1,626 research outputs found

    The emergence of 4-cycles in polynomial maps over the extended integers

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    Let f(x)∈Z[x]f(x) \in \mathbb{Z}[x]; for each integer α\alpha it is interesting to consider the number of iterates nαn_{\alpha}, if possible, needed to satisfy fnα(α)=αf^{n_{\alpha}}(\alpha) = \alpha. The sets {α,f(α),…,fnα−1(α),α}\{\alpha, f(\alpha), \ldots, f^{n_{\alpha} - 1}(\alpha), \alpha\} generated by the iterates of ff are called cycles. For Z[x]\mathbb{Z}[x] it is known that cycles of length 1 and 2 occur, and no others. While much is known for extensions to number fields, we concentrate on extending Z\mathbb{Z} by adjoining reciprocals of primes. Let Z[1/p1,…,1/pn]\mathbb{Z}[1/p_1, \ldots, 1/p_n] denote Z\mathbb{Z} extended by adding in the reciprocals of the nn primes p1,…,pnp_1, \ldots, p_n and all their products and powers with each other and the elements of Z\mathbb{Z}. Interestingly, cycles of length 4, called 4-cycles, emerge for polynomials in Z[1/p1,…,1/pn][x]\mathbb{Z}\left[1/p_1, \ldots, 1/p_n\right][x] under the appropriate conditions. The problem of finding criteria under which 4-cycles emerge is equivalent to determining how often a sum of four terms is zero, where the terms are ±1\pm 1 times a product of elements from the list of nn primes. We investigate conditions on sets of primes under which 4-cycles emerge. We characterize when 4-cycles emerge if the set has one or two primes, and (assuming a generalization of the ABC conjecture) find conditions on sets of primes guaranteed not to cause 4-cycles to emerge.Comment: 14 pages, 1 figur

    The \u3ci\u3eCotton\u3c/i\u3e and \u3ci\u3eSugar\u3c/i\u3e Subsidies Decisions: WTO\u27s Dispute Settlement System Rebalances the Agreement on Agriculture

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    As far back as David Ricardo\u27s shattering insight as to comparative advantage in 1817, agriculture has enjoyed special favor in trade. The unique place of farming was so well established by the time the 1947 General Agreement on Tariffs and Trade ( GATT ) was negotiated that GATT\u27s tight disciplines on government interference with free trade not only exempted government protections to growers, but in fact were drafted to be fully consistent with the agricultural policies of the major signatories. While it would be an exaggeration to argue that GATT\u27 s first half century was without impact on agricultural benefits, the sector at any rate took center stage during negotiations to create the World Trade Organization ( WTO ) because by the time these talks began in 1986, subsidy-induced overproduction had led to widespread displacement of efficient producers from their traditional markets. Many felt this result was far from realization of David Ricardo\u27s compelling economic case for the smallest possible government intervention. While widely hailed for bringing agriculture, at last, under the GATT/WTO umbrella, 1995\u27s Agreement on Agriculture ( Agreement on Agriculture ) more than lived up to the promise of Article 20 that substantial ... reductionsin support and protection resulting in fundamental reform is an ongoing process.\u27\u27 Both as to export subsidies -- those contingent upon export performance and, thus, with the most direct impact on export prices and trade --and the remaining domestic subsidies, the Agreement on Agriculture\u27s ambitions are so modest that many experts believed its generous exemptions and undefined terms rarely would permit successful reining in by dispute settlement panels of the nearly $1 billion a day developed nations provide to their farmers. Two decisions issued by WTO dispute settlement panels on September 8, 2004, belie that prediction. Brazil, an agricultural superpower in its own right, was a complainant in both cases. In the first case, a Panel found United States subsidies to upland cotton were sufficiently in excess of those granted by the UNITED STATES during the baseline 1992 marketing year to be actionable under the Subsidies Agreement, despite the protection of the Peace Clause of the Agreement on Agriculture. The Cotton Panel went on to find that these subsidies caused serious prejudice to Brazil\u27s cotton growers within the meaning of the Subsidies Agreement. In the second case, which involved the EU\u27s Common Agricultural Policy, a Panel held that the EU had exceeded its agreed commitments on sugar in both the amount of exports and the level of subsidies. This paper will analyze the major holdings of the Sugar and Cotton decisions from both a legal and an economic perspective, assess the WTO implications of those holdings on other crops and on Doha Round agriculture negotiations, and examine the effects on other United States exports of the failure of the United States to implement the decisions separate from Doha Round negotiations

    The \u3ci\u3eCotton\u3c/i\u3e and \u3ci\u3eSugar\u3c/i\u3e Subsidies Decisions: WTO\u27s Dispute Settlement System Rebalances the Agreement on Agriculture

