The
Solar Diameter Imager and Surface Mapper
(SODISM) onboard the
Picard
space mission provides wide-field images of the photosphere and chromosphere of the Sun in five narrow bandpasses centered at ...215.0, 393.37, 535.7, 607.1, and 782.2 nm. The
Picard
spacecraft was successfully launched on 15 June 2010 into a Sun-synchronous dawn–dusk orbit. The
Picard
space mission represents a European asset in collecting solar observations useful to improve Earth climatic models. The scientific payload consists of the SODISM imager and of two radiometers,
SOlar VAriability Picard
(SOVAP) and
PREcision MOnitor Sensor
(PREMOS), which measure the Total Solar Irradiance (TSI) and part of the Solar Spectral Irradiance (SSI).
The SODISM telescope continuously monitors solar activity from the middle ultraviolet to the near infrared spectral ranges and produces solar images that feed SSI reconstruction models. Further, SODISM probes the solar interior
via
a helioseismic analysis of the solar disc and limb images at 535.7 nm, and
via
astrometric investigations at the limb. The latter allows us to deduce the spectral dependence of the solar limb profile, and the asphericity of the Sun. Furthermore, SODISM data taken during the transit of Venus allow a determination of the absolute value of the solar diameter. This paper provides a detailed description of the SODISM instrument, including thermo-optical analysis, its different modes of observation, and its first performance in space.
We present a detailed abundance study based on spectroscopic data obtained with HARPS of two solar-analogue main targets for the asteroseismology programme of the CoRoT satellite: HD 42618 and HD ...43587. The atmospheric parameters and chemical composition are accurately determined through a fully differential analysis with respect to the Sun observed with the same instrumental set-up. Several sources of systematic errors largely cancel out with this approach, which allows us to narrow down the 1-σ error bars to typically 20 K in effective temperature, 0.04 dex in surface gravity, and less than 0.05 dex in the elemental abundances. Although HD 42618 fulfils many requirements for being classified as a solar twin, its slight deficiency in metals and its possibly younger age indicate that, strictly speaking, it does not belong to this class of objects. On the other hand, HD 43587 is slightly more massive and evolved. In addition, marked differences are found in the amount of lithium present in the photospheres of these two stars, which might reveal different mixing properties in their interiors. These results will put tight constraints on the forthcoming theoretical modelling of their solar-like oscillations and contribute to increase our knowledge of the fundamental parameters and internal structure of stars similar to our Sun.
Context. The estimate of solar-like oscillation properties, such as their frequencies, amplitudes and lifetimes, is challenging because of their low amplitudes and will benefit from long and ...uninterrupted observing runs. The space telescope CoRoT allows us to obtain high-performance photometric data over a long and quasi continuous period. Among its main targets are stars for which we expect solar-like oscillations. Aims. HD 181420, an F2 main sequence star, has been observed by CoRoT during its first long run covering about 156 days. With this unprecedently high-quality set of data, our aim is to derive the p-mode parameters that can be used to probe the stellar interior. Methods. The CoRoT data obtained on HD 181420 is analysed using a classical Fourier approach for the search for the p mode signature. The p-mode parameters are then derived using global fitting of the power spectrum by a Lorentzian model, as used widely in the solar case. Results. From the p-mode frequencies, the mean value of the large spacing is estimated to be 75 ${\rm \mu Hz}$. The p-mode amplitudes are slightly less than 4 ppm with a line width of about 8 ${\rm \mu Hz}$ at the maximum of the p modes. The inclination angle is estimated to be around $45 \degr$. The large mode line-width combined with the observed mode spacing make it difficult to identify the $\ell=2$ modes and to estimate the rotational splitting. We explore two scenarios for the identification of the modes.
Nowadays, the recommended measures for optimal monitoring of axial Spondyloarthritis (ax-SpA) disease activity are either BASDAI and CRP, or ASDAS-CRP. However, there could be a gap between ...recommendations and daily practice. We aimed to determine the measures collected by rheumatologists in an ax-SpA follow-up visit, and to determine the impact of a meeting (where rheumatologists reached a consensus on the measures to be collected) on the collection of such measures.
