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

University Scholar Series: Marc d\u27Alarcao

Synthetic Organic Chemistry to Shed Light on Type II Diabetes and Cancer On March 16, 2011 Marc d\u27Alarcao spoke in the University Scholar Series hosted by Provost Gerry Selter at the Dr. Martin Luther King, Jr. Library. Marc d\u27Alarcao is a Professor in the Chemistry Department at SJSU. In this seminar, he gives a progress report on his work aimed at developing and synthesizing new compounds that are designed to take advantage of this metabolic difference. His hope is that these compounds will be selectively toxic to cancer cells and may provide a new strategy for treating this major threat to human health.https://scholarworks.sjsu.edu/uss/1007/thumbnail.jp

The Synthesis of Cyclic Combinatorial Circuits

To be added

Cyclic Boolean circuits

A Boolean circuit is a collection of gates and wires that performs a mapping from Boolean inputs to Boolean outputs. The accepted wisdom is that such circuits must have acyclic (i.e., loop-free or feed-forward) topologies. In fact, the model is often defined this way – as a directed acyclic graph (DAG). And yet simple examples suggest that this is incorrect. We advocate that Boolean circuits should have cyclic topologies (i.e., loops or feedback paths). In other work, we demonstrated the practical implications of this view: digital circuits can be designed with fewer gates if they contain cycles. In this paper, we explore the theoretical underpinnings of the idea. We show that the complexity of implementing Boolean functions can be lower with cyclic topologies than with acyclic topologies. With examples, we show that certain Boolean functions can be implemented by cyclic circuits with as little as one-half the number gates that are required by equivalent acyclic circuits

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

The Politics of Selective Default: The Foreign Debts of the Confederate States of America

The Confederate States of America floated two small bond issues in Europe during the American Civil War; cotton bonds that traded primarily in England and junk bonds in Amsterdam. The Confederacy serviced the cotton bonds for the duration of the war and defaulted on the junk bond issue. Evidently the South believed that the cotton bonds provided a financial incentive for England to intervene or give military support. This policy of selective default suggests that reputation spillovers across markets may be smaller than indicated in theoretical models of debt repayment (Cole and Kehoe, 1994).

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,