5,355 research outputs found

    Close-Range Photogrammetric Measurement of Static Deflections for an Aeroelastic Supercritical Wing

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    Close range photogrammetric measurements were made for the lower wing surface of a full span aspect ratio 10.3 aeroelastic supercritical research wing. The measurements were made during wind tunnel tests for quasi-steady pressure distributions on the wing. The tests were conducted in the NASA Langley Transonic Dynamics Tunnel at Mach numbers up to 0.90 and dynamic pressures up to 300 pounds per square foot. Deflection data were obtained for 57 locations on the wing lower surface using dual non-metric cameras. Representative data are presented as graphical overview to show variations and trends of spar deflection with test variables. Comparative data are presented for photogrammetric and cathetometric results of measurements for the wing tip deflections. A tabulation of the basic measurements is presented in a supplement to this report

    Human Factors Considerations for Performance-Based Navigation

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    A transition toward a performance-based navigation system is currently underway in both the United States and around the world. Performance-based navigation incorporates Area Navigation (RNAV) and Required Navigation Performance (RNP) procedures that do not rely on the location of ground-based navigation aids. These procedures offer significant benefits to both operators and air traffic managers. Under sponsorship from the Federal Aviation Administration (FAA), the National Aeronautics and Space Administration (NASA) has undertaken a project to document human factors issues that have emerged during RNAV and RNP operations and propose areas for further consideration. Issues were found to include aspects of air traffic control and airline procedures, aircraft systems, and procedure design. Major findings suggest the need for human factors-specific instrument procedure design guidelines. Ongoing industry and government activities to address air-ground communication terminology, procedure design improvements, and chart-database commonality are strongly encouraged

    The Trusteeship of Legal Rulemaking

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    Professor Robert D. Putnam\u27s work is, in many respects, the contemporary companion to Democracy in America.\u27 It comprehensively surveys and tests common presumptions held about our democracy with apparently very reliable quantitative data. Until recently, a work of this depth and breadth has been unavailable. Putnam sets forth a well supported thesis suggesting that even though American financial capital may be at a high, its social capital has perhaps reached a record low, or at least a level similar to the social, economic, and legal bottleneck of a century ago.\u27 His use of empirical and combined data, however, probes into the American spirit, indeed implying that the present setting is more dangerous. This method is in contrast to many other surveys and commentaries that are based significantly on anecdotal evidence or that worship earlier studies founded on less than empirical or weak social science technique

    IMPLICATIONS OF GLOBAL CLIMATE CHANGE FOR WESTERN AGRICULTURE

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    Global climate change from increases in atmospheric carbon dioxide and other trace gases is an issue of international concern. Adverse climate conditions are expected to reduce crop yields and alter the demand for and supply of water. These potential adjustments imply economic costs to agriculture and its constituents. This paper explores possible economic implications for U.S. agriculture, with particular reference to the West. Results from a series of spatial equilibrium model analyses suggest that climate change is not a food security issue for the United States. However, regional adjustments in agricultural production and associated resource use are expected. This implies additional pressure in rural communities. Environmental quality reductions are also likely.Environmental Economics and Policy,

    Theology, News and Notes - Vol. 23, No. 03

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    Theology News & Notes was a theological journal published by Fuller Theological Seminary from 1954 through 2014.https://digitalcommons.fuller.edu/tnn/1058/thumbnail.jp

    Is there a role for DAZL in human female fertility?

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    The RNA binding protein deleted in azoospermia-like (Dazl) is a key determinant of germ cell maturation and entry into meiosis in rodents and other animal species. Although the complex phenotype of Dazl deficiency in both sexes, with defects at multiple stages of germ cell development and during meiosis, demonstrates its obligate significance in fertility in animal models, its involvement in human fertility is less clear. As an RNA binding protein, identification of the in vivo mRNA targets of DAZL is necessary to understand its influence. Thus far, only a small number of Dazl targets have been identified, which typically have pivotal roles in germ cell development and meiotic progression. However, it is likely that there are a number of additional germ cell and meiosis-relevant transcripts whose translation is affected in the absence of Dazl. Efforts to identify these RNA targets have mainly been focused on spermatogenesis, and restricted to mouse. In women, prophase I occurs in fetal life and it is during this period that the ovarian follicle pool is established, thus factors that have a role in determining the quality and quantity of the ovarian reserve may have significant impact on reproductive outcomes later in adult life. Here, we suggest that DAZL may be one such factor, and there is a need for greater understanding of the role of DAZL in human oogenesis and its contribution to lifelong female fertility
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