2,918 research outputs found
Precision study of B^* B\pi coupling for the static heavy-light meson
We compute the B^*B\pi coupling \hat{g}_{\infty} for static heavy-light meson
using all-to-all propagators. It is shown that low-mode averaging with 100
low-lying eigenmodes indeed improves the signal for the 2-point and 3-point
functions for heavy-light meson significantly. Our study suggests that the
all-to-all propagator will be a very efficient method for high precision
computation of the B^*B\pi coupling especially in unquenched QCD where the
number of configurations is limited.Comment: 30 pages, 25 figures, typos correcte
I-V characteristics of single electron tunneling from symmetric and asymmetric double-barrier tunneling junctions
Copyright 2007 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters, 90(22), 223112, 2007 and may be found at http://dx.doi.org/10.1063/1.274525
A major cellular substrate for protein kinases, annexin II, is a DNA-binding protein
AbstractWe have screened a human cDNA expression library in λgt11 for clones encoding Alu-binding proteins using direct binding of labeled Alu DNA to recombinant phage lysates fixed on a membrane, and isolated a clone 98% identical in sequence to the well-known substrate of protein kinases, annexin II, which was suggested earlier to play a role in transduction of mitogenic signals and DNA replication. A diagnostic property of annexins is their binding to phospholipids in the presence of calcium ions, and we have found that the interaction of proteins of human nuclear extracts with Alu subsequences is suppressed by Ca/phosphatidylserine liposomes, suggesting overlapping of Ca/phospholipid- and DNA-binding domains in annexin II
Fabrication of nanoscale gaps using a combination of self-assembled molecular and electron beam lithographic techniques
Copyright 2006 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters, 88(22), 223111, 2006 and may be found at http://dx.doi.org/10.1063/1.220920
Asexual and sexual replication in sporulating organisms
This paper develops models describing asexual and sexual replication in
sporulating organisms. Replication via sporulation is the replication strategy
for all multicellular life, and may even be observed in unicellular life (such
as with budding yeast). We consider diploid populations replicating via one of
two possible sporulation mechanisms: (1) Asexual sporulation, whereby adult
organisms produce single-celled diploid spores that grow into adults
themselves. (2) Sexual sporulation, whereby adult organisms produce
single-celled diploid spores that divide into haploid gametes. The haploid
gametes enter a haploid "pool", where they may recombine with other haploids to
form a diploid spore that then grows into an adult. We consider a haploid
fusion rate given by second-order reaction kinetics. We work with a simplified
model where the diploid genome consists of only two chromosomes, each of which
may be rendered defective with a single point mutation of the wild-type. We
find that the asexual strategy is favored when the rate of spore production is
high compared to the characteristic growth rate from a spore to a reproducing
adult. Conversely, the sexual strategy is favored when the rate of spore
production is low compared to the characteristic growth rate from a spore to a
reproducing adult. As the characteristic growth time increases, or as the
population density increases, the critical ratio of spore production rate to
organism growth rate at which the asexual strategy overtakes the sexual one is
pushed to higher values. Therefore, the results of this model suggest that, for
complex multicellular organisms, sexual replication is favored at high
population densities, and low growth and sporulation rates.Comment: 8 pages, 5 figures, to be submitted to Journal of Theoretical
Biology, figures not included in this submissio
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