19 research outputs found
Comentarios en la presentación del libro Ixcan: Masacres y Sobrevivencia, cuarto volumen de la serie Al atardecer de la vida, de Ricardo Falla
No English Abstract¿Cómo podemos definir este cuarto volumen de la colección Al atardecer de la vida? ¿De qué nos habla Ricardo Falla? ¿Sobré qué nos invita a pensar y reflexionar?Masacres y sobrevivencia, el volumen que hoy se presenta en la capital, es el registro pormenorizado de una época en la que se institucionalizó la barbarie o, dicho de otro modo, en la que la barbarie hecha Estado impuso un ciclo de violencia y muerte que todavía no termina. Violencia y muerte ejecutadas con una racionalidad política implacable e impecable
Winter distributions of Dinophysis populations: do they help to predict the onset of the bloom?
Blooms of diarrhetic shellfish toxin (DST) producers of the genus Dinophysis (D. acuminata, D. acuta) pose the main threat to the sustainable exploitation of cultivated mussels and other bivalves on the Atlantic coasts of Europe. Dinophysis species do not rely on cysts as a seeding strategy. Detection and evaluation of holoplanktonic populations surviving after bloom decline may be the key to predict the initiation of next year’s bloom. Three cruises were carried out on the NW Iberian shelf in February 2013 (DINVER 2013), January 2006 (DINVER 2006) and May-June 1993 (MORENA 93) to explore winter (D. acuminata) and pre-bloom (D. acuta) distributions of harmful microalgal species. Sampling protocols were adapted to be able to detect extremely low densities (1-5 cells l-1) of Dinophysis species. Potential inoculum populations in retention areas, as previously described for other species in upwelling regions, were not found on these cruises. Here we explore retrospectively data from these cruises, identify hydrodynamic patterns, and accompanying microplanktonic communities, in an attempt to untangle a crucial question in Dinophysis population dynamics: how to predict the initiation of the Dinophysis growth season.ISSHAEn prens
Assessment of global DNA methylation in peripheral blood cell subpopulations of early rheumatoid arthritis before and after methotrexate
INTRODUCTION: DNA methylation is an epigenetic mechanism regulating gene expression that has been insufficiently studied in the blood of rheumatoid arthritis (RA) patients, as only T cells and total peripheral blood mononuclear cells (PBMCs) from patients with established RA have been studied and with conflicting results. METHOD: Five major blood cell subpopulations: T, B and NK cells, monocytes, and polymorphonuclear leukocytes, were isolated from 19 early RA patients and 17 healthy controls. Patient samples were taken before and 1 month after the start of treatment with methotrexate (MTX). Analysis included DNA methylation with high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry-selected reaction monitoring (HPLC-ESI-MS/MS-SRM) and expression levels of seven methylation-specific enzymes by quantitative polymerase chain reaction (qPCR). RESULTS: Disease-modifying anti-rheumatic drug (DMARD)-naive early RA patients showed global DNA hypomethylation in T cells and monocytes, together with a lower expression of DNA methyltrasnferase 1 (DNMT1), the maintenance DNA methyltransferase, which was also decreased in B cells. Furthermore, significantly increased expression of ten-eleven translocation1 (TET1), TET2 and TET3, enzymes involved in demethylation, was found in monocytes and of TET2 in T cells. There was also modest decreased expression of DNMT3A in B cells and of growth arrest and DNA-damage-inducible protein 45A (GADD45A) in T and B cells. Treatment with MTX reverted hypomethylation in T cells and monocytes, which were no longer different from controls, and increased global methylation in B cells. In addition, DNMT1 and DNMT3A showed a trend to reversion of their decreased expression. CONCLUSIONS: Our results confirm global DNA hypomethylation in patients with RA with specificity for some blood cell subpopulations and their reversal with methotrexate treatment. These changes are accompanied by parallel changes in the levels of enzymes involved in methylation, suggesting the possibility of regulation at this level
Towards a HAB forecast service in the Galician region
We will present the recent developments of our forecasting capabilities to warn of impending harmful algal blooms (HABs) in Galicia, where aquaculture has a strong socio-economic impact. A HAB warning service for monitoring agencies and the aquaculture industry has been developed as a demonstration of a Copernicus marine downstream service coupled to the MyOcean service. In this contribution, we describe the Galician ASIMUTH forecast system and demonstrate its skill in predicting HAB transport and its usefulness to provide assessment for the management of the areas affected by toxic outbreaks. We also describe the Galician pilot HAB bulletins, aimed at distributing forecasts of HAB events that might induce closures of harvesting areas or, when the areas are already closed, at giving information on forthcoming oceanographic conditions that could favour or hamper the opening of an area. Our results show that the model forecasts and the bulletins can provide early warning of the risk of Dinophysis spp. events and the risk of closures linked to the presence of toxins above regulatory levels in harvesting areas.Instituto Español de Oceanografí
Analysis of the Efficiency of the Electrohydrodynamic Propulsion Based on the Biefeld-Brown Effect for Manned and Unmanned Aircrafts
