28 research outputs found

    DEPARTMENT OF DEFENSE JOINT AIRCREW SURVIVAL FLIGHT VEST

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    The purpose of this research is to analyze the feasibility of a joint aircrew survival flight vest program to satisfy the performance requirements across the military Services. The Department of Defense (DOD) has multiple type, model, and series aircraft in its inventory to meet the capabilities validated by the Joint Requirements Oversight Council. Each aircraft comes with a variety of Aviation Life Support Systems such as the aircrew survival flight vest. There are a variety of aircrew survival flight vests across the DOD performing similar functions, such as ballistic protection, signaling and communications, and providing flotation in a maritime environment. In recent years, Defense Acquisitions programs have been becoming more joint by increasing commonality to cut costs by reducing redundant programs among the different services. Currently, the various aircrew flight vests that are being used remain under the control of several program executive offices. This research examined the feasibility of a joint aircrew survival flight vest by using a combination of the case study method and the cost-effectiveness analysis. We conclude that a joint aircrew survival flight vest with a modular design would be the most effective option. The services will have the flexibility to tailor the joint vest with modules to meet performance specifications.Outstanding ThesisMajor, United States Marine CorpsCaptain, United States Marine CorpsEnsign, United States NavyApproved for public release. Distribution is unlimited

    Exceptional Hyperthyroidism and a Role for both Major Histocompatibility Class I and Class II Genes in a Murine Model of Graves' Disease

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    Autoimmune hyperthyroidism, Graves' disease, can be induced by immunizing susceptible strains of mice with adenovirus encoding the human thyrotropin receptor (TSHR) or its A-subunit. Studies in two small families of recombinant inbred strains showed that susceptibility to developing TSHR antibodies (measured by TSH binding inhibition, TBI) was linked to the MHC region whereas genes on different chromosomes contributed to hyperthyroidism. We have now investigated TSHR antibody production and hyperthyroidism induced by TSHR A-subunit adenovirus immunization of a larger family of strains (26 of the AXB and BXA strains). Analysis of the combined AXB and BXA families provided unexpected insight into several aspects of Graves' disease. First, extreme thyroid hyperplasia and hyperthyroidism in one remarkable strain, BXA13, reflected an inability to generate non-functional TSHR antibodies measured by ELISA. Although neutral TSHR antibodies have been detected in Graves' sera, pathogenic, functional TSHR antibodies in Graves' patients are undetectable by ELISA. Therefore, this strain immunized with A-subunit-adenovirus that generates only functional TSHR antibodies may provide an improved model for studies of induced Graves' disease. Second, our combined analysis of linkage data from this and previous work strengthens the evidence that gene variants in the immunoglobulin heavy chain V region contribute to generating thyroid stimulating antibodies. Third, a broad region that encompasses the MHC region on mouse chomosome 17 is linked to the development of TSHR antibodies (measured by TBI). Most importantly, unlike other strains, TBI linkage in the AXB and BXA families to MHC class I and class II genes provides an explanation for the unresolved class I/class II difference in humans

    Modeling of Ti-W Solidification Microstructures Under Additive Manufacturing Conditions

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    Additive manufacturing (AM) processes have many benefits for the fabrication of alloy parts, including the potential for greater microstructural control and targeted properties than traditional metallurgy processes. To accelerate utilization of this process to produce such parts, an effective computational modeling approach to identify the relationships between material and process parameters, microstructure, and part properties is essential. Development of such a model requires accounting for the many factors in play during this process, including laser absorption, material addition and melting, fluid flow, various modes of heat transport, and solidification. In this paper, we start with a more modest goal, to create a multiscale model for a specific AM process, Laser Engineered Net Shaping (LENS™), which couples a continuum-level description of a simplified beam melting problem (coupling heat absorption, heat transport, and fluid flow) with a Lattice Boltzmann-cellular automata (LB-CA) microscale model of combined fluid flow, solute transport, and solidification. We apply this model to a binary Ti-5.5 wt pct W alloy and compare calculated quantities, such as dendrite arm spacing, with experimental results reported in a companion paper

    Idiotypic analysis of antibodies to hen egg-white lysozyme (HEL). II. Distribution and frequency of occurrence of idiotypes shared by A/J anti-HEL antibody.

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    Anti-HEL Ab from one A/J mouse (No. a-4),Ida-4(HEL), was s.c. inoculated into rabbits to induce anti-idiotypic (anti-Id) sera. After absorption with normal A/J Ig, two anti-Id serra (R101 and R102) were obtained. The interaction between 125I-Id(a-4)(HEL) and anti-Id sera was completely inhibited by unlabelled Ida-4(HEL), but not by non-specific Ig. The anti-Id sera were used to investigate the distribution of A/J (No. a-4) anti-HEL idiotypes in sera obtained from HEL-immunized animals. Idiotypes shared by Ida-4(HEL) were also detected in the sera of five examined mouse strains, but not in any of the examined rat, guinea-pig, goat, and sheep sear. Our experiments suggest the presence of inter- as well as intrastrain idiotype in mice. However, cross-reactivity appeared to be weak. When R101 and R102, respectively, were the anti-Id sera used, the frequency of occurrence of Ida-4(HEL) in stain A wa 1/106 and 1/53; in other mouse strains it was 1/277 and 1/85

    A small hypervariable segment in the variable domain of an immunoglobulin light chain stimulates formation of anti-idiotypic suppressor T cells.

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    The induction in BALB/c mice of suppressor T cells that block a delayed-type hypersensitivity (DTH) response to the idiotype of M315, a myeloma protein of BALB/c origin, was examined with a variety of immunoglobulin chains and fragments whose amino acid sequences are known. Normal BALB/c mice receiving either the light chain of M315 (L315, lambda 2 isotype) or the variable (V) domain of this chain prior to sensitization with M315 showed marked suppression of DTH to the M315 idiotype. In contrast, neither the heavy chain nor the variable domain of the heavy chain of M315 affected the DTH response. Two other lambda 2 chains were tested and they also failed to suppress DTH to M315. Comparison of amino acid sequences in the three lambda 2 chains indicates that in L315 at most four V region amino acid substitutions (each resulting from a somatic mutation in the V lambda 2 germ-line gene) determine the specificity of the T-cell suppressor pathway. One of the four is in the framework and probably of negligible importance; the other three, however, are all clustered in the third hypervariable loop of the L315 V domain. The tertiary structure of L315 may also be essential, because disruption of intrachain disulfide bonds abolished the ability of the chain to induce suppression

    Multiplicité de solutions de convection themo-solutale dans une cavité chauffée par le bas

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