101 research outputs found

    Tracking the quark-gluon plasma

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    Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997.Includes bibliographical references (p. 171).by Michael I. Duff.M.Eng

    Field and laboratory validation of remote rover operations Science Team findings: The CanMars Mars Sample Return analogue mission

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    The CanMars Mars Sample Return Analogue Deployment (MSRAD) was a closely simulated, end-to-end Mars Sample Return (MSR) mission scenario, with instrumentation, goals, and constraints modeled on the upcoming NASA Mars 2020 rover mission; this paper reports on the post-mission validation of the exercise. The exercise utilized the CSA Mars Exploration Science Rover (MESR) rover, deployed to Utah, USA, at a Mars-analogue field site. The principal features of the field site located near Green River, Utah are Late Jurassic inverted, fluvial paleochannels, analogous to features on Mars in sites being considered for the ESA ExoMars rover mission and present within the chosen landing site for the Mars 2020 rover mission. The in-simulation (“in-sim”) mission operations team worked remotely from The University of Western Ontario, Canada. A suite of MESR-integrated and hand-held spectrometers was selected to mimic those of the Mars 2020 payload, and a Utah-based, on-site team was tasked with field operations to carry out the data collection and sampling as commanded by the in-sim team. As a validation of the in-sim mission science findings, the field team performed an independent geological assessment. This paper documents the field team's on-site geological assessment and subsequent laboratory and analytical results, then offers a comparison of mission (in-sim) and post-mission (laboratory) science results. The laboratory-based findings were largely consistent with the in-sim rover-derived data and geological interpretations, though some notable exceptions highlight the inherent difficulties in remote science. In some cases, available data was insufficient for lithologic identification given the absence of other important contextual information (e.g., textural information). This study suggests that the in-sim instruments were largely adequate for the Science Team to characterize samples; however, rover-based field work is necessarily hampered by mobility and time constraints with an obvious effect on efficiency but also precision, and to some extent, accuracy of the findings. The data show a dearth of preserved total organic carbon (TOC) – used as a proxy for ancient biosignature preservation potential – in the fluvial-lacustrine system of this field site, suggesting serious consideration with respect to the capabilities and opportunities for addressing the Mars exploration goals. We therefore suggest a thorough characterization of terrestrial sites analogous to those of Mars rover landing sites, and in-depth field studies like CanMars as important, pre-mission strategic exercises

    Optical modeling and polarization calibration for CMB measurements with ACTPol and Advanced ACTPol

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    The Atacama Cosmology Telescope Polarimeter (ACTPol) is a polarization sensitive upgrade to the Atacama Cosmology Telescope. Located at an elevation of 5190 m, ACTPol measures the Cosmic Microwave Background (CMB) temperature and polarization with arcminute-scale angular resolution. Calibration of the detector angles is a critical step in producing maps of the CMB polarization. Polarization angle offsets in the detector calibration can cause leakage in polarization from E to B modes and induce a spurious signal in the EB and TB cross correlations, which eliminates our ability to measure potential cosmological sources of EB and TB signals, such as cosmic birefringence. We present our optical modeling and measurements associated with calibrating the detector angles in ACTPol.Comment: 12 pages, 8 figures, conference proceedings submitted to Proceedings of SPIE; added reference in section 2 and merged repeated referenc

    Mechanical design and development of TES bolometer detector arrays for the Advanced ACTPol experiment

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    The next generation Advanced ACTPol (AdvACT) experiment is currently underway and will consist of four Transition Edge Sensor (TES) bolometer arrays, with three operating together, totaling ~5800 detectors on the sky. Building on experience gained with the ACTPol detector arrays, AdvACT will utilize various new technologies, including 150mm detector wafers equipped with multichroic pixels, allowing for a more densely packed focal plane. Each set of detectors includes a feedhorn array of stacked silicon wafers which form a spline profile leading to each pixel. This is then followed by a waveguide interface plate, detector wafer, back short cavity plate, and backshort cap. Each array is housed in a custom designed structure manufactured from high purity copper and then gold plated. In addition to the detector array assembly, the array package also encloses cryogenic readout electronics. We present the full mechanical design of the AdvACT high frequency (HF) detector array package along with a detailed look at the detector array stack assemblies. This experiment will also make use of extensive hardware and software previously developed for ACT, which will be modified to incorporate the new AdvACT instruments. Therefore, we discuss the integration of all AdvACT arrays with pre-existing ACTPol infrastructure.Comment: 9 pages, 5 figures, SPIE Astronomical Telescopes and Instrumentation conference proceeding

