An effective theory of accelerated expansion

We work out an effective theory of accelerated expansion to describe general phenomena of inflation and acceleration (dark energy) in the Universe. Our aim is to determine from theoretical grounds, in a physically-motivated and model independent way, which and how many (free) parameters are needed to broadly capture the physics of a theory describing cosmic acceleration. Our goal is to make as much as possible transparent the physical interpretation of the parameters describing the expansion. We show that, at leading order, there are five independent parameters, of which one can be constrained via general relativity tests. The other four parameters need to be determined by observing and measuring the cosmic expansion rate only, H(z). Therefore we suggest that future cosmology surveys focus on obtaining an accurate as possible measurement of $H(z)$ to constrain the nature of accelerated expansion (dark energy and/or inflation).Comment: In press; minor changes, results unchange

Nanostructure of Thin Films Grown by Deposition of Isotropically Distributed Gaseous Particles

: Presentación en la conferencia “12th International Conference on Plasma Surface Engineering”Peer reviewe

Eosinophilic esophagitis: A relevant entity for the otolaryngologist

This is the peer reviewed version of the following article: Acta Otorrinolaringológica 67.3 (2016): 167-168, which has been published in final form at http://dx.doi.org/10.1016/j.otorri.2015.06.002Eosinophilic esophagitis (EE) is a recently recognised pathologic entity whose prevalence has risen significantly since it was first described. Its diagnosis represents a challenge for different medical specialties, among which ENT specialists play an important role. Clinical suspicion in a patient with recurrent food impaction or a child with eating disorders and history of hypersensitivity constitutes the first warning sign of a possible EE.The purpose of this review is to highlight EE as a possible differential diagnosis in patients with deglutition disorders and describe the possible clinical symptoms that should alert the ENT specialist to perform appropriate diagnostic tests and procedures. The transnasal esophagoscopy, performed in-office by the ENT, is ideal for reducing possible underdiagnosed cases.Given the fact that an ENT specialist will evaluate a great many patients with deglutition disorders, it is paramount for possible EE cases to be suspected and recognised so that a correct multidisciplinary approach involving not only ENT specialists but also paediatricians, gastroenterologists, allergologists and pathologists can be established. Identifying the dietary component responsible for the esophageal inflammation and removing that food from the patient's diet is the key in the treatment of this immune-mediated disease.La esofagitis eosinofílica (EE) es una entidad clínico patológica reconocida recientemente y con una prevalencia que va en aumento desde su descripción inicial. Su diagnóstico representa un reto para diferentes especialistas, entre los que tiene un rol destacado el otorrinolaringólogo. La sospecha clínica ante un paciente que presenta episodios recidivantes de impactación de alimentos no punzantes o ante un niño con trastornos de la alimentación y antecedentes de atopia constituyen el primer signo de alerta de una posible EE. El objetivo de esta revisión persigue destacar el papel de la EE en el diagnóstico diferencial de los pacientes con trastornos de la deglución, así como dar a conocer las manifestaciones clínicas que deben alertar al otorrinolaringólogo para proseguir la realización de las pruebas encaminadas al diagnóstico de esta enfermedad. La esofagoscopia transnasal, realizada por el otorrinolaringólogo en consulta, ayudará a disminuir el número de casos infradiagnosticados. Dado que gran parte de los pacientes afectos de trastornos de la deglución van a ser evaluados por el otorrinolaringólogo, se hace imprescindible el reconocimiento de la EE, así como el manejo diagnóstico-terapéutico por un equipo multidisciplinar en el que se involucren, además del otorrinolaringólogo, pediatras, digestólogos, alergólogos y patólogos familiarizados con la enfermedad. La identificación del alimento responsable de la inflamación del esófago y su eliminación de la dieta es la clave del tratamiento de este desorden inmunomediad

PAX4 preserves endoplasmic reticulum integrity preventing beta cell degeneration in a mouse model of type 1 diabetes mellitus

