4,985 research outputs found

    Propulsion simulator for magnetically-suspended wind tunnel models

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    The objective of phase two of a current investigation sponsored by NASA Langley Research Center is to demonstrate the measurement of aerodynamic forces/moments, including the effects of exhaust gases, in magnetic suspension and balance system (MSBS) wind tunnels. Two propulsion simulator models are being developed: a small-scale and a large-scale unit, both employing compressed, liquified carbon dioxide as propellant. The small-scale unit was designed, fabricated, and statically-tested at Physical Sciences Inc. (PSI). The large-scale simulator is currently in the preliminary design stage. The small-scale simulator design/development is presented, and the data from its static firing on a thrust stand are discussed. The analysis of this data provides important information for the design of the large-scale unit. A description of the preliminary design of the device is also presented

    The Seigniory of Sark and the Duchy Of Cornwall: Similarities and Differences Including Observations on the Isles of Scilly

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    A unified and robust mathematical model for compressible and incompressible linear elasticity can be obtained by rephrasing the Herrmann formulation within the Hellinger-Reissner principle. This quasi-optimally converging extension of PEERS (Plane Elasticity Element with Reduced Symmetry) is called Dual-Mixed Hybrid formulation (DMH). Explicit residual-based a posteriori error estimates for DMH are introduced and are mathematically shown to be locking-free, reliable, and efficient. The estimator serves as a refinement indicator in an adaptive algorithm for effective automatic mesh generation. Numerical evidence supports that the adaptive scheme leads to optimal convergence for Lam\ue9 and Stokes benchmark problems with singularities

    Women's choices in non-invasive prenatal testing for aneuploidy screening: results from a single centre prior to introduction in England

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    OBJECTIVE: To evaluate patient choices and uptake of non-invasive prenatal testing (NIPT) for aneuploidy screening offered in a contingency model as part of routine care. METHOD: We retrospectively reviewed data for all women with a singleton pregnancy attending for routine first trimester screening over an 18-month period. Women with a 'high-chance' of trisomy 21, 18 or 13 (≥1:150) were offered the choice of no further testing, NIPT or invasive testing, in line with the screening pathway recommended by the UK National Screening Committee. RESULTS: Of 9342 women attending for a first trimester ultrasound scan, 7939 women were included in this study. Of these, 352 had a high-chance screening result for trisomy 21, and 291 (82.7%) opted for NIPT. The proportion of women opting for NIPT decreased as the chance of trisomy 21 increased: uptake was 93.2%, 90.0%, 77.1% and 47.2% for women with a chance of 1:100-150, 1:50-99, 1:10-49 and >1:10, respectively. 516 women (5.5%) accessed primary NIPT screening in the private sector, and 638 women (6.8%) declined any aneuploidy screening or testing. CONCLUSION: Implementation of NIPT testing in a contingency model has a high uptake in a non-research National Health Service setting; the rate of uptake is related to the combined test risk result

    ELBOW FLEXOR MUSCLE FUNCTION AND UPPER ARM GIRTH FOLLOWING CONCURRENT STRENGTH AND ENDURANCE TRAINING IN NON RESISTANCETRAINED FEMALES

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    The study investigated the effects of eight weeks of concurrent muscular strength and endurance resistance training of the non-dominant elbow flexors on muscular strength, endurance, and upper arm girths of previously non resistance-trained females. Subjects (n=12) were assigned to one of 3 training groups. These groups were Strength (S), Endurance (E), or Combined (C) with pre and post-training tests for arm girths, 1 RM preacher curl, maximal isometric torque, peak isokinetic torque at velocities of 30 and 90" s-', and total work during 25 continuous repetitions at 90"s.'. Significant increases in prepost strength and endurance occurred in both C and S groups, but not E, in the absence of any change in arm girth. Furthermore, C training produced equivalent gains in strength and endurance to the S and E groups, respectively

    Disassembly of interchromatin granule clusters alters the coordination of transcription and pre-mRNA splicing

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    To examine the involvement of interchromatin granule clusters (IGCs) in transcription and pre-mRNA splicing in mammalian cell nuclei, the serine-arginine (SR) protein kinase cdc2-like kinase (Clk)/STY was used as a tool to manipulate IGC integrity in vivo. Both immunofluorescence and transmission electron microscopy analyses of cells overexpressing Clk/STY indicate that IGC components are completely redistributed to a diffuse nuclear localization, leaving no residual structure. Conversely, overexpression of a catalytically inactive mutant, Clk/STY(K190R), causes retention of hypophosphorylated SR proteins in nuclear speckles. Our data suggest that the protein-protein interactions responsible for the clustering of interchromatin granules are disrupted when SR proteins are hyperphosphorylated and stabilized when SR proteins are hypophosphorylated. Interestingly, cells without intact IGCs continue to synthesize nascent transcripts. However, both the accumulation of splicing factors at sites of pre-mRNA synthesis as well as pre-mRNA splicing are dramatically reduced, demonstrating that IGC disassembly perturbs coordination between transcription and pre-mRNA splicing in mammalian cell nuclei

    Molecules in the transition disk orbiting T Cha

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    We seek to establish the presence and properties of gas in the circumstellar disk orbiting T Cha, a nearby (d~110 pc), relatively evolved (age ~5-7 Myr) yet actively accreting 1.5 Msun T Tauri star. We used the APEX 12 m radiotelescope to search for submillimeter molecular emission from the T Cha disk, and we reanalyzed archival XMM-Newton spectroscopy of T Cha to ascertain the intervening absorption due to disk gas along the line of sight to the star (N_H). We detected submillimeter rotational transitions of 12CO, 13CO, HCN, CN and HCO+ from the T Cha disk. The 12CO line appears to display a double-peaked line profile indicative of Keplerian rotation. Analysis of the CO emission line data indicates that the disk around T Cha has a mass (M_disk,H_2 = 80 M_earth) similar to, but more compact (R_disk, CO~80 AU) than, other nearby, evolved molecular disks (e.g. V4046 Sgr, TW Hya, MP Mus) in which cold molecular gas has been previously detected. The HCO+/13CO and HCN/13CO, line ratios measured for T Cha appear similar to those of other evolved circumstellar disks (i.e. TW Hya and V4046 Sgr), while the CN/13CO ratio appears somewhat weaker. Analysis of the XMM-Newton data shows that the atomic absorption NHN_H toward T Cha is 1-2 orders of magnitude larger than toward the other nearby T Tauri with evolved disks. Furthermore, the ratio between atomic absorption and optical extinction N_H/A_V toward T Cha is higher than the typical value observed for the interstellar medium and young stellar objects in the Orion Nebula Cluster. This may suggest that the fraction of metals in the disk gas is higher than in the interstellar medium. Our results confirm that pre-main sequence stars older than ~5 Myr, when accreting, retain cold molecular disks, and that those relatively evolved disks display similar physical and chemical properties.Comment: Accepted for publication on A&

    DEVELOPMENT POLICIES IN SOUTHERN ITALY BETWEEN GOVERNMENT AND GOVERNANCE

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    The paper has analysed outputs generated by the development policies implemented in last decades in the South of Italy, starting from the Extraordinary Intervention (since 1950, until 1992) to the European cohesion policy (since 1996). The first one was a high-centralized development policy. Differently, the European cohesion policy is based on multilevel governance, and follows a bottom-up approach oriented to stimulate local stakeholders’ participation. The analysis, exposed in previous paragraphs, has described these two different policy experiences, the related effects on local development and on convergence between North and South of Italy and among European regions. The paper has tried to answer to a fundamental question: what factors have negatively affected the implementation of these policies, generating unexpected effects
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