169 research outputs found

    Upper Atmospheric Monitoring for Ares I-X Ascent Loads and Trajectory Evaluation on the Day-of-Launch

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    During the launch countdown of the Ares I-X test vehicle, engineers from Langley Research Center will use profiles of atmospheric density and winds in evaluating vehicle ascent loads and controllability. A schedule for the release of balloons to measure atmospheric density and winds has been developed by the Natural Environments Branch at Marshall Space Flight Center to help ensure timely evaluation of the vehicle ascent loads and controllability parameters and support a successful launch of the Ares I-X vehicle

    Dissecting the cellular landscape and transcriptome network in viral myocarditis by single-cell RNA sequencing

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    Coxsackievirus B3 (CVB3)-induced myocarditis is commonly employed to study viral pathogenesis in mice.Chronically affected micemaydevelop dilated cardiomyopathy, which may involve the mediation of immune and nonimmune cells. To dissect this complexity, we performed single-cell RNA sequencing on heart cells from healthy and myocarditic mice, leading us to note significant proportions of myeloid cells, T cells, and fibroblasts. Although the transcriptomes of myeloid cells were mainly of M2 phenotype, the Th17 cells, CTLs, and Treg cells had signatures critical for cytotoxic functions. Fibroblasts were heterogeneous expressing genes important in fibrosis and regulation of inflammation and immune responses. The intercellular communication networks revealed unique interactions and signaling pathways in the cardiac cellulome, whereas myeloid cells and T cells had upregulated unique transcription factors modulating cardiac remodeling functions. Together, our data suggest thatM2cells, T cells, and fibroblasts may cooperatively or independently participate in the pathogenesis of viral myocarditis

    Dissecting the cellular landscape and transcriptome network in viral myocarditis by single-cell RNA sequencing

    Get PDF
    Coxsackievirus B3 (CVB3)-induced myocarditis is commonly employed to study viral pathogenesis in mice. Chronically affected mice may develop dilated cardiomyopathy, which may involve the mediation of immune and nonimmune cells. To dissect this complexity, we performed single-cell RNA sequencing on heart cells from healthy and myocarditic mice, leading us to note significant proportions of myeloid cells, T cells, and fibroblasts. Although the transcriptomes of myeloid cells were mainly of M2 phenotype, the Th17 cells, CTLs, and Treg cells had signatures critical for cytotoxic functions. Fibroblasts were heterogeneous expressing genes important in fibrosis and regulation of inflammation and immune responses. The intercellular communication networks revealed unique interactions and signaling pathways in the cardiac cellulome, whereas myeloid cells and T cells had upregulated unique transcription factors modulating cardiac remodeling functions. Together, our data suggest that M2 cells, T cells, and fibroblasts may cooperatively or independently participate in the pathogenesis of viral myocarditis

    Controls on Ecosystem Carbon Dioxide Exchange in Short- and Long-Hydroperiod Florida Everglades Freshwater Marshes

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    Although freshwater wetlands are among the most productive ecosystems on Earth, little is known of carbon dioxide (CO2) exchange in low latitude wetlands. The Everglades is an extensive, oligotrophic wetland in south Florida characterized by short- and long-hydroperiod marshes. Chamber-based CO2 exchange measurements were made to compare the marshes and examine the roles of primary producers, seasonality, and environmental drivers in determining exchange rates. Low rates of CO2 exchange were observed in both marshes with net ecosystem production reaching maxima of 3.77 and 4.28 μmol CO2 m−2 s−1 in short- and long-hydroperiod marshes, respectively. Fluxes of CO2 were affected by seasonality only in the short-hydroperiod marsh, where flux rates were significantly lower in the wet season than in the dry season. Emergent macrophytes dominated fluxes at both sites, though this was not the case for the short-hydroperiod marsh in the wet season. Water depth, a factor partly under human control, significantly affected gross ecosystem production at the short-hydroperiod marsh. As Everglades ecosystem restoration proceeds, leading to deeper water and longer hydroperiods, productivity in short-hydroperiod marshes will likely be more negatively affected than in long-hydroperiod marshes. The Everglades stand in contrast to many freshwater wetlands because of ecosystem-wide low productivity rates

