprehensive assessment of the cosmological model after two decades of dedicated spectroscopic observation. We show that the BAO data alone are able to rule out dark-energy-free models at more than eight standard deviations in an extension to the flat, Λ CDM model that allows for curvature. When combined with Planck Cosmic Microwave Background (CMB) measurements of temperature and polarization, under the same model, the BAO data provide nearly an order of magnitude improvement on curvature constraints relative to primary CMB constraints alone. Independent of distance measurements, the SDSS RSD data complement weak lensing measurements from the Dark Energy Survey (DES) in demonstrating a preference for a flat Λ CDM cosmological model when combined with Planck measurements. The combined BAO and RSD measurements indicate σ_{8} = 0.85 ± 0.03, implying a growth rate that is consistent with predictions from Planck temperature and polarization data and with General Relativity. When combining the results of SDSS BAO and RSD, Planck, Pantheon Type Ia supernovae (SNe Ia), and DES weak lensing and clustering measurements, all multiple-parameter extensions remain consistent with a Λ CDM model. Regardless of cosmological model, the precision on each of the three parameters, Ω_{Λ}, H_{0}, and σ_{8}, remains at roughly 1%, showing changes of less than 0.6% in the central values between models. In a model that allows for free curvature and a time-evolving equation of state for dark energy, the combined samples produce a constraint Ω_{k} = −0.0022 ± 0.0022. The dark energy constraints lead to w_{0} = −0.909 ± 0.081 and w_{a} = −0.49^{+0.35}_{-0.30}, corresponding to an equation of state of w_{p} = 1.018 ± 0.032 at a pivot redshift z_{p} = 0.29 and a Dark Energy Task Force Figure of Merit of 94. The inverse distance ladder measurement under this model yields H_{0} = 68.18 ± 0.79 km s^{-1} Mpc^{-1}, remaining in tension with several direct determination methods; the BAO data allow Hubble constant estimates that are robust against the assumption of the cosmological model. In addition, the BAO data allow estimates of H_{0} that are independent of the CMB data, with similar central values and precision under a Λ CDM model. Our most constraining combination of data gives the upper limit on the sum of neutrino masses at ∑m_{v} < 0.115 eV (95% confidence). Finally, we consider the improvements in cosmology constraints over the last decade by comparing our results to a sample representative of the period 2000–2010. We compute the relative gain across the five dimensions spanned by w, Ω_{k}, ∑m_{v}, H_{0}, H_{0}, and σ_{8} and find that the SDSS BAO and RSD data reduce the total posterior volume by a factor of 40 relative to the previous generation. Adding again the Planck, DES, and Pantheon SN Ia samples leads to an overall contraction in the five-dimensional posterior volume of 3 orders of magnitude

    The 16th Data Release of the Sloan Digital Sky Surveys: First Release from the APOGEE-2 Southern Survey and Full Release of eBOSS Spectra

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    This paper documents the 16th data release (DR16) from the Sloan Digital Sky Surveys (SDSS), the fourth and penultimate from the fourth phase (SDSS-IV). This is the first release of data from the Southern Hemisphere survey of the Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2); new data from APOGEE-2 North are also included. DR16 is also notable as the final data release for the main cosmological program of the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), and all raw and reduced spectra from that project are released here. DR16 also includes all the data from the Time Domain Spectroscopic Survey and new data from the SPectroscopic IDentification of ERosita Survey programs, both of which were co-observed on eBOSS plates. DR16 has no new data from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey (or the MaNGA Stellar Library "MaStar"). We also preview future SDSS-V operations (due to start in 2020), and summarize plans for the final SDSS-IV data release (DR17)

    The 16th Data Release of the Sloan Digital Sky Surveys: First Release from the APOGEE-2 Southern Survey and Full Release of eBOSS Spectra

    Get PDF
    This paper documents the 16th data release (DR16) from the Sloan Digital Sky Surveys (SDSS), the fourth and penultimate from the fourth phase (SDSS-IV). This is the first release of data from the Southern Hemisphere survey of the Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2); new data from APOGEE-2 North are also included. DR16 is also notable as the final data release for the main cosmological program of the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), and all raw and reduced spectra from that project are released here. DR16 also includes all the data from the Time Domain Spectroscopic Survey and new data from the SPectroscopic IDentification of ERosita Survey programs, both of which were co-observed on eBOSS plates. DR16 has no new data from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey (or the MaNGA Stellar Library "MaStar"). We also preview future SDSS-V operations (due to start in 2020), and summarize plans for the final SDSS-IV data release (DR17)
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