Capacidad de las raíces para penetrar sustratos compactados y detectar grietas. Metodología y aplicación a la colonización vegetal de laderas erosionadas en ambiente semiárido

En el presente trabajo, proponemos profundizar en el conocimiento sobre los procesos que limitan la colonización vegetal de laderas erosionadas en ambientes semiáridos, y más específicamente sobre la penetración de raíces en suelos compactados. Para ello, hemos desarrollado una metodología para el estudio de la capacidad de las raíces para penetrar sustratos y detectar grietas en un rango amplio de compactaciones. Hemos analizado además el efecto de la morfología de las raíces, del nivel de resistencia a la penetración y del espesor del nivel más superficial del sustrato en la penetración de las raíces y en la detección de grietas por las raíces. Esta metodología se basa en el uso de discos de cera cuyo nivel de resistencia a la penetración depende de las proporciones de mezcla de parafina y vaselina en condiciones controladas de laboratorio. Para el estudio se utilizó un diseño factorial cruzado 2 x 2 x 5, con dos especies de distinta morfología radicular (pivotante vs. fasciculada), dos espesores de sustrato (3 y 7 mm) y cinco niveles de resistencia a la penetración comprendidos entre 60 y 1500 kPa. Los resultados indican que el nivel de resistencia a la penetración y el espesor del sustrato influyen sobre la tasa (número de raíces por semilla que penetran el sustrato) y velocidad (número de días para que se produzca la primera penetración) de penetración de las raíces para las dos morfologías de raíces estudiadas. Al contrario, no se aprecia ningún efecto del tipo de raíz en la velocidad para penetrar el sustrato. Por otro lado, se ha puesto de manifiesto el papel importante del nivel de resistencia a la penetración y de la morfología de las raíces en la detección de grietas superficiales por las raíces. A partir de los resultados obtenidos, se discuten las distintas estrategias posibles que podrían explicar el éxito de las especies colonizadoras de taludes de carreteras. Asimismo, una estrategia mixta, que contempla la penetración del suelo o la detección de grietas superficiales por las raíces, podría tener éxito en los terraplenes, mientras que en los desmontes con valores limitantes de resistencia a la penetración por las raíces en las capas superficiales del sustrato geológico, la capacidad de las raíces para detectar grietas con un microambiente más favorable podría ser una estrategia de éxito para las plantas.Este trabajo ha sido realizado con la financiación del Ministerio de Ciencia y Tecnología (Proyecto REN 2001-2313 y Programa Ramón y Cajal co-financiado por el Fondo Social Europeo).Peer Reviewe

Antibodies to endothelial cells in Behçet's disease: cell-binding heterogeneity and association with clinical activity

OBJECTIVES--To investigate the prevalence and characteristics of antibodies to endothelial cells (aEC) from large vessel and from microvasculature in a group of patients with Behçet's disease (BD) to determine the relationship of these antibodies with clinical and laboratory features of the disease. METHODS--Thirty patients with BD were prospectively and consecutively studied. The aEC were determined by enzyme-linked immunosorbent assay (ELISA) using endothelial cells derived from human umbilical vein (large vessel) as well as from retroperitoneal adipose tissue (microvasculature). RESULTS--Fifteen patients (50%) had aEC, either directed to large vessel [8(26%) patients] or microvascular [13(43%) patients] endothelial cells. The percentage of active patients was significantly higher in the aEC-positive group [12(80%) patients] compared with the aEC-negative group [5(33%) patients] (p < 0.05). CONCLUSIONS--Patients with BD have a high prevalence of aEC when microvascular endothelial cells are used in the assay. These antibodies seem to be a marker of disease activity in this condition, previously considered as negative for autoantibodies

Hepatitis G virus infection in primary Sjögren's syndrome: analysis in a series of 100 patients.

OBJECTIVE To determine the prevalence and clinical significance of hepatitis G virus (HGV) infection in a large cohort of patients with primary Sjögren¿s syndrome (SS). PATIENTS AND METHODS The study included 100 consecutive patients (92 female and eight male), with a mean age of 62 years (range 31¿80) that were prospectively visited in our unit. All patients fulfilled the European Community criteria for SS and underwent a complete history, physical examination, as well as biochemical and immunological evaluation for liver disease. Two hundred volunteer blood donors were also studied. The presence of HGV-RNA was investigated in the serum of all patients and donors. Aditionally, HBsAg and antibodies to hepatitis C virus were determined. RESULTS Four patients (4%) and six volunteer blood donors (3%) presented HGV-RNA sequences in serum. HGV infection was associated with biochemical signs of liver involvement in two (50%) patients. When compared with primary SS patients without HGV infection, no significant differences were found in terms of clinical or immunological features. HCV coinfection occurs in one (25%) of the four patients with HGV infection. CONCLUSION The prevalence of HGV infection in patients with primary SS is low in the geographical area of the study and HCV coinfection is very uncommon. HGV infection alone does not seen to be an important cause of chronic liver injury in the patients with primary SS in this area

