Modulation of the input–output function by GABAA receptor-mediated currents in rat oculomotor nucleus motoneurons

The neuronal input–output function depends on recruitment threshold and gain of the firing frequency–current (f–I) relationship. These two parameters are positively correlated in ocular motoneurons (MNs) recorded in alert preparation and inhibitory inputs could contribute to this correlation. Phasic inhibition mediated by γ-amino butyric acid (GABA) occurs when a high concentration of GABA at the synaptic cleft activates postsynaptic GABAA receptors, allowing neuronal information transfer. In some neuronal populations, low concentrations of GABA activate non-synaptic GABAA receptors and generate a tonic inhibition, which modulates cell excitability. This study determined how ambient GABA concentrations modulate the input–output relationship of rat oculomotor nucleus MNs. Superfusion of brain slices with GABA (100 μm) produced a GABAA receptor-mediated current that reduced the input resistance, increased the recruitment threshold and shifted the f–I relationship rightward without any change in gain. These modifications did not depend on MN size. In absence of exogenous GABA, gabazine (20 μm; antagonist of GABAA receptors) abolished spontaneous inhibitory postsynaptic currents and revealed a tonic current in MNs. Gabazine increased input resistance and decreased recruitment threshold mainly in larger MNs. The f–I relationship shifted to the left, without any change in gain. Gabazine effects were chiefly due to MN tonic inhibition because tonic current amplitude was five-fold greater than phasic. This study demonstrates a tonic inhibition in ocular MNs that modulates cell excitability depending on cell size. We suggest that GABAA tonic inhibition acting concurrently with glutamate receptors activation could reproduce the positive covariation between threshold and gain reported in alert preparation.España, Ministerio de Ciencia y Tecnología BFU 2009-0786

Log-Gaussian Cox Process in Infinite-Dimensional Spaces.

Política de acceso abierto tomada de: https://v2.sherpa.ac.uk/id/publication/7814This paper introduces new results on doubly stochastic Poisson processes, with log-Gaussian Hilbert-valued random intensity (LGHRI), defined from the Ornstein-Uhlenbeck process (O-U process) in Hilbert spaces. Sufficient conditions are derived for the existence of a counting measure on l2, for this type of doubly stochastic Poisson processes. Functional parameter estimation and prediction is achieved from the discrete-time approximation of the Hilbert-valued O-U process by an autoregressive Hilbertian process of order one (ARH(1) process). The results derived are applied to functional prediction of spatiotemporal log-Gaussian Cox processes, and an application to functional disease mapping is developed. The numerical results given, from the conditional simulation study undertaken, are compared to those ones obtained, when the random intensity is assumed to be a spatiotemporal long-range dependence (LRD) log-Gaussian process

Point pattern analysis and classification on compact two-point homogeneous spaces evolving time.

This paper introduces a new modeling framework for the statistical analysis of point patterns on a manifold Md; defined by a connected and compact two-point homogeneous space, including the special case of the sphere. The presented approach is based on temporal Cox processes driven by a L2(Md)-valued log-intensity. Different aggregation schemes on the manifold of the spatiotemporal point-referenced data are implemented in terms of the time-varying discrete Jacobi polynomial transform of the log-risk process. The n-dimensional microscale point pattern evolution in time at different manifold spatial scales is then characterized from such a transform. The simulation study undertaken illustrates the construction of spherical point process models displaying aggregation at low Legendre polynomial transform frequencies (large scale), while regularity is observed at high frequencies (small scale). K-function analysis supports these results under temporal short, intermediate and long range dependence of the log-risk process

Emotional indicators associated with bullying behaviors victimization

Bullying is a specific expression of violence in the school environment that has become more relevant in recent decades, due to the appearance of new forms of violence. Experiences of bullying are associated with several social interactions, behavioral adjustment, emotional problems, mainly internalized problems such as anxiety, anxiety and anger. The purpose of this research was to evaluate the distress, anxiety, the expression of anger and the use of humor and its association with the roles of bullying and victimization in school situations in secondary school students from Mexico City. 406 high school students from Mexico City participated. The Reynolds RBVSS bullying victimization scales, the anger expression inventory and the humor styles questionnaire were applied to them. The data from this research confirm the association of expression of anger, agony, anxiety, and negative use of humor in bullying behaviors, in different ways in both bullies and victims

