72 research outputs found
Comportamiento acústico y térmico de materiales basados en fibras naturales para la eficiencia energética en edificación
Insulation materials are the first step towards energy efficiency and reducing energy consumption on buildings. The goal of this research is to design acoustic and thermal insulation materials which fulfill several criteria, low cost, biodegradable and recyclable, such as natural fiber-based materials. Thermal and acoustic properties of several nonwovens developed from fique, coir and recycled cotton from denim were characterized. Possible uses are proposed for the manufactured materials bases on the requirements of the Spanish Building Code.El uso de materiales aislantes es el primer paso para reducir la energía requerida para mantener una buena temperatura en el interior de un edificio y alcanzar la eficiencia energética. El objetivo es diseñar materiales para aislamiento acústico y térmico baratos, biodegradables y reciclables como los basados en fibras naturales. En este trabajo se estudian las propiedades térmicas y acústicas de no tejidos basados en fibras de fique, de coco y de algodón reciclado a partir de tejido denim. Se proponen posibles usos para los materiales fabricados basados en las exigencias del Código Técnico
Long-term hippocampal interneuronopathy drives sex-dimorphic spatial memory impairment induced by prenatal THC exposure
Prenatal exposure to Delta(9)-tetrahydrocannabinol (THC), the most prominent active constituent of cannabis, alters neurodevelopmental plasticity with a long-term functional impact on adult offspring. Specifically, THC affects the development of pyramidal neurons and GABAergic interneurons via cannabinoid CB1 receptors (CB1R). However, the particular contribution of these two neuronal lineages to the behavioral alterations and functional deficits induced by THC is still unclear. Here, by using conditional CB1R knockout mice, we investigated the neurodevelopmental consequences of prenatal THC exposure in adulthood, as well as their potential sex differences. Adult mice that had been exposed to THC during embryonic development showed altered hippocampal oscillations, brain hyperexcitability, and spatial memory impairment. Remarkably, we found a clear sexual dimorphism in these effects, with males being selectively affected. At the neuronal level, we found a striking interneuronopathy of CCK-containing interneurons in the hippocampus, which was restricted to male progeny. This THC-induced CCK-interneuron reduction was not evident in mice lacking CB1R selectively in GABAergic interneurons, thus pointing to a cell-autonomous THC action. In vivo electrophysiological recordings of hippocampal LFPs revealed alterations in hippocampal oscillations confined to the stratum pyramidale of CA1 in male offspring. In addition, sharp-wave ripples, a major high-frequency oscillation crucial for learning and memory consolidation, were also altered, pointing to aberrant circuitries caused by persistent reduction of CCK+ basket cells. Taken together, these findings provide a mechanistic explanation for the long-term interneuronopathy responsible for the sex-dimorphic cognitive impairment induced by prenatal THC.The authors declare no conflict of interest. This work was supported by grants PI18-00941 to IG-R cofinanced by the European Development Regional Fund "A way to achieve Europe"; RTI2018-095311-B-100 to MG, BFU2015-66887-R to LM-P, and 2017-SGR-138 to MP from the Generalitat de Catalunya. DG-R was supported by Fundacion Tatiana Perez de Guzman; DG-D was supported by a PhD fellowship from the Spanish Ministry of Economy and Competitiveness (BES-2013-064171). JP-L and JA were supported by FPI and FPU program fellowships, respectively (Ministerio de Educacion, Cultura y Deporte) and S. S-S. was supported by Fondo Social Europeo-YEI (CT101/18-CT102/18PEJD-2018-PRE/BMD-7933). CM is recipient of a Marie Curie program fellowship (747487)
Long-term hippocampal interneuronopathy drives sex-dimorphic spatial memory impairment induced by prenatal THC exposure
Prenatal exposure to Delta(9)-tetrahydrocannabinol (THC), the most prominent active constituent of cannabis, alters neurodevelopmental plasticity with a long-term functional impact on adult offspring. Specifically, THC affects the development of pyramidal neurons and GABAergic interneurons via cannabinoid CB1 receptors (CB1R). However, the particular contribution of these two neuronal lineages to the behavioral alterations and functional deficits induced by THC is still unclear. Here, by using conditional CB1R knockout mice, we investigated the neurodevelopmental consequences of prenatal THC exposure in adulthood, as well as their potential sex differences. Adult mice that had been exposed to THC during embryonic development showed altered hippocampal oscillations, brain hyperexcitability, and spatial memory impairment. Remarkably, we found a clear sexual dimorphism in these effects, with males being selectively affected. At the neuronal level, we found a striking interneuronopathy of CCK-containing interneurons in the hippocampus, which was restricted to male progeny. This THC-induced CCK-interneuron reduction was not evident in mice lacking CB1R selectively in GABAergic interneurons, thus pointing to a cell-autonomous THC action. In vivo electrophysiological recordings of hippocampal LFPs revealed alterations in hippocampal oscillations confined to the stratum pyramidale of CA1 in male offspring. In addition, sharp-wave ripples, a major high-frequency oscillation crucial for learning and memory consolidation, were also altered, pointing to aberrant circuitries caused