Energy Localization in the Peyrard-Bishop DNA model

We study energy localization on the oscillator-chain proposed by Peyrard and Bishop to model the DNA. We search numerically for conditions with initial energy in a small subgroup of consecutive oscillators of a finite chain and such that the oscillation amplitude is small outside this subgroup for a long timescale. We use a localization criterion based on the information entropy and we verify numerically that such localized excitations exist when the nonlinear dynamics of the subgroup oscillates with a frequency inside the reactive band of the linear chain. We predict a mimium value for the Morse parameter $(\mu >2.25)$ (the only parameter of our normalized model), in agreement with the numerical calculations (an estimate for the biological value is $\mu =6.3$). For supercritical masses, we use canonical perturbation theory to expand the frequencies of the subgroup and we calculate an energy threshold in agreement with the numerical calculations

Ladder operators for subtle hidden shape invariant potentials

Ladder operators can be constructed for all potentials that present the integrability condition known as shape invariance, satisfied by most of the exactly solvable potentials. Using the superalgebra of supersymmetric quantum mechanics we construct the ladder operators for two exactly solvable potentials that present a subtle hidden shape invariance.Comment: 9 pages, based on the talk given at International Conference Progress in Supersymmetric Quantum Mechanics (PSQM03), Valladolid, Spain, 15-19 July, 2003, to appear in a Special Issue of J. Phys. A: Math. Ge

Analysis of compound heterozygotes reveals that the mouse floxed Pax6 tm1Ued allele produces abnormal eye phenotypes

Analysis of abnormal phenotypes produced by different types of mutations has been crucial for our understanding of gene function. Some floxed alleles that retain a neomycin-resistance selection cassette (neo cassette) are not equivalent to wild-type alleles and provide useful experimental resources. Pax6 is an important developmental gene and the aim of this study was to determine whether the floxed Pax6(tm1Ued) (Pax6(fl)) allele, which has a retained neo cassette, produced any abnormal eye phenotypes that would imply that it differs from the wild-type allele. Homozygous Pax6(fl/fl) and heterozygous Pax6(fl/+) mice had no overt qualitative eye abnormalities but morphometric analysis showed that Pax6(fl/fl) corneas tended be thicker and smaller in diameter. To aid identification of weak effects, we produced compound heterozygotes with the Pax6(Sey-Neu) (Pax6(−)) null allele. Pax6(fl/−) compound heterozygotes had more severe eye abnormalities than Pax6(+/−) heterozygotes, implying that Pax6(fl) differs from the wild-type Pax6(+) allele. Immunohistochemistry showed that the Pax6(fl/−) corneal epithelium was positive for keratin 19 and negative for keratin 12, indicating that it was abnormally differentiated. This Pax6(fl) allele provides a useful addition to the existing Pax6 allelic series and this study demonstrates the utility of using compound heterozygotes with null alleles to unmask cryptic effects of floxed alleles. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11248-016-9962-4) contains supplementary material, which is available to authorized users

Targeted Deletion of Kcne2 Causes Gastritis Cystica Profunda and Gastric Neoplasia

Gastric cancer is the second leading cause of cancer death worldwide. Predisposing factors include achlorhydria, Helicobacter pylori infection, oxyntic atrophy and TFF2-expressing metaplasia. In parietal cells, apical potassium channels comprising the KCNQ1 α subunit and the KCNE2 β subunit provide a K+ efflux current to facilitate gastric acid secretion by the apical H+K+ATPase. Accordingly, genetic deletion of murine Kcnq1 or Kcne2 impairs gastric acid secretion. Other evidence has suggested a role for KCNE2 in human gastric cancer cell proliferation, independent of its role in gastric acidification. Here, we demonstrate that 1-year-old Kcne2−/− mice in a pathogen-free environment all exhibit a severe gastric preneoplastic phenotype comprising gastritis cystica profunda, 6-fold increased stomach mass, increased Ki67 and nuclear Cyclin D1 expression, and TFF2- and cytokeratin 7-expressing metaplasia. Some Kcne2−/−mice also exhibited pyloric polypoid adenomas extending into the duodenum, and neoplastic invasion of thin walled vessels in the sub-mucosa. Finally, analysis of human gastric cancer tissue indicated reduced parietal cell KCNE2 expression. Together with previous findings, the results suggest KCNE2 disruption as a possible risk factor for gastric neoplasia

HORNEOPHYTON, A NECESSARY CHANGE OF NAME FOR HORNEA

Volume: 6Start Page: 142End Page: 14

Integrated information system for order planning, control and cost estimation in laser job shops

Lo que me propongo desarrollar a continuación es la idea según la cual, los procesos de justicia transicional deberían incluir entre sus mínimos normativos una noción de ciudadanía y de agencia política mucho más exigente que aquella que tradicionalmente está asociada al marco conceptual de la democracia liberal. En esta dirección, considero que la aproximación realizada por Hannah Arendt sobre la revolución como constitutio libertatis arroja elementos claves que pueden ser de utilidad en la búsqueda de consolidar la ciudadanía en los procesos de justicia transicional cuyo principal objetivo es la transición hacia regímenes democráticos.What I attempt to develop is the idea that the processes of transitional justice should include in their minimum normative frame, a notion of citizenship and political agency much more demanding than that traditionally is associated with the conceptual framework of liberal democracy. In this direction, I think that the approach made by Hannah Arendt on revolution as constitutio libertatis sheds light on key and useful elements in seeking to consolidate citizenship in transitional justice processes whose main objective is the transition to democratic regimes