13 research outputs found

    Seven Sisters: a mission to study fundamental plasma physical processes in the solar wind and a pathfinder to advance space weather prediction

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    This paper summarizes the Seven Sisters solar wind mission concept and the outstanding science questions motivating the mission science objectives. The Seven Sisters mission includes seven individual spacecraft designed to uncover fundamental physical processes in the solar wind and provides up to ≈ 2 days of advanced space weather warnings for 550 Earth days during the mission. The mission will collect critical measurements of the thermal and suprathermal plasma and magnetic fields, utilizing, for the first time, Venus–Sun Lagrange points. The multi-spacecraft configuration makes it possible to distinguish between spatial and temporal changes, define gradients, and quantify cross-scale transport in solar wind structures. Seven Sisters will determine the 3-D structure of the solar wind and its transient phenomena and their evolution in the inner heliosphere. Data from the Seven Sisters mission will allow the identification of physical processes and the quantification of the relative contribution of different mechanisms responsible for suprathermal particle energization in the solar wind

    Daedalus : a low-flying spacecraft for in situ exploration of the lower thermosphere-ionosphere

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    The Daedalus mission has been proposed to the European Space Agency (ESA) in response to the call for ideas for the Earth Observation program's 10th Earth Explorer. It was selected in 2018 as one of three candidates for a phase-0 feasibility study. The goal of the mission is to quantify the key electrodynamic processes that determine the structure and composition of the upper atmosphere, the gateway between the Earth's atmosphere and space. An innovative preliminary mission design allows Daedalus to access electrodynamics processes down to altitudes of 150 km and below. Daedalus will perform in situ measurements of plasma density and temperature, ion drift, neutral density and wind, ion and neutral composition, electric and magnetic fields, and precipitating particles. These measurements will unambiguously quantify the amount of energy deposited in the upper atmosphere during active and quiet geomagnetic times via Joule heating and energetic particle precipitation, estimates of which currently vary by orders of magnitude between models and observation methods. An innovation of the Daedalus preliminary mission concept is that it includes the release of subsatellites at low altitudes: combined with the main spacecraft, these subsatellites will provide multipoint measurements throughout the lower thermosphereionosphere (LTI) region, down to altitudes below 120 km, in the heart of the most under-explored region in the Earth's atmosphere. This paper describes Daedalus as originally proposed to the ESA.Peer reviewe

    Descriptive analysis of long COVID sequelae identified in a multidisciplinary clinic serving hospitalised and non-hospitalised patients

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    Background There are emerging data of long-term effects of coronavirus disease 2019 (COVID-19) comprising a diversity of symptoms. The aim of this study was to systematically describe and measure pulmonary and extra-pulmonary post-COVID-19 complications in relation to acute COVID-19 severity. Methods Patients attending a standard of care 3 months post-hospitalisation follow-up visit and those referred by their general practitioner because of persistent post-COVID-19 symptoms were included. Patients underwent symptomatic, quality of life, pulmonary (lung function and high-resolution computed tomography (HRCT)), cardiac (high-resolution ECG), physical (1-min sit and stand test (1-MSTST), handgrip strength, cardiopulmonary exercise testing (CPET)) and cognitive evaluations. Results All 34 hospitalised and 22 out of 23 non-hospitalised patients had ≄1 complaint or abnormal finding at follow-up. Overall, 67% of patients were symptomatic (Medical Research Council (MRC) ≄2 or COPD assessment test (CAT) ≄10), with no difference between hospitalised versus non-hospitalised patients. Pulmonary function (forced expiratory volume in 1 s (FEV1) or diffusing capacity of the lung for carbon monoxide (DLCO)) <80% of predicted) was impaired in 68% of patients. DLCO was significantly lower in those hospitalised compared to non-hospitalised (70.1±18.0 versus 80.2±11.2% predicted, p=0.02). Overall, 53% had an abnormal HRCT (predominantly ground-glass opacities) with higher composite computed tomography (CT) scores in hospitalised versus non-hospitalised patients (2.3 (0.1–4.8) and 0.0 (0.0–0.3), p<0.001). 1-MSTST was below the 25th percentile in almost half of patients, but no signs of cardiac dysfunction were found. Cognitive impairments were present in 59–66% of hospitalised and 31–44% of non-hospitalised patients (p=0.08). Conclusion Three months after COVID-19 infection, patients were still symptomatic and demonstrated objective respiratory, functional, radiological and cognitive abnormalities, which were more prominent in hospitalised patients. Our study underlines the importance of multidimensional management strategies in these patients

