2,347 research outputs found

    MISSE Thermal Control Materials with Comparison to Previous Flight Experiments

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    Many different passive thermal control materials were flown as part of the Materials on International Space Station Experiment (MISSE), including inorganic coatings, anodized aluminum, and multi-layer insulation materials. These and other material samples were exposed to the low Earth orbital environment of atomic oxygen, ultraviolet radiation, thermal cycling, and hard vacuum, though atomic oxygen exposure was limited for some samples. Materials flown on MISSE-1 and MISSE-2 were exposed to the space environment for nearly four years. Materials flown on MISSE-3, MISSE-4, and MISSE-5 were exposed to the space environment for one year. Solar absorptance, infrared emittance, and mass measurements indicate the durability of these materials to withstand the space environment. Effects of short duration versus long duration exposure on ISS are explored, as well as comparable data from previous flight experiments, such as the Passive Optical Sample Assembly (POSA), Optical Properties Monitor (OPM), and Long Duration Exposure Facility (LDEF)

    Successful use of neck snares to live-capture red foxes

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    Box traps and foot-hold snares are common methods to live-capture study animals. However, these methods are frequently ineffective due to factors such as weather constraints, food availability, and target animal behavior. During a study of red fox (Vulpes vulpes) behavior, we examined the use of neck snares to live-trap study animals. We modified the neck snare using swivel cam-locks, deer stops to minimize damage to the animal. Additionally, we utilized our knowledge of red-fox behavior to set traps in a way that would reduce trauma to the captured animals. We snared 21 red foxes during the 3-year study with only 2 fatal injuries. Sixteen of these animals were followed with radio-telemetry for 3 to 28 months. With the data we collected during the radio-telemetry, we calculated home ranges. Home range size estimates calculated during the first few months for each fox were not different than those collected during the rest of the season. Most of the estimated home ranges for these red foxes did not encompass the snare location, suggesting either avoidance of the trap location or that the foxes were caught while investigating the status of another territory. Because captured red foxes were active the evening immediately after capture and all captured females reared young that spring, we determined that neck snares did not greatly affect their behavior. Thus, this method is a successful alternative way to live-capture red foxes for radio-telemetry studies

    Maintaining Credibility and Authority as an Instructor of Color in Diversity-Education Classrooms: A Qualitative Inquiry

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    The movement for multicultural or diversity-centered education has resulted in changes to the academic demography of the United States (Banks, 1991; Butler & Walter, 1991; Goodstein, 1994; Morey & Kitano, 1997). Institutions of higher education have integrated the voices, knowledge, and lived experiences of various underrepresented cultures and excluded groups into their formal academic curriculum. A recent survey by the American Association of Colleges and Universities (AACU) shows that 63% of colleges and universities report that they have in place, or are in the process of developing, a diversity education component in their undergraduate curriculum (AACU, 2003). Of those that have implemented dimensions of diversity into their curriculum, the majority of campuses (68%) require their students to take at least one course from among a list of approved diversity-education courses. The success of many colleges and universities at integrating this level of multicultural or diversity education into the academic curriculum marks a significant higher education milestone. However, an organized and entrenched resistance to this movement has emerged at both individual and organizational levels (Butler & Walter, 1991; Jayne, 1991). The diversity-education classroom, in particular, is a site wherein this conflict takes on particular meaning for instructors of color at all academic ranks including graduate teaching assistants and full professors (Perry, Moore, Acosta, Edwards, & Frey, 2006; Turner, 2002). Much of the existing scholarship on higher education and multicultural classrooms has focused on the impact of backlash and resistance in the general academic workplace (Yang, Barrayo, & Timpsin, 2003; Timpsin, 2003). Our current study is part of a larger investigation into the professional, emotional, and physical labor associated with teaching diversity-education courses in higher education

    A blocking ELISA for the detection of specific antibodies to bovine respiratory syncytial virus

