525 research outputs found

    Extended flight evaluation of a near-term pitch active control system

    Get PDF
    Fuel savings can be achieved by moving the center of gravity of an aircraft aft which reduces the static stability margin and consequently the trim drag. However, flying qualities of an aircraft with relaxed static stability can be significantly degraded. The flying qualities can be restored by using a pitch active control system (PACS). This report documents the work accomplished during a follow-on program (see NASA CR-165951 for initial program report) to perform extended flight tests of a near-term PACS. The program included flying qualities analyses, piloted flight simulation tests, aircraft preparation and flight tests to demonstrate that the near-term PACS provided good flying qualities within the linear static stability envelope to a negative 3% static stability margin

    An experimental study of the flow variables at the minimum pressure station of ninety-degree pipe bends

    Get PDF
    Flow variables related to minimum pressure in circular pipe bend

    PASD1 (PAS domain containing 1)

    Get PDF
    Review on PASD1 (PAS domain containing 1), with data on DNA, on the protein encoded, and where the gene is implicated

    SSX2IP (synovial sarcoma, X breakpoint 2 interacting protein)

    Get PDF
    Review on SSX2IP (synovial sarcoma, X breakpoint 2 interacting protein), with data on DNA, on the protein encoded, and where the gene is implicated

    Implementation of a non-emergent medical transportation programme at an integrated health system

    Get PDF
    OBJECTIVES: To implement a unified non-emergency medical transportation (NEMT) service across a large integrated healthcare delivery network. METHODS: We assessed needs among key organisational stakeholders, then reviewed proposals. We selected a single NEMT vendor best aligned with organisational priorities and implemented this solution system-wide. RESULTS: Our vendor\u27s hybrid approach combined rideshares with contracted vehicles able to serve patients with equipment and other needs. After 6195 rides in the first year, we observed shorter wait times and lower costs compared with our prior state. DISCUSSION: Essential lessons included (1) understanding user and patient needs, (2) obtaining complete, accurate and comprehensive baseline data and (3) adapting existing workflows-rather than designing de novo-whenever possible. CONCLUSIONS: Our implementation of a single-vendor NEMT solution validates the need for NEMT at large healthcare organisations, geographical challenges to establishing NEMT organisation-wide, and the importance of baseline data and stakeholder engagement

    The aggregation of cytochrome C may be linked to its flexibility during refolding

    Get PDF
    Large-scale expression of biopharmaceutical proteins in cellular hosts results in production of large insoluble mass aggregates. In order to generate functional product, these aggregates require further processing through refolding with denaturant, a process in itself that can result in aggregation. Using a model folding protein, cytochrome C, we show how an increase in final denaturant concentration decreases the propensity of the protein to aggregate during refolding. Using polarised fluorescence anisotropy, we show how reduced levels of aggregation can be achieved by increasing the period of time the protein remains flexible during refolding, mediated through dilution ratios. This highlights the relationship between the flexibility of a protein and its propensity to aggregate. We attribute this behaviour to the preferential urea-residue interaction, over self-association between molecules

    Logarithmic perturbation theory for quasinormal modes

    Get PDF
    Logarithmic perturbation theory (LPT) is developed and applied to quasinormal modes (QNMs) in open systems. QNMs often do not form a complete set, so LPT is especially convenient because summation over a complete set of unperturbed states is not required. Attention is paid to potentials with exponential tails, and the example of a Poschl-Teller potential is briefly discussed. A numerical method is developed that handles the exponentially large wavefunctions which appear in dealing with QNMs.Comment: 24 pages, 4 Postscript figures, uses ioplppt.sty and epsfig.st

    Asymptotic quasinormal modes of Reissner-Nordstr\"om and Kerr black holes

    Full text link
    According to a recent proposal, the so-called Barbero-Immirzi parameter of Loop Quantum Gravity can be fixed, using Bohr's correspondence principle, from a knowledge of highly-damped black hole oscillation frequencies. Such frequencies are rather difficult to compute, even for Schwarzschild black holes. However, it is now quite likely that they may provide a fundamental link between classical general relativity and quantum theories of gravity. Here we carry out the first numerical computation of very highly damped quasinormal modes (QNM's) for charged and rotating black holes. In the Reissner-Nordstr\"om case QNM frequencies and damping times show an oscillatory behaviour as a function of charge. The oscillations become faster as the mode order increases. At fixed mode order, QNM's describe spirals in the complex plane as the charge is increased, tending towards a well defined limit as the hole becomes extremal. Kerr QNM's have a similar oscillatory behaviour when the angular index m=0m=0. For l=m=2l=m=2 the real part of Kerr QNM frequencies tends to 2Ω2\Omega, Ω\Omega being the angular velocity of the black hole horizon, while the asymptotic spacing of the imaginary parts is given by 2πTH2\pi T_H.Comment: 13 pages, 7 figures. Added result on the asymptotic spacing of the imaginary part, minor typos correcte

    Analogue peptides for the immunotherapy of human acute myeloid leukemia

    Get PDF
    Accepted manuscript. The final publication is available at: http://link.springer.com/article/10.1007%2Fs00262-015-1762-9The use of peptide vaccines, enhanced by adjuvants, has shown some efficacy in clinical trials. However, responses are often short-lived and rarely induce notable memory responses. The reason is that self-antigens have already been presented to the immune system as the tumor develops, leading to tolerance or some degree of host tumor cell destruction. To try to break tolerance against self-antigens, one of the methods employed has been to modify peptides at the anchor residues to enhance their ability to bind major histocompatibility complex molecules, extending their exposure to the T-cell receptor. These modified or analogue peptides have been investigated as stimulators of the immune system in patients with different cancers with variable but sometimes notable success. In this review we describe the background and recent developments in the use of analogue peptides for the immunotherapy of acute myeloid leukemia describing knowledge useful for the application of analogue peptide treatments for other malignancies
    • …
    corecore