15,417 research outputs found
Crowd-anticrowd theory of the Minority Game
The Minority Game is a simple yet highly non-trivial agent-based model for a
complex adaptive system. Despite its importance, a quantitative explanation of
the game's fluctuations which applies over the entire parameter range of
interest has so far been lacking. We provide such a quantitative description
based on the interplay between crowds of like-minded agents and their
anti-correlated partners (anticrowds).Comment: Shortened version of cond-mat/0003486. Submitted for publicatio
Dynamics of the Time Horizon Minority Game
We present exact analytic results for a new version of the Minority Game (MG)
in which strategy performance is recorded over a finite time horizon. The
dynamics of this Time Horizon Minority Game (THMG) exhibit many distinct
features from the MG and depend strongly on whether the participants are fed
real, or random, history strings. The THMG equations are equivalent to a Markov
Chain, and yield exact analytic results for the volatility given a specific
realization for the quenched strategy disorder.Comment: Latex file, 11 pages, 6 figure
Mixed population Minority Game with generalized strategies
We present a quantitative theory, based on crowd effects, for the market
volatility in a Minority Game played by a mixed population. Below a critical
concentration of generalized strategy players, we find that the volatility in
the crowded regime remains above the random coin-toss value regardless of the
"temperature" controlling strategy use. Our theory yields good agreement with
numerical simulations.Comment: Revtex file + 3 figure
The Unusual Substrate Specificity of a Virulence Associated Serine Hydrolase from the Highly Toxic Bacterium, \u3cem\u3eFrancisella tularensis\u3c/em\u3e
Francisella tularensis is the causative agent of the highly, infectious disease, tularemia. Amongst the genes identified as essential to the virulence of F. tularensis was the proposed serine hydrolase FTT0941c. Herein, we purified FTT0941c to homogeneity and then characterized the folded stability, enzymatic activity, and substrate specificity of FTT0941c. Based on phylogenetic analysis, FTT0941c was classified within a divergent Francisella subbranch of the bacterial hormone sensitive lipase (HSL) superfamily, but with the conserved sequence motifs of a bacterial serine hydrolase. FTT0941c showed broad hydrolase activity against diverse libraries of ester substrates, including significant hydrolytic activity across alkyl ester substrates from 2 to 8 carbons in length. Among a diverse library of fluorogenic substrates, FTT0941c preferred α-cyclohexyl ester substrates, matching with the substrate specificity of structural homologues and the broad open architecture of its modeled binding pocket. By substitutional analysis, FTT0941c was confirmed to have a classic catalytic triad of Ser115, His278, and Asp248 and to remain thermally stable even after substitution. Its overall substrate specificity profile, divergent phylogenetic homology, and preliminary pathway analysis suggested potential biological functions for FTT0941c in diverse metabolic degradation pathways in F. tularensis
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