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    A blocking enzyme-linked immunosorbent assay (ELISA) has been adapted to detect specific antibodies in bovine sera to respiratory syncytial virus using a horseradish peroxidase-labeled monclonal antibody to the fusion protein of the virus. This assay plus an indirect blocking ELISA and indirect ELISA were used to detect antibodies to the bovine respiratory syncytial virus (BRSV) in 159 field-origin bovine sera. Results of these assays were compared with serum antibody titers measured by the serum neutralization (SN) test. Over a 56-day period, the mean neutralization titers and the mean delta absorbance values for the blocking ELISA, on the same sera, showed similar declines. However, the calculated correlation coefficients between mean SN titer and mean absorbance value for the blocking ELISA of the individual sera ranged from -0.2 to -0.5 depending on the source of sera. Similar values were obtained whether using crude or purified viral antigen in the assays. Corresponding calculated correlation coefficients were generally higher for the indirect blocking ELISA or indirect ELISA than for the blocking ELISA. The blocking ELISA was between 70 and 64% as sensitive as the serum neutralization test with a specificity of 100 or 90% using the crude and purified viral antigen, respectively. The indirect blocking ELISA and indirect ELISA had similar calculated sensitivities and specificities. The blocking ELISA was faster to run than either of the other ELISA’s or the neutralization test. Further, nonspecific background absorbance was obviated because the blocking ELISA detects antibodies to 1 specific viral protein, the fusion protein. These studies suggest that the blocking ELISA should be useful as a serological test for BRSV antibodies

    A CM construction for curves of genus 2 with p-rank 1

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    We construct Weil numbers corresponding to genus-2 curves with pp-rank 1 over the finite field \F_{p^2} of p2p^2 elements. The corresponding curves can be constructed using explicit CM constructions. In one of our algorithms, the group of \F_{p^2}-valued points of the Jacobian has prime order, while another allows for a prescribed embedding degree with respect to a subgroup of prescribed order. The curves are defined over \F_{p^2} out of necessity: we show that curves of pp-rank 1 over \F_p for large pp cannot be efficiently constructed using explicit CM constructions.Comment: 19 page

    [(1,2,5,6-η)-Cyclo­octa-1,5-diene]bis­(1-isopropyl-3-methyl­imidazolin-2-yl­idene)rhodium(I) tetra­fluorido­borate

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    In the title compound, [Rh(C8H12)(C7H12N2)2]BF4, the square-planar Rh complex cation and the BF4 − anion are both bis­ected by a crystallographic twofold rotation axis. The Rh and B atoms lie on this axis and all others are in general positions. In the crystal, two unique C—H⋯F hydrogen-bonding inter­actions are present, which involve both imidazolin-2-yl­idene H atoms. They form two separate C(5) motifs, the combination of which is a rippled hydrogen-bonded sheet structure in the ab plane

    Open String Wavefunctions in Warped Compactifications

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    We analyze the wavefunctions for open strings in warped compactifications, and compute the warped Kahler potential for the light modes of a probe D-brane. This analysis not only applies to the dynamics of D-branes in warped backgrounds, but also allows to deduce warping corrections to the closed string Kahler metrics via their couplings to open strings. We consider in particular the spectrum of D7-branes in warped Calabi-Yau orientifolds, which provide a string theory realizations of the Randall-Sundrum scenario. We find that certain background fluxes, necessary in the presence of warping, couple to the fermionic wavefunctions and qualitatively change their behavior. This modified dependence of the wavefunctions are needed for consistency with supersymmetry, though it is present in non-supersymmetric vacua as well. We discuss the deviations of our setup from the RS scenario and, as an application of our results, compute the warping corrections to Yukawa couplings in a simple model. Our analysis is performed both with and without the presence of D-brane world-volume flux, as well as for the case of backgrounds with varying dilaton.Comment: 52 pages, refs. added, minor correction

    Electromagnetic waves and electron anisotropies downstream of supercritical interplanetary shocks

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    We present waveform observations of electromagnetic lower hybrid and whistler waves with f_ci << f < f_ce downstream of four supercritical interplanetary (IP) shocks using the Wind search coil magnetometer. The whistler waves were observed to have a weak positive correlation between \partialB and normalized heat flux magnitude and an inverse correlation with T_eh/T_ec. All were observed simultaneous with electron distributions satisfying the whistler heat flux instability threshold and most with T_{perp,h}/T_{para,h} > 1.01. Thus, the whistler mode waves appear to be driven by a heat flux instability and cause perpendicular heating of the halo electrons. The lower hybrid waves show a much weaker correlation between \partialB and normalized heat flux magnitude and are often observed near magnetic field gradients. A third type of event shows fluctuations consistent with a mixture of both lower hybrid and whistler mode waves. These results suggest that whistler waves may indeed be regulating the electron heat flux and the halo temperature anisotropy, which is important for theories and simulations of electron distribution evolution from the sun to the earth.Comment: 20 pages, 3 PDF figures, submitted to Journal of Geophysical Researc
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