1,158 research outputs found

    Development of Thermal Protection Materials for Future Mars Entry, Descent and Landing Systems

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    Entry Systems will play a crucial role as NASA develops the technologies required for Human Mars Exploration. The Exploration Technology Development Program Office established the Entry, Descent and Landing (EDL) Technology Development Project to develop Thermal Protection System (TPS) materials for insertion into future Mars Entry Systems. An assessment of current entry system technologies identified significant opportunity to improve the current state of the art in thermal protection materials in order to enable landing of heavy mass (40 mT) payloads. To accomplish this goal, the EDL Project has outlined a framework to define, develop and model the thermal protection system material concepts required to allow for the human exploration of Mars via aerocapture followed by entry. Two primary classes of ablative materials are being developed: rigid and flexible. The rigid ablatives will be applied to the acreage of a 10x30 m rigid mid L/D Aeroshell to endure the dual pulse heating (peak approx.500 W/sq cm). Likewise, flexible ablative materials are being developed for 20-30 m diameter deployable aerodynamic decelerator entry systems that could endure dual pulse heating (peak aprrox.120 W/sq cm). A technology Roadmap is presented that will be used for facilitating the maturation of both the rigid and flexible ablative materials through application of decision metrics (requirements, key performance parameters, TRL definitions, and evaluation criteria) used to assess and advance the various candidate TPS material technologies

    The Effect of Galaxy Interactions on Molecular Gas Properties

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    © 2018. The American Astronomical Society. All rights reserved.Galaxy interactions are often accompanied by an enhanced star formation rate (SFR). Since molecular gas is essential for star formation, it is vital to establish whether and by how much galaxy interactions affect the molecular gas properties. We investigate the effect of interactions on global molecular gas properties by studying a sample of 58 galaxies in pairs and 154 control galaxies. Molecular gas properties are determined from observations with the JCMT, PMO, and CSO telescopes and supplemented with data from the xCOLD GASS and JINGLE surveys at 12CO(1-0) and 12CO(2-1). The SFR, gas mass (), and gas fraction (f gas) are all enhanced in galaxies in pairs by ∼2.5 times compared to the controls matched in redshift, mass, and effective radius, while the enhancement of star formation efficiency (SFE ≡SFR/) is less than a factor of 2. We also find that the enhancements in SFR, and f gas, increase with decreasing pair separation and are larger in systems with smaller stellar mass ratio. Conversely, the SFE is only enhanced in close pairs (separation <20 kpc) and equal-mass systems; therefore, most galaxies in pairs lie in the same parameter space on the SFR- plane as controls. This is the first time that the dependence of molecular gas properties on merger configurations is probed statistically with a relatively large sample and a carefully selected control sample for individual galaxies. We conclude that galaxy interactions do modify the molecular gas properties, although the strength of the effect is dependent on merger configuration.Peer reviewedFinal Accepted Versio

    Clec16a is critical for autolysosome function and Purkinje cell survival

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    CLEC16A is in a locus genetically linked to autoimmune diseases including multiple sclerosis, but the function of this gene in the nervous system is unknown. Here we show that two mouse strains carrying independent Clec16a mutations developed neurodegenerative disease characterized by motor impairments and loss of Purkinje cells. Neurons from Clec16a-mutant mice exhibited increased expression of the autophagy substrate p62, accumulation of abnormal intra-axonal membranous structures bearing the autophagy protein LC3, and abnormal Golgi morphology. Multiple aspects of endocytosis, lysosome and Golgi function were normal in Clec16a-deficient murine embryonic fibroblasts and HeLa cells. However, these cells displayed abnormal bulk autophagy despite unimpaired autophagosome formation. Cultured Clec16a-deficient cells exhibited a striking accumulation of LC3 and LAMP-1 positive autolysosomes containing undigested cytoplasmic contents. Therefore Clec16a, an autophagy protein that is critical for autolysosome function and clearance, is required for Purkinje cell survival

    The Children's Respiratory and Environmental Workgroup (CREW) birth cohort consortium: design, methods, and study population

