Intercomparación en análisis cuantitativo por espectrómetro de dispersión de energía de rayos X (EDE)

Las intercomparaciones son una base sólida para consolidar un sistema de calidad y un sustento importante en las aspiraciones para obtener la certificación de un laboratorio. Con éstas, el desempeño analítico de cada laboratorio tiene una evaluación objetiva al comparar sus valores con los mejores resultados de otros laboratorios, asegurando siempre la confidencialidad de los participantes [1]. El Centro Nacional de Metrología (CENAM) organizó el primer ejercicio de intercomparación de microanálisis por espectrometría de discriminación de energía de rayos X (EDE). Se realizó una invitación pública a los laboratorios que desearan participar en la prueba 610-IL-0998, logrando la participación de 7 laboratorios. Los resultados indican que los laboratorios que utilizaron materiales de referencia y accesorios que permiten tener mayor control sobre el proceso de medición obtienen resultados con menor sesg

Interplay between the vortex phase coherence and extended disorder defects in the vortex-liquid regime of thin films and superlattices of 123 superconductors

a-axis oriented (CuO_2 planes perpendicular to the substrate) films and superlattices grown on cubic substrates show a structure with 90° microdomains. The microdomains are grains with a 90° rotation of the c axis. In the vortex liquid region, this microstructure induces a change from the usual three-dimensional (3D) behavior of the anisotropy toward a 2D behavior, in a temperature range above the usual crossover from 2D to 3D. Moreover, when the thickness of the superconducting part of the multilayers becomes smaller (or of the same order as) than the microdomain size the 3D dimensional anisotropy behavior is recovered

Course Recommendation based on Sequences: An Evolutionary Search of Emerging Sequential Patterns

To provide a good study plan is key to avoid students’ failure. Academic advising based on student’s preferences, complexity of the semester, or even background knowledge is usually considered to reduce the dropout rate. This article aims to provide a good course index to recommend courses to students based on the sequence of courses already taken by each student. Hence, unlike existing long-term course planning methods, it is based on graduate students to model the course and not on external factors that might introduce some bias in the process. The proposal includes a novel sequential pattern mining algorithm, called (ES)2P (Evolutionary Search of Emerging Sequential Patterns), that properly identifies paths followed by good students and not followed by not so good students, as a long-term course planning approach. A major feature of the proposed (ES)2P algorithm is its ability to extract the best k solutions, that is, those with a best recommendation index score instead of returning the whole set of solutions above a predefined threshold. A real study case is performed including more than 13,000 students belonging to 13 faculties to demonstrate the usefulness of the proposal not only to recommend study plans but also to give advices at different stages of the students’ learning process

Reconstructing the trajectory of the August 1680 hurricane from contemporary records

This paper draws on a range of contemporary documentary evidence from the New and Old Worlds as well as from the oceanic regions to reconstruct the trajectory and intensity of an Atlantic hurricane from August 1680. In doing so, it offers the example of one of the earliest and most comprehensive hurricane reconstructions thus far attempted. The source material includes evidence from land-based observers and some of the earliest examples of instrumental barometric data from the Caribbean and from Europe; importantly, it also calls on the written accounts offered in ships' logbooks from various parts of the Atlantic. The latter provide the opportunity of tracking the system across the otherwise data-deficient areas of the North Atlantic as it recurved toward Europe. The findings are of intrinsic interest in documenting a notable historical event. They also offer a methodological model of how such a variety of documentary sources can be drawn together and used to identify, track, and reconstruct such events from the distant past and thereby improve the chronology of hurricanes and make more reliable our interpretation of their changing frequencies

Reproduction of the wedge sole (Dicologoglossa cuneata Moreau) in captivity: spawning parameters and influence of the natural temperature

