Higher Order Supersymmetric Truncated Oscillators

We study the supersymmetric partners of the harmonic oscillator with an infinite potential barrier at the origin and obtain the conditions under which it is possible to add levels to the energy spectrum of these systems. It is found that instead of the usual rule for non-singular potentials, where the order of the transformation corresponds to the maximum number of levels which can be added, now it is the integer part of half the order of the transformation which gives the maximum number of levels to be created.Comment: This article is a natural continuation of arXiv:1603.05173 and arXiv:1310.562

Relativistic stars in f(R) and scalar-tensor theories

We study relativistic stars in the context of scalar tensor theories of gravity that try to account for the observed cosmic acceleration and satisfy the local gravity constraints via the chameleon mechanism. More specifically, we consider two types of models: scalar tensor theories with an inverse power law potential and f(R) theories. Using a relaxation algorithm, we construct numerically static relativistic stars, both for constant energy density configurations and for a polytropic equation of state. We can reach a gravitational potential up to $\Phi\sim 0.3$ at the surface of the star, even in f(R) theories with an "unprotected" curvature singularity. However, we find static configurations only if the pressure does not exceed one third of the energy density, except possibly in a limited region of the star (otherwise, one expects tachyonic instabilities to develop). This constraint is satisfied by realistic equations of state for neutron stars.Comment: 20 pages, 10 Figs, revtex4; v2. minor corrections and changes; v3: a few changes, matches published versio

Ks1, an epithelial cell-specific gene, responds to early signals of head formation in Hydra

As a molecular marker for head specification in Hydra, we have cloned an epithelial cell-specific gene which responds to early signals of head formation. The gene, designated ks1, encodes a 217-amino acid protein lacking significant sequence similarity to any known protein. KS1 contains a N-terminal signal sequence and is rich in charged residues which are clustered in several domains. ks1 is expressed in tentacle-specific epithelial cells (battery cells) as well as in a small fraction of ectodermal epithelial cells in the gastric region subjacent to the tentacles. Treatment with the protein kinase C activator 12-O-tetradecanoylphorbol-13- acetate (TPA) causes a rapid increase in the level of ks1 mRNA in head-specific epithelial cells and also induces ectopic ks1 expression in cells of the gastric region. Sequence elements in the 5 ¢-flanking region of ks1 that are related to TPA-responsive elements may mediate the TPA inducibility of ks1 expression. The pattern of expression of ks1 suggests that a ligand-activated diacylglycerol second messenger system is involved in head-specific differentiation

A Literature Review on Electricity Transmission Expansion Planning: The Mexican Case

Numéro de référence interne originel : a1.1 g 113

Determining the BDMPS transport coefficient via medium-modified fragmentation functions

In nucleus-nucleus collisions at RHIC and LHC, partons produced at high transverse momentum can undergo multiple scattering within the collision region prior to fragmenting into hadrons. We have studied the resulting medium-modified fragmentation function based on a calculation of the BDMPS-Z medium-induced gluon radiation for a dense, expanding medium of small finite extension. Here we explain how the BDMPS transport coefficient which measures the energy density attained in the collision, can be extracted from the observed modification of high-pt hadroproduction. We also comment on the significant remaining uncertainties in extracting the transport coefficient from data.Comment: 4 pages, 4 postscript figures. Proceedings for Quark Matter 200