    Get PDF
    As far back as David Ricardo\u27s shattering insight as to comparative advantage in 1817, agriculture has enjoyed special favor in trade. The unique place of farming was so well established by the time the 1947 General Agreement on Tariffs and Trade ( GATT ) was negotiated that GATT\u27s tight disciplines on government interference with free trade not only exempted government protections to growers, but in fact were drafted to be fully consistent with the agricultural policies of the major signatories. While it would be an exaggeration to argue that GATT\u27 s first half century was without impact on agricultural benefits, the sector at any rate took center stage during negotiations to create the World Trade Organization ( WTO ) because by the time these talks began in 1986, subsidy-induced overproduction had led to widespread displacement of efficient producers from their traditional markets. Many felt this result was far from realization of David Ricardo\u27s compelling economic case for the smallest possible government intervention. While widely hailed for bringing agriculture, at last, under the GATT/WTO umbrella, 1995\u27s Agreement on Agriculture ( Agreement on Agriculture ) more than lived up to the promise of Article 20 that substantial ... reductionsin support and protection resulting in fundamental reform is an ongoing process.\u27\u27 Both as to export subsidies -- those contingent upon export performance and, thus, with the most direct impact on export prices and trade --and the remaining domestic subsidies, the Agreement on Agriculture\u27s ambitions are so modest that many experts believed its generous exemptions and undefined terms rarely would permit successful reining in by dispute settlement panels of the nearly $1 billion a day developed nations provide to their farmers. Two decisions issued by WTO dispute settlement panels on September 8, 2004, belie that prediction. Brazil, an agricultural superpower in its own right, was a complainant in both cases. In the first case, a Panel found United States subsidies to upland cotton were sufficiently in excess of those granted by the UNITED STATES during the baseline 1992 marketing year to be actionable under the Subsidies Agreement, despite the protection of the Peace Clause of the Agreement on Agriculture. The Cotton Panel went on to find that these subsidies caused serious prejudice to Brazil\u27s cotton growers within the meaning of the Subsidies Agreement. In the second case, which involved the EU\u27s Common Agricultural Policy, a Panel held that the EU had exceeded its agreed commitments on sugar in both the amount of exports and the level of subsidies. This paper will analyze the major holdings of the Sugar and Cotton decisions from both a legal and an economic perspective, assess the WTO implications of those holdings on other crops and on Doha Round agriculture negotiations, and examine the effects on other United States exports of the failure of the United States to implement the decisions separate from Doha Round negotiations

    Quest religious orientation among church leaders in Australia: A function of psychological predisposition or openness to mystical experience?

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    Quest religious orientation among church leaders signifies a style of leadership committed to religious explorations more than to religious certainties. This study sets out to explore the extent to which quest religious orientation among religious leaders is a function of psychological predisposition (conceptualized in terms of psychological type theory) or a function of distinctive forms of religious experience (conceptualized in terms of Happold’s model of mysticism) among a sample of 1,265 church leaders who participated in the 2011 Australian National Church Life Survey. The data demonstrated that higher levels of mystical orientation were associated with psychological predisposition, involving extraversion, intuition, feeling and perceiving. After controlling for sex, age, education, denominational groups and psychological type, higher levels of mystical orientation were also associated with higher levels of quest religious orientation. Mystical orientation partly mediated the effect of intuition on question orientation, but psychological preferences (for intuition and for perceiving) and mystical orientation seemed independently to promote quest religious orientation. Thus, church leaders committed to religious explorations rather than to religious certainties seemed to have been shaped both by psychological predisposition and by distinctive forms of religious experience

    Ramsey Theory Problems over the Integers: Avoiding Generalized Progressions

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    Two well studied Ramsey-theoretic problems consider subsets of the natural numbers which either contain no three elements in arithmetic progression, or in geometric progression. We study generalizations of this problem, by varying the kinds of progressions to be avoided and the metrics used to evaluate the density of the resulting subsets. One can view a 3-term arithmetic progression as a sequence x,fn(x),fn(fn(x))x, f_n(x), f_n(f_n(x)), where fn(x)=x+nf_n(x) = x + n, nn a nonzero integer. Thus avoiding three-term arithmetic progressions is equivalent to containing no three elements of the form x,fn(x),fn(fn(x))x, f_n(x), f_n(f_n(x)) with fn∈Ftf_n \in\mathcal{F}_{\rm t}, the set of integer translations. One can similarly construct related progressions using different families of functions. We investigate several such families, including geometric progressions (fn(x)=nxf_n(x) = nx with n>1n > 1 a natural number) and exponential progressions (fn(x)=xnf_n(x) = x^n). Progression-free sets are often constructed "greedily," including every number so long as it is not in progression with any of the previous elements. Rankin characterized the greedy geometric-progression-free set in terms of the greedy arithmetic set. We characterize the greedy exponential set and prove that it has asymptotic density 1, and then discuss how the optimality of the greedy set depends on the family of functions used to define progressions. Traditionally, the size of a progression-free set is measured using the (upper) asymptotic density, however we consider several different notions of density, including the uniform and exponential densities.Comment: Version 1.0, 13 page
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