58 research outputs found

    What Families, Clinicians and Payors Need to Know About Transitional Rehabilitation

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    When a person sustains a traumatic brain injury (TBI), he and his family are thrust into a health care system that is unfamiliar and difficult to navigate. Too often, patients do not have access to the full continuum of treatment - especially transitional rehabilitation (TR). This article addresses why that is so and ways to change it

    The Simons Observatory: Magnetic Shielding Measurements for the Universal Multiplexing Module

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    The Simons Observatory (SO) includes four telescopes that will measure the temperature and polarization of the cosmic microwave background using over 60,000 highly sensitive transition-edge bolometers (TES). These multichroic TES bolometers are read out by a microwave RF SQUID multiplexing system with a multiplexing factor of 910. Given that both TESes and SQUIDs are susceptible to magnetic field pickup and that it is hard to predict how they will respond to such fields, it is important to characterize the magnetic response of these systems empirically. This information can then be used to limit spurious signals by informing magnetic shielding designs for the detectors and readout. This paper focuses on measurements of magnetic pickup with different magnetic shielding configurations for the SO universal multiplexing module (UMM), which contains the SQUIDs, associated resonators, and TES bias circuit. The magnetic pickup of a prototype UMM was tested under three shielding configurations: no shielding (copper packaging), aluminum packaging for the UMM, and a tin/lead-plated shield surrounding the entire dilution refrigerator 100 mK cold stage. The measurements show that the aluminum packaging outperforms the copper packaging by a shielding factor of 8-10, and adding the tin/lead-plated 1K shield further increases the relative shielding factor in the aluminum configuration by 1-2 orders of magnitude.Comment: 7 pages, 4 figure, conference proceedings submitted to the Journal of Low Temperature Physic

    Developing a New Generation of Integrated Micro-Spec Far Infrared Spectrometers for the EXperiment for Cryogenic Large-Aperture Intensity Mapping (EXCLAIM)

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    The current state of far-infrared astronomy drives the need to develop compact, sensitive spectrometers for future space and ground-based instruments. Here we present details of the μ\rm \mu-Spec spectrometers currently in development for the far-infrared balloon mission EXCLAIM. The spectrometers are designed to cover the 555714 μ\rm 555 - 714\ \mum range with a resolution of $\rm R\ =\ \lambda / \Delta\lambda\ =\ 512atthe at the \rm 638\ \mumbandcenter.ThespectrometerdesignincorporatesaRowlandgratingspectrometerimplementedinaparallelplatewaveguideonalowlosssinglecrystalSichip,employingNbmicrostripplanartransmissionlinesandthinfilmAlkineticinductancedetectors(KIDs).TheEXCLAIMm band center. The spectrometer design incorporates a Rowland grating spectrometer implemented in a parallel plate waveguide on a low-loss single-crystal Si chip, employing Nb microstrip planar transmission lines and thin-film Al kinetic inductance detectors (KIDs). The EXCLAIM \rm \muSpecdesignisanadvancementuponasuccessful-Spec design is an advancement upon a successful \rm R = 64\ \muSpecprototype,andcanbeconsideredasubmmsuperconductingphotonicintegratedcircuit(PIC)thatcombinesspectraldispersionanddetection.Thedesignoperatesinasingle-Spec prototype, and can be considered a sub-mm superconducting photonic integrated circuit (PIC) that combines spectral dispersion and detection. The design operates in a single M{=}2gratingorder,allowingonespectrometertocoverthefullEXCLAIMbandwithoutrequiringamultiorderfocalplane.TheEXCLAIMinstrumentwillflysixspectrometers,whicharefabricatedonasingle150mmdiameterSiwafer.FabricationinvolvesaflipwaferbondingprocesswithpatterningofthesuperconductinglayersonbothsidesoftheSidielectric.Thespectrometersaredesignedtooperateat100mK,andwillinclude355AlKIDdetectorstargetingagoalofNEP grating order, allowing one spectrometer to cover the full EXCLAIM band without requiring a multi-order focal plane. The EXCLAIM instrument will fly six spectrometers, which are fabricated on a single 150 mm diameter Si wafer. Fabrication involves a flip-wafer-bonding process with patterning of the superconducting layers on both sides of the Si dielectric. The spectrometers are designed to operate at 100 mK, and will include 355 Al KID detectors targeting a goal of NEP {\sim}8\times10^{-19} \rm W/\sqrt{Hz}.Wesummarizethedesign,fabrication,andongoingdevelopmentofthese. We summarize the design, fabrication, and ongoing development of these \rm \mu$-Spec spectrometers for EXCLAIM.Comment: 9 pages, 5 figures, to appear in the Proceedings of the SPIE Astronomical Telescopes + Instrumentation (2022

    Central venous catheter use in severe malaria: time to reconsider the World Health Organization guidelines?

