Context
. The characterisation of Earth-size exoplanets through transit photometry has stimulated new generations of high-precision instruments. In that respect, the Characterising Exoplanet ...Satellite (CHEOPS) is designed to perform photometric observations of bright stars to obtain precise radii measurements of transiting planets. The CHEOPS instrument will have the capability to follow up bright hosts provided by radial-velocity facilities. With the recent launch of the Transiting Exoplanet Survey Satellite (TESS), CHEOPS may also be able to confirm some of the long-period TESS candidates and to improve the radii precision of confirmed exoplanets.
Aims
. The high-precision photometry of CHEOPS relies on careful on-ground calibration of its payload. For that purpose, intensive pre-launch campaigns of measurements were carried out to calibrate the instrument and characterise its photometric performances. This work reports on the main results of these campaigns. It provides a complete analysis of data sets and estimates in-flight photometric performance by means of an end-to-end simulation. Instrumental systematics were measured by carrying out long-term calibration sequences. Using an end-to end model, we simulated transit observations to evaluate the impact of in-orbit behaviour of the satellite and to determine the achievable precision on the planetary radii measurement.
Methods
. After introducing key results from the payload calibration, we focussed on the data analysis of a series of long-term measurements of uniformly illuminated images. The recorded frames were corrected for instrumental effects and a mean photometric signal was computed on each image. The resulting light curve was corrected for systematics related to laboratory temperature fluctuations. Transit observations were simulated, considering the payload performance parameters. The data were corrected using calibration results and estimates of the background level and position of the stellar image. The light curve was extracted using aperture photometry and analysed with a transit model using a Markov chain Monte Carlo algorithm.
Results
. In our analysis, we show that the calibration test set-up induces thermally correlated features in the data that can be corrected in post-processing to improve the quality of the light curves. We find that on-ground photometric performances of the instrument measured after this correction is of the order of 15 parts per million over five hours. Using our end-to-end simulation, we determine that measurements of planet-to-star radii ratio with a precision of 2% for a Neptune-size planet transiting a K-dwarf star and 5% for an Earth-size planet orbiting a Sun-like star are possible with CHEOPS. These values correspond to transit depths obtained with signal-to-noise ratios of 25 and 10, respectively, allowing the characterisation and detection of these planets. The pre-launch CHEOPS performances are shown to be compliant with the mission requirements.
Context. The characterisation of Earth-size exoplanets through transit photometry has stimulated new generations of high-precision instruments. In that respect, the Characterising Exoplanet Satellite ...(CHEOPS) is designed to perform photometric observations of bright stars to obtain precise radii measurements of transiting planets. The CHEOPS instrument will have the capability to follow up bright hosts provided by radial-velocity facilities. With the recent launch of the Transiting Exoplanet Survey Satellite (TESS), CHEOPS may also be able to confirm some of the long-period TESS candidates and to improve the radii precision of confirmed exoplanets. Aims. The high-precision photometry of CHEOPS relies on careful on-ground calibration of its payload. For that purpose, intensive pre-launch campaigns of measurements were carried out to calibrate the instrument and characterise its photometric performances. This work reports on the main results of these campaigns. It provides a complete analysis of data sets and estimates in-flight photometric performance by means of an end-to-end simulation. Instrumental systematics were measured by carrying out long-term calibration sequences. Using an end-to end model, we simulated transit observations to evaluate the impact of in-orbit behaviour of the satellite and to determine the achievable precision on the planetary radii measurement. Methods. After introducing key results from the payload calibration, we focussed on the data analysis of a series of long-term measurements of uniformly illuminated images. The recorded frames were corrected for instrumental effects and a mean photometric signal was computed on each image. The resulting light curve was corrected for systematics related to laboratory temperature fluctuations. Transit observations were simulated, considering the payload performance parameters. The data were corrected using calibration results and estimates of the background level and position of the stellar image. The light curve was extracted using aperture photometry and analysed with a transit model using a Markov chain Monte Carlo algorithm. Results. In our analysis, we show that the calibration test set-up induces thermally correlated features in the data that can be corrected in post-processing to improve the quality of the light curves. We find that on-ground photometric performances of the instrument measured after this correction is of the order of 15 parts per million over five hours. Using our end-to-end simulation, we determine that measurements of planet-to-star radii ratio with a precision of 2% for a Neptune-size planet transiting a K-dwarf star and 5% for an Earth-size planet orbiting a Sun-like star are possible with CHEOPS. These values correspond to transit depths obtained with signal-to-noise ratios of 25 and 10, respectively, allowing the characterisation and detection of these planets. The pre-launch CHEOPS performances are shown to be compliant with the mission requirements.
