1,127 research outputs found

    Using the correlation dimension to detect non-linear dynamics: Evidence from the Athens Stock Exchange

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    The standardised residuals from GARCH models fitted to three stock indices of the Athens Stock Exchange are examined for evidence of chaotic behaviour. In each case the correlation dimension is calculated for a range of embedding dimensions. The results do not support the hypothesis of chaotic behaviour; it appears that each set of residuals is iid.Non-linear Dynamics, Stock Indices, Chaos, Correlation Dimension

    Automata network models of galaxy evolution

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    Two ideas appear frequently in theories of star formation and galaxy evolution: (1) star formation is nonlocally excitatory, stimulating star formation in neighboring regions by propagation of a dense fragmenting shell or the compression of preexisting clouds; and (2) star formation is nonlocally inhibitory, making H2 regions and explosions which can create low-density and/or high temperature regions and increase the macroscopic velocity dispersion of the cloudy gas. Since it is not possible, given the present state of hydrodynamic modeling, to estimate whether one of these effects greatly dominates the other, it is of interest to investigate the predicted spatial pattern of star formation and its temporal behavior in simple models which incorporate both effects in a controlled manner. The present work presents preliminary results of such a study which is based on lattice galaxy models with various types of nonlocal inhibitory and excitatory couplings of the local SFR to the gas density, temperature, and velocity field meant to model a number of theoretical suggestions

    Recent challenges to nation-building in Kanaky New Caledonia

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    "After significant decolonisation in the 1950s, New Caledonia’s destiny was reversed in the 1960s for reasons of French national prestige and strategic nickel resources. The lesson of the 1980s is that regression was a mistake. Today, everyone in the restricted New Caledonian citizenship of longterm residents has accepted self-government; they differ over the degree of separation from France, that is, the specific details of sovereignty. The exact legal boundary between enlarged autonomy and full sovereignty, especially in a globalising world that compromises even French independence (for example, the European Union, or multinational corporations), has yet to be determined. In March 2011, at a colloquium in Noumea that presented comparative perspectives on decolonisation, legal scholars suggested that so-called ‘reserved’ powers — which loyalists want France to keep — such as defense and public order, are not carved in stone in French law. Instead, they constitute bundles of administrative responsibilities, some of which are already shared, so the exact category of the country’s future status may be less important than the principles that local leaders bring to the negotiating table and find consensual ways to implement ..." - page 9AusAI

    Cardiovascular disease: the universal slayer

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    This voracious killer is strengthened by particular lifestyle choices – can you escape its morbid embrace

    A study of isometric and pulsed isometric fatigue of the digital flexor muscle group

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    http://www.worldcat.org/oclc/2834695

    Improving the Pipeline for Developing and Testing Pharmacological Treatments in Pregnancy

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    In a Perspective, Lucy Chappell and Anna David discuss ways to develop and test pharmacological treatments in pregnancy

    Canopy spectral reflectance as an indirect selection tool for yield in wheat

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    Measurement of yield and its components is typically a laborious and expensive process in most wheat (Triticum aestivum L.) breeding programs due to the need for large seed quantities and multi-location testing. High-throughput phenotyping for traits that are associated with yield may enable breeders to more effectively select genotypes with high yield potential in earlier generations when genetic diversity may be higher and in a single environment thereby lowering costs. This study was designed to determine the efficacy of utilizing canopy spectral reflectance indices as indirect selection criteria for grain yield and its components in soft red winter wheat. Two experiments were conducted over two crop seasons near Columbia, Missouri, including one with thirty-six genotypes previously selected for high or low grain yield that were arranged in a replicated, randomized complete block design and one with 1AL.1RS and 1BL.1RS wheat-rye translocation, along with respective controls, in three different genetic backgrounds, arranged in a split plot design. Canopy spectral reflectance, chlorophyll, and canopy temperature data were collected on clear days with low humidity during the boot, heading, anthesis, early grainfill, and dough developmental stages and analyzed for their association with grain yield and its components. Spectral reflectance indices measured at anthesis were most closely associated with yield and among those, CI, GNDVI, R760/R730, and R780/R740 were most strongly correlated with grain yield and related components. Coefficients of determination exceeded 0.6 for harvest index and 0.5 for grain number m-2 and grain yield m-2. Results of these experiments suggested that these indices may be effectively used as supplemental selection criteria for grain yield and related components in wheat

    Aristotle and Augustine on voluntary action and freedom and weakness of the will

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    Aristotle's remarks on free will suggest, not so much an argument for the existence of free will, as an account of its nature. This account depends on his making no hard distinction between what we call 'free action' and 'voluntary action'. For him, these would be interchangeable terms. The Aristotelian can, then, point out that, if we give up our belief in free will, we must give up many other natural beliefs too. In particular, we must stop believing in voluntary action.There are, in Aristotelian terms, three conditions (not two, as Aristotle himself evidently supposed), which any behaviour must satisfy to count as free/ voluntary action. The behaviour (i) must not be compelled, but must be performed by the agent's own power and desire; (ii) must not be done in ignorance, but must be action on relevant knowledge; and (iii) must not be irrational, but must result from the combination of the agent's own power and desire with the agent's relevant knowledge. (i) leads me to discuss Aristotle's account of what he calls kineseis; (ii) leads me into epistemology; (iii) into an account of Aristotle's theory of proairesis and practical reasoning as the cause of voluntary action.by akrasia, deliberate choice of what I sincerely believe I should not choose. This seems to be voluntary action which is not caused as Aristotle says voluntary action should be. But the three conditions of voluntary action which I say Aristotle should be committed to can be used to show that the existing forms of akrasia make no counter example to Aristotle's theory, but rather an interesting adjunct to it.My study of Augustine's theory of freedom begins with a survey of a crucial text, the de Libero Arbitrio (Ch.5). I then apply an analogous schema to that found in Aristotle. Augustine too depends on the idea that to analyse free action is to analyse voluntary action; he also equates these two types with responsible action. He too believes (i) that ignorance usually makes for involuntariness, and (ii) that there can be no voluntary action which is compelled or which the agent could not have done otherwise. In his later works, these doctrines are often obscured by his interest in original sin and predestination (neither of which topics, be it noted, are focuses of this thesis). But they remain his doctrines. Does Augustine have (iii) any doctrine that voluntary action must be rational? While he does not develop any theory of practical reasoning like Aristotle's, he does develop a theory of practical wisdom. It is an essential feature of all human desire, and hence of all voluntary action, that it aims at happiness, which properly understood is identical with possession of The Good, i.e. of God. From this Augustine draws the conclusion that, to explain any behaviour as a voluntary action or choice, it is necessary and sufficient to specify some good at which it is to be understood as aiming.This sets up for Augustine a problem analogous to Aristotle's problem about akrasia. How is a voluntary choice of evil explicable? Augustine's reply is that human desires have been disordered by the Fall, and so we often choose, not evils per se, but lesser goods than we ought. But this prompts the question: How is a first voluntary choice of evil explicable? Augustine's reply is simply that it is not. Since a voluntary action or choice must be explained by reference to some good at which it aims, a voluntary choice of evil per se cannot be explained at all. This does not mean that there was no voluntary choice of evil; but it does mean that, in principle, that choice is inexplicable- a mystery. Thus Augustine, unlike Aristotle, in this one exceptional case (but in no others) affirms that there can be genuinely voluntary action which is not, in the relevant sense, rational
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