    Field and laboratory validation of remote rover operations Science Team findings: The CanMars Mars Sample Return analogue mission

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    The CanMars Mars Sample Return Analogue Deployment (MSRAD) was a closely simulated, end-to-end Mars Sample Return (MSR) mission scenario, with instrumentation, goals, and constraints modeled on the upcoming NASA Mars 2020 rover mission; this paper reports on the post-mission validation of the exercise. The exercise utilized the CSA Mars Exploration Science Rover (MESR) rover, deployed to Utah, USA, at a Mars-analogue field site. The principal features of the field site located near Green River, Utah are Late Jurassic inverted, fluvial paleochannels, analogous to features on Mars in sites being considered for the ESA ExoMars rover mission and present within the chosen landing site for the Mars 2020 rover mission. The in-simulation (“in-sim”) mission operations team worked remotely from The University of Western Ontario, Canada. A suite of MESR-integrated and hand-held spectrometers was selected to mimic those of the Mars 2020 payload, and a Utah-based, on-site team was tasked with field operations to carry out the data collection and sampling as commanded by the in-sim team. As a validation of the in-sim mission science findings, the field team performed an independent geological assessment. This paper documents the field team's on-site geological assessment and subsequent laboratory and analytical results, then offers a comparison of mission (in-sim) and post-mission (laboratory) science results. The laboratory-based findings were largely consistent with the in-sim rover-derived data and geological interpretations, though some notable exceptions highlight the inherent difficulties in remote science. In some cases, available data was insufficient for lithologic identification given the absence of other important contextual information (e.g., textural information). This study suggests that the in-sim instruments were largely adequate for the Science Team to characterize samples; however, rover-based field work is necessarily hampered by mobility and time constraints with an obvious effect on efficiency but also precision, and to some extent, accuracy of the findings. The data show a dearth of preserved total organic carbon (TOC) – used as a proxy for ancient biosignature preservation potential – in the fluvial-lacustrine system of this field site, suggesting serious consideration with respect to the capabilities and opportunities for addressing the Mars exploration goals. We therefore suggest a thorough characterization of terrestrial sites analogous to those of Mars rover landing sites, and in-depth field studies like CanMars as important, pre-mission strategic exercises

    Para-infectious brain injury in COVID-19 persists at follow-up despite attenuated cytokine and autoantibody responses

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    To understand neurological complications of COVID-19 better both acutely and for recovery, we measured markers of brain injury, inflammatory mediators, and autoantibodies in 203 hospitalised participants; 111 with acute sera (1–11 days post-admission) and 92 convalescent sera (56 with COVID-19-associated neurological diagnoses). Here we show that compared to 60 uninfected controls, tTau, GFAP, NfL, and UCH-L1 are increased with COVID-19 infection at acute timepoints and NfL and GFAP are significantly higher in participants with neurological complications. Inflammatory mediators (IL-6, IL-12p40, HGF, M-CSF, CCL2, and IL-1RA) are associated with both altered consciousness and markers of brain injury. Autoantibodies are more common in COVID-19 than controls and some (including against MYL7, UCH-L1, and GRIN3B) are more frequent with altered consciousness. Additionally, convalescent participants with neurological complications show elevated GFAP and NfL, unrelated to attenuated systemic inflammatory mediators and to autoantibody responses. Overall, neurological complications of COVID-19 are associated with evidence of neuroglial injury in both acute and late disease and these correlate with dysregulated innate and adaptive immune responses acutely

    Prolonged COVID-19 symptom duration in people with systemic autoimmune rheumatic diseases: results from the COVID-19 Global Rheumatology Alliance Vaccine Survey

