Una revolución sobre ruedas

Treball final de Grau en Periodisme. Codi: PE0932. Curs acadèmic 2014-201

Resonance tongues and spectral gaps in quasi-periodic schrödinger operators with one or more frequencies. A numerical exploration

Abstract. In this paper we investigate numerically the spectrum of some representative examples of discrete one-dimensional Schr¨odinger operators with quasi-periodic potential in terms of a perturbative constant b and the spectral parameter a. Our examples include the well-known Almost Mathieu model, other trigonometric potentials with a single quasi-periodic frequency and generalisations with two and three frequencies. We computed numerically the rotation number and the Lyapunov exponent to detect open and collapsed gaps, resonance tongues and the measure of the spectrum. We found that the case with one frequency was significantly different from the case of several frequencies because the latter has all gaps collapsed for a sufficiently large value of the perturbative constant and thus the spectrum is a single spectral band with positive Lyapunov exponent. In contrast, in the cases with one frequency considered, gaps are always dense in the spectrum, although some gaps may collapse either for a single value of the perturbative constant or for a range of values. In all cases we found that there is a curve in the (a, b)-plane which separates the regions where the Lyapunov exponent is zero in the spectrum and where it is positive. Along this curve, which is b = 2 in the Almost Mathieu case, the measure of the spectrum is zero.Preprin

Toward an Understanding of Extracellular tRNA Biology

Extracellular RNAs (exRNAs) including abundant full length tRNAs and tRNA fragments (tRFs) have recently garnered attention as a promising source of biomarkers and a novel mediator in cell-to-cell communication in eukaryotes. Depending on the physiological state of cells, tRNAs/tRFs are released to the extracellular space either contained in extracellular vesicles (EVs) or free, through a mechanism that is largely unknown. In this perspective article, we propose that extracellular tRNAs (ex-tRNAs) and/or extracellular tRFs (ex-tRFs) are relevant paracrine signaling molecules whose activity depends on the mechanisms of release by source cells and capture by recipient cells. We speculate on how ex-tRNA/ex-tRFs orchestrate the effects in target cells, depending on the type of sequence and the mechanisms of uptake. We further propose that tRNA modifications may be playing important roles in ex-tRNA biology

Role of health professionals of sexual health and reproduction clinics in the influenza vaccination in pregnant women

La gripe es un importante problema de salud pública, también en gestantes, con más riesgo de infección y complicaciones que el resto de la población, sobre todo en casos de comorbilidad1. La principal estrategia preventiva es la vacunación antigripal (VAG). Una vacuna inactivada y, por tanto, segura durante la gestación, que además reduce el riesgo de hospitalización por gripe2, incluso en lactantes hasta los 6 meses de edad3. Sin embargo, aunque numerosas sociedades científicas e instituciones sanitarias recomiendan la VAG en cualquier trimestre de gestación, la cobertura continúa siendo baja. En España, en 2007/08 se situó en un 4,1% según datos autoinformado

Concordancia entre los antecedentes de vacunación antigripal referidos por las gestantes en Cataluña y los registrados en la historia clínica

Fundamentos. En ocasiones y cuando no se dispone de un registro, la vacunación antigripal (VAG) se fundamenta en los antecedentes vacunales referidos por los ciudadanos. Cuando existe la posibilidad de comparar ambas fuentes de información, a veces se han observado discrepancias entre las mismas. Los objetivos de este estudio fueron: conocer la cobertura de VAG en gestantes tanto referida como registrada en la historia clínica, determinar la concordancia entre ambas fuentes de información y cuantificar las oportunidades perdidas de VAG debidas a los errores en la verbalización. Método. De junio a septiembre después de las campañas de VAG 2013/2014 y 2014/2015 se aplicó una encuesta transversal a una muestra aleatoria de 657 gestantes atendidas en siete ASSIR (Centros Públicos de Atención Sexual y Reproductiva) de Cataluña. Se recogieron los antecedentes de VAG referidos por las gestantes y los del registro de vacunaciones de la historia clínica informatizada. Se calcularon la cobertura vacunal para cada fuente de información, la concordancia entre ambas (índice Kappa) y la proporción de gestantes que manifestaron haber recibido la VAG sin haberla recibido. Este indicador se analizó según las distintas variables comparándose con la globalidad a través de la prueba de Ji cuadrado. El nivel significación estadística aceptado fue de p< 0,05. Resultados. La cobertura vacunal referida fue del 22,2% (IC 95%: 19,0%-25,4%) y del 15,4% (IC 95%: 12,6%-18,2%) según el registro de vacunaciones (p=0,0019). A pesar de la buena concordancia entre ambas fuentes (Kappa=0,738), una de cada tres gestantes que manifestaron estar vacunadas no lo estaba según el registro. La menor concordancia y las oportunidades perdidas de VAG se produjeron en los estratos sociales altos, a edades fértiles intermedias y cuando se tenían conocimientos y experiencias previas de VAG. Conclusiones. La cobertura de VAG en gestantes continua siendo baja. A pesar de la buena concordancia entre ambas fuentes de información, una de cada tres no vacunadas cree estarlo, pudiendo perder una oportunidad de vacunación.Background. Sometimes and when a registry is not available, influenza vaccination (IV) is based on vaccination records reported by citizens. When the opportunity of comparing both information sources exists, sometimes, discrepancies between both have been observed. The objectives of this study are: to know the IV coverage in pregnant women (both referred and recorded in the clinical history), to determine the concordance between both sources of information and to quantify the lost opportunities of IV due to errors in verbalization. Method. From June to September after the IV campaigns 2013/2014 and 2014/2015, a cross-sectional survey was carried out to a random sample of 657 pregnant women assisted in seven ASSIR (Public Centers for Sexual and Reproductive Care) in Catalonia. The history of IV referred by the pregnant women and those of the vaccination record of the computerized clinical history were collected. Vaccination coverage was calculated for each source of information, it was also calculated the concordance between both (Kappa index) and the proportion of pregnant women who reported receiving the IV without having received it. This indicator was analyzed according to the different variables compared to globality through the Chi-square test. The accepted statistical significance level was p <0.05. Results. The referred vaccination coverage was 22.2% (95% CI: 19.0% -25.4%) and 15.4% (95% CI: 12.6% -18.2%) according to the vaccination record (p = 0.0019). Despite the good concordance between both sources (Kappa = 0.738), one out of every three pregnant women who said they were vaccinated was not according to the registry. The lower concordance and the lost opportunities of IV occurred in the upper social strata, at intermediate fertile ages and when there was previous knowledge and experience of IV. Conclusions. The coverage of IV in pregnant women continues to be low. In spite of the good concordance between both sources of information, one out of three unvaccinated believe that they have been vaccinated, as result they can lose a vaccination opportunity

