New Bounds on Isotropic Lorentz Violation

Violations of Lorentz invariance that appear via operators of dimension four or less are completely parameterized in the Standard Model Extension (SME). In the pure photonic sector of the SME, there are nineteen dimensionless, Lorentz-violating parameters. Eighteen of these have experimental upper bounds ranging between 10^{-11} and 10^{-32}; the remaining parameter, k_tr, is isotropic and has a much weaker bound of order 10^{-4}. In this Brief Report, we point out that k_tr gives a significant contribution to the anomalous magnetic moment of the electron and find a new upper bound of order 10^{-8}. With reasonable assumptions, we further show that this bound may be improved to 10^{-14} by considering the renormalization of other Lorentz-violating parameters that are more tightly constrained. Using similar renormalization arguments, we also estimate bounds on Lorentz violating parameters in the pure gluonic sector of QCD.Comment: 10 pages, 1 figure. v2: reference adde

Trade Friction, Dispute Settlement and Structural Adjustment, Or, Why Canada-Wheat Doesn’t Matter in North American Trade Relations

This article examines the substance of the WTO panel decision for Canada-Wheat as it relates to trade friction in North American agricultural markets. I provide an overview of recent economic literature on state trading enterprises (STEs) and examine the WTO’s approach to regulating the behaviour of STEs. The Canada-Wheat panel was the first WTO panel to consider Canada’s single-desk marketing system for Western Canadian wheat and barley and was the first test of the WTO’s regulation of STEs under GATT Article XVII. The panel rejected the American argument, opting for a line of reasoning that highlights the rules of non-discrimination while maintaining some of the ambiguity of Article XVII. I conclude by examining the competitive pressures that exacerbate trade frictions between North American wheat producers. From a legal perspective, this panel decision is significant because it clarifies the WTO’s position on STEs, to a certain extent. In the context of continental politics, however, the ruling will likely have little impact on Canada/U.S. trade relations because it must be analyzed in relation to the domestic demands that arise from ongoing structural adjustment in both nations’ agricultural sectors.agricultural exports, Canadian Wheat Board, dispute settlement, state trading enterprises, World Trade Organization, Agribusiness, Agricultural and Food Policy, Crop Production/Industries, International Relations/Trade, Political Economy,

Exact Stochastic Simulation of Chemical Reactions with Cycle Leaping

The stochastic simulation algorithm (SSA), first proposed by Gillespie, has become the workhorse of computational biology. It tracks integer quantities of the molecular species, executing reactions at random based on propensity calculations. An estimate for the resulting quantities of the different species is obtained by averaging the results of repeated trials. Unfortunately, for models with many reaction channels and many species, the algorithm requires a prohibitive amount of computation time. Many trials must be performed, each forming a lengthy trajectory through the state space. With coupled or reversible reactions, the simulation often loops through the same sequence of states repeatedly, consuming computing time, but making no forward progress. We propose a algorithm that reduces the simulation time through cycle leaping: when cycles are encountered, the exit probabilities are calculated. Then, in a single bound, the simulation leaps directly to one of the exit states. The technique is exact, sampling the state space with the expected probability distribution. It is a component of a general framework that we have developed for stochastic simulation based on probabilistic analysis and caching

Turning Points during the U.S. Civil War: Views from the Grayback Market

This paper introduces a new high frequency time series of Confederate money prices taken from the newspapers of Richmond and leading cities in the Eastern Confederacy. The new Grayback series is tested for “turning points.” The empirical analysis suggests that “turning points” in the Confederate Grayback market were different from those identified in the Union Greenback market by Willard et al. (1996). It appears that war did not always have symmetric effects on Northern and Southern money prices.Confederacy, turning points

The global cultural commons after Cancun: identity, diversity and citizenship

The cultural politics of global trade is a new and unexplored terrain because the public domain of culture has long been associated with national sovereignty. States everywhere have invested heavily in national identity. But in an age of globalization, culture and sovereignty have become more complex propositions, subject to global pressures and national constraints. This paper argues three main points. First, new information technologies increasingly destabilize traditional private sector models for disseminating culture. At the same time, international legal rules have become more restrictive with respect to investment and national treatment, two areas at the heart of cultural policy. Second, Doha has significant implications for the future of the cultural commons. Ongoing negotiations around TRIPS, TRIMS, GATS and dispute settlement will impose new restrictions on public authorities who wish to appropriate culture for a variety of public and private ends. Finally, there is a growing backlash against the WTO’s trade agenda for broadening and deepening disciplines in these areas. These issues have become highly politicized and fractious, and are bound to vex future rounds as the global south, led by Brazil, India and China flexes its diplomatic muscle