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    OBJECTIVE: We investigated prolonged COVID-19 symptom duration, defined as lasting 28 days or longer, among people with systemic autoimmune rheumatic diseases (SARDs). METHODS: We analysed data from the COVID-19 Global Rheumatology Alliance Vaccine Survey (2 April 2021-15 October 2021) to identify people with SARDs reporting test-confirmed COVID-19. Participants reported COVID-19 severity and symptom duration, sociodemographics and clinical characteristics. We reported the proportion experiencing prolonged symptom duration and investigated associations with baseline characteristics using logistic regression. RESULTS: We identified 441 respondents with SARDs and COVID-19 (mean age 48.2 years, 83.7% female, 39.5% rheumatoid arthritis). The median COVID-19 symptom duration was 15 days (IQR 7, 25). Overall, 107 (24.2%) respondents had prolonged symptom duration (≥28 days); 42/429 (9.8%) reported symptoms lasting ≥90 days. Factors associated with higher odds of prolonged symptom duration included: hospitalisation for COVID-19 vs not hospitalised and mild acute symptoms (age-adjusted OR (aOR) 6.49, 95% CI 3.03 to 14.1), comorbidity count (aOR 1.11 per comorbidity, 95% CI 1.02 to 1.21) and osteoarthritis (aOR 2.11, 95% CI 1.01 to 4.27). COVID-19 onset in 2021 vs June 2020 or earlier was associated with lower odds of prolonged symptom duration (aOR 0.42, 95% CI 0.21 to 0.81). CONCLUSION: Most people with SARDs had complete symptom resolution by day 15 after COVID-19 onset. However, about 1 in 4 experienced COVID-19 symptom duration 28 days or longer; 1 in 10 experienced symptoms 90 days or longer. Future studies are needed to investigate the possible relationships between immunomodulating medications, SARD type/flare, vaccine doses and novel viral variants with prolonged COVID-19 symptoms and other postacute sequelae of COVID-19 among people with SARDs

    Early experience of COVID-19 vaccination in adults with systemic rheumatic diseases : Results from the COVID-19 Global Rheumatology Alliance Vaccine Survey

