7,188 research outputs found

    Generalized Affine Coherent States: A Natural Framework for Quantization of Metric-like Variables

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    Affine variables, which have the virtue of preserving the positive-definite character of matrix-like objects, have been suggested as replacements for the canonical variables of standard quantization schemes, especially in the context of quantum gravity. We develop the kinematics of such variables, discussing suitable coherent states, their associated resolution of unity, polarizations, and finally the realization of the coherent-state overlap function in terms of suitable path-integral formulations.Comment: 17 pages, LaTeX, no figure

    Debt Repayment: A Typology

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    This research paper presents a four-category typology of the debt market based on attitudinal and behavioral data associated with the repayment of student loans.  Qualitative interviews incorporating the Zaltman Metaphor Elicitation Technique (ZMET®) as well as a quantitative survey were used to obtain the data so the typology could be created.  The four groups identified were the Life Indebted, the Traditionalist, the Entrepreneur, and the Expedient Payee.  

    Summary of LaRC 2-inch Erectable Joint Hardware Heritage Test Data

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    As the National Space Transportation System (STS, also known as the Space Shuttle) went into service during the early 1980's, NASA envisioned many missions of exploration and discovery that could take advantage of the STS capabilities. These missions included: large orbiting space stations, large space science telescopes and large spacecraft for manned missions to the Moon and Mars. The missions required structures that were significantly larger than the payload volume available on the STS. NASA Langley Research Center (LaRC) conducted studies to design and develop the technology needed to assemble the large space structures in orbit. LaRC focused on technology for erectable truss structures, in particular, the joint that connects the truss struts at the truss nodes. When the NASA research in large erectable space structures ended in the early 1990's, a significant amount of structural testing had been performed on the LaRC 2-inch erectable joint that was never published. An extensive set of historical information and data has been reviewed and the joint structural testing results from this historical data are compiled and summarized in this report

    Epigenetics and the overhealing wound: the role of DNA methylation in fibrosis

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    Fibrosis is a progressive and potentially fatal process that can occur in numerous organ systems. Characterised by the excessive deposition of extracellular matrix proteins such as collagens and fibronectin, fibrosis affects normal tissue architecture and impedes organ function. Although a considerable amount of research has focused on the mechanisms underlying disease pathogenesis, current therapeutic options do not directly target the pro-fibrotic process. As a result, there is a clear unmet clinical need to develop new agents. Novel findings implicate a role for epigenetic modifications contributing to the progression of fibrosis by alteration of gene expression profiles. This review will focus on DNA methylation; its association with fibroblast differentiation and activation and the consequent buildup of fibrotic scar tissue. The potential use of therapies that modulate this epigenetic pathway for the treatment of fibrosis in several organ systems is also discussed
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