Micro-X is a sounding rocket-borne instrument that uses a microcalorimeter array to perform high-resolution X-ray spectroscopy. This instrument flew for the first time on July 22nd, 2018, from the ...White Sands Missile Range, USA. This flight marks the first successful operation of a transition-edge sensor array and its time-division multiplexing readout system in space. This launch was dedicated to the observation of the supernova remnant Cassiopeia A. A failure in the attitude control system prevented the rocket from pointing and led to no time on target. The onboard calibration source provided X-rays in flight, and it is used to compare detector performance during preflight integration, flight, and after the successful post-flight recovery. This calibration data demonstrate the capabilities of the detector in a space environment as well as its potential for future flight.
The Micro-X sounding rocket flew for the first time on July 22, 2018, becoming the first program to fly Transition-Edge Sensors and multiplexing SQUID readout electronics in space. While a rocket ...pointing failure led to no time on-target, the success of the flight systems was demonstrated. The successful flight operation of the instrument puts the program in a position to modify the payload for indirect galactic dark matter searches. The payload modifications are motivated by the science requirements of this observation. Micro-X can achieve world-leading sensitivity in the keV regime with a single flight. Dark matter sensitivity projections have been updated to include recent observations and the expected sensitivity of Micro-X to these observed fluxes. If a signal is seen (as seen in the X-ray satellites), Micro-X can differentiate an atomic line from a dark matter signature.
We present the analysis of 21 bright X-ray knots in the Cassiopeia A supernova remnant from observations spanning 10 yr. We performed a comprehensive set of measurements to reveal the kinematic and ...thermal state of the plasma in each knot, using a combined analysis of two high energy resolution High Energy Transmission Grating (HETG) and four medium energy resolution Advanced CCD Imaging Spectrometer (ACIS) sets of spectra. The ACIS electron temperature estimates agree with the HETG-derived values for approximately half of the knots studied, yielding one of the first comparisons between high resolution temperature estimates and ACIS-derived temperatures. We did not observe the expected spectral evolution-predicted from the ionization age and density estimates for each knot-in all but three of the knots studied. The incompatibility of these measurements with our assumptions has led us to propose a dissociated ejecta model, with the metals unmixed inside the knots, which could place strong constraints on supernova mixing models.
IMPORTANCE: Administration of corticosteroids to women at high risk for delivery in the late preterm period (34-36 weeks’ gestation) improves short-term neonatal outcomes. The cost implications of ...this intervention are not known. OBJECTIVE: To compare the cost-effectiveness of treatment with antenatal corticosteroids with no treatment for women at risk for late preterm delivery. DESIGN, SETTING, AND PARTICIPANTS: This secondary analysis of the Antenatal Late Preterm Steroids trial, a multicenter randomized clinical trial of antenatal corticosteroids vs placebo in women at risk for late preterm delivery conducted from October 30, 2010, to February 27, 2015. took a third-party payer perspective. Maternal costs were based on Medicaid rates and included those of betamethasone, as well as the outpatient visits or inpatient stay required to administer betamethasone. All direct medical costs for newborn care were included. For infants admitted to the neonatal intensive care unit, comprehensive daily costs were stratified by the acuity of respiratory illness. For infants admitted to the regular newborn nursery, nationally representative cost estimates from the literature were used. Effectiveness was measured as the proportion of infants without the primary outcome of the study: a composite of treatment in the first 72 hours of continuous positive airway pressure or high-flow nasal cannula for 2 hours or more, supplemental oxygen with a fraction of inspired oxygen of 30% or more for 4 hours or more, and extracorporeal membrane oxygenation or mechanical ventilation. This secondary analysis was initially started in June 2016 and revision of the analysis began in May 2017. EXPOSURES: Bethamethasone treatment. MAIN OUTCOMES AND MEASURES: Incremental cost-effectiveness ratio. RESULTS: Costs were determined for 1426 mother-infant pairs in the betamethasone group (mean SD maternal age, 28.6 6.3 years; 827 58.0% white) and 1395 mother-infant pairs in the placebo group (mean SD maternal age, 27.9 6.2 years; 794 56.9% white). Treatment with betamethasone was associated with a total mean (SD) woman-infant–pair cost of $4681 ($5798), which was significantly less than the mean (SD) amount of $5379 ($8422) for women and infants in the placebo group (difference, $698; 95% CI, $186-$1257; P = .02). The Antenatal Late Preterm Steroids trial determined that betamethasone use is effective: respiratory morbidity deceased by 2.9% (95% CI, −0.5% to −5.4%). Thus, the cost-effectiveness ratio was −23 986. Inspection of the bootstrap replications confirmed that treatment was the dominant strategy in 5000 samples (98.8%). Sensitivity analyses showed that these results held under most assumptions. CONCLUSIONS AND RELEVANCE: The findings suggest that antenatal betamethasone treatment is associated with a statistically significant decrease in health care costs and with improved outcomes; thus, this treatment may be an economically desirable strategy.
Micro-X is a sounding rocket-borne X-ray telescope that uses a transition edge sensor microcalorimeter array to provide high-energy-resolution spectroscopy. Micro-X is a versatile instrument with ...plans to observe the Puppis A supernova remnant during its first flight, as well as future observations of the Milky Way to search for X-ray signals from decaying dark matter. Commissioning and functionality testing are complete, and the thermal performance of the system has been validated. We are currently evaluating the detector performance in the flight cryostat with the flight multiplexing electronics. Operating in this setup has allowed us to characterize sources of detector and readout noise, as well as to implement mitigation techniques to improve performance in anticipation of the upcoming flight. We present an overview of important noise considerations in addition to an update on latest detector performance.
An important property of dendritic cells (DC), which contributes crucially to their strong immunogenic function, is their capacity to migrate from sites of antigen capture to the draining lymphoid ...organs. Here we studied in detail the migratory pathway and the differentiation of DC during migration in a skin organ culture model and, for comparison, in the conventional contact hypersensitivity system. We report several observations on the capacity of cutaneous DC to migrate in mouse ear skin. (i) Upon application of contact allergens in vivo the density of Langerhans cells in epidermal sheets decreased, as determined by immunostaining for major histocompatibility complex class II, ADPase, F4/80, CD11b, CD32, NLDC-145/DEC-205, and the cytoskeleton protein vimentin. Evaluation was performed by computer assisted morphometry. (ii) Chemically related nonsensitizing or tolerizing compounds left the density of Langerhans cells unchanged. (iii) Immunohistochemical double-staining of dermal sheets from skin organ cultures for major histocompatibility complex class II and CD54 excluded blood vessels as a cutaneous pathway of DC migration. (iv) Electron microscopy of organ cultures revealed dermal accumulations of DC (including Birbeck granule containing Langerhans cells) within typical lymphatic vessels. (v) Populations of migrating DC in organ cultures upregulated markers of maturity (the antigen recognized by monoclonal antibody 2A1, CD86), but retained indicators of immaturity (invariant chain, residual antigen processing function). These data provide additional evidence that during both the induction of contact hypersensitivity and in skin organ culture, Langerhans cells physically leave the epidermis. Both Langerhans cells and dermal DC enter lymphatic vessels. DC mature while they migrate through the skin.
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