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    Funding Information: Competing interests SES has received funding from the Vasculitis Foundation and the Vasculitis Clinical Research Consortium unrelated to this work. JL has received research grant funding from Pfizer unrelated to this work. ES is a Board Member of the Canadian Arthritis Patient Alliance, a patient run, volunteer-based organisation whose activities are primarily supported by independent grants from pharmaceutical companies. MP was supported by a Rheumatology Research Foundation Scientist Development grant. DA-R is a Scientific Advisor for GlaxoSmithKilne unrelated to this work. FB reports personal fees from Boehringer, Bone Therapeutics, Expanscience, Galapagos, Gilead, GSK, Merck Sereno, MSD, Nordic, Novartis, Pfizer, Regulaxis, Roche, Sandoz, Sanofi, Servier, UCB, Peptinov, TRB Chemedica and 4P Pharma outside of the submitted work. No funding relevant to this manuscript. RC: speakers bureau for Janssen, Roche, Sanofi, AbbVie. KD reports no COI-unpaid volunteer president of the Autoinflammatory Alliance. Any grants or funding from pharma is received by the non-profit organisation only. CLH received funding under a sponsored research agreement unrelated to the data in the paper from Vifor Pharmaceuticals. LeK has received a research grant from Lilly unrelated to this work. AHJK participated in consulting, advisory board or speaker's bureau for Alexion Pharmaceuticals, Aurinia Pharmaceuticals, Annexon Biosciences, Exagen Diagnostics and GlaxoSmithKilne and received funding under a sponsored research agreement unrelated to the data in the paper from GlaxoSmithKline. JSingh has received consultant fees from Crealta/ Horizon, Medisys, Fidia, PK Med, Two Labs, Adept Field Solutions, Clinical Care Options, Clearview Healthcare Partners, Putnam Associates, Focus Forward, Navigant Consulting, Spherix, MedIQ, Jupiter Life Science, UBM, Trio Health, Medscape, WebMD and Practice Point Communications; and the National Institutes of Health and the American College of Rheumatology. JSingh owns stock options in TPT Global Tech, Vaxart Pharmaceuticals and Charlotte’s Web Holdings. JSingh previously owned stock options in Amarin, Viking and Moderna Pharmaceuticals. JSingh is on the speaker’s bureau of Simply Speaking. JSingh is a member of the executive of Outcomes Measures in Rheumatology (OMERACT), an organisation that develops outcome measures in rheumatology and receives arms-length funding from eight companies. JSingh serves on the FDA Arthritis Advisory Committee. JSingh is the chair of the Veterans Affairs Rheumatology Field Advisory Committee. JSingh is the editor and the Director of the University of Alabama at Birmingham (UAB) Cochrane Musculoskeletal Group Satellite Center on Network Meta-analysis. NSingh is supported by funding from the Rheumatology Research Foundation Investigator Award and the American Heart Association. MFU-G has received research support from Pfizer and Janssen, unrelated to this work. SB reports personal fees from Novartis, AbbVie, Pfizer and Horizon Pharma, outside the submitted work. RG reports personal fees from AbbVie New Zealand, Cornerstones, Janssen New Zealand and personal fees and non-financial support Pfizer New Zealand (all <US$10 000) outside the submitted work. PMM reports personal fees from AbbVie, Eli Lilly, Janssen, Novartis, Pfizer and UCB, grants and personal fees from Orphazyme, outside the submitted work. PCR reports personal fees from AbbVie, Gilead, Lilly and Roche, grants and personal fees from Novartis, UCB Pharma, Janssen and Pfizer and non-financial support from BMS, outside the submitted work. PS reports honoraria from Social media editor for @ACR_Journals, outside the submitted work. ZSW reports grants from NIH, BMS and Principia/ Sanofi and personal fees from Viela Bio and MedPace, outside the submitted work. JY reports personal fees from Pfizer and Eli Lilly, and grants and personal fees from AstraZeneca, outside the submitted work. MJL reports grants from American College of Rheumatology, during the conduct of the study and consulting fees from AbbVie, Amgen, Actelion, Boehringer Ingelheim, BMS, Celgene, Gilead, J&J, Mallinckrodt, Novartis, Pfizer, Roche, Sandoz, Sanofi, Sobi and UCB, outside the submitted work. LGR was supported by the Intramural Research Program of the National Institute of Environmental Health Sciences (NIEHS; ZIAES101074) of the National Institutes of Health. JH reports grants from Childhood Arthritis and Rheumatology Research Alliance (CARRA) and Rheumatology Research Alliance, and personal fees from Novartis, Pfizer and Biogen, outside the submitted work. JSimard received research grant funding from the National Institutes of Health unrelated to this work (NIAMS: R01 AR077103 and NIAID R01 AI154533). JSparks has performed consultancy for AbbVie, Boehringer Ingelheim, Bristol-Myers Squibb, Gilead, Inova Diagnostics, Optum and Pfizer unrelated to this work. Funding Information: Funding This study was supported by the European Alliance of Associations for Rheumatology and American College of Rheumatology Research and Education Foundation. Dr. Lisa Rider's involvement was supported in part by the Intramural Research Program of the National Institutes of Health, National Institute of Environmental Health Sciences. Publisher Copyright: © Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.Background. We describe the early experiences of adults with systemic rheumatic disease who received the COVID-19 vaccine. Methods From 2 April to 30 April 2021, we conducted an online, international survey of adults with systemic rheumatic disease who received COVID-19 vaccination. We collected patient-reported data on clinician communication, beliefs and intent about discontinuing disease-modifying antirheumatic drugs (DMARDs) around the time of vaccination, and patient-reported adverse events after vaccination. Results We analysed 2860 adults with systemic rheumatic diseases who received COVID-19 vaccination (mean age 55.3 years, 86.7% female, 86.3% white). Types of COVID-19 vaccines were Pfizer-BioNTech (53.2%), Oxford/AstraZeneca (22.6%), Moderna (21.3%), Janssen/Johnson & Johnson (1.7%) and others (1.2%). The most common rheumatic disease was rheumatoid arthritis (42.3%), and 81.2% of respondents were on a DMARD. The majority (81.9%) reported communicating with clinicians about vaccination. Most (66.9%) were willing to temporarily discontinue DMARDs to improve vaccine efficacy, although many (44.3%) were concerned about rheumatic disease flares. After vaccination, the most reported patient-reported adverse events were fatigue/somnolence (33.4%), headache (27.7%), muscle/joint pains (22.8%) and fever/chills (19.9%). Rheumatic disease flares that required medication changes occurred in 4.6%. Conclusion. Among adults with systemic rheumatic disease who received COVID-19 vaccination, patient-reported adverse events were typical of those reported in the general population. Most patients were willing to temporarily discontinue DMARDs to improve vaccine efficacy. The relatively low frequency of rheumatic disease flare requiring medications was reassuring.publishersversionPeer reviewe
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