[Aims/hypothesis]: A strategy to enhance pancreatic islet functional beta cell mass (BCM) while restraining inflammation, through the manipulation of molecular and cellular targets, would provide a means to counteract the deteriorating glycaemic control associated with diabetes mellitus. The aims of the current study were to investigate the therapeutic potential of such a target, the islet-enriched and diabetes-linked transcription factor paired box 4 (PAX4), to restrain experimental autoimmune diabetes (EAD) in the RIP-B7.1 mouse model background and to characterise putative cellular mechanisms associated with preserved BCM. [Methods]: Two groups of RIP-B7.1 mice were genetically engineered to: (1) conditionally express either PAX4 (BPTL) or its diabetes-linked mutant variant R129W (mutBPTL) using doxycycline (DOX); and (2) constitutively express luciferase in beta cells through the use of RIP. Mice were treated or not with DOX, and EAD was induced by immunisation with a murine preproinsulin II cDNA expression plasmid. The development of hyperglycaemia was monitored for up to 4 weeks following immunisation and alterations in the BCM were assessed weekly by non-invasive in vivo bioluminescence intensity (BLI). In parallel, BCM, islet cell proliferation and apoptosis were evaluated by immunocytochemistry. Alterations in PAX4- and PAX4R129W-mediated islet gene expression were investigated by microarray profiling. PAX4 preservation of endoplasmic reticulum (ER) homeostasis was assessed using thapsigargin, electron microscopy and intracellular calcium measurements. [Results]: PAX4 overexpression blunted EAD, whereas the diabetes-linked mutant variant PAX4R129W did not convey protection. PAX4-expressing islets exhibited reduced insulitis and decreased beta cell apoptosis, correlating with diminished DNA damage and increased islet cell proliferation. Microarray profiling revealed that PAX4 but not PAX4R129W targeted expression of genes implicated in cell cycle and ER homeostasis. Consistent with the latter, islets overexpressing PAX4 were protected against thapsigargin-mediated ER-stress-related apoptosis. Luminal swelling associated with ER stress induced by thapsigargin was rescued in PAX4-overexpressing beta cells, correlating with preserved cytosolic calcium oscillations in response to glucose. In contrast, RNA interference mediated repression of PAX4-sensitised MIN6 cells to thapsigargin cell death. [Conclusions/interpretation]: The coordinated regulation of distinct cellular pathways particularly related to ER homeostasis by PAX4 not achieved by the mutant variant PAX4R129W alleviates beta cell degeneration and protects against diabetes mellitus. The raw data for the RNA microarray described herein are accessible in the Gene Expression Omnibus database under accession number GSE62846

MEGARA-GTC stellar spectral library – II. MEGASTAR first release

MEGARA is an optical integral field and multi-object fibre-based spectrograph for the 10.4 m Gran Telescopio CANARIAS that offers medium-to-high spectral resolutions (FWHM) of R ≃ 6000, 12 000, 20 000. Commissioned at the telescope in 2017, it started operation as a common-user instrument in 2018. We are creating an instrument-oriented empirical spectral library from MEGARA-GTC stars observations, MEGASTAR, crucial for the correct interpretation of MEGARA data. This piece of work describes the content of the first release of MEGASTAR, formed by the spectra of 414 stars observed with R ≃ 20 000 in the spectral intervals 6420–6790 Å and 8370–8885 Å, and obtained with a continuum average signal-to-noise ratio around 260. We describe the release sample, the observations, the data reduction procedure and the MEGASTAR data base. Additionally, we include in Appendix A an atlas with the complete set of 838 spectra of this first release of the MEGASTAR catalogue.This work has been supported by MINECO-FEDER grants AYA2016-75808-R, AYA2016-79724-C4-3-P, RTI2018-096188-BI00, AYA2017-90589-REDT and has been partially funded by FRACTAL, INAOE, and CIEMAT

CdsH contributes to the replication of salmonella typhimurium inside epithelial cells in a cysteine-supplemented medium

Indexación ScopusSalmonella Typhimurium is a facultative, intracellular pathogen whose products range from self-limited gastroenteritis to systemic diseases. Food ingestion increases biomolecules’ concentration in the intestinal lumen, including amino acids such as cysteine, which is toxic in a concentration-dependent manner. When cysteine’s intracellular concentration reaches toxic levels, S. Typhimurium expresses a cysteine-inducible enzyme (CdsH), which converts cysteine into pyruvate, sulfide, and ammonia. Despite this evidence, the biological context of cdsH’s role is not completely clear, especially in the infective cycle. Since inside epithelial cells both cdsH and its positive regulator, ybaO, are overexpressed, we hypothesized a possible role of cdsH in the intestinal phase of the infection. To test this hypothesis, we used an in vitro model of HT-29 cell infection, adding extra cysteine to the culture medium during the infective process. We observed that, at 6 h post-invasion, the wild type S. Typhimurium proliferated 30% more than the ∆cdsH strain in the presence of extra cysteine. This result shows that cdsH contributes to the bacterial replication in the intracellular environment in increased concentrations of extracellular cysteine, strongly suggesting that cdsH participates by increasing the bacterial fitness in the intestinal phase of the S. Typhimurium infection. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.https://www.mdpi.com/2076-2607/8/12/201

Growth of SiO2 Thin Films by Plasma-Assisted Reactive Magnetron Sputtering under the Impingement of Positive and Negative Ions

Presentación en la VII Reunión Bienal del Grupo Especializado de Física de Estado SólidoPeer reviewe

Proteomics: a poweful tool to deepen the molecular mechanisms of ischemic stroke

Comunicaciones a congreso