Properties of noncommutative axionic electrodynamics

Using the gauge-invariant but path-dependent variables formalism, we compute the static quantum potential for noncommutative axionic electrodynamics, and find a radically different result than the corresponding commutative case. We explicitly show that the static potential profile is analogous to that encountered in both non-Abelian axionic electrodynamics and in Yang-Mills theory with spontaneous symmetry breaking of scale symmetry.Comment: 4 pages. To appear in PR

Coulomb's law corrections from a gauge-kinetic mixing

We study the static quantum potential for a gauge theory which includes the mixing between the familiar photon $U(1)_{QED}$ and a second massive gauge field living in the so-called hidden-sector $U(1)_h$. Our discussion is carried out using the gauge-invariant but path-dependent variables formalism, which is alternative to the Wilson loop approach. Our results show that the static potential is a Yukawa correction to the usual static Coulomb potential. Interestingly, when this calculation is done inside a superconducting box, the Coulombic piece disappears leading to a screening phase.Comment: 4 page

Electrochemical behavior of Sn-Zn alloys with different grain structures in chloride-containing solutions

In the present research the electrochemical behavior of the Sn-Zn alloys (Sn-1 wt.%Zn, Sn-4 wt.%Zn and 8.9 wt.%Zn) in 3% NaCl solution is analyzed using potentiodynamic cyclic polarization measurements and Electrochemical Impedance Spectroscopy (EIS) technique. Specimens were longitudinally solidified with simultaneous heat extraction in two opposite directions. Working electrodes were constructed using longitudinal and cross sections of the specimens with both types of structure: columnar and equiaxed. Results obtained from the polarization curves indicated that the two types of grain structures of Sn-Zn alloys (Sn-1 wt.%Zn, Sn-4 wt.%Zn and Sn-8.9 wt.%Zn) corresponding to longitudinal section present a pseudo passive zone. In the case of specimens from cross sections of the samples, the columnar and equiaxed zones of Sn-8.9 wt.%Zn are the only ones that do not have this pseudo passive region. In addition, the interdendritic zone of alloys is susceptible to corrosion by dealloying because this phase is zinc-rich. This type of corrosion also occurs in the zinc rich lamellar structure present in the eutectic. The percentage of zinc in the alloy increases with increasing susceptibility to pitting corrosion. The EIS values obtained revealed that the susceptibility to corrosion increases with increasing zinc content in alloys, for both the columnar and equiaxed zones. In addition, the columnar zones of Sn-4 wt.%Zn and Sn-8.9 wt.%Zn specimens are more resistant to corrosion than the equiaxed grain specimens. However, the equiaxed zone of Sn-1 wt.%Zn alloy is less susceptible to corrosion than the columnar zone. After adjustment by equivalent circuits it is revealed that the equiaxed zone of Sn-8.9 wt.%Zn alloy has a second porous layer composed of corrosion products on the electrode surface.Fil: Mendez, Claudia Marcela. Universidad Nacional de Misiones. Facultad de Ciencias Exactas, Químicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; ArgentinaFil: Scheiber, Verónica L.. Provincia de Misiones. Comité de Desarrollo e Innovación Tecnológica. Centro de Desarrollo e Innovación Tecnológica; ArgentinaFil: Rozicki, Roberto S.. Universidad Nacional de Misiones. Facultad de Ciencias Exactas, Químicas y Naturales; ArgentinaFil: Kociubczyk, Alex Iván. Universidad Nacional de Misiones. Facultad de Ciencias Exactas, Químicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; ArgentinaFil: Ares, Alicia Esther. Universidad Nacional de Misiones. Facultad de Ciencias Exactas, Químicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; Argentin

Design of Machine Learning Models for the Prediction of Transcription Factor Binding Regions in Bacterial DNA

