Risk stratifiers for arrhythmic and non-arrhythmic mortality after acute myocardial infarction

Open Access. Publicado online: 2-Jul-2018The effective discrimination between patients at risk of Arrhythmic Mortality (AM) and Non-Arrhythmic Mortality (NAM) constitutes one of the important unmet clinical needs. Successful risk assessment based on Electrocardiography (ECG) records is greatly improved by the combination of different indices reflecting not only the pathological substrate but also the autonomic regulation of cardiac electrophysiology. This study assesses the cardiac risk stratification capacity of two new Heart Rate Variability (HRV) parameters, Breath Concurrence 6 (BC6) -sinusoidal RR variability of 6 heart beats per breath cycle- and Primary Ectopia (PE) -presence of early ventricular contractions of any etiology- together with the Deceleration Capacity (DC). While BC6 characterizes the response to physiological and pathophysiological stimuli, PE qualifies autonomic cardiac electrophysiology. The analysis of the European Myocardial Infarct Amiodarone Trial (EMIAT) database indicates that BC6 is related with the risk of Arrhythmic Mortality (AM) and PE with the risk of Non-Arrhythmic Mortality. BC6 is the only single parameter that significantly discriminates between AM and NAM. While the combination of BC6 and DC contributes to the identification of AM risk, PE together with DC improves the prediction of NAM in patients with severe ischemic heart disease

Estudio cuantitativo de los intercambios de calor y humedad en superficies geográficas basado en datos meteorológicos

The purpose of this project is the development and testing of a new geographical surface heat exchange measurement technique. The proposed approach is based on the indirect evaluation of advective moist air heat fluxes and employs the most simple instrumentation available at the moment, consisting on a network of automatic meteorological stations. Urban surfaces will play a key role on this project, as it is focused on the evaluation of mean urban heat exchanges. Consequently, this research connects with previous works about urban climatology and, more specifically, its more noted manifestation, the Urban Heat Island (UHI). The Spanish city of Seville will be used to test the model. This document is organized as follows: Chapter 1 reviews the state of the art regarding urban climatology, including basic definitions, thermodynamic basis, general behavior of UHIs and their effects on health, environment and economy. Chapter 2 explains and develops the theoretical framework of the project, discussing its applicability conditions, associated risks and thermodynamic and fluid mechanics background. Chapter 3 will focus on the qualitative explanation of the required tools, explaining the design requirements, limitations and results. Chapter 4 will show an organized set of results for the city of Seville (Spain), which include tables, graphs and statistical distributions for each tested configuration. Chapter 5 will extract key conclusions about this methodology and the obtained results. Future steps are also explored.El propósito de este proyecto es el desarrollo y comprobación de un nuevo método para la medición de los intercambios de calor y humedad globales en superficies geográficas. Se realizará un análisis convectivo del flujo de aire sobre el terreno, combinando para ello las extensas bases de datos diezminutales de ciertas estaciones de la AEMET y diversas fuentes de radiación solar global. Debido a su especial interés económico, urbanístico y sanitario, el proyecto se centrará en la evaluación del ampliamente conocido Efecto Isla de Calor. Las estaciones meteorológicas automáticas de Sevilla serán utilizadas para probar el modelo teórico y extraer valiosas conclusiones para futuros desarrollos. Los datos meteorológicos empleados en este proyecto han sido cedidos por la Agencia Estatal de Meteorología (AEMET) y su coste asciende a 2340,42 €. Los datos de radiación solar global han sido proporcionados por el Grupo de Termodinámica y Energías Renovables (GTER) de la Escuela Técnica Superior de Ingeniería de la Universidad de Sevilla.Universidad de Sevilla. Grado en Ingeniería Aeroespacia

Novel Electromagnetic Space Applications: Electron-Based Touchless Potential Sensing and Low-Gravity Magnetohydrodynamics

The commercialization of the sub-orbital environment, the ambition to make humans a multi-planetary species, and the urgent need for sustainable space operations are driving the development of a new generation of space systems. The use of electromagnetic forces (and electromagnetism, in general) is proposed in this dissertation to enable mid-distance, contactless actuation and sensing for space technology development. Following this paradigm, two applications are explored: electron-based touchless spacecraft potential sensing, and low-gravity magnetohydrodynamics.The electron-based touchless potential sensing method was recently introduced to characterize the electrostatic state of non-cooperative objects in GEO and deep space. Applications span from arcing prevention to space debris removal. Although the fundamentals of this approach were studied in previous works, several open questions remained regarding the effect of complex geometries and differential charging on the sensing process. Such questions are here addressed with efficient numerical tools and vacuum chamber experiments, providing key insights into the behavior of realistic spacecraft formations. In addition, new active photoelectron-based sensing strategies are proposed that overcome some of the challenges of previous implementations.The concept of low-gravity magnetohydrodynamics is also introduced as a way to actuate low-gravity fluid mechanics systems using magnetic forces. The theoretical foundations of the field are established from the analytical, numerical, and experimental perspectives with particular attention to the equilibrium, stability, and modal response of gas-liquid interfaces. Specific features of bubbles and droplets are also explored. Finally, the use of magnetic polarization and Lorentz forces in low-gravity fluid systems is discussed together with some of their applications, which include phase separation, magnetic positive positioning, and low-gravity electrolysis. The development of such technologies is initiated with support from microgravity research campaigns at ZARM's drop tower and Blue Origin's New Shepard suborbital rocket

