403 research outputs found

    Canonical wave packets in quantum cosmology

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    We discuss the construction of wave packets resulting from the solutions of a class of Wheeler-DeWitt equations in Robertson-Walker type cosmologies, for arbitrary curvature. We show that there always exists a ``canonical initial slope" for a given initial wave function, which optimizes some desirable properties of the resulting wave packet, most importantly good classical-quantum correspondence. This can be properly denoted as a canonical wave packet. We introduce a general method for finding these canonical initial slopes which is generalization of our earlier work.Comment: 19 pages, 8 figure

    Methods of Analysis Used in U.S. Government Nutrition Investiagation at the University of Tennessee

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    The following methods and results represent the manner in which the analyses of the nutrition investigation have been carried on in the University laboratories for several years, and also many additional improvements of standard methods different from other laboratories. In classifying the analyses the four main heads which are discussed are: 1) Determination of Ash, 2) Determination of Nitrogen, 3) Determination of Water and Fat, & 4) Determination of Heat of Combustion. In making the determination of each constituent the following order will be taken through each determination, being thus grouped to make a more systematic arrangement: (1) Preparation of Sample amount taken for analysis, (2) Reagents used in making determination, (3) Apparatus, (4) General remarks and peculiaritie

    Stephani-Schutz quantum cosmology

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    We study the Stephani quantum cosmological model in the presence of a cosmological constant in radiation dominated Universe. In the present work the Schutz's variational formalism which recovers the notion of time is applied. This gives rise to Wheeler-DeWitt equations which can be cast in the form of Schr\"odinger equations for the scale factor. We find their eigenvalues and eigenfunctions by using the Spectral Method. Then we use the eigenfunctions in order to construct wave packets and evaluate the time-dependent expectation value of the scale factor, which is found to oscillate between non-zero finite maximum and minimum values. Since the expectation value of the scale factor never tends to the singular point, we have an initial indication that this model may not have singularities at the quantum level.Comment: 6 pages, 4 figures, 1 table, to appear in PL

    Methods of Analysis Used in U.S. Government Nutrition

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    The following methods and results represent the manner in which the analyses of the nutrition investigation have been carried on in the University laboratories for several years, and also many additional improvements of standard methods different from other laboratories. In classifying the analyses the four main heads which are discussed are: (1) Determination of Ash (2) Determination of Nitrogen (3) Determination of Water and Fat (4) Determination of Heat of Combustion. In making the determination of each constituent the following order will be taken throughout each determination, being thus grouped to make a more systematic arrangement: (1) Preparation of Sample and amount taken for analysis, (2) Reagents used in making determination, (3) Appararus, (4) General remarks and peculiarities

    Viruses as co-factors for the initiation or exacerbation of lung fibrosis

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    Idiopathic pulmonary fibrosis (IPF) remains exactly that. The disease originates from an unknown cause, and little is known about the mechanisms of pathogenesis. While the disease is likely multi-factorial, evidence is accumulating to implicate viruses as co-factors (either as initiating or exacerbating agents) of fibrotic lung disease. This review summarizes the available clinical and experimental observations that form the basis for the hypothesis that viral infections may augment fibrotic responses. We review the data suggesting a link between hepatitis C virus, adenovirus, human cytomegalovirus and, in particular, the Epstein-Barr gammaherpesvirus, in IPF. In addition, we highlight the recent associations made between gammaherpesvirus infection and lung fibrosis in horses and discuss the various murine models that have been used to investigate the contribution of gammaherpesviruses to fibrotic progression. We review the work demonstrating that gammaherpesvirus infection of Th2-biased mice leads to multi-organ fibrosis and highlight studies showing that gammaherpesviral infections of mice either pre- or post-fibrotic challenge can augment the development of fibrosis. Finally, we discuss potential mechanisms whereby viral infections may amplify the development of fibrosis. While none of these studies prove causality, we believe the evidence suggests that viral infections should be considered as potential initiators or exacerbating agents in at least some cases of IPF and thereby justify further study

    State of the science 60th anniversary review

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    No abstract.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/60971/1/23643_ftp.pd

    Grandparenting a child with a disability: An emotional rollercoaster

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    Objectives: As our knowledge about the experiences of grandparents when their grandchild has a disability is extremely limited, the purpose of this research was to explore the emotional journey of Australian grandparents. Method: This qualitative research utilised purposive sampling and semi-structured in-depth interviews to explore the experiences of 22 Australian grandparents, whose grandchild had been diagnosed with a disability. Results: Three key themes characterised grandparent’s emotional journey: Adjusting (the transition from anger to acceptance), The ‘Double Grief’ (sadness about what might have been for both their child and grandchild) and Pride in Family (pride in family’s ability to adjust to the challenges of the situation). Conclusion: As the first Australian study to explore the experiences of grandparents when their grandchild has a disability, the research provides important new knowledge about the emotional journey for grandparents. Unlike overseas research, Australian grandparents view themselves as being there to support their own children, rather than ‘holding the family together’. The findings will inform current policy debates about the role of grandparents and highlight the importance of support services that help facilitate grandparent’s role within their famil
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