4,118 research outputs found

    Examining the Impact of Parental Socialization on the Coping Styles of Black Graduate Students Faced with Microaggressions

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    This article explores case examples of two graduate students who endure microaggressions from their math professor at a predominantly White university. The role that parental socialization plays in how these students developed their racial identities and the coping strategies they employed, is analyzed through the lens of Triple Quandary theory (Boykin and Toms 1 985). Findings from this investigation suggest that parental socialization is critical in preparing these students to cope with and respond to microaggressions in protective and adaptive ways. This paper illuminates coping styles, although divergent, that served these graduate students\u27 needs and protected their individual racial identities. Further, the support these students received from their faculty advisor who is also Black, exemplifies the importance of mentorship and advocacy from faculty of color to Black college students\u27 success. Direction for continuity in parental teachings for K-12 and university level educators are discussed

    Note on restoring manifest rotational symmetry in hyperfine and fine structure in light-front QED

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    We study the part of the renormalized, cutoff QED light-front Hamiltonian that does not change particle number. The Hamiltonian contains interactions that must be treated in second-order bound state perturbation theory to obtain hyperfine structure. We show that a simple unitary transformation leads directly to the familiar Breit-Fermi spin-spin and tensor interactions, which can be treated in degenerate first-order bound-state perturbation theory, thus simplifying analytic light-front QED calculations. To the order in momenta we need to consider, this transformation is equivalent to a Melosh rotation. We also study how the similarity transformation affects spin-orbit interactions.Comment: 17 pages, latex fil

    Quarkonia in Hamiltonian Light-Front QCD

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    A constituent parton picture of hadrons with logarithmic confinement naturally arises in weak coupling light-front QCD. Confinement provides a mass gap that allows the constituent picture to emerge. The effective renormalized Hamiltonian is computed to O(g2){\cal O}(g^2), and used to study charmonium and bottomonium. Radial and angular excitations can be used to fix the coupling α\alpha, the quark mass MM, and the cutoff Λ\Lambda. The resultant hyperfine structure is very close to experiment.Comment: 9 pages, 1 latex figure included in the text. Published version (much more reader-friendly); corrected error in self-energ

    The \u3cem\u3efeoABC\u3c/em\u3e Locus of \u3cem\u3eYersinia pestis\u3c/em\u3e Likely Has Two Promoters Causing Unique Iron Regulation

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    The FeoABC ferrous transporter is a wide-spread bacterial system. While the feoABC locus is regulated by a number of factors in the bacteria studied, we have previously found that regulation of feoABC in Yersinia pestis appears to be unique. None of the non-iron responsive transcriptional regulators that control expression of feoABC in other bacteria do so in Y. pestis. Another unique factor is the iron and Fur regulation of the Y. pestis feoABC locus occurs during microaerobic but not aerobic growth. Here we show that this unique iron-regulation is not due to a unique aspect of the Y. pestis Fur protein but to DNA sequences that regulate transcription. We have used truncations, alterations, and deletions of the feoA::lacZ reporter to assess the mechanism behind the failure of iron to repress transcription under aerobic conditions. These studies plus EMSAs and DNA sequence analysis have led to our proposal that the feoABC locus has two promoters: an upstream P1 promoter whose expression is relatively iron-independent but repressed under microaerobic conditions and the known downstream Fur-regulated P2 promoter. In addition, we have identified two regions that bind Y. pestis protein(s), although we have not identified these protein(s) or their function. Finally we used iron uptake assays to demonstrate that both FeoABC and YfeABCD transport ferrous iron in an energy-dependent manner and also use ferric iron as a substrate for uptake

    Discovery of near-Earth asteroids by CCD scanning

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    The found near-Earth asteroid are different objects with peculiar orbits. With the new technique of CCD scanning we entered the domain of the smallest, the fastest, and the closest near-Earth asteroids. The results are presented

    Analytic Treatment of Positronium Spin Splittings in Light-Front QED

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    We study the QED bound-state problem in a light-front hamiltonian approach. Starting with a bare cutoff QED Hamiltonian, HBH_{_{B}}, with matrix elements between free states of drastically different energies removed, we perform a similarity transformation that removes the matrix elements between free states with energy differences between the bare cutoff, Λ\Lambda, and effective cutoff, \lam (\lam < \Lam). This generates effective interactions in the renormalized Hamiltonian, HRH_{_{R}}. These effective interactions are derived to order α\alpha in this work, with α≪1\alpha \ll 1. HRH_{_{R}} is renormalized by requiring it to satisfy coupling coherence. A nonrelativistic limit of the theory is taken, and the resulting Hamiltonian is studied using bound-state perturbation theory (BSPT). The effective cutoff, \lam^2, is fixed, and the limit, 0 \longleftarrow m^2 \alpha^2\ll \lam^2 \ll m^2 \alpha \longrightarrow \infty, is taken. This upper bound on \lam^2 places the effects of low-energy (energy transfer below \lam) emission in the effective interactions in the ∣ee‾>| e {\overline e} > sector. This lower bound on \lam^2 insures that the nonperturbative scale of interest is not removed by the similarity transformation. As an explicit example of the general formalism introduced, we show that the Hamiltonian renormalized to O(α)O(\alpha) reproduces the exact spectrum of spin splittings, with degeneracies dictated by rotational symmetry, for the ground state through O(α4)O(\alpha^4). The entire calculation is performed analytically, and gives the well known singlet-triplet ground state spin splitting of positronium, 7/6α2Ryd7/6 \alpha^2 Ryd. We discuss remaining corrections other than the spin splittings and how they can be treated in calculating the spectrum with higher precision.Comment: 46 pages, latex, 3 Postscript figures included, section on remaining corrections added, title changed, error in older version corrected, cutoff placed in a windo

    Waterfowl and Allies Guild

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    The South Carolina Department of Natural Resources published guides to many threatened animals living in the state. This guide gives information about the Waterfowl and Allies Guild, including description, status, habitat, conservation challenges & recommendations, and measures of success

    Choroidal microvascular repair after argon laser photocoagulation. Ultrastructural observations

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    Acute laser injury to the tapetum of the feline retina produces thrombosis of the choriocapillaris. Early changes are characterized by the appearance of platelet-fibrin thrombi within capillary loops and disruption of endothelial integrity. By 4 days, thrombi have disappeared, and the endothelium shows regenerative changes. No endothelial cell mitotic activity is seen. The endothelial cytoplasm becomes plump, and there is a loss of the fenestrations adjacent to Bruch's membrane. By 10-20 days, the capillary structure shows gradual restoration. At 30 days, endothelial cell fenestrae are clearly evident adjacent to Bruch's membrane. The reparative process in this model appears to evolve as a result of thrombolysis and endothelial cell activation
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