by persistent reduction of CCK+ basket cells. Taken together, these findings provide a mechanistic explanation for the long-term interneuronopathy responsible for the sex-dimorphic cognitive impairment induced by prenatal THC.The authors declare no conflict of interest. This work was supported by grants PI18-00941 to IG-R cofinanced by the European Development Regional Fund "A way to achieve Europe"; RTI2018-095311-B-100 to MG, BFU2015-66887-R to LM-P, and 2017-SGR-138 to MP from the Generalitat de Catalunya. DG-R was supported by Fundacion Tatiana Perez de Guzman; DG-D was supported by a PhD fellowship from the Spanish Ministry of Economy and Competitiveness (BES-2013-064171). JP-L and JA were supported by FPI and FPU program fellowships, respectively (Ministerio de Educacion, Cultura y Deporte) and S. S-S. was supported by Fondo Social Europeo-YEI (CT101/18-CT102/18PEJD-2018-PRE/BMD-7933). CM is recipient of a Marie Curie program fellowship (747487)
An update to Hippocampome.org by integrating single-cell phenotypes with circuit function in vivo
Understanding brain operation demands linking basic behavioral traits to cell-type specific dynamics of different brain-wide subcircuits. This requires a system to classify the basic operational modes of neurons and circuits. Single-cell phenotyping of firing behavior during ongoing oscillations in vivo has provided a large body of evidence on entorhinal-hippocampal function, but data are dispersed and diverse. Here, we mined literature to search for information regarding the phase-timing dynamics of over 100 hippocampal/entorhinal neuron types defined in . We identified missing and unresolved pieces of knowledge (e.g., the preferred theta phase for a specific neuron type) and complemented the dataset with our own new data. By confronting the effect of brain state and recording methods, we highlight the equivalences and differences across conditions and offer a number of novel observations. We show how a heuristic approach based on oscillatory features of morphologically identified neurons can aid in classifying extracellular recordings of single cells and discuss future opportunities and challenges towards integrating single-cell phenotypes with circuit function.Peer reviewe
Tailoring of magnetocaloric effect in Ni45.5Mn43.0In11.5 metamagnetic shape memory alloy
We investigate the direct and inverse magnetocaloric effect in Ni45.5Mn43.0In11.5 Heusler alloy ribbons comparing the results obtained for the as-quenched sample with the ones after different annealing procedures. An enhancement and shift of the entropy maximum to near room temperature is observed in all annealed samples. A remarkable magnetocaloric effect is observed in samples with short-time treatment (10 minutes) and at the lowest annealing temperature. We show that the suppressing of uncompensated martensitic transition and thermal hysteresis are both influenced by the heat treatment. Also, an improvement on Curie’s temperature is observed and, at low magnetic field, it has been risen up to 310 K. Our results demonstrate that the martensitic transformation is highly sensitive to the applied magnetic field and also to the annealing treatment, which means that the magnetocaloric effect can be tuned showing different behaviors for each sample.Authors are thankful to Spanish MICINN for financial support: MAT2009-13108-C02-01-02 and MAT2010-20798-C05-04. L. Gonzalez also thanks MICINN for a FPI Grant and J. García FICYT for a “Severo Ochoa” Grant
Sublayer- and cell-type-specific neurodegenerative transcriptional trajectories in hippocampal sclerosis
Hippocampal sclerosis, the major neuropathological hallmark of temporal lobe epilepsy, is characterized by different patterns of neuronal loss. The mechanisms of cell-type-specific vulnerability and their progression and histopathological classification remain controversial. Using single-cell electrophysiology in vivo and immediate-early gene expression, we reveal that superficial CA1 pyramidal neurons are overactive in epileptic rodents. Bulk tissue and single-nucleus expression profiling disclose sublayer-specific transcriptomic signatures and robust microglial pro-inflammatory responses. Transcripts regulating neuronal processes such as voltage channels, synaptic signaling, and cell adhesion are deregulated differently by epilepsy across sublayers, whereas neurodegenerative signatures primarily involve superficial cells. Pseudotime analysis of gene expression in single nuclei and in situ validation reveal separated trajectories from health to epilepsy across cell types and identify a subset of superficial cells undergoing a later stage in neurodegeneration. Our findings indicate that sublayer- and cell-type-specific changes associated with selective CA1 neuronal damage contribute to progression of hippocampal sclerosis.This work was supported by grants from MICINN (RTI2018-098581-B-I00 to L.M.P.), Fundación Tatiana Pérez de Guzman el Bueno, and the SynCogDis Network (SAF2014-52624-REDT and SAF2017- 90664-REDT to L.M.P. and A. Bayes). Collaboration between L.M.d.l.P. and Y.H. was supported by Human Frontiers Science Program (HFSP) grant RGP0022/2013. J.P.L.-A. was supported by grants from MICIU co-financed by ERDF (RYC-2015-18056 and RTI2018-102260-B-I00) and Severo Ochoa grant SEV-2017-0723. R.R.-V. and A. Bayes were supported by MINECO BFU2015-69717-P and RTI2018-097037-B-100 and a Marie Curie career integration grant (ref. 304111). A.V.M. was supported by MICINN (SAF2017- 85717-R) and Fundación Alicia Koplowitz. A. Barco was supported by grants SAF2017-87928-R from MICINN co-financed by ERDF and RGP0039/2017 from the Human Frontiers Science Program Organization. The Instituto de Neurociencias is a ‘‘Centre of Excellence Severo Ochoa.’’ D.G.-D. and C.M.N. hold PhD fellowships from MICINN (BES-2013-064171 and BES2016-076281, respectively).Peer reviewe
