A chondrule in the Chainpur meteorite

Glass occurrence in chondrules as evidence for formation by rapid cooling of liquid droplets - chondritic meteorite

Tripartite entanglement from interlinked χ(2)\chi^{(2)} parametric interactions

We examine the tripartite entanglement properties of an optical system using interlinked $\chi^{(2)}$ interactions, recently studied experimentally in terms of its phase-matching properties by Bondani et al [M. Bondani, A. Allevi, E. Gevinti, A. Agliati, and A. Andreoni, arXiv:quant-ph/0604002.]. We show that the system does produce output modes which are genuinely tripartite entangled and that detection of this entanglement depends crucially on the correlation functions which are measured, with a three-mode Einstein-Podolsky-Rosen inequality being the most sensitive.Comment: 15 pages, 5 figure

A Trigonometric Parallax of Sgr B2

We have measured the positions of water masers in Sgr B2, a massive star forming region in the Galactic center, relative to an extragalactic radio source with the Very Long Baseline Array. The positions measured at 12 epochs over a time span of one year yield the trigonometric parallax of Sgr B2 and hence a distance to the Galactic center of Ro=7.9 (+0.8/-0.7) kpc. The proper motion of Sgr B2 relative to Sgr A* suggests that Sgr B2 is about 0.13 kpc nearer than the Galactic center, assuming a low-eccentricity Galactic orbit.Comment: Submitted to ApJ; 4 tables; 3 figures. Version 2 corrects Fig. 2 which was missing some dat

Trigonometric Parallaxes of Massive Star Forming Regions: G012.88+0.48 and W33

We report trigonometric parallaxes for water masers in the G012.88+0.48 region and in the massive star forming complex W33 (containing G012.68--0.18, G012.81--0.19, G012.90--0.24, G012.90--0.26), from the Bar and Spiral Structure Legacy (BeSSeL) survey using the Very Long Baseline Array. The parallax distances to all these masers are consistent with $2.40^{+0.17}_{-0.15}$ kpc, which locates the W33 complex and G012.88+0.48 in the Scutum spiral arm. Our results show that W33 is a single star forming complex at about two-thirds the kinematic distance of 3.7 kpc. The luminosity and mass of this region, based on the kinematic distance, have therefore been overestimated by more than a factor of two. The spectral types in the star cluster in W33\,Main have to be changed by 1.5 points to later types.Comment: 9 pages, 11 figures, 2 tables; accepted for publication at A&

Adherence to prophylaxis in adolescents and young adults with severe haemophilia, A qualitative study with patients

© 2018 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.Abstract Introduction: Reported levels of adherence to prophylaxis among young people with haemophilia (YPH) vary widely and are predominately based on estimations made by healthcare professionals and parents. Reasons for (non)adherence among YPH in particular have not been evidenced. Aim: to examine experiences in relation to prophylaxis with YPH themselves, and barriers and facilitators to their adherence. Methods: 11 Participants were recruited in five haemophilia centres across England and Wales. All patients who met the inclusion criteria (aged 12-25, diagnosed with haemophilia, on prophylaxis) were approached during a routine check-up appointment, and all participants who agreed to take part were interviewed. Interviews were audio recorded, transcribed and analysed using Interpretative Phenomenological Analysis. Results: Self-reported adherence to prophylaxis was good. Few participants admitted to intentionally skipping injections although they reported sometimes forgetting. However, due to the increasingly personalised and flexible approach to prophylaxis, adherence is not straightforward to define. Barriers to adherence included a busy lifestyle, dislike of the intravenous injection, venous access issues, anxiety or stress and being out of one’s normal routine. Support was an important facilitator to adherence, including support from health professionals at the haemophilia centre as well as friends. Parents appear to be very involved with their sons’ haemophilia management, even after their sons leave home. Conclusion: What this study adds is that the increasingly flexible and personalized approach to managing prophylaxis in haemophilia may sometimes lead to confusion around treatment frequency and dosing. This may lead to accidental non-adherence, which is distinct from both skipping and forgetting. Advice from haemophilia teams may not always be consistent, and is likely to be interpreted differently by different individuals. Some additional training and education of patients and their families to increase their knowledge and skills around prophylaxis may reduce this confusion and therefore is likely to improve adherence further.Peer reviewedFinal Published versio

A Parallax-based Distance Estimator for Spiral Arm Sources

The spiral arms of the Milky Way are being accurately located for the first time via trigonometric parallaxes of massive star forming regions with the BeSSeL Survey, using the Very Long Baseline Array and the European VLBI Network, and with the Japanese VERA project. Here we describe a computer program that leverages these results to significantly improve the accuracy and reliability of distance estimates to other sources that are known to follow spiral structure. Using a Bayesian approach, sources are assigned to arms based on their (l,b,v) coordinates with respect to arm signatures seen in CO and HI surveys. A source's kinematic distance, displacement from the plane, and proximity to individual parallax sources are also considered in generating a full distance probability density function. Using this program to estimate distances to large numbers of star forming regions, we generate a realistic visualization of the Milky Way's spiral structure as seen from the northern hemisphere.Comment: 25 pages with 16 figures; to appear in Ap

Radio signatures of solar energetic particles during the 23rd solar cycle

We present the association rates between solar energetic particles (SEPs) and the radio emission signatures in the corona and IP space during the entire solar cycle 23. We selected SEPs associated with X and M-class flares from the visible solar hemisphere. All SEP events are also accompanied by coronal mass ejections. Here, we focus on the correlation between the SEP events and the appearance of radio type II, III and IV bursts on dynamic spectra. For this we used the available radio data from ground-based stations and the Wind/WAVES spacecraft. The associations are presented separately for SEP events accompanying activity in the eastern and western solar hemisphere. We find the highest association rate of SEP events to be with type III bursts, followed by types II and IV. Whereas for types III and IV no longitudinal dependence is noticed, these is a tendency for a higher SEP-association rate with type II bursts in the eastern hemisphere. A comparison with reports from previous studies is briefly discussed.Comment: http://adsabs.harvard.edu.ezproxy.obspm.fr/abs/2013CEAB...37..541