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    Spinor and Twistor Formulations of Tensionless Bosonic Strings in Four Dimensions

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    Spinor and twistor formulations of tensionless bosonic strings in 4-dimensional Minkowski space are constructed. We begin with a first-order action that is equivalent to the Nambu-Goto action in the tensionful case and that leads to a spinorial action in the tensionless case. From this spinorial action, we find an alternative spinorial action useful for constructing a simple twistor formulation of tensionless strings. The twistor formulation is steadily constructed in accordance with a fundamental concept of twistor theory. We investigate local internal symmetries inherent in the twistorial action for a tensionless string and carry out some classical analyses of the tensionless string expressed in a twistorial form.Comment: 30 pages, no figures, minor corrections, a footnote added, published versio

    Simon Grant, Monti, Martin Osherson, Daniel

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    The classical theory of preference among monetary bets represents people as expected utility maximizers with nondecreasing concave utility functions. Critics of this account often rely on assumptions about preferences over wide ranges of total wealth. We derive a prediction of the theory that bears on bets at any fixed level of wealth, and test the prediction behaviorally. Our results are discrepant with the classical account. Competing theories are also examined in light of our data.

    Reflections on Meaningfulness and its Social Relevance

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    Philosophers who write about the meaning of life are few nowadays. Thesubject has lost its attractiveness. Perceived from a viewpoint of logical positivism or language philosophy, the whole issue of meaningfulness seems rather pointless. It is often considered to be related to metaphysics, making it less suitable for philosophical inquiry. The topic of meaningfulness seems too intangible. Indeed, the few philosophers that have embarked on examining meaningfulness have proven to be well aware of the challenges this poses. At times they acknowledge that the more they concentrate on the subject, the more it seems to fall apart into unintelligible pieces about whichnothing of philosophical value can be said

    Health Development and Primary Health Care

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    INTRODUCTIONThe peoples and countries of the Third World are struggling to overcome the effects of centuries of colonial dependency and unequal world relationships. These effects can be seen clearly in the area of human health. For example, of the 1978 world total of 17 million early childhood deaths (i.e., those under five years of age) around 97% took place in the Third World (1). If all the countries of the world had the same early childhood mortality rates as those of Northern Europe there would have been only 2 million such deaths. The relationship between such appaling health conditions health conditions and wider social structures is highlighted in the Six World Health Situation Report (1973-1977), prepared by the World Health Organization (2)

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    Locating Media in Cultural Theories

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    Media as constituting mass-produced vehicles of information existed long before Benjamin made his proclamation about the end of a cultural epoch 1 However media s sphere of influence has never diversified as quickly as in our current period Media today replicate in unfamiliar ways everyday across the globe 2 and in versions of the newly emerged media culture the difficulty of conceptualizing the unthought is no less problematic than in metropolitan counterpart
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