136 research outputs found
Sphinx measurements of the 2009 solar minimum x-ray emission
The SphinX X-ray spectrophotometer on the CORONAS-PHOTON spacecraft measured
soft X-ray emission in the 1-15 keV energy range during the deep solar minimum
of 2009 with a sensitivity much greater than GOES. Several intervals are
identified when the X-ray flux was exceptionally low, and the flux and solar
X-ray luminosity are estimated. Spectral fits to the emission at these times
give temperatures of 1.7-1.9 MK and emission measures between 4 x 10^47 cm^-3
and 1.1 x 10^48 cm^-3. Comparing SphinX emission with that from the Hinode
X-ray Telescope, we deduce that most of the emission is from general coronal
structures rather than confined features like bright points. For one of 27
intervals of exceptionally low activity identified in the SphinX data, the
Sun's X-ray luminosity in an energy range roughly extrapolated to that of ROSAT
(0.1-2.4 keV) was less than most nearby K and M dwarfs.Comment: Astrophysical Journal, in press. 14 pp, 3 figure
Socio-demographic factors related to under-diagnosis of childhood asthma in Upper Silesia, Poland
Introduction
The presented study of 4,535 children aged 7–17 years in the Upper Silesian region of Poland yielded 186 cases of previously known asthma, and 44 children with newly diagnosed asthma. The aim of the presented study was to identify non-medical factors that could explain why children with a newly established diagnosis (‘undiagnosed asthma’) had not been diagnosed in the past.
Material and Methods
The study was performed according to a case-control design. Parents of the children answered questionnaires on socio-economic status and family-related factors. Statistical determinants of undiagnosed asthma were explored using raw (OR) and logistic odds ratios with their 95% confidence intervals (logOR, 95%CI).
Results
Children with undiagnosed asthma were younger compared to the group with previously known asthma (11.3±2.1 vs. 12.6±2.5 years; p=0.0008). Newly diagnosed cases were more frequent in children who had less parental attention (less than 1 hour/day spent by parent with child – OR=4.36; 95%CI: 1.76–10.81) and who were not registered with specialized health care (OR=2.20; 95%CI: 0.95–5.06). Results of logistic regression analysis suggest that under-diagnosis of asthma is related to age below 12 years – logOR = 3.59 (95%CI: 1.28–10.36), distance to a health centre > 5 km – logOR = 3.45 (95%CI: 1.05–11.36), time spent with child < 1 hour/day – logOR = 6.28 (95%CI: 1.98–19.91).
Conclusions
Among non-medical determinants of undiagnosed asthma the age of a child plays a major role. Another factors of importance is the large distance between residence and health centre, and low parental attention at home
SphinX soft X-ray spectrophotometer: Science objectives, design and performance
The goals and construction details of a new design Polish-led X-ray spectrophotometer are described. The instrument is aimed to observe emission from entire solar corona and is placed as a separate block within the Russian TESIS X- and EUV complex aboard the CORONAS-PHOTON solar orbiting observatory. SphinX uses silicon PIN diode detectors for high time resolution measurements of the solar spectra in the range 0.8–15 keV. Its spectral resolution allows for discerning more than hundred separate energy bands in this range. The instrument dynamic range extends two orders of magnitude below and above these representative for GOES. The relative and absolute accuracy of spectral measurements is expected to be better than few percent, as follows from extensive ground laboratory calibrations
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