    Ares I-X Best Estimated Trajectory Analysis and Results

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    The Ares I-X trajectory reconstruction produced best estimated trajectories of the flight test vehicle ascent through stage separation, and of the first and upper stage entries after separation. The trajectory reconstruction process combines on-board, ground-based, and atmospheric measurements to produce the trajectory estimates. The Ares I-X vehicle had a number of on-board and ground based sensors that were available, including inertial measurement units, radar, air-data, and weather balloons. However, due to problems with calibrations and/or data, not all of the sensor data were used. The trajectory estimate was generated using an Iterative Extended Kalman Filter algorithm, which is an industry standard processing algorithm for filtering and estimation applications. This paper describes the methodology and results of the trajectory reconstruction process, including flight data preprocessing and input uncertainties, trajectory estimation algorithms, output transformations, and comparisons with preflight predictions

    Ares I-X Best Estimated Trajectory and Comparison with Pre-Flight Predictions

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    The Ares I-X trajectory reconstruction produced best estimated trajectories of the flight test vehicle ascent through stage separation, and of the first and upper stage entries after separation. The trajectory reconstruction process combines on-board, ground-based, and atmospheric measurements to produce the trajectory estimates. The Ares I-X vehicle had a number of on-board and ground based sensors that were available, including inertial measurement units, radar, air- data, and weather balloons. However, due to problems with calibrations and/or data, not all of the sensor data were used. The trajectory estimate was generated using an Iterative Extended Kalman Filter algorithm, which is an industry standard processing algorithm for filtering and estimation applications. This paper describes the methodology and results of the trajectory reconstruction process, including flight data preprocessing and input uncertainties, trajectory estimation algorithms, output transformations, and comparisons with preflight predictions

    Attitudes toward cost-conscious care among U.S. physicians and medical students: analysis of national cross-sectional survey data by age and stage of training

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    Abstract Background The success of initiatives intended to increase the value of health care depends, in part, on the degree to which cost-conscious care is endorsed by current and future physicians. This study aimed to first analyze attitudes of U.S. physicians by age and then compare the attitudes of physicians and medical students. Methods A paper survey was mailed in mid-2012 to 3897 practicing physicians randomly selected from the American Medical Association Masterfile. An electronic survey was sent in early 2015 to all 5,992 students at 10 U.S. medical schools. Survey items measured attitudes toward cost-conscious care and perceived responsibility for reducing healthcare costs. Physician responses were first compared across age groups (30–40 years, 41–50 years, 51–60 years, and > 60 years) and then compared to student responses using Chi square tests and logistic regression analyses (controlling for sex). Results A total of 2,556 physicians (65%) and 3395 students (57%) responded. Physician attitudes generally did not differ by age, but differed significantly from those of students. Specifically, students were more likely than physicians to agree that cost to society should be important in treatment decisions (p < 0.001) and that physicians should sometimes deny beneficial but costly services (p < 0.001). Students were less likely to agree that it is unfair to ask physicians to be cost-conscious while prioritizing patient welfare (p < 0.001). Compared to physicians, students assigned more responsibility for reducing healthcare costs to hospitals and health systems (p < 0.001) and less responsibility to lawyers (p < 0.001) and patients (p < 0.001). Nearly all significant differences persisted after controlling for sex and when only the youngest physicians were compared to students. Conclusions Physician attitudes toward cost-conscious care are similar across age groups. However, physician attitudes differ significantly from medical students, even among the youngest physicians most proximate to students in age. Medical student responses suggest they are more accepting of cost-conscious care than physicians and attribute more responsibility for reducing costs to organizations and systems rather than individuals. This may be due to the combined effects of generational differences, new medical school curricula, students’ relative inexperience providing cost-conscious care within complex healthcare systems, and the rapidly evolving U.S. healthcare system.https://deepblue.lib.umich.edu/bitstream/2027.42/146517/1/12909_2018_Article_1388.pd

    The State of Coral Reef Ecosystems of the United States and Pacific Freely Associated States: 2002

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    Called for by the U.S. Coral Reef Task Force’s (USCRTF) National Action Plan to Conserve Coral Reefs, this is the first biennial report on the condition of coral reefs. It is the scientific baseline for subsequent reports on the health of U.S. coral reef ecosystems that are to be used by NOAA and others to evaluate the efficacy of coral reef conservation and management practices. The National Oceanic and Atmospheric Administration’s National Ocean Service led the development of this report. It was authored by 38 experts and supported by 79 contributors from government agencies and non-governmental organizations across the nation and internationally. Over 100 Task Force members and other notable scientists have reviewed this document
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