2,396 research outputs found
The Orbital Calibration 2 (OrCa2) CubeSat Mission
The Georgia Institute of Technology (Georgia Tech), in collaboration with the Georgia Tech Research Institute (GTRI), has developed the Orbital Calibration 2 (OrCa2) mission in an effort to improve space domain awareness. OrCa2’s external panels have precise and well-characterized reflective properties that will permit various calibration activities from ground-based optical sensors, with the goal of improving the tracking and detection of resident space objects (RSOs). OrCa2 is a 12U CubeSat designed, fabricated, assembled, and tested almost entirely in-house using GT/GTRI facilities. It will be regularly observed using Georgia Tech’s Space Object Research Telescope (GT-SORT). A number of experiments can be conducted with these measurements, such as pose estimation, validation of RSO trajectory propagations with complementary ground-based laser ranging data, multi-spectral analysis, low-light detection algorithms, and validation of atmospheric scattering models. An onboard imager will serve as both a low-accuracy star camera, as well as an on-orbit optical tracking system capable of RSO streak detection, with a mission goal of gathering simultaneous ground-based and space-borne tracking data of one or more RSOs. Additionally, the OrCa2 spacecraft will host an experimental radiation dosimeter, an experimental software defined radio (SDR) receiver, and an experimental power system. OrCa2 is currently manifested to launch in Q1 2024. An overview of the design, concept of operations, and expected outcomes of the mission will be presented
Pharmacology: The Pharmacodynamics of Nutrients and Nutrient Interactions in Biological Functions
Life-Threatening Clostridial Sepsis in a Postmenopausal Patient with Degenerating Uterine Leiomyoma
Clostridium perfringens is a fulminant infection that affects patients with a high rate of morbidity and mortality. Fortunately, C. perfringens-associated sepsis and death in the gynecologic patient is rarely encountered. We report a case of intrauterine C. perfringens presenting as life-threatening sepsis in a postmenopausal patient
Prospects for the Precision Measurement of the W Mass with the CMS Detector at the LHC
The precise measurement of the mass of the W boson constitutes an important consistency check of the Standard Model and is sensitive to supersymmetric corrections. Together with the top quark mass, the W mass discriminates between the Standard Model and supersymmetric extensions. In this note, methods are presented which employ the large number of Z bosons produced at the LHC to significantly reduce theoretical and experimental uncertainties on the W mass measurement. A precision of about 40 MeV (20 MeV) with the first 1 fb^-1 (10 fb^-1) of integrated luminosity during the low luminosity run of the LHC is expected
Mutations in the mitochondrial cysteinyl-tRNA synthase gene, CARS2, lead to a severe epileptic encephalopathy and complex movement disorder
Background: Mitochondrial disease is often suspected in cases of severe epileptic encephalopathy especially when a complex movement disorder, liver involvement and progressive developmental regression are present. Although mutations in either mitochondrial DNA or POLG are often present, other nuclear defects in mitochondrial DNA replication and protein translation have been associated with a severe epileptic encephalopathy.
Methods: and results We identified a proband with an epileptic encephalopathy, complex movement disorder and a combined mitochondrial respiratory chain enzyme deficiency. The child presented with neurological regression, complex movement disorder and intractable seizures. A combined deficiency of mitochondrial complexes I, III and IV was noted in liver tissue, along with increased mitochondrial DNA content in skeletal muscle. Incomplete assembly of complex V, using blue native polyacrylamide gel electrophoretic analysis and complex I, using western blotting, suggested a disorder of mitochondrial transcription or translation. Exome sequencing identified compound heterozygous mutations in CARS2, a mitochondrial aminoacyl-tRNA synthetase. Both mutations affect highly conserved amino acids located within the functional ligase domain of the cysteinyl-tRNA synthase. A specific decrease in the amount of charged mt-tRNACys was detected in patient fibroblasts compared with controls. Retroviral transfection of the wild-type CARS2 into patient skin fibroblasts led to the correction of the incomplete assembly of complex V, providing functional evidence for the role of CARS2 mutations in disease aetiology.
Conclusions: Our findings indicate that mutations in CARS2 result in a mitochondrial translational defect as seen in individuals with mitochondrial epileptic encephalopathy
Measurements of Non-Wetting Phase Trapping Applied to Carbon Dioxide Storage
We measure the trapped non-wetting phase saturation as a function of the initial saturation in sand packs. The application of the work is for carbon dioxide (CO2) storage in aquifers where capillary trapping is a rapid and effective mechanism to render injected CO2 immobile. We used analogue fluids at ambient conditions. The trapped saturation initially rises linearly with initial saturation to a value of 0.11 for oil/water systems and 0.14 for gas/water systems. There then follows a region where the residual saturation is constant with further increases in initial saturation
from global food systems to individual exposures and mechanisms
Funding Information: This work was supported by Cancer Research UK [Ref: C33493/A29678] and World Cancer Research Fund International [Ref: IIG_FULL_2020_033]. Publisher Copyright: © 2022, The Author(s), under exclusive licence to Springer Nature Limited.Ultra-processed foods (UPFs) have become increasingly dominant globally, contributing to as much as 60% of total daily energy intake in some settings. Epidemiological evidence suggests this worldwide shift in food processing may partly be responsible for the global obesity epidemic and chronic disease burden. However, prospective studies examining the association between UPF consumption and cancer outcomes are limited. Available evidence suggests that UPFs may increase cancer risk via their obesogenic properties as well as through exposure to potentially carcinogenic compounds such as certain food additives and neoformed processing contaminants. We identify priority areas for future research and policy implications, including improved understanding of the potential dual harms of UPFs on the environment and cancer risk. The prevention of cancers related to the consumption of UPFs could be tackled using different strategies, including behaviour change interventions among consumers as well as bolder public health policies needed to improve food environments.publishersversionpublishe
Overview of the Kepler Science Processing Pipeline
The Kepler Mission Science Operations Center (SOC) performs several critical
functions including managing the ~156,000 target stars, associated target
tables, science data compression tables and parameters, as well as processing
the raw photometric data downlinked from the spacecraft each month. The raw
data are first calibrated at the pixel level to correct for bias, smear induced
by a shutterless readout, and other detector and electronic effects. A
background sky flux is estimated from ~4500 pixels on each of the 84 CCD
readout channels, and simple aperture photometry is performed on an optimal
aperture for each star. Ancillary engineering data and diagnostic information
extracted from the science data are used to remove systematic errors in the
flux time series that are correlated with these data prior to searching for
signatures of transiting planets with a wavelet-based, adaptive matched filter.
Stars with signatures exceeding 7.1 sigma are subjected to a suite of
statistical tests including an examination of each star's centroid motion to
reject false positives caused by background eclipsing binaries. Physical
parameters for each planetary candidate are fitted to the transit signature,
and signatures of additional transiting planets are sought in the residual
light curve. The pipeline is operational, finding planetary signatures and
providing robust eliminations of false positives.Comment: 8 pages, 3 figure
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