87 research outputs found

    The Accelerated Kepler Problem

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    The accelerated Kepler problem is obtained by adding a constant acceleration to the classical two-body Kepler problem. This setting models the dynamics of a jet-sustaining accretion disk and its content of forming planets as the disk loses linear momentum through the asymmetric jet-counterjet system it powers. The dynamics of the accelerated Kepler problem is analyzed using physical as well as parabolic coordinates. The latter naturally separate the problem's Hamiltonian into two unidimensional Hamiltonians. In particular, we identify the origin of the secular resonance in the accelerated Kepler problem and determine analytically the radius of stability boundary of initially circular orbits that are of particular interest to the problem of radial migration in binary systems as well as to the truncation of accretion disks through stellar jet acceleration.Comment: 16 pages, 9 figures, in press at Celestial Mechanics and Dynamical Astronom

    Ethical Assumptions in Economic Theory: Some Lessons from the History of Credit and Bankruptcy

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    This paper evaluates the economic assumptions of economic theory via an examination of the capitalist transformation of creditor–debtor relations in the 18th century. This transformation enabled masses of people to obtain credit without moral opprobrium or social subordination. Classical 18th century economics had the ethical concepts to appreciate these facts. Ironically, contemporary economic theory cannot. I trace this fault to its abstract representations of freedom, efficiency, and markets. The virtues of capitalism lie in the concrete social relations and social meanings through which capital and commodities are exchanged. Contrary to laissez faire capitalism, the conditions for sustaining these concrete capitalist formations require limits on freedom of contract and the scope of private property rights.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42724/1/10677_2004_Article_2202.pd

    Death and the “life review” in Halakhah

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    Coping with old age involves resolving the task of “integrity versus despair,” which demands a nondefensive confrontation with the inevitability of death. Halakhah (Jewish ethics) also considered this task critical in later years of life, spoke of death's inevitability, and attempted to discourage denial of death. The Jewish approach seems compatible with Butler's concept of “life review” as a reconciliation with death and a reintegration of one's identity that occurs throughout later years. While the Eriksonian goal is confronting old age with a certain capacity for “wisdom,” the rabbis maintained that such wisdom must culminate in the creative act of repentance.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45115/1/10943_2004_Article_BF00996254.pd

    Self-help groups challenge health care systems in the US and UK

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    Purpose: This research considers how self-help groups (SHGs) and self- help organizations (SHOs) contribute to consumerist trends in two different societies: United States and United Kingdom. How do the health care systems and the voluntary sectors affect the kinds of social changes that SHGs/SHOs make? Methodology/approach: A review of research on the role of SHGs/SHOs in contributing to national health social movements in the UK and US was made. Case studies of the UK and the US compare the characteristics of their health care systems and their voluntary sector. Research reviews of two community level self-help groups in each country describe the kinds of social changes they made. Findings: The research review verified that SHGs/SHOs contribute to national level health social movements for patient consumerism. The case studies showed that community level SHGs/SHOs successfully made the same social changes but on a smaller scale as the national movements, and the health care system affects the kinds of community changes made. Research limitations: A limited number of SHGs/SHOs within only two societies were studied. Additional SHGs/SHOs within a variety of societies need to be studied. Originality/value of chapter Community SHGs/SHOs are often trivialized by social scientists as just inward-oriented support groups, but this chapter shows that local groups contribute to patient consumerism and social changes but in ways that depend on the kind of health care system and societal context

    Natural triangulations associated to a surface

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