Varespladib and cardiovascular events in patients with an acute coronary syndrome: the VISTA-16 randomized clinical trial

IMPORTANCE: Secretory phospholipase A2(sPLA2) generates bioactive phospholipid products implicated in atherosclerosis. The sPLA2inhibitor varespladib has favorable effects on lipid and inflammatory markers; however, its effect on cardiovascular outcomes is unknown. OBJECTIVE: To determine the effects of sPLA2inhibition with varespladib on cardiovascular outcomes. DESIGN, SETTING, AND PARTICIPANTS: A double-blind, randomized, multicenter trial at 362 academic and community hospitals in Europe, Australia, New Zealand, India, and North America of 5145 patients randomized within 96 hours of presentation of an acute coronary syndrome (ACS) to either varespladib (n = 2572) or placebo (n = 2573) with enrollment between June 1, 2010, and March 7, 2012 (study termination on March 9, 2012). INTERVENTIONS: Participants were randomized to receive varespladib (500 mg) or placebo daily for 16 weeks, in addition to atorvastatin and other established therapies. MAIN OUTCOMES AND MEASURES: The primary efficacy measurewas a composite of cardiovascular mortality, nonfatal myocardial infarction (MI), nonfatal stroke, or unstable angina with evidence of ischemia requiring hospitalization at 16 weeks. Six-month survival status was also evaluated. RESULTS: At a prespecified interim analysis, including 212 primary end point events, the independent data and safety monitoring board recommended termination of the trial for futility and possible harm. The primary end point occurred in 136 patients (6.1%) treated with varespladib compared with 109 patients (5.1%) treated with placebo (hazard ratio [HR], 1.25; 95%CI, 0.97-1.61; log-rank P = .08). Varespladib was associated with a greater risk of MI (78 [3.4%] vs 47 [2.2%]; HR, 1.66; 95%CI, 1.16-2.39; log-rank P = .005). The composite secondary end point of cardiovascular mortality, MI, and stroke was observed in 107 patients (4.6%) in the varespladib group and 79 patients (3.8%) in the placebo group (HR, 1.36; 95% CI, 1.02-1.82; P = .04). CONCLUSIONS AND RELEVANCE: In patients with recent ACS, varespladib did not reduce the risk of recurrent cardiovascular events and significantly increased the risk of MI. The sPLA2inhibition with varespladib may be harmful and is not a useful strategy to reduce adverse cardiovascular outcomes after ACS. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01130246. Copyright 2014 American Medical Association. All rights reserved

Pain Experience and Sensory Changes in Astronauts During and After Short-Lasting Commercial Spaceflight: A Proof-of-Concept Study

Space travel has been associated with musculoskeletal pain, yet little is known about the nociceptive changes and pain experience during spaceflight. This preliminary study aims to investigate the pain experience and sensory alterations in astronauts following a 17-day mission to the International Space Station (ISS) on Axiom Space\u27s AX-1 commercial space flight. Two participants were enrolled, and data were collected pre-flight, in-flight, post-flight, and three-month post-flight. Validated pain questionnaires assessed anxiety, catastrophizing, impact on physical and mental health, disability, and overall pain experience. Qualitative interviews were conducted post-landing and conditioned pain modulation (CPM) and quantitative sensory testing (QST) were performed. Both astronauts reported musculoskeletal pain during and after the flight, which was managed with anti-inflammatories and stretching techniques. Pain levels returned to baseline after three months. Pain questionnaires revealed heightened pain experiences in-flight and immediately post-flight, although their adequacy in assessing pain in space is uncertain. Qualitative interviews allowed astronauts to describe their pain experiences during the flight. Sensory changes included increased mechanical touch detection thresholds, temporal pain summation, heat pain thresholds, and differences in conditioned pain modulation post-flight. This preliminary study suggested that spaceflight may affect various aspects of sensory perception and regulation in astronauts, albeit in a variable manner. More data are needed to gain insight of on gain and loss of sensory functions during space missions. Further investigation into the multifactorial stressors affecting the somatosensory system during space travel could contribute to advancements in space and pain medicine

