272 research outputs found
Enumerating Abelian Returns to Prefixes of Sturmian Words
We follow the works of Puzynina and Zamboni, and Rigo et al. on abelian
returns in Sturmian words. We determine the cardinality of the set
of abelian returns of all prefixes of a Sturmian word in
terms of the coefficients of the continued fraction of the slope, dependingly
on the intercept. We provide a simple algorithm for finding the set
and we determine it for the characteristic Sturmian words.Comment: 19page
Geometric representation of interval exchange maps over algebraic number fields
We consider the restriction of interval exchange transformations to algebraic
number fields, which leads to maps on lattices. We characterize
renormalizability arithmetically, and study its relationships with a
geometrical quantity that we call the drift vector. We exhibit some examples of
renormalizable interval exchange maps with zero and non-zero drift vector, and
carry out some investigations of their properties. In particular, we look for
evidence of the finite decomposition property: each lattice is the union of
finitely many orbits.Comment: 34 pages, 8 postscript figure
Cyclotomic valuation of -Pochhammer symbols and -integrality of basic hypergeometric series
We give a formula for the cyclotomic valuation of -Pochhammer symbols in
terms of (generalized) Dwork maps. We also obtain a criterion for the
-integrality of basic hypergeometric series in terms of certain step
functions, which generalize Christol step functions. This provides suitable
-analogs of two results proved by Christol: a formula for the -adic
valuation of Pochhammer symbols and a criterion for the -integrality of
hypergeometric series
Seasonal changes in weight, condition and nutrition of free-ranging and captive muskox females
The interaction studied via femtoscopy in p + Nb reactions at
We report on the first measurement of and correlations via
the femtoscopy method in p+Nb reactions at , studied with the High Acceptance Di-Electron Spectrometer
(HADES). By comparing the experimental correlation function to model
calculations, a source size for pairs of and a slightly
smaller value for of is extracted.
Using the geometrical extent of the particle emitting region, determined
experimentally with correlations as reference together with a source
function from a transport model, it is possible to study different sets of
scattering parameters. The correlation is proven sensitive to
predicted scattering length values from chiral effective field theory. We
demonstrate that the femtoscopy technique can be used as valid alternative to
the analysis of scattering data to study the hyperon-nucleon interaction.Comment: 12 pages, 11 figure
Pfmrk, a MO15-related protein kinase from Plasmodium falciparum. Gene cloning, sequence, stage-specific expression and chromosome localization.
Cyclin-dependent kinases (Cdks) play a central role in the regulation of the eukaryotic cell cycle. A novel gene encoding a Cdk-like protein, Pfmrk, has been isolated from the human malaria parasite Plasmodium falciparum. The gene has no introns and comprises an open reading frame encoding a protein of 324 amino acids with a predicted molecular mass of 38 kDa. Database searches revealed a striking similarity to the Cdk subfamily with the highest similarity to human MO15 (Cdk7). The overall sequence of Pfmrk shares 62% similarity and 46% identity with human MO15, in comparison to the 49-58% similarity and 34-43% identity with other human Cdks. Pfmrk contains two unique inserts: one consisting of 5 amino acids just before the cyclin-binding motif and the other composed of 13 amino acids within the T-loop equivalent region. Southern blots of genomic DNA digests and chromosomal separations showed that Pfmrk is a single-copy gene conserved between several parasite strains and is located on chromosome 10. A 2500-nucleotide transcript of this gene is expressed predominantly in the sexual blood stages (gametocytes), suggesting that Pfmrk may be involved in sexual stage development
Limit theorems for self-similar tilings
We study deviation of ergodic averages for dynamical systems given by
self-similar tilings on the plane and in higher dimensions. The main object of
our paper is a special family of finitely-additive measures for our systems. An
asymptotic formula is given for ergodic integrals in terms of these
finitely-additive measures, and, as a corollary, limit theorems are obtained
for dynamical systems given by self-similar tilings.Comment: 36 pages; some corrections and improved exposition, especially in
Section 4; references adde
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