539 research outputs found
Technical Challenges and Opportunities of Centralizing Space Science Mission Operations (SSMO) at NASA Goddard Space Flight Center
The NASA Goddard Space Science Mission Operations project (SSMO) is performing a technical cost-benefit analysis for centralizing and consolidating operations of a diverse set of missions into a unified and integrated technical infrastructure. The presentation will focus on the notion of normalizing spacecraft operations processes, workflows, and tools. It will also show the processes of creating a standardized open architecture, creating common security models and implementations, interfaces, services, automations, notifications, alerts, logging, publish, subscribe and middleware capabilities. The presentation will also discuss how to leverage traditional capabilities, along with virtualization, cloud computing services, control groups and containers, and possibly Big Data concepts
Lunisolar Perturbations of High-Eccentricity Orbits Such as the Magnetospheric Multiscale Mission
For highly eccentric orbits such as that of the Magnetospheric Multiscale (MMS)mission, with apogee radius now 29.34 Earth radii, the third-body effects of Sun andMoon are the major perturbations. One key consequence is an oscillation in MMSperigee altitude, on an approximately 6 year cycle. This variation has already requiredperigee-raise maneuvers to avoid an untimely reentry. There is also a long-termevolution in the orientation of the MMS orbit, with period roughly twice as long. Thiseffect may potentially be useful for MMS science studies, as it can bring the spacecraftinto new regions of the magnetosphere
The effect of population-based blood pressure screening on long-term cardiometabolic morbidity and mortality in Germany: A regression discontinuity analysis
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The Carnegie-Chicago Hubble Program. VIII. An Independent Determination of the Hubble Constant Based on the Tip of the Red Giant Branch
We present a new and independent determination of the local value of the Hubble constant based on a calibration of the tip of the red giant branch (TRGB) applied to Type Ia supernovae (SNe Ia). We find a value of H0 = 69.8 Ā± 0.8 (Ā±1.1% stat) Ā± 1.7 (Ā±2.4% sys) km sā1 Mpcā1. The TRGB method is both precise and accurate and is parallel to but independent of the Cepheid distance scale. Our value sits midway in the range defined by the current Hubble tension. It agrees at the 1.2Ļ level with that of the Planck Collaboration et al. estimate and at the 1.7Ļ level with the Hubble Space Telescope (HST) SHoES measurement of H0 based on the Cepheid distance scale. The TRGB distances have been measured using deep HST Advanced Camera for Surveys imaging of galaxy halos. The zero-point of the TRGB calibration is set with a distance modulus to the Large Magellanic Cloud of 18.477 Ā± 0.004 (stat) Ā± 0.020 (sys) mag, based on measurement of 20 late-type detached eclipsing binary stars, combined with an HST parallax calibration of a 3.6 Ī¼m Cepheid Leavitt law based on Spitzer observations. We anchor the TRGB distances to galaxies that extend our measurement into the Hubble flow using the recently completed Carnegie Supernova Project I ( CSP-I ) sample containing about 100 well-observed SNe Ia . There are several advantages of halo TRGB distance measurements relative to Cepheid variables; these include low halo reddening, minimal effects of crowding or blending of the photometry, only a shallow (calibrated) sensitivity to metallicity in the I band, and no need for multiple epochs of observations or concerns of different slopes with period. In addition, the host masses of our TRGB host-galaxy sample are higher, on average, than those of the Cepheid sample, better matching the range of host-galaxy masses in the CSP-I distant sample and reducing potential systematic effects in the SNe Ia measurements
Towards Fairer Datasets: Filtering and Balancing the Distribution of the People Subtree in the ImageNet Hierarchy
Computer vision technology is being used by many but remains representative
of only a few. People have reported misbehavior of computer vision models,
including offensive prediction results and lower performance for
underrepresented groups. Current computer vision models are typically developed
using datasets consisting of manually annotated images or videos; the data and
label distributions in these datasets are critical to the models' behavior. In
this paper, we examine ImageNet, a large-scale ontology of images that has
spurred the development of many modern computer vision methods. We consider
three key factors within the "person" subtree of ImageNet that may lead to
problematic behavior in downstream computer vision technology: (1) the stagnant
concept vocabulary of WordNet, (2) the attempt at exhaustive illustration of
all categories with images, and (3) the inequality of representation in the
images within concepts. We seek to illuminate the root causes of these concerns
and take the first steps to mitigate them constructively.Comment: Accepted to FAT* 202
The Carnegie-Chicago Hubble Program. VIII. An Independent Determination of the Hubble Constant Based on the Tip of the Red Giant Branch
We present a new and independent determination of the local value of the