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    Background: Single birth cohort studies have been the basis for many discoveries about early life risk factors for childhood asthma but are limited in scope by sample size and characteristics of the local environment and population. The Children’s Respiratory and Environmental Workgroup (CREW) was established to integrate multiple established asthma birth cohorts and to investigate asthma phenotypes and associated causal pathways (endotypes), focusing on how they are influenced by interactions between genetics, lifestyle, and environmental exposures during the prenatal period and early childhood. Methods and results: CREW is funded by the NIH Environmental influences on Child Health Outcomes (ECHO) program, and consists of 12 individual cohorts and three additional scientific centers. The CREW study population is diverse in terms of race, ethnicity, geographical distribution, and year of recruitment. We hypothesize that there are phenotypes in childhood asthma that differ based on clinical characteristics and underlying molecular mechanisms. Furthermore, we propose that asthma endotypes and their defining biomarkers can be identified based on personal and early life environmental risk factors. CREW has three phases: 1) to pool and harmonize existing data from each cohort, 2) to collect new data using standardized procedures, and 3) to enroll new families during the prenatal period to supplement and enrich extant data and enable unified systems approaches for identifying asthma phenotypes and endotypes. Conclusions: The overall goal of CREW program is to develop a better understanding of how early life environmental exposures and host factors interact to promote the development of specific asthma endotypes.HHS/NIH [5UG3OD023282]; Columbia University [P01ES09600, R01 ES008977, P30ES09089, R01 ES013163, R827027]; Tucson Children's Respiratory Study (TCRS) [NHLBI 132523]; Infant Immune Study (IIS) [HL-56177]; Childhood Origins of Asthma Study (COAST) [P01 HL070831, U10 HL064305, R01 HL061879]; Wayne County Health, Environment, Allergy and Asthma Longitudinal Study (WHEALS) [R01 AI050681, R56 AI050681, R01 AI061774, R21 AI059415, K01 AI070606, R21 AI069271, R01 HL113010, R21 ES022321, P01 AI089473, R21 AI080066, R01 AI110450, R01 HD082147]; Fund for Henry Ford Health System; Childhood Allergy Study (CAS) [R01 AI024156, R03 HL067427, R01 AI051598]; Blue Cross Foundation Johnson; Fund for Henry Ford Hospital; Microbes, Allergy, Asthma and Pets (MAAP) [P01 AI089473]; Infant Susceptibility to Pulmonary Infections and Asthma following RSV Exposure (INSPIRE) [NIH/NIAID U19 AI 095227, NIH/NCATS UL1 TR 002243, NIH/NIAID K24 AI 077930, NIH/NHLBI R21 HD 087864, NIH/NHLBI X01 HL 134583]; Wisconsin Infant Study Cohort (WISC) [U19 AI104317, NCATS UL1TR000427]; Upper Midwest Agricultural Safety and Health Center (UMASH) [U54 OH010170]; RTI International, Research Triangle Park, North Carolina, USA; NIH [U24OD023382]; Urban Environment and Childhood Asthma Study (URECA) [NO1-AI-25482, HHSN272200900052C, HHSN272201000052I, NCRR/NIH RR00052, M01RR00533, 1UL1RR025771, M01RR00071, 1UL1RR024156, UL1TR001079, 5UL1RR024992-02, NCATS/NIH UL1TR000040]; Cincinnati Childhood Allergy and Air Pollution Study (CCAAPS) [R01 ES11170, R01 ES019890]; Epidemiology of Home Allergens and Asthma Study (EHAAS) [R01 AI035786]Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

    Reproducibility of an HPLC-ESI-MS/MS Method for the Measurement of Stable-Isotope Enrichment of in Vivo-Labeled Muscle ATP Synthase Beta Subunit

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    We sought to evaluate the reproducibility of a liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based approach to measure the stable-isotope enrichment of in vivo-labeled muscle ATP synthase β subunit (β-F1-ATPase), a protein most directly involved in ATP production, and whose abundance is reduced under a variety of circumstances. Muscle was obtained from a rat infused with stable-isotope-labeled leucine. The muscle was homogenized, β-F1-ATPase immunoprecipitated, and the protein was resolved using 1D-SDS PAGE. Following trypsin digestion of the isolated protein, the resultant peptide mixtures were subjected to analysis by HPLC-ESI-MS/MS, which resulted in the detection of multiple β-F1-ATPase peptides. There were three β-F1-ATPase unique peptides with a leucine residue in the amino acid sequence, and which were detected with high intensity relative to other peptides and assigned with >95% probability to β-F1-ATPase. These peptides were specifically targeted for fragmentation to access their stable-isotope enrichment based on MS/MS peak areas calculated from extracted ion chromatographs for selected labeled and unlabeled fragment ions. Results showed best linearity (R2 = 0.99) in the detection of MS/MS peak areas for both labeled and unlabeled fragment ions, over a wide range of amounts of injected protein, specifically for the β-F1-ATPase134-143 peptide. Measured stable-isotope enrichment was highly reproducible for the β-F1-ATPase134-143 peptide (CV = 2.9%). Further, using mixtures of synthetic labeled and unlabeled peptides we determined that there is an excellent linear relationship (R2 = 0.99) between measured and predicted enrichment for percent enrichments ranging between 0.009% and 8.185% for the β-F1-ATPase134-143 peptide. The described approach provides a reliable approach to measure the stable-isotope enrichment of in-vivo-labeled muscle β-F1-ATPase based on the determination of the enrichment of the β-F1-ATPase134-143 peptide

    Performance of Three-Biomarker Immunohistochemistry for Intrinsic Breast Cancer Subtyping in the AMBER Consortium

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    Classification of breast cancer into intrinsic subtypes has clinical and epidemiologic importance. To examine accuracy of immunohistochemistry (IHC)-based methods for identifying intrinsic subtypes, a three-biomarker IHC panel was compared to the clinical record and RNA-based intrinsic (PAM50) subtypes
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