Retención de agua en suelos de cítricos con manejo ecológico y con manejo convencional. Modelos de regresión

Hemos estudiado con un método experimental normalizado las características de retención de agua de 43 muestras de tierra fina compactadas y sin compactar, procedentes de suelos dedicados al cultivo de cítricos con manejo ecológico (22) y con manejo convencional (21), así como sus características intrínsecas relativas a: textura; contenido en carbonatos; y materia orgánica. El % de arcilla varió entre un 5% y un 49%, siendo ligeramente más arenosas las muestras del manejo ecológico, que sin embargo presentaron un mayor contenido en materia orgánica, con los valores más frecuentes comprendidos en el intervalo 1,5% - 3,5%. La compactación supuso un aumento de la porosidad útil pero no dio lugar a un aumento de la precisión del método de caracterización hídrica de las muestras. Realizamos un análisis de regresión lineal múltiple paso a paso con la humedad volumétrica a cada succión mátrica como variable dependiente, y con las características intrínsecas como variables independientes. Previamente, los valores de cada parámetro fueron normalizados en relación con su media armónica. La mayor explicación de la varianza se consiguió en las muestras del manejo ecológico (>90%) con la textura y con la materia orgánica, para succiones mayores que 20 KPa, tanto en muestras compactadas como sin compactar

A Dashboard to Support Decision-Making Processes in Learning Ecosystems

There are software solutions to solve most of the problems related to information management in any company or institutions, but still, there is a problem for transforming information into knowledge. Technological ecosystems emerge as a solution to combine existing tools and human resources to solve different problems of knowledge management. In particular, when the ecosystem is focused on learning processes associated with knowledge are named learning ecosystems. The learning ecosystem metamodel defined in previous works solves several problems related to the definition and implementation of these solutions. However, there are still challenges associated with improving the analysis and visualization of information as a way to discover knowledge and support decision making processes. On the other hand, there is a metamodel proposal to define customized dashboards for supporting decision-making processes. This proposal aims to integrate both metamodels as a way to improve the definition of learning ecosystems

Implantación de arbustos pascícolas como integración ganadera en los agrosistemas

Durante varios años (1985-1995) se han venido realizando una serie de ensayos sobre la metodología para una implantación de arbustos pascicolas con doble finalidad: a) integración ganadera en agrosistemas de montaña y b) recuperación de zonas marginales. Para la obtención de estos objetivos se ha hecho hincapie y se han obtenido resultados en las siguientes actuaciones: – Selección de especies arbustivas pascicolas que compaginen su palatabilidad con la adaptación a condiciones de cultivos abandonados en climas mediterráneos y a suelos con problemas de erosión hídrica. Se seleccionaron las siguientes especies: Medicago arborea, Psoralea bituminosa, Atriplex nummularia y Atriplex halimus. – Técnicas de multiplicación, de estas especies, tendentes a conseguir mejores rendimientos en germinación de semillas y obtención de plantones más vigorosos y con un sistema radicular bien desarrollado para su buena implantación en el campo. Se obtuvieron resultados de volumen y biomasa del vuelo y de biomasa de raíces. – Técnicas de plantación de arbustos tendentes a conseguir, en su realización, una mínima alteración de la estructura del suelo y de la biodiversidad del ecosistema preexistente. A tal fin se desarrolló y aplicó un instrumental (de sistema de envase de los plantones y de útil de plantación) apropiado para un buen amarre de los plantones en el campo

NiFe and NiCo core-shell nanoparticles supported on graphene as efficient catalysts for oxygen evolution reaction

The development of inexpensive and abundant catalysts for water electrolysis is underway and a wide variety of transition metal-based carbon composites are being explored for the redox reactions involved in the electrochemical cycle of water, being Oxygen Evolution Reaction (OER) the bottleneck of this process. Herein, NiFe and NiCo core-shell nanoparticles supported on graphene 3D aerogels were developed for Oxygen Evolution Reaction. These hybrids were synthesised via freeze-casting method and thermal reduction, enabling an ultra-dispersion of the nanoparticles along the graphene oxide flakes, precise control over the nanoparticle size, and forming an active core-shell structure. The as-processed NiFe and NiCo core-shell nanoparticles consistently maintaining a low metal content of 10wt% supported on graphene were successfully tested for OER and compared to the current state-of-the-art (NiFe Layered Double Hydroxides), obtaining overpotentials ranging from 400 to 450 mV at 10 mA cm-2, a Tafel slope of 84.8 mV dec-1, and great stability over 12 h