Presented at the 4th XoveTIC Conference, A Coruña, Spain, 7–8 October 2021.[Abstract] Transcription Factors (TFs) are proteins that regulate the expression of genes by binding to their promoter regions. There is great interest in understanding in which regions TFs will bind to the DNA sequence of an organism and the possible genetic implications that this entails. Occasionally, the sequence patterns (motifs) that a TF binds are not well defined. In this work, machine learning (ML) models were applied to TF binding data from ChIP-seq experiments. The objective was to detect patterns in TF binding regions that involved structural (DNAShapeR) and compositional (kmers) characteristics of the DNA sequence. After the application of random forest and Glmnet ML techniques with both internal and external validation, it was observed that two types of generated descriptors (HelT and tetramers) were significantly better than the others in terms of prediction, achieving values of more than 90%.This work has received financial support from the Xunta de Galicia and the European Union (European Social Fund (ESF)). This project was also supported by the General Directorate of Culture, Education and University Management of Xunta de Galicia (Ref. ED431G/01, ED431D 2017/16).Xunta de Galicia; ED431G/01Xunta de Galicia; ED431D 2017/1

Geografía de la expansión de la Leishmaniasis en el conflicto armado en Colombia (Antioquia)

La prevalencia e incidencia de enfermedades tropicales transmitidas por vectores está determinada por la presencia de condiciones ambientales propicias para el vector y la vulnerabilidad social de poblaciones que habitan sus áreas endémicas. Fenómenos sociales como la guerra y el desplazamiento de poblaciones afectadas, deterioran aún más su vulnerabilidad social e incrementan espacialmente el número de casos de población afectada por enfermedades tropicales. En el departamento de Antioquia (Colombia) los casos de Leishmaniasis aumentaron notoriamente a partir de la década de los 90 debido a las olas de desplazamiento forzado que se presentaron como consecuencia del recrudecimiento del conflicto armado en el país

Spherical solutions of the Schr\"odinger-Poisson system with core-tail structure

We construct spherically symmetric equilibrium solutions of the Schr\"odinger-Poisson (SP) system of equations with a core-tail structure that could serve as models of Fuzzy Dark Matter (FDM) halos. The core is assumed to be a solitonic ground state equilibrium configuration of the SP equations, and the tail is integrated from a transition radius onwards. The total mass of the system parametrizes the family of solutions and constrains the tail density profile. The tail has a radial velocity profile, whereas the core is stationary. We investigate the evolution of these equilibrium configurations and find that the tail initially perturbs the core, and consequently, the whole solution oscillates around a virialized solution that we call 'relaxed', whose average also has a core-tail structure. We measure the departure of the relaxed configuration from the equilibrium solution in order to estimate the utility of the latter. We also find that the core-halo scaling relation of equilibrium configurations has an exponent $\alpha=1/3$, whereas relaxed configurations exhibit a scaling with $\alpha=0.54$.Comment: 10 pages, 10 figures. Accepted for publication in Phys. Rev.

Construction and evolution of equilibrium configurations of the Schr\"odinger-Poisson system in the Madelung frame

We present the construction of ground state equilibrium configurations of the Schr\"odinger-Poisson (SP) system in the Madelung frame and evolve such configuration using finite volume methods. We compare the behavior of these configurations when evolved within the SP and Madelung frames, in terms of conservation of mass and energy. We also discuss the issues of the equations in the Madelung frame and others inherent to the numerical methods used to solve them.Comment: 12 pages, 4 figures. Invited contributio

Stationary solutions of the Schr\"odinger-Poisson-Euler system and their stability

We present the construction of stationary boson-fermion spherically symmetric configurations governed by Newtonian gravity. Bosons are described in the Gross-Pitaevskii regime and fermions are assumed to obey Euler equations for an inviscid fluid with polytropic equation of state. The two components are coupled through the gravitational potential. The families of solutions are parametrized by the central value of the wave function describing the bosons and the central denisty of the fluid. We explore the stability of the solutions using numerical evolutions that solve the time dependent Schr\"odinger-Euler-Poisson system, using the truncation error of the numerical methods as the perturbation. We find that all configurations are stable as long as the polytropic equation of state (EoS) is enforced during the evolution. When the configurations are evolved using the ideal gas EoS they all are unstable that decay into a sort of twin solutions that approach a nearly stationary configuration. We expect these solutions and their evolution serve to test numerical codes that are currently being used in the study of Fuzzy Dark Matter plus baryons.Comment: 7 pages, accepted in Phys. Lett.