In this work, the wedge sole (Dciologoglossa cuneata) spawning under natural thermocycle has been studied. The spawning parameters were similar to those of other flatfish in captivity, the relative fecundity being very high (1.7&plusmn;0.1 &middot;106 eggs Kg female-1 per spawning season). The percentage of floating eggs decreased in parallel to the time and was directly related to egg diameter, daily relative fecundity and fertilization rate. Nevertheless, the hatching rate variations were not correlated to any other spawning parameter. The temperature range during the spawning season was very wide (11-21 &ordm;C) though the largest spawns occurred between 12 and 16 &ordm;C . The natural temperature cycle influenced wedge sole egg production, the winter temperature minimum indicating the onset of spawning, but the variations in the reproductive season did not appear to affect the daily egg production. Future research should focus on the photoperiod and its interaction with temperature as key factor for spawning. This work was supported by Interreg Project 0251_ECOAQUA_5_E, financed by the EDRF (European Regional Development Fund). www.juntadeandalucia.es/agriculturaypesca/ifapa/ecoaqua.. &nbsp;El presente trabajo trata del estudio de las puestas de la aced&iacute;a (Dicologoglossa cuneata) en cautividad bajo condiciones naturales de temperatura. Los par&aacute;metros de puesta fueron similares a los de otros peces planos en cautividad, siendo la fecundidad relativa muy alta (1.7&plusmn;0.1 &middot;106 huevos Kg hembra-1 por estaci&oacute;n reproductora). El porcentaje de huevos flotantes disminuy&oacute; paralelamente con el tiempo y fue directamente proporcional al di&aacute;metro de huevos, fecundidad relativa diaria y tasa de fecundaci&oacute;n. Sin embargo, las variaciones de la tasa de eclosi&oacute;n no estuvieron correlacionadas con ning&uacute;n par&aacute;metro de puesta. El rango de temperatura durante la estaci&oacute;n de puesta fue muy amplio (11-21 &ordm;C), aunque las mayores puestas tuvieron lugar entre 12 y 16 &ordm;C. El ciclo natural de temperatura tuvo efectos sobre la producci&oacute;n de huevos de aced&iacute;a, con los m&iacute;nimos invernales indicando el comienzo de la puesta, aunque las variaciones dentro de la estaci&oacute;n de puesta no pareci&oacute; afectar a la producci&oacute;n diaria de huevos. Este trabajo fue apoyado por el proyecto Interreg 0251_ECOAQUA_5_E , financiado por el FEDER (Fondo Europeo de Desarrollo Regional).www.juntadeandalucia.es/agriculturaypesca/ifapa/ecoaqua.</p

Transcriptomics and the mediterranean diet: A systematic review

The Mediterranean diet has been proven to be highly effective in the prevention of cardiovascular diseases and cancer and in decreasing overall mortality. Nowadays, transcriptomics is gaining particular relevance due to the existence of non-coding RNAs capable of regulating many biological processes. The present work describes a systematic review of current evidence supporting the influence of the Mediterranean diet on transcriptomes of different tissues in various experimental models. While information on regulatory RNA is very limited, they seem to contribute to the effect. Special attention has been given to the oily matrix of virgin olive oil. In this regard, monounsaturated fatty acid-rich diets prevented the expression of inflammatory genes in different tissues, an action also observed after the administration of olive oil phenolic compounds. Among these, tyrosol, hydroxytyrosol, and secoiridoids have been found to be particularly effective in cell cycle expression. Less explored terpenes, such as oleanolic acid, are important modulators of circadian clock genes. The wide range of studied tissues and organisms indicate that response to these compounds is universal and poses an important level of complexity considering the different genes expressed in each tissue and the number of different tissues in an organism

ICA UNICA: épocas para el control de malezas

La papa forma parte de la veinte especies que alimentan el 90% de la población mundial v ocupa el cuarto lugar después del trigo. del arroz y del maíz. En los últimos años se han incrementado las hectáreas sembradas en más de 17 millones en el mundo. de las cuales el 5% corresponde a Sudamérica. EI cultivo de la papa se destaca en la actividad agropecuaria nacional por los aspectos relacionados en forma directa con su explotación por la variada cantidad de actividades que se generan en torno a este producto

Nonlocal Equation of State in Anisotropic Static Fluid Spheres in General Relativity

We show that it is possible to obtain credible static anisotropic spherically symmetric matter configurations starting from known density profiles and satisfying a nonlocal equation of state. These particular types of equation of state describe, at a given point, the components of the corresponding energy-momentum tensor not only as a function at that point, but as a functional throughout the enclosed configuration. To establish the physical plausibility of the proposed family of solutions satisfying nonlocal equation of state, we study the constraints imposed by the junction and energy conditions on these bounded matter distributions. We also show that it is possible to obtain physically plausible static anisotropic spherically symmetric matter configurations, having nonlocal equations of state\textit{,}concerning the particular cases where the radial pressure vanishes and, other where the tangential pressures vanishes. The later very particular type of relativistic sphere with vanishing tangential stresses is inspired by some of the models proposed to describe extremely magnetized neutron stars (magnetars) during the transverse quantum collapse.Comment: 21 pages, 1 figure, minor changes in the text, references added, two new solutions studie