Falsifying cosmological models based on a non-linear electrodynamics

Recently, the nonlinear electrodynamics (NED) has been gaining attention to generate primordial magnetic fields in the Universe and also to resolve singularity problems. Moreover, recent works have shown the crucial role of the NED on the inflation. This paper provides a new approach based on a new model of NED as a source of gravitation to remove the cosmic singularity at the big bang and explain the cosmic acceleration during the inflation era on the background of stochastic magnetic field. Also, we found a realization of a cyclic Universe, free of initial singularity, due to the proposed NED energy density. In addition, we explore whether a NED field without or with matter can be the origin of the late-time acceleration. For this we obtain explicit equations for $H(z)$ and perform a MCMC analysis to constrain the NED parameters by using $31$ observational Hubble data (OHD) obtained from cosmic chronometers covering the redshift range $0 < z < 1.97$; and with the joint-light-analysis (JLA) SNIa compilation consisting in $740$ data points in the range $0.01<z<1.2$. All our constraints on the current magnetic field give $B_{0}\sim 10^{-31}\mathrm{cm^{-1}}$, which are larger than the upper limit $10^{-33}\mathrm{cm^{-1}}$ by the Planck satellite implying that NED cosmologies could not be suitable to explain the Universe late-time dynamics. However, the current data is able to falsify the scenario at late times. Indeed, one is able to reconstruct the deceleration parameter $q(z)$ using the best fit values of the parameters obtained from OHD and SNIa data sets. If the matter component is not included, the data sets predict an accelerated phase in the early Universe, but a non accelerated Universe is preferred in the current epoch...Comment: 20 pages, two-column, 14 figures. Accepted for publication in the European Physical Journal

Compromisos municipales. En el contexto del proyecto URB-AL B "Energías renovables y redes de desarrollo local"

Amb la revolució industrial es va passar de les energies renovables a las energies fòssils, afavorint la producció centralitzada d’energies, que es convertia així en un problema regional o nacional però ja no local. Avui, es veuen les ciutats com promotores de desenvolupament econòmic, el que inclou l’auto aprovisionament energètic. L’article detalla els continguts del programa europeu URB-AL tipus B centrat en Energies Renovables i Xarxes de Desenvolupament Local, les seves prioritats i activitats, els nous Centres E+D (energia y desenvolupament local) i alguns casos municipals de millora energètica.Con la revolución industrial se pasó de las energías renovables a las energías fósiles, favoreciendo la producción centralizada de energías, que se convertía así en un problema regional o nacional pero ya no local. Hoy, se ven las ciudades como promotoras de desarrollo económico, lo que incluye el autoabastecimiento energético. El artículo detalla los contenidos del programa europeo URB-AL tipo B centrado en “Energías Renovables y Redes de Desarrollo Local”, sus prioridades y actividades, los nuevos Centros E+D (energía y desarrollo local) y algunos casos municipales de mejora energética.The industrial revolution led to renewable energies being replaced by fossil energy. This favoured the centralized production of energy, which then became a regional or national problem rather than a local one. Today, cities are seen as drivers of economic development. This role includes providing their own energy. The article details the contents of the European Programme URB-AL type B, which is focussed on renewable energies and networks for local development. It discusses the activities and priorities of this programme, the new E+D centres (energy and local development) and some municipal examples of energy improvement. Compromisos municipales.Peer Reviewe

A magnified glance into the dark sector: probing cosmological models with strong lensing in A1689

In this paper we constrain four alternative models to the late cosmic acceleration in the Universe: Chevallier-Polarski-Linder (CPL), interacting dark energy (IDE), Ricci holographic dark energy (HDE), and modified polytropic Cardassian (MPC). Strong lensing (SL) images of background galaxies produced by the galaxy cluster Abell $1689$ are used to test these models. To perform this analysis we modify the LENSTOOL lens modeling code. The value added by this probe is compared with other complementary probes: Type Ia supernovae (SNIa), baryon acoustic oscillations (BAO), and cosmic microwave background (CMB). We found that the CPL constraints obtained of the SL data are consistent with those estimated using the other probes. The IDE constraints are consistent with the complementary bounds only if large errors in the SL measurements are considered. The Ricci HDE and MPC constraints are weak but they are similar to the BAO, SNIa and CMB estimations. We also compute the figure-of-merit as a tool to quantify the goodness of fit of the data. Our results suggest that the SL method provides statistically significant constraints on the CPL parameters but weak for those of the other models. Finally, we show that the use of the SL measurements in galaxy clusters is a promising and powerful technique to constrain cosmological models. The advantage of this method is that cosmological parameters are estimated by modelling the SL features for each underlying cosmology. These estimations could be further improved by SL constraints coming from other galaxy clusters.Comment: 13 pages, 5 figures, accepted for publication in Ap

Role of Aeromonas hydrophila flagella glycosylation in adhesion to Hep-2 cells, biofilm formation and immune stimulation.

Polar flagellin proteins from Aeromonas hydrophila strain AH-3 (serotype O34) were found to be O-glycosylated with a heterogeneous heptasaccharide glycan. Two mutants with altered (light and strong) polar flagella glycosylation still able to produce flagella were previously obtained, as well as mutants lacking the O34-antigen lipopolysaccharide (LPS) but with unaltered polar flagella glycosylation. We compared these mutants, altogether with the wild type strain, in different studies to conclude that polar flagella glycosylation is extremely important for A. hydrophila adhesion to Hep-2 cells and biofilm formation. Furthermore, the polar flagella glycosylation is an important factor for the immune stimulation of IL-8 production via toll receptor 5 (TLR5)

Acute bilateral emphysematous pyelonephritis successfully managed by medical therapy alone: A case report and review of the literature

BACKGROUND: Bilateral emphysematous pyelonephritis is a life threatening condition usually occurring in diabetics. Management of this condition has traditionally been aggressive and surgery is considered mandatory. However, this is itself a hazardous intervention in a septic, unstable patient with circulatory or liver failure. When bilateral disease is present, the need for long-term dialysis is obviously unavoidable. CASE PRESENTATION: We herein report one of the few cases of bilateral emphysematous pyelonephritis successfully managed by non-surgical treatment