Esterification of Free Fatty Acids with Glycerol within the Biodiesel Production Framework

Companies in the field of the collection and treatment of waste cooking oils (WCO) for subsequent biodiesel production usually have to cope with high acidity oils, which cannot be directly transformed into fatty acid methyl esters due to soap production. Since glycerine is the main byproduct of biodiesel production, these high acidity oils could be esterified with the glycerine surplus to transform the free fatty acids (FFA) into triglycerides before performing the transesterification. In this work, commercial glycerol was esterified with commercial fatty acids and commercial fatty acid/lampante olive oil mixtures over tin (II) chloride. In the first set of experiments, the esterification of linoleic acid with glycerol excess from 20 to 80% molar over the stoichiometric was performed. From 20% glycerol excess, there was no improvement in FFA reduction. Using 20% glycerol excess, the performance of a biochar obtained from heavy metal-contaminated plant roots was compared to that of SnCl2. Then, the effect of the initial FFA content was assessed using different oleic acid/lampante olive oil mixtures. The results illustrated that glycerolysis was impeded at initial FFA contents lower than 10%. Finally, the glycerolysis of a WCO with 9.94% FFA was assayed, without success

El desarrollo profesional docente derivado de la aplicación de los Proyectos de Trabajo en un aula infantil. Un estudio de caso.

This article presents an ethnographic case-study developed in a preschool classroom. It is a qualitative research that focuses its inquiry into the ability of the Project Approach to contribute to the professional development of the teacher. It examines if the role adopted by the teacher to work with Project Approach facilitates her professional development because it helps her to improve the strategies of attention to the diversity of students and their families. The results show the feelings of uncertainty that the teacher experiences and her difficulties to shift from the traditional methodology to the implementation of the Project Approach. A transit from a management teacher role towards assuming the role of companion in student learning is shown. Finally, we identify some resistance in the school culture that slow down the implementation of this method both in the classroom as its transfer to other educational levels of the center.Este artículo presenta una etnografía desarrollada en un aula infantil a través de un estudio de caso. Se trata de una investigación cualitativa que focaliza su indagación en la capacidad de los Proyectos de Trabajo para contribuir al desarrollo profesional de la docente. Se analiza si el rol que la docente adopta al trabajar por Proyectos de Trabajo facilita su desarrollo profesional en tanto en  cuanto le ayuda a mejorar las estrategias de atención a la diversidad del alumnado y sus familias. Los resultados obtenidos arrojan los sentimientos de incertidumbre que experimenta la docente y sus dificultades para transitar desde la metodología tradicional hasta la implantación de Proyectos de Trabajo. Se muestra el tránsito desde un rol docente directivo hasta la asunción de un papel de acompañante en el aprendizaje del alumnado. Finalmente se identifican algunas resistencias en la cultura del centro que ralentizan la implantación de este método tanto en el aula, como su transferencia al resto de etapas del centro