The potential ecotoxicological effects of mixtures of contaminants in the aquatic environment are generating a global concern. Benthic invertebrates, such as the crustacean Gammarus fossarum, are key ...in the functioning of aquatic ecosystems, and are frequently used as sentinel species of water quality status. The aim of this work was to study the effects of amixture of themost frequently detected surfactants in the bioconcentration kinetics of two pharmaceuticals in G. fossarum, evaluating their potential enhancing or suppressing effects. Laboratory exposure experiments for both pharmaceuticals and surfactants (concentration ratio 1:25) were set up for two individual compounds, the anxiolytic oxazepam and the antibiotic sulfamethoxazole. Gammarid samples were processed using microQuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) extraction. Pharmaceuticals concentration in the organisms was followed-up by means of nanoliquid chromatography coupled to tandem mass spectrometry (nanoLC-MS/MS). Results indicated a similar mode of action of the surfactants in the bioconcentration kinetics of both drugs, decreasing the accumulation rate in the organism. Oxazepam showed a higher accumulation potential than sulfamethoxazole in all cases. Depuration experiments for oxazepam also demonstrated the high depurative capacity of gammarids, eliminating N50% of the concentration of oxazepam in b6 h.
Objectives To determine the incidence and prevalence of systemic sclerosis (SSc) in adults, its epidemiological tendencies over time, and its possible key determinants. Methods We performed a ...systematic literature review using the keywords “systemic sclerosis,” “incidence,” “prevalence,” and “epidemiology.” Results We found 32 articles published from 1969 to 2006 in which the prevalence of SSc ranged from 7/million to 489/million and its incidence from 0.6/million/y to 122/million/y. There were many geographical variations: SSc prevalence was higher in the USA (276/million in 1990) and Australia (233/million in 1999) than in Japan and Europe, where a north–south gradient was also observed (France: 158/million in 2001 and England: 88/million in 2000). In some regions (Ontario, Rome, near London’s airports) there was an unusually high number of SSc cases (3, 5, or 1000 times greater than expected), suggesting spatiotemporal clustering, although no key determinants could be identified. Furthermore, there seemed to be a trend toward an increase in the incidence of SSc over time, but this tendency is uncertain due to lack of uniformity in study methods and designs. We also found that susceptibility to the disease differed according to sex, age, and race. Conclusion Uniform clinico-epidemiological studies with standard diagnostic and classification criteria are needed to refine the epidemiological features of SSc. Homogeneous study methods with exhaustive case ascertainment as seen in a “capture-recapture” analysis will also be necessary to obtain reliable data.
Acute pneumonia (AP) induces an excess of mortality among the elderly. We evaluated the value of a new predictive biomarker index compared to usual prognosis scores for predicting in-hospital and ...1-year mortalities in elderly inpatients with AP.
Retrospective study in 6 clinical departments of a university hospital.
Burgundy university hospital (France).
All patients aged 75 and over with AP and hospitalized between January 1 and June 30, 2013, in the departments of medicine (5) and intensive care (1) of our university hospital.
A new index, which we named UBMo, was created by multiplying the uremia (U in the formula) by the N-terminal-pro-brain natriuretic peptide (NT-proBNP) plasmatic rate (B), divided by the monocyte count (Mo).
Among the 217 patients included, there were 138 community-acquired pneumonia, 56 nursing home-acquired pneumonia, and 23 hospital-acquired pneumonia. In-hospital and 1-year mortality rates were respectively 19.8% and 43.8%. In multivariate analysis, Pneumonia Severity Index (PSI), unlike CURB-65 (confusion, urea >7 mmol/L, respiratory rate ≥30 breaths/min, blood pressure <90 mmHg systolic or ≤60 mmHg diastolic, age ≥65) score, was associated with in-hospital and 1-year mortalities. UBMo index performed better than PSI and CURB-65 scores in predicting both in-hospital and 1-year mortalities. For in-hospital mortality, the areas under the receiver operating characteristic curves (AUCs) were 0.89 (95% CI = 0.84-0.94), 0.72 (95% CI = 0.65-0.80), and 0.63 (95% CI = 0.54-0.72), respectively, for the 3 scores. For 1-year mortality, the AUCs were 0.93 (95% CI = 0.89-0.98), 0.66 (95% CI = 0.59-0.74), and 0.58 (95% CI = 0.50-0.66), respectively, for the 3 scores. The cut point for the UBMo index of 20,000 × 10
ng·mmol/L had a sensitivity of 93.1% and 80.9% and a specificity of 76.3% and 95.8%, respectively, for in-hospital and 1-year mortalities.
If confirmed by prospective studies, the UBMo index appears very efficient in identifying patients at high risk of in-hospital and 1-year mortalities after an AP.
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