805 research outputs found

    \u27We are the Big Six:’ Maasai Perceptions and Organization of Cultural Tourism in Kenya

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    Kenya’s wildlife has long been considered an international treasure. Travelling to the renowned Masai Mara National Reserve (MMNR) to capture the ‘big five,’ those five large wild animals considered to be Africa’s greatest, with their camera lenses, visitors will also see or even meet local Maasai living and/or working in the area. Employing ethnographic methods this research examines three sites: the Enkang Oloirien Village Homestay, Olapa village and the main entrance to the MMNR where Maasai women sell souvenirs to explore Maasai perceptions and organization of cultural tourism. Responding to literature which considers benefits from tourism to accrue when hosts control cultural representation, this thesis reveals the incorporation of cultural tourism into daily life and how images and narratives with both Maasai and foreign origins are mixed, employed, manipulated and resisted at tourism sites, to achieve the central benefits of meeting basic needs, educating children, and supplementing and bolstering pastoral activities

    On the vanishing viscosity limit in a disk

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    We say that the solution u to the Navier-Stokes equations converges to a solution v to the Euler equations in the vanishing viscosity limit if u converges to v in the energy norm uniformly over a finite time interval. Working specifically in the unit disk, we show that a necessary and sufficient condition for the vanishing viscosity limit to hold is the vanishing with the viscosity of the time-space average of the energy of u in a boundary layer of width proportional to the viscosity due to modes (eigenfunctions of the Stokes operator) whose frequencies in the radial or the tangential direction lie between L and M. Here, L must be of order less than 1/(viscosity) and M must be of order greater than 1/(viscosity)

    Setting up tracking tools for NuFact bowtie decay ring studies

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    This paper describes the setting up of ray-tracing tools, and preliminary beam dynamics studies concerning the NuFact bowtie decay ring

    A New Method for Laminar Boundary Layer Transition Visualization in Flight: Color Changes in Liquid Crystal Coatings

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    The visualization of laminar to turbulent boundary layer transition plays an important role in flight and wind tunnel aerodynamic testing of aircraft wing and body surfaces. Visualization can help provide a more complete understanding of both transition location as well as transition modes; without visualization, the transition process can be very difficult to understand. In the past, the most valuable transition visualization methods for fight applications included sublimating chemicals and oil flows. Each method has advantages and limitations. In particular, sublimating chemicals are impractical to use in subsonic applications much above 20,000 feet because of the greatly reduced rates of sublimation at lower temperatures (less than -4 degrees Fahrenheit). Both oil flow and sublimating chemicals have the disadvantage of providing only one good data point per flight. Thus, for many important flight conditions, transition visualization has not been readily available. This paper discusses a new method for visualizing transition in fight by the use of liquid crystals. The new method overcomes the limitations of past techniques, and provides transition visualization capability throughout almost the entire altitude and speed ranges of virtually all subsonic aircraft flight envelopes. The method also has wide applicability for supersonic transition visualization in flight and for general use in wind tunnel research over wide subsonic and supersonic speed ranges

    On the flow map for 2D Euler equations with unbounded vorticity

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    In Part I, we construct a class of examples of initial velocities for which the unique solution to the Euler equations in the plane has an associated flow map that lies in no Holder space of positive exponent for any positive time. In Part II, we explore inverse problems that arise in attempting to construct an example of an initial velocity producing an arbitrarily poor modulus of continuity of the flow map.Comment: http://iopscience.iop.org/0951-7715/24/9/013/ for published versio

    The Death Domain Kinase RIP Protects Thymocytes from Tumor Necrosis Factor Receptor Type 2–induced Cell Death

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    Fas and the tumor necrosis factor receptor (TNFR)1 regulate the programmed cell death of lymphocytes. The death domain kinase, receptor interacting protein (rip), is recruited to the TNFR1 upon receptor activation. In vitro, rip−/− fibroblasts are sensitive to TNF-induced cell death due to an impaired nuclear factor κB response. Because rip−/− mice die at birth, we were unable to examine the effects of a targeted rip mutation on lymphocyte survival. To address the contribution of RIP to immune homeostasis, we examined lethally irradiated mice reconstituted with rip−/− hematopoietic precursors. We observed a decrease in rip−/− thymocytes and T cells in both wild-type C57BL/6 and recombination activating gene 1−/− irradiated hosts. In contrast, the B cell and myeloid lineages are unaffected by the absence of rip. Thus, the death domain kinase rip is required for T cell development. Unlike Fas-associated death domain, rip does not regulate T cell proliferation, as rip−/− T cells respond to polyclonal activators. However, rip-deficient mice contain few viable CD4+ and CD8+ thymocytes, and rip−/− thymocytes are sensitive to TNF-induced cell death. Surprisingly, the rip-associated thymocyte apoptosis was not rescued by the absence of TNFR1, but appears to be rescued by an absence of TNFR2. Taken together, this study implicates RIP and TNFR2 in thymocyte survival
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