    Achievements and Lessons Learned From Successful Small Satellite Missions for Space Weather-Oriented Research

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    When the first CubeSats were launched nearly two decades ago, few people believed that the miniature satellites would likely prove to be a useful scientific tool. Skeptics abounded. However, the last decade has seen the highly successful implementation of space missions that make creative and innovative use of fast-advancing CubeSat and small satellite technology to carry out important science experiments and missions. Several projects now have used CubeSats to obtain first-of-their-kind observations and findings that have formed the basis for high-profile engineering and science publications, thereby establishing without doubt the scientific value and broad utility of CubeSats. In this paper, we describe recent achievements and lessons learned from a representative selection of successful CubeSat missions with a space weather focus. We conclude that these missions were successful in part because their limited resources promoted not only mission focus but also appropriate risk-taking for comparatively high science return. Quantitative analysis of refereed publications from these CubeSat missions and several larger missions reveals that mission outcome metrics compare favorably when publication number is normalized by mission cost or if expressed as a weighted net scientific impact of all mission publications.Plain Language SummarySpace missions using very small satellites and low resources have demonstrated they can accomplish high quality science, overcoming initial low expectations of many inside the space science community. We focus on one class of small satellites known as “CubeSats.” CubeSats comprise a small number of modular cubes, each the size of a typical tissue box and weighing approximately one kg (like a pineapple). We discuss five CubeSat missions that operated during the last 10 years, each having total mission mass of three kg and total mission costs of slightly more than 1 million US dollars. These missions had focused goals targeting different aspects of space weather. For each mission, we summarize its scientific achievements and lessons learned, many of them common lessons. Larger missions have flown during this same time with overall mass ranging from hundreds to thousands of kilograms and mission costs many hundreds of thousands to over 1 billion US dollars. We compare the relative science value of these smallest and larger missions through the publications they produce in professional journals. Though CubeSat missions yield far fewer total publications compared to larger missions, the cost per publication is lower while still producing comparably high scientific impact.Key PointsMany National Science Foundation/National Aeronautics and Space Administration-funded CubeSat missions have contributed significantly to space weather research and applicationsLow-cost missions benefit from a rapid “fly learn-modify-refly” cycleCubeSat science productivity is comparably high to larger missions if normalized by cost or by weighted impact of refereed publicationsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/173087/1/swe21336.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/173087/2/swe21336_am.pd

    Elevated body weight modulates subcortical volume change and associated clinical response following electroconvulsive therapy