A comparative life cycle assessment of single-use fibre drums versus reusable steel drums

This paper deals with a comparative analysis of two different packaging and transport scenarios, which exemplifies the implications of choosing between single-use and reusable packaging. In particular, transport of a batch of chemicals by means of disposable fibre drums vs. reusable steel drums is investigated from a life cycle perspective, and the associated environmental impact in terms of Global Warming Potential, Acidification Potential, Gross Energy Requirement and solid waste generation is assessed. Results prove beyond reasonable doubt that, even in the case of durable packaging containers requiring the use of comparatively energy-intensive materials for their production, the reuse scenario is characterized by lower environmental impact indicators across the board, and as such is the most advisable and environmentally sound option

Single-use vs reusable transport packaging: a comparative life cycle analysis

This paper deals with a comparative analysis of two different packaging and transport scenarios, which exemplifies the mplications of choosing between single-use and reusable packaging. In particular, transport of a batch of chemicals by means of disposable fibre drums vs. reusable steel drums is investigated from a life cycle perspective, and the associated environmental impact in terms of Global Warming Potential, Acidification Potential, Gross Energy Requirement and solid waste generation is assessed. Results prove beyond reasonable doubt that, even in the case of durable packaging containers requiring the use of comparatively energy-intensive materials for their production, the reuse scenario is characterized by lower environmental impact indicators across the board, and as such is the most advisable and environmentally sound option.Postprint (author’s final draft

First data of the Colombia Lightning Mapping Array - COLMA

The first data set of VHF lightning mapping using a Lightning Mapping Array system - LMA in a tropical region is presented in this paper. Six sensors were installed at the north of Colombia near Santa Marta city. Since the installation of the LMA network in 2015, up to 7000 intra-cloud (IC) discharges from September to November 2015 have been analyzed. The data suggests that, the electrical charge distribution in tropical thunderstorms shows higher vertical development reaching higher altitudesPreprin

A novel sigma factor reveals a unique regulon controlling cell-specific recombination in Mycoplasma genitalium

The Mycoplasma genitalium MG428 protein shows homology to members of the sigma-70 family of sigma factors. Herein, we found that MG428 activates transcription of recA, ruvA and ruvB as well as several genes with unknown function. Deletion of MG_428 or some of the up-regulated unknown genes led to severe recombination defects. Single cell analyses revealed that activation of the MG428-regulon is a rare event under laboratory growth conditions. A conserved sequence with sigma-70 promoter architecture (TTGTCA-N-ATTWAT) was identified in the upstream region of all of the MG428-regulated genes or operons. Primer extension analyses demonstrated that transcription initiates immediately downstream of this sigma70-type promoter in a MG428-dependent manner. Furthermore, mutagenesis of the conserved −10 and −35 elements corroborated the requirement of these regions for promoter function. Therefore, a new mycoplasma promoter directs transcription of a unique recombination regulon. Additionally, MG428 was found to interact with the RNAP core enzyme, reinforcing the predicted role of this protein as an alternative sigma factor. Finally, our results indicate that MG428 contributes to the generation of genetic diversity in this model organism. Since recombination is an important mechanism to generate antigenic variation, MG428 emerges as a novel factor contributing to M. genitalium virulence

Natural observatories for lightning research in Colombia

This paper presents a selected, not exhaustive, description of lightning research in Colombia over time, based on natural observatories for experimentation and measurement; and introduces the DABEIBA Lightning Research Center as a new institutional cooperation to concentrate several instruments such as Lightning Mapping Array - LMA, high speed cameras, high energy detectors, by different scientific parties in a single area for tropical lightning research. © 2018 IEEE.Peer ReviewedPostprint (published version