A consensual meeting of a local network of 32 rheumatologists proposed, four months later, to report at least the BASDAI score in the medical file of every ax-SpA patient at every follow-up visit. An independent investigator reviewed the medical files of 10 consecutive patients per rheumatologist, seen twice during the year (e.g. before and after the meeting). The most frequently collected measures were assessed, and then, the frequency of collection before and after the meeting was compared.
A total of 456 medical files from 228 patients were reviewed. Treatment (>60%), CRP (51.3%) and total BASDAI (28.5%) were the most reported measures in medical files. Before/After the meeting, the frequencies of collected measures in medical files were 28.5%/51.7%, 51.3%/52.2%, 16.7%/31.6% and 0.9%/6.1% for BASDAI, CRP, BASDAI + CRP and ASDAS, respectively reaching a statistically significance for BASDAI, ASDAS and BASDAI+CRP (p<0.05).
This study revealed a low rate of systematic report of the recommended outcome measures in ax-SpA. However, it suggests that a consensual meeting involving practicing rheumatologists might be relevant to improve the implementation of such recommendations.
The quest for the solar g modes Appourchaux, T.; Belkacem, K.; Broomhall, A.-M. ...
The Astronomy and astrophysics review,
02/2010, Volume:
18, Issue:
1-2
Journal Article
Peer reviewed
Open access
Solar gravity modes (or g modes)—oscillations of the solar interior on which buoyancy acts as the restoring force—have the potential to provide unprecedented inference on the structure and dynamics ...of the solar core, inference that is not possible with the well-observed acoustic modes (or p modes). The relative high amplitude of the g-mode eigenfunctions in the core and the evanesence of the modes in the convection zone make the modes particularly sensitive to the physical and dynamical conditions in the core. Owing to the existence of the convection zone, the g modes have very low amplitudes at photospheric levels, which makes the modes extremely hard to detect. In this article, we review the current state of play regarding attempts to detect g modes. We review the theory of g modes, including theoretical estimation of the g-mode frequencies, amplitudes and damping rates. Then we go on to discuss the techniques that have been used to try to detect g modes. We review results in the literature, and finish by looking to the future, and the potential advances that can be made—from both data and data-analysis perspectives—to give unambiguous detections of individual g modes. The review ends by concluding that, at the time of writing, there is indeed a consensus amongst the authors that
there is currently no undisputed detection of solar g modes
.
Objective
An annual assessment of cardiovascular (CV) risk factors in rheumatoid arthritis (RA) is recommended, but its practical modalities have not been determined. The objective was to assess the ...feasibility and usefulness of a standardized CV risk assessment in RA, performed by rheumatologists during outpatient clinics.
Methods
We used a cross‐sectional design within a network of rheumatologists. Each rheumatologist included 5 consecutive unselected patients with definite RA. Data collection included standardized assessment of CV risk factors: blood pressure, interpretation of glycemia and of lipid levels, and calculation of the Framingham CV risk score. Outcome criteria included feasibility (missing data and time taken to assess the patients) and usefulness (the CV risk assessment was considered useful if at least 1 modifiable and previously unknown CV risk factor was evidenced).
Results
Twenty‐two rheumatologists (77% in office‐based practice) assessed 110 RA patients. The mean ± SD age was 57 ± 10 years, and the mean ± SD RA duration was 11 ± 9 years; 50 patients (45%) were treated with biologic agents, and 76% were women. Regarding feasibility, missing data were most frequent for glycemia (27% of patients) and cholesterolemia (14% of patients). The mean ± SD duration of the CV risk assessment was 15 ± 5 minutes. The CV risk assessment was considered useful in 33 patients (30%), evidencing dyslipidemia (15% of patients) or high blood pressure (9% of patients) as the most frequently previously unknown CV risk factor.
