The Mid-infrared Instrument for JWST and Its In-flight Performance

The Mid-Infrared Instrument (MIRI) extends the reach of the James Webb Space Telescope (JWST) to 28.5 μm. It provides subarcsecond-resolution imaging, high sensitivity coronagraphy, and spectroscopy at resolutions of λ/Δλ ∼ 100-3500, with the high-resolution mode employing an integral field unit to provide spatial data cubes. The resulting broad suite of capabilities will enable huge advances in studies over this wavelength range. This overview describes the history of acquiring this capability for JWST. It discusses the basic attributes of the instrument optics, the detector arrays, and the cryocooler that keeps everything at approximately 7 K. It gives a short description of the data pipeline and of the instrument performance demonstrated during JWST commissioning. The bottom line is that the telescope and MIRI are both operating to the standards set by pre-launch predictions, and all of the MIRI capabilities are operating at, or even a bit better than, the level that had been expected. The paper is also designed to act as a roadmap to more detailed papers on different aspects of MIRI

The Science Performance of JWST as Characterized in Commissioning

This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies.Comment: 5th version as accepted to PASP; 31 pages, 18 figures; https://iopscience.iop.org/article/10.1088/1538-3873/acb29

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

Sliding window logic simulation

Existing digital logic simulators typically depend on a discrete-time model of circuit behaviour. Whilst this approach is sufficient in many cases for the validation of the behaviour of synchronous circuits, it is not good at identifying glitches that are narrower than the available time resolution. Moreover, it is not generally feasible to accommodate uncertainty in delay time in such a way as to detect at an early design stage glitches that only occur under worst-case layout-specific or environment dependent timing conditions. This paper presents a technique, based upon abstract interpretation, that, given any synchronous or asynchronous circuit, allows possible glitches to be detected within a particular time window given known starting conditions. Since the underlying model is based upon dense (continuous) time, all possible glitches are detected regardless of how narrow they may be. Adopting a window length equivalent to the worst-case uncertainty in delay, then ‘sliding ’ the window in time such that each successive window overlaps the previous window allows all possible glitches to be identified, without a need for exact timing information. Using this algorithm, it is possible to construct a logic simulator that is capable of automatically detecting possible glitches early in the design life cycle, before layout-specific timing parameters can be determined.

Depression: an exploratory parallel-group randomised controlled trial of Antenatal guided self help for WomeN (DAWN): study protocol for a randomised controlled trial

BACKGROUND: Depression is a common antenatal mental disorder and is associated with an increased risk of adverse effects on the fetus and significant morbidity for the mother; if untreated it can also continue into the post-natal period and affect mother-infant interactions. There has been little research evaluating the effectiveness or cost-effectiveness of antenatal psychological interventions for antenatal depression, particularly for mild to moderate disorders. International guidelines recommend a stepped care approach starting with Guided Self Help, and the aim of this exploratory trial is to investigate Guided Self Help modified for pregnancy. METHODS: The DAWN trial is an exploratory randomised controlled trial of the effectiveness and cost-effectiveness of antenatal Guided Self Help, modified for pregnancy and delivered by National Health Service Psychological Wellbeing Practitioners. Antenatal Guided Self Help, in addition to usual care, is compared with usual care for pregnant women diagnosed with mild to moderate depression and mixed anxiety and depression, using the Structured Clinical Interview for DSM-IV Disorders. Modifications for pregnancy include perinatal mental health training, addressing pregnancy-specific worries and including sections on health issues in pregnancy and planning for parenthood. Women allocated to Guided Self Help will be seen for up to eight sessions by a Psychological Wellbeing Practitioner (including an initial assessment session); there will also be an appointment at 12 weeks after delivery. Research measures including the Edinburgh Postnatal Depression Scale (primary outcome) and other measures of depression, anxiety, quality of life and service use will be collected from women before random allocation, 14 weeks after random allocation and at 12 weeks after delivery. Potential psychological mechanisms of the intervention will be explored using the Pregnancy-Related Thoughts Questionnaire and the Metacognitive Awareness Questionnaire. DISCUSSION: The DAWN trial is the first exploratory trial to investigate the efficacy of antenatal Guided Self Help for pregnant women with mild to moderate depression meeting DSM-IV diagnostic criteria. Recruitment started January 2015 and is expected to be completed by July 2016. TRIAL REGISTRATION: ISRCTN registry: ISRCTN83768230. Registered on 8 August 2014. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13063-016-1632-6) contains supplementary material, which is available to authorized users

Parents’ and caregivers’ experiences and behaviours when eating out with children with a food hypersensitivity

Abstract Background For parents and caregivers of food hypersensitive (FH) children, accommodating their child’s dietary needs when eating out can be a challenging experience. This study explored caregivers’ experiences and behaviours when eating out with their FH child in order to gain insights into how they support and prepare their child in negotiating safe eating out experiences. Methods A cross-sectional, qualitative design was used. In depth, semi-structured interviews were carried out with 15 caregivers of children with FH. Interviews were analysed using framework analysis. Results Caregivers reported a number of issues relating to eating out with their FH child, or allowing their child to eat out without their supervision. Through themes of ‘family context’, ‘child-focused concerns’, and ‘venue issues’, caregivers described how they managed these and explained the limitations and sacrifices that FH imposed on their child, themselves, and family members. Conclusions Through deeper understanding of the anxieties, negotiations and compromises experienced by caregivers of children with FH when they are eating out, clinicians and support charities can tailor their support to meet the needs of caregivers and children. Support and education provision should focus on providing caregivers of children with FH the tools and strategies to help enable safe eating out experiences