Stretched Exponential Relaxation in the Biased Random Voter Model

We study the relaxation properties of the voter model with i.i.d. random bias. We prove under mild condions that the disorder-averaged relaxation of this biased random voter model is faster than a stretched exponential with exponent $d/(d+\alpha)$, where $0<\alpha\le 2$ depends on the transition rates of the non-biased voter model. Under an additional assumption, we show that the above upper bound is optimal. The main ingredient of our proof is a result of Donsker and Varadhan (1979).Comment: 14 pages, AMS-LaTe

On the Trail of the Decadent Polyglot

At the risk of beating a dead horse to death, I desire to add my lick. Students are not adequately trained to communicate in science, and the objective-type test is not helping. When linguistic fluency is equated with drooling in one\u27s beard, and semantics is some sort of erotic deviation, one must not be surprised to learn that etymology is the study of incests. Most of the kids have become aware that mini means small, and that lunar means moon, and we should be grateful for such small advances, but the slippage in other areas is less cause for a gaudeamus igitur. A rara avis indeed who knows the plural of data, media, algae, or compendia

Transient Random Walks in Random Environment on a Galton-Watson Tree

We consider a transient random walk $(X_n)$ in random environment on a Galton--Watson tree. Under fairly general assumptions, we give a sharp and explicit criterion for the asymptotic speed to be positive. As a consequence, situations with zero speed are revealed to occur. In such cases, we prove that $X_n$ is of order of magnitude $n^{\Lambda}$, with $\Lambda \in (0,1)$. We also show that the linearly edge reinforced random walk on a regular tree always has a positive asymptotic speed, which improves a recent result of Collevecchio \cite{Col06}

Kinetics of Radioiodinated Heptadecanoic Acid and Metabolites in the Normal and Ischaemic Canine Heart

This study was undertaken to elucidate if the myocardial elimination rate of the radioactivity after administration of radioiodinated heptadecanoic acid was related to beta-oxidation of the fatty acid or related to washout of free radioiodide. In samples of normal and ischaemic myocardium the distribution of the radioactivity over free radioiodide, heptadecanoic acid and lipids was determined. In normal myocardium the major component was free radioiodide, only a small percentage being heptadecanoic acid. In ischaemic myocardium more radiolabelled lipids were present and less free iodide when compared with normal myocardium. The percentage heptadecanoic acid was slightly increased. It is concluded that radioiodinated heptadecanoic acid behaves like the natural analogues regarding uptake and distribution. However, washout of free radioiodide determines the elimination rate as observed during a scintigraphic stud

Quantum state estimation and large deviations

In this paper we propose a method to estimate the density matrix \rho of a d-level quantum system by measurements on the N-fold system. The scheme is based on covariant observables and representation theory of unitary groups and it extends previous results concerning the estimation of the spectrum of \rho. We show that it is consistent (i.e. the original input state \rho is recovered with certainty if N \to \infty), analyze its large deviation behavior, and calculate explicitly the corresponding rate function which describes the exponential decrease of error probabilities in the limit N \to \infty. Finally we discuss the question whether the proposed scheme provides the fastest possible decay of error probabilities.Comment: LaTex2e, 40 pages, 2 figures. Substantial changes in Section 4: one new subsection (4.1) and another (4.2 was 4.1 in the previous version) completely rewritten. Minor changes in Sect. 2 and 3. Typos corrected. References added. Accepted for publication in Rev. Math. Phy

Survival, extinction and approximation of discrete-time branching random walks

We consider a general discrete-time branching random walk on a countable set X. We relate local, strong local and global survival with suitable inequalities involving the first-moment matrix M of the process. In particular we prove that, while the local behavior is characterized by M, the global behavior cannot be completely described in terms of properties involving M alone. Moreover we show that locally surviving branching random walks can be approximated by sequences of spatially confined and stochastically dominated branching random walks which eventually survive locally if the (possibly finite) state space is large enough. An analogous result can be achieved by approximating a branching random walk by a sequence of multitype contact processes and allowing a sufficiently large number of particles per site. We compare these results with the ones obtained in the continuous-time case and we give some examples and counterexamples.Comment: 32 pages, a few misprints have been correcte

Prospective, Randomized, Controlled Trial of Tissue Adhesive (2-Octylcyanoacrylate) vs Standard Wound Closure Techniques for Laceration Repair

Objective: To compare a new tissue adhesive, 2-octylcyanoacrylate, with standard wound closure techniques for the repair of traumatic lacerations. Methods: A prospective, randomized, controlled clinical trial enrolled consecutive patients >1 year of age with non-bite, non-crush-induced lacerations who presented 3 months) was assessed by physicians using a previously validated categorical cosmetic scale and by patients using a 100-mm visual analog scale. Results : There were 63 patients randomized to the octylcyanoacrylate group and 61 patients treated with standard wound closure techniques. The 2 treatment groups were similar with respect to age, gender, race, medical history, and wound characteristics. At the 5-to-10-day follow-up, only 1 wound was infected and only 2 wounds required reclosure due to dehiscence. These 3 patients received treatment with octylcyanoacrylate. At long-term follow-up, the cosmetic appearances were similar according to the patients (octylcyanoacrylate, 83.8 ± 19.4 mm vs standard techniques, 82.5 ± 17.6 mm; p = 0.72) and the physicians (optimal cosmetic appearance, 77% vs 80%; p = 0.67). Conclusions: Wounds treated with octylcyanoacrylate and standard wound closure techniques have similar cosmetic appearances 3 months later.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75580/1/j.1553-2712.1998.tb02590.x.pd