83,193 research outputs found

    Supersymmetry and the AdS Higgs Phenomenon

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    We examine the AdS Higgs phenomenon for spin-1 fields, and demonstrate that graviphotons pick up a dynamically generated mass in AdS_4, once matter boundary conditions are relaxed. We perform an explicit one-loop calculation of the graviphoton mass, and compare this result with the mass generated for the graviton in AdS. In this manner, we obtain a condition for unbroken supersymmetry. With this condition, we examine both N=2 and N=4 gauged supergravities coupled to matter multiplets, and find that for both cases the ratio between dynamically generated graviton and graviphoton masses is consistent with unbroken supersymmetry.Comment: 12 pages, JHEP forma

    Nuclear RNA Surveillance in \u3cem\u3eSaccharomyces cerevisiae\u3c/em\u3e: Trf4p-dependent Polyadenylation of Nascent Hypomethylated tRNA and an Aberrant Form of 5S rRNA

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    1-Methyladenosine modification at position 58 of tRNA is catalyzed by a two-subunit methyltransferase composed of Trm6p and Trm61p in Saccharomyces cerevisiae. Initiator tRNA (tRNAiMet) lacking m1A58 (hypomethylated) is rendered unstable through the cooperative function of the poly(A) polymerases, Trf4p/Trf5p, and the nuclear exosome. We provide evidence that a catalytically active Trf4p poly(A) polymerase is required for polyadenylation of hypomethylated tRNAiMet in vivo. DNA sequence analysis of tRNAiMet cDNAs and Northern hybridizations of poly(A)+ RNA provide evidence that nascent pre-tRNAiMet transcripts are targeted for polyadenylation and degradation. We determined that a mutant U6 snRNA and an aberrant form of 5S rRNA are stabilized in the absence of Trf4p, supporting that Trf4p facilitated RNA surveillance is a global process that stretches beyond hypomethylated tRNAiMet. We conclude that an array of RNA polymerase III transcripts are targeted for Trf4p/ Trf5p-dependent polyadenylation and turnover to eliminate mutant and variant forms of normally stable RNAs

    Mass in anti-de Sitter spaces

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    The boundary stress tensor approach has proven extremely useful in defining mass and angular momentum in asymptotically anti-de Sitter spaces with CFT duals. An integral part of this method is the use of boundary counterterms to regulate the gravitational action and stress tensor. In addition to the standard gravitational counterterms, in the presence of matter we advocate the use of a finite counterterm proportional to phi^2 (in five dimensions). We demonstrate that this finite shift is necessary to properly reproduce the expected mass/charge relation for R-charged black holes in AdS_5.Comment: 15 pages, late

    Faculty Perceptions of Academic Freedom at a Private Religious University

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    Academic freedom is viewed by many in higher education as an indispensible foundational principle offering protection to university faculty. University faculty working within schools of education rely on the protection of academic freedom to pursue and develop new knowledge, frameworks, and pedagogies with which they can train and equip the next generation of classroom teachers and school administrators. Private religious universities have been a part of the American education landscape since the founding of Harvard University, yet the perception exists that faculty at religious universities are de facto inhibited by the religious commitment of many of these institutions. This study examines the concept of academic freedom as viewed by 18 senior faculty at Regent University, a private religious institution. Findings demonstrate faculty generally support an institutional perspective of academic freedom and express a high level of comfort with limited restrictions on academic freedom in light of the university’s religious mission. Implications exist for all faculty, especially those at religious institutions

    The Effect of Expertise on the Quality of Appraisal Services

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    This article examines the quality of appraisals as a function of expertise. In paraticular, we compare novices (beginning real estate students) to experts (practicing certified and/or designated appraisers) on three performance criteria. First, we examine differences in the values that these two groups attach to various property features. Second, we investigate the variation between their final market value estimates. The last task studied is whether appraisers can reliably provide a range about their market value that includes the actual sale price of the property. The results are based on a controlled experiment involving seventy-two novices and sixty-nine experts, where each participant was asked to determine a fair market value of a single-family home. Findings indicate that experienced appraisers do in fact exhibit less variation in their valuation of property characteristics, hence there is greater agreement in their market value estimates than is the case with novices. However, more experienced decision-makers tend to be overconfident of their ability: they are less likely to specify a range that includes the sale price than are novices.
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