Charge-Transfer induced EUV and Soft X-ray emissions in the Heliosphere

We study the EUV/soft X-ray emission generated by charge transfer between solar wind heavy ions and interstellar H and He neutral atoms in the inner Heliosphere. We present heliospheric maps and spectra for stationary solar wind, depending on solar cycle phase, solar wind anisotropies and composition, line of sight direction and observer position. A time-dependant simulation of the X-ray intensity variations due to temporary solar wind enhancement is compared to XMM Newton recorded data of the Hubble Deep Field North observation (Snowden et al. 2004). Results show that the heliospheric component can explain a large fraction of the line intensity below 1.3 keV, strongly attenuating the need for soft X-ray emission from the Local Interstellar Bubble.Comment: 18 pages, 13 figures (5 in online material,for colour figures contact the authors), 3 tables, accepted in A&

Reproducibility of bowel ultrasonography in the evaluation of Crohn's disease

BACKGROUND: Bowel ultrasonography is increasingly used in the detection and follow-up of patients with Crohn's disease, but a limitation to its further diffusion is the lack of standardisation of ultrasonography parameters. AIMS: This study aimed to standardise the most common bowel ultrasonography parameters in order to develop an unequivocal imaging interpretation and to assess bowel ultrasonography reproducibility. PATIENTS: Twenty patients with Crohn's disease were examined. METHODS: Six ultrasonographers (mean bowel ultrasonography experience=16 years) performed the study. They chose and discussed a common assessment methodology concerning eight ultrasonography parameters: bowel wall thickness, bowel wall pattern, bowel wall blood flow, enlarged mesenteric lymph nodes, mesenteric hypertrophy, abdominal free fluid, and stenosis or fistulae at four preliminary meetings. The day of the study operators were randomised to two rooms where they independently and in turn performed ultrasonography scans. Interobserver agreement was scored by kappa statistics. RESULTS: Excellent k values were observed for bowel wall thickness (0.72-1). k Values were poor for bowel wall pattern (-0.22-0.85) and good for bowel wall blood flow (0.53-0.89). The presence of lymph nodes was reproducible (0.56-0.90) except in one case (0.25). Concordance on free fluid was excellent (0.85-1), whereas that on mesenteric hypertrophy was generally poor (0.14-0.69). Agreement was excellent for stenosis (0.81-1) whereas that for fistula was fair in room abscesses (0.31-0.48) and very good in room B (0.87-1). CONCLUSION: Bowel ultrasonography signs used in Crohn's disease can be standardised as most of them showed a fair to good reproducibility. In particular, bowel wall thickness, the most relevant parameter for Crohn's disease detection, showed an excellent reproducibilit