Identificación de Fusarium cf. verticillioides como agente causal de la enfermedad Pokka boheng en caña de azúcar en el departamento de Antioquia, Colombia

The cultivation of sugarcane represents an important part in the Colombian economy due to the diverse applications in industries like liquor, food, paper and biofuels. Sugarcane worldwide production is affected by the presence of phytopathogenic agents, mainly filamentous fungi such as Physalospora tucumanensis (red rot disease) and Fusarium spp. To date in Colombia, Pokka boheng disease whose causal agent is the fungus Fusarium verticillioides, has not been reported, which is why it is necessary to identify appropriately this microorganism, responsible for losses in productivity and food contamination. In order to isolate and identify the infectious agent from symptomatic tissues, disinfection and culture in liquid and solid culture mediums were performed in malt extract (2%) and yeast extract (0.2%) both liquid and solid, for 7 days. After several replicates in agar plate, a purification was made along with a morphological characterization based on the shape and color of the mycelium, as well as the type of spores generated. Additionally, the genetic material was extracted and gene markers (ITS, Elongation Factor 1-α (EF) and β-Tubulin (Btub)) were amplified by PCR. Then, DNA sequencing was used to obtain the data to make a phylogenetic reconstruction by probabilistic methods (Maximum Likelihood and Bayesian Inference). The isolated strain, named as EA-FP0013 was located in the Fujikuroi complex group, with high probable identity to Fusarium verticillioides. Thus, early and species-specific identification of these fungal isolates by molecular methods may allow the timely diagnosis of emerging pathophysiological diseases of interest in the region, and thus propose the respective control strategies.El cultivo de la caña de azúcar representa una parte importante en la economía de Colombia debido a las diversas aplicaciones en industrias como licor, alimentos, papel y biocombustibles. Su producción en todo el mundo se ve afectada por la presencia de agentes fitopatógenos, principalmente hongos filamentosos como Physalospora tucumanensis (agente causal de la enfermedad “Pudrición roja”) y Fusarium spp. Hasta la fecha, en Colombia, no se ha reportado la enfermedad de Pokka boheng en este cultivo cuyo agente causal es el hongo Fusarium verticillioides, por lo que es necesario identificar adecuadamente este microorganismo, responsable de las pérdidas en productividad y contaminación de los alimentos. Con el fin de aislar e identificar el agente infeccioso de los tejidos sintomáticos, se realizó la desinfección y posterior siembra de éstos en medios de cultivo extracto de malta (2 %) y extracto de levadura (0.2 %) tanto líquido como sólido durante 7 días. A partir de varias placas petri, se realizó la respectiva purificación y una caracterización morfológica basada en la forma y el color del micelio, así como el tipo de esporas generadas. Adicionalmente, el material genético se extrajo y se amplificaron los marcadores genéticos (ITS, factor de elongación 1-α (EF) y β-tubulina (Btub)) por PCR. Luego, se utilizó la secuenciación del ADN para obtener los datos para realizar una reconstrucción filogenética mediante métodos probabilísticos (máxima verosimilitud e inferencia bayesiana). La cepa aislada, nombrada como EA-FP0013 se localizó en el grupo del complejo Fujikuroi, con una alta identidad probable para Fusarium verticillioides. Por lo tanto, la identificación temprana y específica de especie de estos aislados fúngicos, utilizando métodos moleculares, puede permitir el diagnóstico oportuno de enfermedades fisiopatológicas emergentes de interés para la región, y así proponer las estrategias de control respectivas

Consumo de éxtasis y búsqueda de armonía: referentes de una identidad juvenil

Se presenta la relación que se establece entre prácticas de consumo, adscripciones identitarias juveniles y la escena electrónica en la ciudad de Medellín. La investigación es de carácter cualitativo e interpretativo. Las grandes categorías de análisis son: dimensiones subjetivas de la identidad, prácticas y representaciones sociales. Se emplearon entrevistas a profundidad, con guía semiestructurada. El estudio señala el uso de estas sustancias como parte de la identidad psicosocial a través de la adscripción a unas prácticas juveniles de consumo, cargadas de matices simbólicos (búsqueda de armonía), en un marco cultural determinado y de la significación que se le da al empleo de los fármacos de la interacción, de la identificación y de la diferenciación social, en escenarios y/o eventos de carácter lúdico y de diversión, como es la escena electrónica

