22,236 research outputs found
Three predictions on July 2012 Federal Elections in Mexico based on past regularities
Electoral systems are subject of study for physicist and mathematicians in
last years given place to a new area: sociophysics. Based on previous works of
the author on the Mexican electoral processes in the new millennium, he found
three characteristics appearing along the 2000 and 2006 preliminary dataset
offered by the electoral authorities, named PREP: I) Error distributions are
not Gaussian or Lorentzian, they are characterized for power laws at the center
and asymmetric lobes at each side. II) The Partido Revolucionario Institucional
(PRI) presented a change in the slope of the percentage of votes obtained when
it go beyond the 70% of processed certificates; hence it have an improvement at
the end of the electoral computation. III) The distribution of votes for the
PRI is a smooth function well described by Daisy model distributions of rank
in all the analyzed cases, presidential and congressional elections in
2000, 2003 and 2006. If all these characteristics are proper of the Mexican
reality they should appear in the July 2012 process. Here I discuss some
arguments on why such a behaviors could appear in the present processComment: 6 pages, one tabl
Finite Volume Scaling of Pseudo Nambu-Goldstone Bosons in QCD
We consider chiral perturbation theory in a finite volume and in a mixed
regime of quark masses. We take N_l light quarks near the chiral limit, in the
so-called epsilon-regime, while the remaining N_h quarks are heavier and in the
standard p-regime. We compute in this new mixed regime the finite-size scaling
of the light meson correlators in the scalar, pseudoscalar, vector and axial
vector channels.Using the replica method, we easily extend our results to the
partially quenched theory. With the help of our results, lattice QCD
simulations with 2+1 flavors can safely investigate pion physics with very
light up and down quark masses even in the region where the pion's correlation
length overcomes the size of the space-time lattice.Comment: 32 pages, 6 figures, published versio
Tissue-nonspecific alkaline phosphatase promotes axonal growth of hippocampal neurons
Axonal growth is essential for establishing neuronal circuits during brain development and for regenerative processes in the adult brain. Unfortunately, the extracellular signals controlling axonal growth are poorly understood. Here we report that a reduction in extracellular ATP levels by tissue-nonspecific alkaline phosphatase (TNAP) is essential for the development of neuritic processes by cultured hippocampal neurons. Selective blockade of TNAP activity with levamisole or specific TNAP knockdown with short hairpin RNA interference inhibited the growth and branching of principal axons, whereas addition of alkaline phosphatase (ALP) promoted axonal growth. Neither activation nor inhibition of adenosine receptors affected the axonal growth, excluding the contribution of extracellular adenosine as a potential hydrolysis product of extracellular ATP to the TNAP-mediated effects. TNAP was colocalized at axonal growth cones with ionotropic ATP receptors (P2X7 receptor), whose activation inhibited axonal growth. Additional analyses suggested a close functional interrelation of TNAP and P2X7 receptors whereby TNAP prevents P2X7 receptor activation by hydrolyzing ATP in the immediate environment of the receptor. Furthermore inhibition of P2X7 receptor reduced TNAP expression, whereas addition of ALP enhanced P2X7 receptor expression. Our results demonstrate that TNAP, regulating both ligand availability and protein expression of P2X7 receptor, is essential for axonal development
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