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Bacillus anthracis has four plasmid possible virulence genotypes: pXO1+/pXO2+, pXO1+/pXO2-, pXO1-/pXO2+ or pXO1-/pXO2-. Due to the lack of a specific chromosomal marker for B. anthracis, differentiation of the pXO1-/pXO2- form of B. anthracis from closely related Bacillus cereus group species is difficult. In this study, we evaluate the ability of sspE,(More)
We study a family of nonparametric tests of density ratio ordering between two continuous probability distributions on the real line. Density ratio ordering is satisfied when the two distributions admit a nonincreasing density ratio. Equivalently, density ratio ordering is satisfied when the ordinal dominance curve associated with the two distributions is(More)
We develop improved statistical procedures for testing the null hypothesis of stochastic monotonicity. Stochastic monotonicity can be reformulated in terms of the concavity of cross-sections of a copula function; our test statistic is based on a empirical measure of departures from concavity. While existing tests of stochastic monotonicity deliver a(More)
Economic and financial time series frequently exhibit time irreversible dynamics. For instance, there is considerable evidence of asymmetric fluctuations in many macroeconomic and financial variables, and certain game theoretic models of price determination predict asymmetric cycles in price series. In this paper, we make two primary contributions to the(More)
Consider a sequence X = (X0,X1, . . .) of random elements of a real separable Hilbert space H , whose €rst di‚erence is a standard linear process with long run covariance operator Λ. We show that, under a mild summability condition, the set of vectors x ∈ H for which 〈Xt ,x〉 is stationary given a suitable initialization X0 is the kernel of Λ. We call this(More)
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