Hubble constant based on a calibration of the Tip of the Red Giant Branch
(TRGB) applied to Type Ia supernovae (SNeIa). We find a value of Ho = 69.8 +/-
0.8 (+/-1.1\% stat) +/- 1.7 (+/-2.4\% sys) km/sec/Mpc. The TRGB method is both
precise and accurate, and is parallel to, but independent of the Cepheid
distance scale. Our value sits midway in the range defined by the current
Hubble tension. It agrees at the 1.2-sigma level with that of the Planck 2018
estimate, and at the 1.7-sigma level with the SHoES measurement of Ho based on
the Cepheid distance scale. The TRGB distances have been measured using deep
Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) imaging of
galaxy halos. The zero point of the TRGB calibration is set with a distance
modulus to the Large Magellanic Cloud of 18.477 +/- 0.004 (stat) +/-0.020 (sys)
mag, based on measurement of 20 late-type detached eclipsing binary (DEB)
stars, combined with an HST parallax calibration of a 3.6 micron Cepheid
Leavitt law based on Spitzer observations. We anchor the TRGB distances to
galaxies that extend our measurement into the Hubble flow using the recently
completed Carnegie Supernova Project I sample containing about 100
well-observed SNeIa. There are several advantages of halo TRGB distance
measurements relative to Cepheid variables: these include low halo reddening,
minimal effects of crowding or blending of the photometry, only a shallow
(calibrated) sensitivity to metallicity in the I-band, and no need for multiple
epochs of observations or concerns of different slopes with period. In
addition, the host masses of our TRGB host-galaxy sample are higher on average
than the Cepheid sample, better matching the range of host-galaxy masses in the
CSP distant sample, and reducing potential systematic effects in the SNeIa
measurements.Comment: 60 pages, 20 figures, accepted for publication in the Astrophysical
Journa
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āScrutinised, judged and sabotagedā: A qualitative video diary study of first-time breastfeeding mothers
Objective To explore how support impacted on mothersā breastfeeding experiences in the first few weeks following birth. Design A qualitative approach explored real-time experiences of breastfeeding captured by five first-time mothers in the South of England on camcorder as video diaries. A multi-dimensional approach involving thematic analysis ensured both the audio and visual elements of the data were analysed. Findings Mothers felt āunder surveillanceā by the biomedical approach to support from the healthcare team. At best mothers felt reassured that they were āon the right trackā. When mothers felt their breastfeeding was constantly being examined, criticised and threatened they felt āscrutinised, judged and sabotagedā. When they found it difficult to access healthcare support, or they avoided it altogether to circumvent further scrutiny, they felt āabandoned and aloneā. Key conclusions Collecting audio-visual data in real-time adds fresh insights into how support impacts mothersā experiences of breastfeeding. The biomedical approach to support for breastfeeding is not effective. Scrutinising, judging and/or sabotaging mothersā attempts to breastfeed can have long-lasting effects on maternal emotional wellbeing. Implications for practice Breastfeeding support might be improved by adopting a more social model of care. Future research needs to explore how relationship-based support can be provided by the health service
The nucleotide composition of microsatellites impacts both replication fidelity and mismatch repair in human colorectal cells
Microsatellite instability is a key mechanism of colon carcinogenesis. We have previously studied mutations within a (CA)13 microsatellite using an enhanced green fluorescent protein (EGFP)-based reporter assay that allows the distinction of replication errors and mismatch repair (MMR) activity. Here we utilize this assay to compare mutations of mono- and dinucleotide repeats in human colorectal cells. HCT116 and HCT116+chr3 cells were stably transfected with EGFP-based plasmids harboring A10, G10, G16, (CA)13 and (CA)26 repeats. EGFP-positive mutant fractions were quantitated by flow cytometry, mutation rates were calculated and the mutant spectrum was analyzed by cycle sequencing. EGFP fluorescence pattern changed with the microsatellite's nucleotide sequence and cell type and clonal variations were observed in mononucleotide repeats. Replication errors (as calculated in HCT116) at A10 repeats were 5ā10-fold higher than in G10, G16 were 30-fold higher than G10 and (CA)26 were 10-fold higher than (CA)13. The mutation rates in hMLH1-proficient HCT116+chr3 were 30ā230-fold lower than in HCT116. MMR was more efficient in G16 than in A10 clones leading to a higher stability of poly-G tracts. Mutation spectra revealed predominantly 1-unit deletions in A10, (CA)13 and G10 and 2-unit deletions or 1-unit insertion in (CA)26. These findings indicate that both replication fidelity and MMR are affected by the microsatellite's nucleotide composition
Environmental and microbial factors influencing methane and nitrous oxide fluxes in Mediterranean cork oak woodlands: trees make a difference
Original Researchinfo:eu-repo/semantics/publishedVersio
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