The phenomenon known as the Biefeld-Brown effect or ionic wind has been the subject of study since its discovery with the aim of being applied to aircraft propulsion. Electrohydrodynamic (EHD) thrusters have been developed in a thorough and detailed way since 2000. Subsequently, some attempts have been made to extend them to electric-powered atmospheric aircrafts. This paper is framed in this field by performing a rigorous and detailed analysis of the energy efficiency, measured as the ratio of thrust to energy consumed, for both EHD systems and conventional electric propulsion. This is done using simple EHD thruster configurations together with accurate measurements of the current consumed under controlled environmental conditions. The results are not only compared with the performance of an electric propulsion motor-propeller set, but also consider future research, summarizing the issues that arise to scale them. Future designs of low weight, high performance thrusters might allow this technology to be applied to manned or remotely piloted aircrafts
Sizing Methodology of a Fast Charger for Public Service Electric Vehicles Based on Supercapacitors
In this article, a new methodology for the sizing of a fast-charging station for electric vehicles is presented. The proposed method is applicable to public service vehicles on urban journeys. Its use has been conceived for vehicles equipped with an energy storage system based on supercapacitors (SCs), which are already functional in several countries. The proposed charging station also uses a bank of SCs of variable capacitance. During the study, mathematical expressions will be obtained for the electrical variables involved in vehicle charging: instantaneous current, peak current, charging time, dissipated energy, and the efficiency of energy transference. From these, each of the components of the system will be dimensioned: the capacitance of the charger with its different variable steps, the initial voltage of the charger, and the current smoothing inductor. The proposed charger presents the advantage of allowing energy to be evacuated to the electric vehicle very quickly and with high performance, all without using an external power source or high-power converters. The proposed architecture minimizes the disturbances that, with conventional methods, would appear on the electrical grid, preventing the installation of fast-charging stations at many grid nodes, as is currently the case. Finally, the charger control algorithm is considerably simplified as it only depends on the initial voltage of the vehicle’s accumulator
Supercapacitors in Constant-Power Applications: Mathematical Analysis for the Calculation of Temperature
A set of analytical equations for the calculation of the temperature in supercapacitors operating in constant-power applications is presented in this paper. Although the main operation modes of supercapacitors are constant-current and constant-power charge and discharge, this study was focused on the latter, since both sources and loads act as constant-power systems in a wide range of power conversion facilities. The starting point of this study is the classical supercapacitor model based on electrical and thermal parameters provided by manufacturers or also obtained by experimental means. The proposed mathematical analysis is based on the so-called incomplete gamma function that presents two major advantages over previously existing methods. Firstly, it is not necessary to solve any differential equations system by means of numerical methods, which reduces the required computational effort. Secondly, no simplifications to relief the calculations are made in the computation of any variable. The new formulation renders valid solutions even for high-power demand situations. Moreover, the temperature of the supercapacitor can be expressed as a function of time or any other electrical variable in the charging and discharging processes. Therefore, the proposed formulas are especially remarkable for the electrical and thermal dimensioning of supercapacitors
DNA methylation of peripheral blood cell subpopulations in patients with early rheumatoid arthritis before and after methotrexate treatment
Experimental characterization of a coherent multi-carrier Tx-Rx system based on Rationally Synchronized Oscillators
In situ antenna diagnostics and characterization system based on RFIDand Remotely Piloted Aircrafts
A cost-effective solution for in situ antenna characterization and diagnostics based on Radio FrequencyIDentification technology and Remotely Piloted Aircrafts is presented. The cost-effectiveness of the pro-posed solution is achieved by replacing the radio frequency equipment on-board the small aircrafts withRadio Frequency IDentification tags, while the Antenna Under Test is connected to a Radio FrequencyIDentification reader, thus reducing the weight and complexity of the payload of the aircrafts dedicatedto antenna measurement task. Received Signal Strength measurements are geo-referred with centimeter-level accuracy thanks to a Real Time Kinematic system. An iterative phase retrieval technique based onthe Sources Reconstruction Method is used to recover an equivalent magnetic currents distribution onthe Antenna Under Test aperture plane. The reconstructed currents distribution provides antenna diag-nostics information and enables the calculation of the antenna radiation pattern. The presented methodhas been validated by means of measurements in the UHF band for two different antenna arrays withexcellent result