Consumo de alcohol y factores de riesgo en estudiantes de dos universidades Colombianas

The objective of the current research was to identify the risk factors associated to alcohol consumption of Colombian University students. 397 women and 312 men, students from two private and Catholic universities in the city of Medellín (Colombia) took part in it. The results identified as risk factors the difficulties to say 'no' to the people (p=0.012) and the consumption of psychoactive substances by members of the family (p=0.022).El objetivo fue identificar factores de riesgo del consumo de alcohol en estudiantes universitarios colombianos. Participaron 397 mujeres y 312 hombres, estudiantes de dos universidades privadas y católicas de la ciudad de Medellín (Colombia). Los resultados identificaron como factores de riesgo las dificultades para decir “no” a la gente (p=0.012) y el consumo de sustancias psicoactivas por miembros de la familia (p=0.022)

Hardware-aware Training Techniques for Improving Robustness of Ex-Situ Neural Network Transfer onto Passive TiO2 ReRAM Crossbars

Passive resistive random access memory (ReRAM) crossbar arrays, a promising emerging technology used for analog matrix-vector multiplications, are far superior to their active (1T1R) counterparts in terms of the integration density. However, current transfers of neural network weights into the conductance state of the memory devices in the crossbar architecture are accompanied by significant losses in precision due to hardware variabilities such as sneak path currents, biasing scheme effects and conductance tuning imprecision. In this work, training approaches that adapt techniques such as dropout, the reparametrization trick and regularization to TiO2 crossbar variabilities are proposed in order to generate models that are better adapted to their hardware transfers. The viability of this approach is demonstrated by comparing the outputs and precision of the proposed hardware-aware network with those of a regular fully connected network over a few thousand weight transfers using the half moons dataset in a simulation based on experimental data. For the neural network trained using the proposed hardware-aware method, 79.5% of the test set's data points can be classified with an accuracy of 95% or higher, while only 18.5% of the test set's data points can be classified with this accuracy by the regularly trained neural network.Comment: 15 pages, 11 figure

Misión CubeSat FS2017: desarrollo de software para una misión satelital universitaria

Siguiendo los lineamientos establecidos en el Plan Espacial Nacional [1], la Comisión Nacional de Actividades Espaciales (CONAE) ha creado la Unidad de Formación Superior (UFS) para capacitar recursos humanos de alto nivel en ciencia y tecnologías espaciales, a fin de satisfacer las necesidades de las instituciones/ empresas científico-tecnológicas argentinas. En asociación con varias universidades nacionales, la UFS ha implementado nuevos programas de maestría en diferentes áreas tecnológicas que cubren las especialidades de un sistema espacial. En ese contexto, el objetivo primario de la misión FS2017 (Formador Satelital 2017) es proveer a los maestrandos de la UFS entrenamiento práctico en los aspectos técnicos y programáticos de una misión espacial. Este trabajo presenta un resumen de la implementación del software (SW) de la misión, dividido en 2 segmentos: SW de tierra y SW de vuelo. Se abordan conceptos generales de la misión, el enfoque de management, la arquitectura y las características técnicas de la implementación.Eje: Innovación en Sistemas de Software.Red de Universidades con Carreras en Informática (RedUNCI

Do nutritional supplements have a role in age macular degeneration prevention?

Purpose. To review the proposed pathogenic mechanisms of age macular degeneration (AMD), as well as the role of antioxidants (AOX) and omega-3 fatty acids (omega-3) supplements in AMD prevention. Materials and Methods. Current knowledge on the cellular/molecular mechanisms of AMD and the epidemiologic/experimental studies on the effects of AOX and omega-3 were addressed all together with the scientific evidence and the personal opinion of professionals involved in the Retina Group of the OFTARED (Spain). Results. High dietary intakes of omega-3 and macular pigments lutein/zeaxanthin are associated with lower risk of prevalence and incidence in AMD. The Age-Related Eye Disease study (AREDS) showed a beneficial effect of high doses of vitamins C, E, beta-carotene, and zinc/copper in reducing the rate of progression to advanced AMD in patients with intermediate AMD or with one-sided late AMD. The AREDS-2 study has shown that lutein and zeaxanthin may substitute beta-carotene because of its potential relationship with increased lung cancer incidence. Conclusion. Research has proved that elder people with poor diets, especially with low AOX and omega-3 micronutrients intake and subsequently having low plasmatic levels, are more prone to developing AMD. Micronutrient supplementation enhances antioxidant defense and healthy eyes and might prevent/retard/modify AMD