Magnetic phase separation in microgravity

The absence of strong buoyancy forces severely complicates the management of multiphase flows in microgravity. Different types of space systems, ranging from in-space propulsion to life support, are negatively impacted by this effect. Multiple approaches have been developed to achieve phase separation in microgravity, whereas they usually lack the robustness, efficiency, or stability that is desirable in most applications. Complementary to existing methods, the use of magnetic polarization has been recently proposed to passively induce phase separation in electrolytic cells and other two-phase flow devices. This article illustrates the dia- and paramagnetic phase separation mechanism on MilliQ water, an aqueous MnSO4 solution, lysogeny broth, and olive oil using air bubbles in a series of drop tower experiments. Expressions for the magnetic terminal bubble velocity are derived and validated and several wall–bubble and multi-bubble magnetic interactions are reported. Ultimately, the analysis demonstrates the feasibility of the dia- and paramagnetic phase separation approach, providing a key advancement for the development of future space systems

Magnetic phase separation in microgravity

The absence of strong buoyancy forces severely complicates the management of multiphase flows in microgravity. Different types of space systems, ranging from in-space propulsion to life support, are negatively impacted by this effect. Multiple approaches have been developed to achieve phase separation in microgravity, whereas they usually lack the robustness, efficiency, or stability that is desirable in most applications. Complementary to existing methods, the use of magnetic polarization has been recently proposed to passively induce phase separation in electrolytic cells and other two-phase flow devices. This article illustrates the dia- and paramagnetic phase separation mechanism on MilliQ water, an aqueous MnSO4 solution, lysogeny broth, and olive oil using air bubbles in a series of drop tower experiments. Expressions for the magnetic terminal bubble velocity are derived and validated and several wall–bubble and multi-bubble magnetic interactions are reported. Ultimately, the analysis demonstrates the feasibility of the dia- and paramagnetic phase separation approach, providing a key advancement for the development of future space systems

Selected indigenous drought tolerant rhizobium strains as promising biostimulants for common bean in Northern Spain

Drought is the most detrimental abiotic stress in agriculture, limiting crop growth and yield and, currently, its risk is increasing due to climate change. Thereby, ensuring food security will be one of the greatest challenges of the agriculture in the nearest future, accordingly it is essential to look for sustainable strategies to cope the negative impact of drought on crops. Inoculation of pulses with biostimulants such as rhizobium strains with high nitrogen fixation efficiency and drought-tolerance, has emerged as a promising and sustainable production strategy. However, some commercial inoculums are not effective under field conditions due to its lower effectiveness against indigenous rhizobium strains in the establishment of the symbiosis. Thus, in the present study, we evaluated the ability to improve drought tolerance in common bean plants of different indigenous rhizobia strains isolated from nearby crop fields in the Basque Country either affected by drought or salinity. The plants in this trial were grown in a climatic chamber under controlled conditions and exposed to values of 30% relative soil water content at the time of harvest, which is considered a severe drought. From the nine bacteria strains evaluated, three were found to be highly efficient under drought (namely 353, A12 and A13). These strains sustained high infectiveness (nodulation capacity) and effectiveness (shoot biomass production) under drought, even surpassing the plants inoculated with the CIAT899 reference strain, as well as the chemically N-fertilized plants. The tolerance mechanisms developed by plants inoculated with 353, A12 and A13 strains were a better adjustment of the cell wall elasticity that prevents mechanical damages in the plasma membrane, a higher WUE and an avoidance of the phenological delay caused by drought, developing a greater number of flowers. These results provide the basis for the development of efficient common bean inoculants able to increase the yield of this crop under drought conditions in the Northern Spain and, thus, to be used as biostimulants. In addition, the use of these efficient nitrogen fixation bacteria strains is a sustainable alternative to chemical fertilization, reducing cost and minimizing its negative impact on environment.This work was founded by Basque Government: Grupo de Investigación del Sistema Universitario Vasco IT1022-16 and T1682-22; and proyects from the Dirección de Calidad e Industrias Alimentarias. Dpto. de Desarrollo Económico e Infraestructuras (32-2016-00043; 37-2017-00047; 00049-IDA-2019-38) and Dpto. De Desarrollo Económico Sostenibilidad y Medio Ambiente (00039-IDA2021-45). A. Del-Canto was the recipient of a predoctoral fellowship granted by the Education Department of the Basque Country Government, Spain

Idiopathic acute transverse myelitis: outcome and conversion to multiple sclerosis in a large series

