15,974 research outputs found
Supercritical super-Brownian motion with a general branching mechanism and travelling waves
We consider the classical problem of existence, uniqueness and asymptotics of
monotone solutions to the travelling wave equation associated to the parabolic
semi-group equation of a super-Brownian motion with a general branching
mechanism. Whilst we are strongly guided by the probabilistic reasoning of
Kyprianou (2004) for branching Brownian motion, the current paper offers a
number of new insights. Our analysis incorporates the role of Seneta-Heyde
norming which, in the current setting, draws on classical work of Grey (1974).
We give a pathwise explanation of Evans' immortal particle picture (the spine
decomposition) which uses the Dynkin-Kuznetsov N-measure as a key ingredient.
Moreover, in the spirit of Neveu's stopping lines we make repeated use of
Dynkin's exit measures. Additional complications arise from the general nature
of the branching mechanism. As a consequence of the analysis we also offer an
exact X(log X)^2 moment dichotomy for the almost sure convergence of the
so-called derivative martingale at its critical parameter to a non-trivial
limit. This differs to the case of branching Brownian motion and branching
random walk where a moment `gap' appears in the necessary and sufficient
conditions.Comment: 34 page
Dynamics of a suspension of interacting yolk-shell particles
In this work we study the self-diffusion properties of a liquid of hollow
spherical particles (shells)bearing a smaller solid sphere in their interior
(yolks). We model this system using purely repulsive hard-body interactions
between all (shell and yolk) particles, but assume the presence of a background
ideal solvent such that all the particles execute free Brownian motion between
collisions,characterized by short-time self-diffusion coefficients D0s for the
shells and D0y for the yolks. Using a softened version of these interparticle
potentials we perform Brownian dynamics simulations to determine the mean
squared displacement and intermediate scattering function of the yolk-shell
complex. These results can be understood in terms of a set of effective
Langevin equations for the N interacting shell particles, pre-averaged over the
yolks' degrees of freedom, from which an approximate self-consistent
description of the simulated self-diffusion properties can be derived. Here we
compare the theoretical and simulated results between them, and with the
results for the same system in the absence of yolks. We find that the yolks,
which have no effect on the shell-shell static structure, influence the dynamic
properties in a predictable manner, fully captured by the theory.Comment: 5 pages, 1 figur
The in resummed chiral effective field theory
We study the unitarized meson-baryon scattering amplitude at leading order in
the strangeness sector using time-ordered perturbation theory for a
manifestly Lorentz-invariant formulation of chiral effective field theory. By
solving the coupled-channel integral equations with the full off-shell
dependence of the effective potential and applying subtractive renormalization,
we analyze the renormalized scattering amplitudes and obtain the two-pole
structure of the resonance. We also point out the necessity of
including higher-order terms.Comment: 16 pages, 3 figures, 5 table
Allelic variation of low molecular weight glutenin subunits composition and the revealed genetic diversity in durum wheat Triticum turgidum L. ssp. durum
Low molecular weight glutenin subunits (LMW-GS) play an important role in determining the bread-making characteristics of dough in the end-use quality of wheat. In this study, A total of 149 worldwide-originated durum wheat were used to analyze the composition of LMW-GS using MALDI-TOF-MS. Based on the allelic variation of glutenin subunits, the genetic diversity was evaluated for the 149 durum wheat. Five types of alleles were identified at the Glu-A3 locus with Glu-A3e, Glu-A3a/c, Glu-A3f, Glu-A3d and Glu-A3b accounting for 43.0%, 16.1%, 12.8%, 10.1% and 7.4 % of the accessions, respectively. Five types of alleles were identified at the Glu-B3 locus: Glu-B3d (60.4%), Glu-B3b (6.0%), Glu-B3c (6.0%), Glu-B3h (2.7%) and Glu-B3f (0.7%). Two novel alleles encoding abnormal subunits 40500 Da and 41260 Da were identified at the Glu-A3 and Glu-B3 loci, respectively. Further studies are needed to match these novel alleles to previously discovered novel alleles. Moreover, the genetic diversity analysis indicated that great genetic variation existed in durum wheat among encoding loci of glutenin subunits, released periods of varieties and different geographical origins. The results provide more important information of potential germplasm for the improvement of durum wheat and common wheat
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