Students factors affecting undergraduates perceptions of their teaching and learning process within ECTS experience

Introduction: In the present study, we investigated the potential factors that influenced the level of students satisfaction with the teaching¿learning process (TLP), from the perspective of students participating in the European Credit Transfer System (ECTS) experience. Method: A total of 1490 students from the Universities of Almería and Granada (Spain) participated in an evaluation of their class discipline area. They completed the new revised protocol for evaluating the ECTS experience. Analyses of variance were carried out, taking the following factors as independent variables: student¿s grade average, year in school, study discipline, credit load in terms of ECTS credits assigned to a subject, the e-learning approach. Perception of the TLP was used as the dependent variable. Results: The data analyses showed variability of the degree of statistically significance among the factors that influenced students¿ perceptions of the TLP. These factors included: Student¿s grade average (in favor of high performers), year in school (in favor of earlier years), ECTS load (in favor of subjects with a medium load of credits), and e-learning (in favor of its use). These research findings provided evidence to explore the delineation of a potential profile of factors that trigger a favorable perception of the TLP. Discussion and Conclusion: The present findings certainly have implications to deepen our understanding of the core beliefs, commitment, and the experience in shaping the implementation of the European Higher Education Area through the ECTS

Wafer-scale detachable monocrystalline Germanium nanomembranes for the growth of III-V materials and substrate reuse

Germanium (Ge) is increasingly used as a substrate for high-performance optoelectronic, photovoltaic, and electronic devices. These devices are usually grown on thick and rigid Ge substrates manufactured by classical wafering techniques. Nanomembranes (NMs) provide an alternative to this approach while offering wafer-scale lateral dimensions, weight reduction, limitation of waste, and cost effectiveness. Herein, we introduce the Porous germanium Efficient Epitaxial LayEr Release (PEELER) process, which consists of the fabrication of wafer-scale detachable monocrystalline Ge NMs on porous Ge (PGe) and substrate reuse. We demonstrate monocrystalline Ge NMs with surface roughness below 1 nm on top of nanoengineered void layer enabling layer detachment. Furthermore, these Ge NMs exhibit compatibility with the growth of III-V materials. High-resolution transmission electron microscopy (HRTEM) characterization shows Ge NMs crystallinity and high-resolution X-ray diffraction (HRXRD) reciprocal space mapping endorses high-quality GaAs layers. Finally, we demonstrate the chemical reconditioning process of the Ge substrate, allowing its reuse, to produce multiple free-standing NMs from a single parent wafer. The PEELER process significantly reduces the consumption of Ge during the fabrication process which paves the way for a new generation of low-cost flexible optoelectronics devices.Comment: 17 pages and 6 figures along with 3 figures in supporting informatio

Seminari d'Estudis i Recerques Prehistòriques (SERP). Núcleo de cohesión en formación e investigación en Prehistoria de la Universidad de Barcelona desde 1987

El artículo es un resumen amplio de todas las actividades científicas y académicas llevadas a cabo por el SERP (Seminari d'Estudis i Recerques Prehistòriques) desde su fundación en 1987 por parte del Dr. Fullola. Abarca desde programas de excavaciones a proyectos internacionales pasando por temas de Patrimonio arqueológico o de historiografía, entre muchos otros. Además del resumen de dichas actividades, se añade también una completa lista de publicaciones, la gran mayoría en revistas de impacto nacional e internacional. Se incide especialmente en siete líneas básicas de trabajo dentro del grupo, la arqueopetrología, la arqueozoología, el arte prehistórico, la geoarqueología, la paleobotánica, la tecnología, el patrimonio y los estudios territoriales. También se repasan todos y cada uno de los yacimientos objeto de excavación por parte del SERP en estos últimos tres decenios