1,899 research outputs found

    Men\u27s health: How men understand the concept of health and how this understanding shapes actions

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    The purpose of this research was to explore how men understand the concept of health, and how this understanding shapes actions. This dissertation developed as a result of both working at a Community Health Centre, and having an awareness that in Australia, statistics indicate that men\u27s health is steadily deteriorating. A theoretical framework implementing the concepts of health, socialisation (masculinity) and cognition was utilised to guide the research. The research involved interviewing six male participants, who were university students ranging in age from 20 to 40 years. Participants were questioned regarding their perceptions of health and health management. Interview transcripts were analysed utilising a symbolic interaction perspective, where the five major themes of family I friends, personal experience, exercise, food, and seriousness of concern emerged. The results of the study indicate that when analysing the five major themes, the concepts of health and cognition impacted upon participants responses to health concerns and health management. In contrast, men did not explicitly discuss masculinity as impacting upon health concerns or health management. Future research to explore how men understand the concept of health and how this understanding shapes actions could focus upon age differences, gender comparisons, or individuals not studying at university

    The structure and function of supported molybdenum nitride hydrodenitrogenation catalysts

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    A series of [gamma]-Al2O3 supported Mo nitrides were prepared by the temperature programmed reaction of supported molybdates with NH3. Several loadings, heating rates, and space velocities were employed in an attempt to vary the properties of the nitride. The structure and composition of the supported nitrides depended on the structure of the precursor oxide and the conditions employed in nitriding the oxide. The ease with which the oxide was nitrided improved with increasing Mo loading. Nitride domains in the low-loaded materials (4 and 8 wt% Mo) were highly dispersed and X-ray amorphous while the higher-loaded catalysts (16 wt% Mo) consisted of [gamma]-Mo2N crystallites. The response of the high-loaded materials to the various nitriding conditions was similar to that observed for unsupported [gamma]-Mo2N. The supported Mo nitrides were active for the hydrodenitrogenation of pyridine. In fact, their activities were superior to that of a commercial sulfided Ni---Mo hydrotreating catalyst and comparable to those of the unsupported Mo nitrides. The catalytic properties of the supported Mo nitrides depended on the size and composition of the Mo nitride domains. We believe that the most active sites were located at the perimeters of two-dimensional, raft-like domains. Regions near the perimeter also appeared to be nitrogen deficient. Lower activity sites were associated with the [gamma]-Mo2N crystallite surfaces.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31902/1/0000855.pd

    Thyroxine Binding to Type III Iodothyronine Deiodinase

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    Iodothyronine deiodinases (Dios) are important selenoproteins that control the concentration of the active thyroid hormone (TH) triiodothyronine through regioselective deiodination. The X-ray structure of a truncated monomer of Type III Dio (Dio3), which deiodinates TH inner rings through a selenocysteine (Sec) residue, revealed a thioredoxin-fold catalytic domain supplemented with an unstructured Ω-loop. Loop dynamics are driven by interactions of the conserved Trp207 with solvent in multi-microsecond molecular dynamics simulations of the Dio3 thioredoxin(Trx)-fold domain. Hydrogen bonding interactions of Glu200 with residues conserved across the Dio family anchor the loop\u27s N-terminus to the active site Ser-Cys-Thr-Sec sequence. A key long-lived loop conformation coincides with the opening of a cryptic pocket that accommodates thyroxine (T4) through an I…Se halogen bond to Sec170 and the amino acid group with a polar cleft. The Dio3-T4 complex is stabilized by an I…O halogen bond between an outer ring iodine and Asp211, consistent with Dio3 selectivity for inner ring deiodination. Non-conservation of residues, such as Asp211, in other Dio types in the flexible portion of the loop sequence suggests a mechanism for regioselectivity through Dio type-specific loop conformations. Cys168 is proposed to attack the selenenyl iodide intermediate to regenerate Dio3 based upon structural comparison with related Trx-fold proteins

    The Implementation of Maximum Likelihood Estimation in Space Launch System Vehicle Design

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    The Space Launch System uses a Maximum Likelihood Estimation process in conjunction with Design of Experiments to develop statistically representative vehicles for the Block 1 configuration. These vehicles are then used to estimate maximum load conditions for simulating stressing cases in other simulations. This paper discusses the modeling process and how SLS captures manufacturing uncertainty in the launch vehicle design. It also provides an overview of the differences between Block 1 statistical representations. This paper also discusses proper grid choice as well as which uncertainties drive the vehicle design

    The Implementation of Maximum Likelihood Estimation in Space Launch System Vehicle Design

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    As NASAs Space Launch System (SLS) approaches first launch, the design has matured to a point where the manufacturing uncertainty has decreased now that many of the components of the launch vehicle have been manufactured and the flight engines have been successfully tested. Prior to this point, a method was required to qualify and capture the impact of the differences between simulation and reality, as well as any uncertainties in the SLS design. Two primary categories of uncertainty arise during the launch vehicle design process. The first represents flight-day uncertainties including dispersions due to winds and temperatures. These are typically examined by performing a Monte Carlo on 6 Degree of Freedom (6-DOF) simulations. The second category of uncertainties represents any manufacturing variations that are present at the individual component level of the launch vehicle design. These variations are constructed using statistical masses and tend to become better understood and refined as the design cycle matures, finally resulting in the launch vehicle as constructed and tested

    Quadrilateral-octagon coordinates for almost normal surfaces

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    Normal and almost normal surfaces are essential tools for algorithmic 3-manifold topology, but to use them requires exponentially slow enumeration algorithms in a high-dimensional vector space. The quadrilateral coordinates of Tollefson alleviate this problem considerably for normal surfaces, by reducing the dimension of this vector space from 7n to 3n (where n is the complexity of the underlying triangulation). Here we develop an analogous theory for octagonal almost normal surfaces, using quadrilateral and octagon coordinates to reduce this dimension from 10n to 6n. As an application, we show that quadrilateral-octagon coordinates can be used exclusively in the streamlined 3-sphere recognition algorithm of Jaco, Rubinstein and Thompson, reducing experimental running times by factors of thousands. We also introduce joint coordinates, a system with only 3n dimensions for octagonal almost normal surfaces that has appealing geometric properties.Comment: 34 pages, 20 figures; v2: Simplified the proof of Theorem 4.5 using cohomology, plus other minor changes; v3: Minor housekeepin

    Methods and systems for advanced spaceport information management

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    Advanced spaceport information management methods and systems are disclosed. In one embodiment, a method includes coupling a test system to the payload and transmitting one or more test signals that emulate an anticipated condition from the test system to the payload. One or more responsive signals are received from the payload into the test system and are analyzed to determine whether one or more of the responsive signals comprises an anomalous signal. At least one of the steps of transmitting, receiving, analyzing and determining includes transmitting at least one of the test signals and the responsive signals via a communications link from a payload processing facility to a remotely located facility. In one particular embodiment, the communications link is an Internet link from a payload processing facility to a remotely located facility (e.g. a launch facility, university, etc.)
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