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    <p>Abstract</p> <p>Background</p> <p>To optimize the fluid status of adult patients with severe malaria, World Health Organization (WHO) guidelines recommend the insertion of a central venous catheter (CVC) and a target central venous pressure (CVP) of 0-5 cmH<sub>2</sub>O. However there are few data from clinical trials to support this recommendation.</p> <p>Methods</p> <p>Twenty-eight adult Indian and Bangladeshi patients admitted to the intensive care unit with severe <it>falciparum </it>malaria were enrolled in the study. All patients had a CVC inserted and had regular CVP measurements recorded. The CVP measurements were compared with markers of disease severity, clinical endpoints and volumetric measures derived from transpulmonary thermodilution.</p> <p>Results</p> <p>There was no correlation between the admission CVP and patient outcome (p = 0.67) or disease severity (p = 0.33). There was no correlation between the baseline CVP and the concomitant extravascular lung water (p = 0.62), global end diastolic volume (p = 0.88) or cardiac index (p = 0.44). There was no correlation between the baseline CVP and the likelihood of a patient being fluid responsive (p = 0.37). On the occasions when the CVP was in the WHO target range patients were usually hypovolaemic and often had pulmonary oedema by volumetric measures. Seven of 28 patients suffered a complication of the CVC insertion, although none were fatal.</p> <p>Conclusion</p> <p>The WHO recommendation for the routine insertion of a CVC, and the maintenance of a CVP of 0-5 cmH<sub>2</sub>O in adults with severe malaria, should be reconsidered.</p

    Feasibility, safety, acceptability, and yield of office-based, screening transnasal esophagoscopy (with video)

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    Endoscopic screening for esophageal neoplasia can identify patients eligible for early intervention for pre-cancerous lesions. Unsedated transnasal esophagoscopy may provide an efficient and accurate endoscopic assessment with fewer risks and less cost compared to conventional upper endoscopy

    The Simons Observatory Large Aperture Telescope Receiver

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    The Simons Observatory (SO) Large Aperture Telescope Receiver (LATR) will be coupled to the Large Aperture Telescope located at an elevation of 5,200 m on Cerro Toco in Chile. The resulting instrument will produce arcminute-resolution millimeter-wave maps of half the sky with unprecedented precision. The LATR is the largest cryogenic millimeter-wave camera built to date with a diameter of 2.4 m and a length of 2.6 m. It cools 1200 kg of material to 4 K and 200 kg to 100 mk, the operating temperature of the bolometric detectors with bands centered around 27, 39, 93, 145, 225, and 280 GHz. Ultimately, the LATR will accommodate 13 40 cm diameter optics tubes, each with three detector wafers and a total of 62,000 detectors. The LATR design must simultaneously maintain the optical alignment of the system, control stray light, provide cryogenic isolation, limit thermal gradients, and minimize the time to cool the system from room temperature to 100 mK. The interplay between these competing factors poses unique challenges. We discuss the trade studies involved with the design, the final optimization, the construction, and ultimate performance of the system

    The Simons Observatory microwave SQUID multiplexing detector module design

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    Advances in cosmic microwave background (CMB) science depend on increasing the number of sensitive detectors observing the sky. New instruments deploy large arrays of superconducting transition-edge sensor (TES) bolometers tiled densely into ever larger focal planes. High multiplexing factors reduce the thermal loading on the cryogenic receivers and simplify their design. We present the design of focal-plane modules with an order of magnitude higher multiplexing factor than has previously been achieved with TES bolometers. We focus on the novel cold readout component, which employs microwave SQUID multiplexing (μ\mumux). Simons Observatory will use 49 modules containing 60,000 bolometers to make exquisitely sensitive measurements of the CMB. We validate the focal-plane module design, presenting measurements of the readout component with and without a prototype detector array of 1728 polarization-sensitive bolometers coupled to feedhorns. The readout component achieves a 95%95\% yield and a 910 multiplexing factor. The median white noise of each readout channel is 65 pA/Hz\mathrm{pA/\sqrt{Hz}}. This impacts the projected SO mapping speed by <8%< 8\%, which is less than is assumed in the sensitivity projections. The results validate the full functionality of the module. We discuss the measured performance in the context of SO science requirements, which are exceeded.Comment: Accepted to The Astrophysical Journa

    Tracking the X-ray Polarization of the Black Hole Transient Swift J1727.8-1613 during a State Transition

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    We report on a campaign on the bright black hole X-ray binary Swift J1727.8-1613 centered around five observations by the Imaging X-ray Polarimetry Explorer (IXPE). This is the first time it has been possible to trace the evolution of the X-ray polarization of a black hole X-ray binary across a hard to soft state transition. The 2--8 keV polarization degree slowly decreased from \sim4\% to \sim3\% across the five observations, but remained in the North-South direction throughout. Using the Australia Telescope Compact Array (ATCA), we measure the intrinsic 7.25 GHz radio polarization to align in the same direction. Assuming the radio polarization aligns with the jet direction (which can be tested in the future with resolved jet images), this implies that the X-ray corona is extended in the disk plane, rather than along the jet axis, for the entire hard intermediate state. This in turn implies that the long (\gtrsim10 ms) soft lags that we measure with the Neutron star Interior Composition ExploreR (NICER) are dominated by processes other than pure light-crossing delays. Moreover, we find that the evolution of the soft lag amplitude with spectral state differs from the common trend seen for other sources, implying that Swift J1727.8-1613 is a member of a hitherto under-sampled sub-population.Comment: Submitted to ApJ. 20 pages, 8 figure
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