Conclusion
The assessment of CV risk factors is feasible, but labor intensive, during an outpatient rheumatology clinic. This assessment identified modifiable CV risk factors in 30% of the patients. These results suggest that RA patients are not sufficiently assessed and treated for CV risk factors.
TNFα overproduction is thought to occur in SSc, 3 and although preliminary evaluations of the short term effects of etanercept in SSc reported no toxicity, 4 in vitro data have suggested that TNFα ...has antifibrotic activity. 5, 6 Although no conclusion can be reached with case reports, it is noteworthy that our patient, like the reported patients with RA with fatal fibrosis exacerbation, 1 was concomitantly treated with azathioprine and anti-TNF. ...TNFα may trigger fibrosis in patients with underlying interstitial lung disease, possibly irrespective of the associated disease, and should therefore be used with extreme caution in such patients.
The Global Oscillation at Low Frequencies (GOLF) experiment is a resonant scattering spectrophotometer on board the Solar and Heliospheric Observatory (SoHO) mission, originally designed to measure ...the disk-integrated solar oscillations of the Sun. This instrument was designed in a relative photometric mode involving both wings of the neutral sodium doublet (D1 at λ 5896 and D2 at λ 5890 Å). However, a “one-wing” photometric mode has been selected to ensure 100% continuity in the measurements after a problem in the polarization mechanisms. Thus the velocity is obtained from only two points on the same wing of the lines. This operating configuration imposes tighter constraints on the stability of the instrument with a higher sensitivity to instrumental variations. In this paper we discuss the evolution of the instrument during the last 8 years in space and the corrections applied to the measured counting rates due to known instrumental effects. We also describe a scaling procedure to obtain the variation of the Doppler velocity based on our knowledge of the sodium profile slope and we compare it to previous velocity estimations.
Objectives. To evaluate the predictive value of TNFRII 196R, PTPN22 1858T and HLA-shared epitope (SE) alleles, RFs and anti-citrullinated protein antibodies (ACPAs) for RA diagnosis in a cohort of ...patients with very early arthritis. Methods. We followed up 284 patients who had swelling of at least two joints that had persisted for longer than 4 weeks but had been evolving for <6 months. At 2 yrs, patients were classified as having RA or non-RA rheumatic diseases according to the ACR criteria. Patients were genotyped with respect to TNFRII 196M/R and PTPN22 1858C/T polymorphisms and HLA-SE. The presence of IgA, IgG and IgM RF isotypes and ACPA was sought in sera collected at disease onset. Results. HLA-SE alleles alone, concomitant presence of TNFRII 196R and PTPN22 1858T alleles, IgA, IgG and IgM RF alone and ACPA were found to be significantly associated with RA diagnosis. Using logistic regression analysis, the concomitant presence of RF and ACPA at disease onset was the best association to predict RA diagnosis. In patients (n = 34) who did not fulfil the ACR criteria for RA at inclusion but who progressed to ACR positivity, the study of the genetic risk markers did not contribute to predict RA diagnosis at 2 yrs. Conclusions. PTPN22 1858T, TNFRII 196R and HLA-SE alleles do not improve the predictive value of RF and ACPA for RA diagnosis in our cohort, and do not contribute to an earlier diagnosis in undifferentiated patients initially negative for RF and ACPA.
Helioseismology with PICARD Corbard, T; Salabert, D; Boumier, P ...
Journal of physics. Conference series,
01/2013, Volume:
440, Issue:
1
Journal Article
Peer reviewed
Open access
PICARD is a CNES micro-satellite launched in June 2010 17. Its main goal is to measure the solar shape, total and spectral irradiance during the ascending phase of the activity cycle. The SODISM ...telescope onboard PICARD also allows us to conduct a program for helioseismology in intensity at 535.7 nm 5. One-minute cadence low-resolution full images are available for a so-called medium-l program, and high-resolution images of the limb recorded every 2 minutes are used to study mode amplification near the limb in the perspective of g-mode search. First analyses and results from these two programs are presented here.
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