Neutron radiobiology studies with a pure cold neutron beam

Data on the radiobiological effects of thermal neutrons are usually obtained from irradiations in a mixed field of neutrons of different energies and gamma rays or from conversion of proton data with similar energies to those created in the neutron capture on nitrogen. Experimental data from irradiations in a pure thermal or cold neutron beam can help to find new values for neutron relative biological effectiveness (RBE) factors, which are useful for BNCT (Boron Neutron Capture Therapy) and radiation protection applications. We present a new experimental setup for radiobiological studies at a cold neutron beam at Institut Laue-Langevin, a beam without fast neutron component and almost no gamma ray contribution. After the irradiation, survival assays are performed to obtain the survival curves. Finally, comparing with a reference photon irradiation, the thermal neutron RBE factors can be calculated. The methodology is outlined at the example of A375 melanoma cells for which new radiobiological data were obtained.We acknowledge financial support for this work from the Fundación Científica de la Asociación Española Contra el Cáncer (AECC) under grant PS16163811PORR, Junta de Andalucía (Andalusian Regional Government), under contract P11-FQM-8229, Spanish MINECO and FEDER funds under contract FIS2015-69941-C2-1-P, the grant agreement ILL-UGR and the founders of the University of Granada Chair Neutrons for Medicine: Spanish Fundación ACS and Capitán Antonio. M.P. acknowledges a grant under the program Becas de Iniciación a la Investigación from the Universidad de Granada (Plan Propio de Investigación). The open access fee was covered by FILL2030, a European Union project within the European Commission’s Horizon 2020 Research and Innovation programme under grant agreement N°731096

Manejo de malezas durante y después del establecimiento de maní perenne.

A field study was conducted to evaluate the effect of dimethenamid and imazethapyr followed by clethodim and bromoxynil, on rhizoma perennial peanut (Arachis glabrata) during and after establishment.There were no significant differences in any of the parameters measured among rhizoma perennial peanut accessions as a result of the effects of herbicides. Excellent grass control was obtained when dimethenamid (preemergence) at 1.68 and 3.36 kg ai/ha was applied during the first month as compared with the use of imazethapyr. At 26 weeks after herbicide application (WAH) excellent grass control was obtained in all herbicide treatments. At 52 WAH no differences were observed for broadleaf and grass density. No differences were detected for dry weight of rhizoma perennial peanut and weeds among herbicide treatments at the 26- and 52-WAH harvests. Plots receiving imazethapyr as an early postemergence (POE) had 44 g/m2 more dry weight of weeds than plots with dimethenamid at the lowest rate, but no differences were found among the other treatments. The lowest weight of rhizoma perennial peanut was with imazethapyr early POE, as compared with the three other herbicide treatments. No difference was observed with dimethenamid at either rate. After two years, density of broadleaves was the highest (55.6 plants per square meter) with imazethapyr applied early POE. Density of grasses was lower with imazethapyr preemergence and dimethenamid at a lower rate than with the other two herbicide treatments. Overall, taking into account all rates and dates of herbicide applications, the best weed control was obtained with the early application dates. Se estableció un experimento de campo para evaluar el efecto de dimethenamid e imazethapyr seguido de clethodim y bromoxynil en maní perenne (Arachis glabrata), en y durante el establecimiento del mismo. No hubo diferencias significativas entre las variedades de maní perenne para el efecto de herbicida en ninguno de los parámetros medidos. Se obtuvo un excelente control de gramíneas con dimethenamid a 1.68 y 3.36 kg ¡a/ha el primer mes después de la aplicación en comparación con la aplicación de imazethapyr. A las 26 semanas después de la aplicación de los herbicidas se obtuvo excelente control de gramíneas con todos los tratamientos de herbicidas. A las 52 semanas después de la aplicación no hubo diferencias en la densidad de malezas de hoja ancha ni de gramíneas en ninguno de los tratamientos de herbicidas. No hubo diferencias en el peso seco del maní ni en el de malezas entre los tratamientos de herbicidas a las 26 y 52 semanas después de la aplicación. El peso seco de las malezas que recibieron imazethapyr postemergente temprano fue 44 g/m2 mayor que el de las malezas que recibieron dimethenamid a la dosis menor, pero no se observó diferencias entre los otros tratamientos. El menor rendimiento del maní perenne se obtuvo con la aplicación de imazethapyr postemergente temprano. Después de dos años de establecido, imazethapyr aplicado postemergente temprano produjo la mayor densidad de malezas de hoja ancha, con 55.6 plantas por metro cuadrado. La densidad de gramíneas fue menor con imazethapyr preemergente y con dimethenamid a la dosis de 1.68 kg ¡a/ha que con los otros dos tratamientos. En general, las aplicaciones de los herbicidas de forma preemergente resultaron en mayor rendimiento del maní perenne.