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    Background: Obesity is a frequent somatic comorbidity of major depression, and it has been associated with worse clinical outcomes and brain structural abnormalities. Converging evidence suggests that electroconvulsive therapy (ECT) induces both clinical improvements and increased subcortical grey matter volume in patients with depression. However, it remains unknown whether increased body weight modulates the clinical response and structural neuroplasticity that occur with ECT. Methods: To address this question, we conducted a longitudinal investigation of structural MRI data from the Global ECT-MRI Research Collaboration (GEMRIC) in 223 patients who were experiencing a major depressive episode (10 scanning sites). Structural MRI data were acquired before and after ECT, and we assessed change in subcortical grey matter volume using FreeSurfer and Quarc. Results: Higher body mass index (BMI) was associated with a significantly lower increase in subcortical grey matter volume following ECT. We observed significant negative associations between BMI and change in subcortical grey matter volume, with pronounced effects in the thalamus and putamen, where obese participants showed increases in grey matter volume that were 43.3% and 49.6%, respectively, of the increases found in participants with normal weight. As well, BMI significantly moderated the association between subcortical grey matter volume change and clinical response to ECT. We observed no significant association between BMI and clinical response to ECT. Limitations: Because only baseline BMI values were available, we were unable to study BMI changes during ECT and their potential association with clinical and grey matter volume change. Conclusion: Future studies should take into account the relevance of body weight as a modulator of structural neuroplasticity during ECT treatment and aim to further explore the functional relevance of this novel finding.Funding Agencies|German Research Foundation (DFG)German Research Foundation (DFG) [FOR2107 DA1151/5-1, DA1151/5-2, SFB-TRR58]; Interdisciplinary Center for Clinical Research (IZKF) of the medical faculty of Munster [Dan3/012/17, SEED 11/19]; NIH/NIMHUnited States Department of Health &amp; Human ServicesNational Institutes of Health (NIH) - USANIH National Institute of Mental Health (NIMH) [U01 MH110008, R01 MH092301]; NIH/MIMH [U01 MH111826]; Lundbeck FoundationLundbeckfonden</p

    Brain Changes Induced by Electroconvulsive Therapy Are Broadly Distributed

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    BACKGROUND: Electroconvulsive therapy (ECT) is associated with volumetric enlargements of corticolimbic brain regions. However, the pattern of whole-brain structural alterations following ECT remains unresolved. Here, we examined the longitudinal effects of ECT on global and local variations in gray matter, white matter, and ventricle volumes in patients with major depressive disorder as well as predictors of ECT-related clinical response. METHODS: Longitudinal magnetic resonance imaging and clinical data from the Global ECT-MRI Research Collaboration (GEMRIC) were used to investigate changes in white matter, gray matter, and ventricle volumes before and after ECT in 328 patients experiencing a major depressive episode. In addition, 95 nondepressed control subjects were scanned twice. We performed a mega-analysis of single subject data from 14 independent GEMRIC sites. RESULTS: Volumetric increases occurred in 79 of 84 gray matter regions of interest. In total, the cortical volume increased by mean +/- SD of 1.04 +/- 1.03% (Cohens d = 1.01, p amp;lt; .001) and the subcortical gray matter volume increased by 1.47 +/- 1.05% (d = 1.40, p amp;lt; .001) in patients. The subcortical gray matter increase was negatively associated with total ventricle volume (Spearmans rank correlation rho = -.44, p amp;lt; .001), while total white matter volume remained unchanged (d = -0.05, p = .41). The changes were modulated by number of ECTs and mode of electrode placements. However, the gray matter volumetric enlargements were not associated with clinical outcome. CONCLUSIONS: The findings suggest that ECT induces gray matter volumetric increases that are broadly distributed. However, gross volumetric increases of specific anatomically defined regions may not serve as feasible biomarkers of clinical response.Funding Agencies|Western Norway Regional Health Authority [911986, 912238]; University of Bergen; Fulbright Program; National Institute of Mental HealthUnited States Department of Health &amp; Human ServicesNational Institutes of Health (NIH) - USANIH National Institute of Mental Health (NIMH) [MH092301, MH110008, U01 MH11826]; Interdisciplinary Center for Clinical Research of the Medical Faculty of Munster [Dan 3/012/17]; Lundbeck FoundationLundbeckfonden; Carlos III Health InstituteInstituto de Salud Carlos III [CPII16/00048]; Innovative Medical Research [RE111604, RE111722, RO1 MH111359, U24 DA041123]; German Research FoundationGerman Research Foundation (DFG) [FOR2107 DA1151/5-1, DA1151/5-2, SFB-TRR58]</p
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