Background: in 2002, the Transverse Myelitis Consortium Working Group (TMCWG) proposed the diagnostic criteria for idiopathic acute transverse myelitis (IATM) to delimit and unify this group of patients. This study aimed to describe the conversion rate to multiple sclerosis (MS) and variables associated with conversion, and to analyze functional outcome and prognostic factors associated with functional recovery in patients who fulfilled the current TMCWG criteria for definite and possible IATM. Methods: eighty-seven patients diagnosed with IATM between 1989 and 2011 were retrospectively reviewed. Two patients with positive neuromyelitis optica IgG serum antibodies were excluded. Epidemiological, clinical, laboratory, magnetic resonance imaging (MRI) data and outcome of 85 patients were analyzed. Results: eleven (13%) patients converted to MS after a median follow-up of 2.9 years (interquartile range 1.0-4.8). Early-age onset of symptoms was related to conversion to MS. Only 9.4% of patients with IATM were unable to walk unassisted at the end of follow-up. Urinary sphincter dysfunction (odds ratio [OR] 3.37, 95% confidence interval [CI] 1.04-10.92) and longitudinally extensive transverse myelitis (LETM) on MRI (OR 12.34, 95% CI 3.38-45.00) were associated with a poorer outcome (Rankin ≥ 2). Conclusions: at least 13% of patients who fulfill the TMCWG criteria for definite and possible IATM will convert to MS. Functional recovery in IATM is poorer in patients with urinary sphincter dysfunction at admission or LETM on MRI

Baseline MxA mRNA expression predicts interferon beta response in multiple sclerosis patients

Background Myxovirus resistance protein A (MxA) is a molecule induced after interferon-beta injection, mostly used to evaluate its bioactivity. There is little available data on clinical utility of baseline MxA mRNA status. The objective of the study is to investigate whether baseline MxA mRNA expression can predict relapse and disease progression in multiple sclerosis patients treated with interferon-beta. Methods Baseline blood samples were obtained before the first interferon-beta dose was administered to evaluate MxA mRNA expression using real-time polymerase chain reaction (PCR). Demographic and clinical variables were prospectively recorded to define treatment responder and non responder groups. Results 104 patients were included in the study. Baseline MxA mRNA expression was significantly lower in the group of patients who met the definition of responders (1.07 vs 1.95, Student t test, p<0.0001). A threshold of 1.096 was established using Receiver Operating Characteristic analysis to differentiate between responders and non-responders (sensitivity 73.9%, specificity 69.0%). Survival analysis using this threshold showed that time to next relapse (p<0.0001) and to EDSS progression (p = 0.01) were significantly higher in patients with lower MxA titers. Conclusion The results suggest that baseline MxA mRNA levels may be useful for predicting whether multiple sclerosis patients will respond or not to interferon-beta treatment

Changes in environmental CO2 concentration can modify Rhizobium-soybean specificity and condition plant fitness and productivity

(EN) Over the past 10 years, it has been demonstrated in the literature that legume responses to elevated [CO2], whether positive, negative, or null, are in part dependent on the Rhizobium species and genotypes that establish symbiosis with the plant. However, all the strains used in these past experiments were isolated in field conditions at ambient [CO2]. We studied for first time the fitness response of soybean inoculated with a Rhizobium strain that has been previously isolated from nodules of plants grown at elevated [CO2] in field conditions at a FACE site. In experiments developed in controlled growth chambers, and in the field under ambient [CO2], the plants inoculated with the strain isolated at elevated [CO2] showed similar response as plants without inoculation. We hypothesize that deficient nodulation may be associated with a change in root exudates caused by the change in [CO2]. This study showed that the strains isolated in nodules at elevated [CO2] are not capable of properly nodulating soybean plants grown at ambient [CO2] and that the origin of strains do not ensure the performance of plants under the same conditions. However, more research is needed in order to understand how changes in environmental conditions can affect the symbiotic relationship and ultimately how we can improve plant fitness in a changeable world.This research was financially supported by the following grant: GRUPO GobiernoVasco-IT1022-16

Oral contraceptives do not modify the risk of a second attack and disability accrual in a prospective cohort of women with a clinically isolated syndrome and early multiple sclerosis

To evaluate whether oral contraceptive (OC) use is associated with the risk of a second attack and disability accrual in women with a clinically isolated syndrome (CIS) and early multiple sclerosis (MS). Reproductive information from women included in the Barcelona CIS prospective cohort was collected through a self-reported cross-sectional survey. We examined the relationship of OC exposure with the risk of a second attack and confirmed Expanded Disability Status Scale of 3.0 using multivariate Cox regression models, adjusted by age, topography of CIS, oligoclonal bands, baseline brain T2 lesions, body size at menarche, smoking, and disease-modifying treatment (DMT). OC and DMT exposures were considered as time-varying variables. Findings were confirmed with sensitivity analyses using propensity score models. A total of 495 women were included, 389 (78.6%) referred to ever use OC and 341 (68.9%) started OC before the CIS. Exposure to OC was not associated with a second attack (adjusted hazard ratio (aHR) = 0.73, 95% confidence interval (CI) = 0.33-1.61) or disability accrual (aHR = 0.81, 95% CI = 0.17-3.76). Sensitivity analyses confirmed these results. OC use does not modify the risk of second attack or disability accrual in patients with CIS and early MS, once considered as a time-dependent exposure and adjusted by other potential confounders