Inverse Current Source Density Method in Two Dimensions: Inferring Neural Activation from Multielectrode Recordings
The recent development of large multielectrode recording arrays has made it affordable for an increasing number of laboratories to record from multiple brain regions simultaneously. The development of analytical tools for array data, however, lags behind these technological advances in hardware. In this paper, we present a method based on forward modeling for estimating current source density from electrophysiological signals recorded on a two-dimensional grid using multi-electrode rectangular arrays. This new method, which we call two-dimensional inverse Current Source Density (iCSD 2D), is based upon and extends our previous one- and three-dimensional techniques. We test several variants of our method, both on surrogate data generated from a collection of Gaussian sources, and on model data from a population of layer 5 neocortical pyramidal neurons. We also apply the method to experimental data from the rat subiculum. The main advantages of the proposed method are the explicit specification of its assumptions, the possibility to include system-specific information as it becomes available, the ability to estimate CSD at the grid boundaries, and lower reconstruction errors when compared to the traditional approach. These features make iCSD 2D a substantial improvement over the approaches used so far and a powerful new tool for the analysis of multielectrode array data. We also provide a free GUI-based MATLAB toolbox to analyze and visualize our test data as well as user datasets
Subjective evaluation in acoustics through listening tests: difference testing in sound insulation, room acoustics and soundscapes
En las diferentes áreas de la acústica se utilizan a día de hoy diversas métricas e indicadores para caracterizar el comportamiento sonoro de los entornos y su impacto sobre la vida de los seres humanos. Aunque los parámetros utilizados en las diversas áreas han sido descritos a lo largo de las décadas tratando de tener en cuenta la percepción humana del sonido, en los últimos años se está produciendo de manera más evidente un cambio paradigmático centrado en desarrollar mejores parámetros, así como en mejorar los parámetros ya existentes, con el fin de asegurar que estos sean todo lo representativos posible de la percepción subjetiva del sonido. Para ello, se están llevado a cabo pruebas subjetivas en las que se consulta a muestras de la población acerca de su percepción subjetiva de diferentes estímulos sonoros. La finalidad de estas pruebas, que se pueden llevar a cabo en entornos reales (encuestas in situ) o en laboratorio (listening tests), es conocer, a partir de sus respuestas, cómo se comporta el sistema auditivo humano y así valorar la adecuación de los indicadores actuales y realizar mejoras en caso necesario. El principal obstáculo para que estas pruebas permitan alcanzar de manera satisfactoria este fin es la alta heterogeneidad de metodologías utilizadas para realizarlas, lo que lleva a que diversas investigaciones estén sujetas a diferentes fuentes de sesgo y métodos de análisis, dificultando la comparación de sus resultados. Este hecho resta relevancia a sus conclusiones y dificulta la realización de análisis conjuntos en base a los resultados de varias pruebas, lo que permitiría obtener mejoras de los indicadores representativas de todas las situaciones acústicas valoradas por todas ellas. Esta tesis doctoral tiene como principal objetivo la realización de contribuciones metodológicas que faciliten la definición de metodologías homogéneas, precisas y de mínimo sesgo, con herramientas de análisis altamente informativas para la realización de pruebas perceptuales en entornos de laboratorio (listening tests) en las áreas de aislamiento acústico, acústica de recintos y paisaje sonoro. Estas contribuciones metodológicas se identificaron tras el estudio pormenorizado de los tipos de listening tests utilizados a día de hoy en cada una de las áreas, evaluando sus ventajas, inconvenientes y principales fuentes de sesgo, así como estudiando en profundidad el estado del arte en otras áreas de la evaluación sensorial donde las pruebas perceptuales tienen un bagaje mayor y donde la calidad de las diferentes metodologías se encuentra, a día de hoy, más minuciosamente estudiada. Así, se realizaron contribuciones metodológicas específicas para el diseño, realización y análisis de listening tests especialmente apropiadas para los fines más relevantes en cada una de las áreas. Estas contribuciones, basadas en métodos comparativos de testeo de las diferencias (difference testing), no solo se centraron en una homogeneización metodológica en cada una de las tres áreas, sino también en una homogeneización transversal, que pueda facilitar la descripción de un marco metodológico común basado en difference testing que permita la utilización de métodos de análisis altamente informativos y apenas utilizados a día de hoy en acústica como son los modelos Thurstonianos. Estas contribuciones fueron evaluadas mediante la realización de tres listening tests, uno en cada una de las áreas de estudio. Así, en el área de aislamiento acústico, se llevó a cabo un listening test siguiendo un protocolo 2-AC atributivo de testeo de las diferencias con una amplia muestra de 119 participantes, con la finalidad de evaluar la molestia percibida por estos ante diferentes tipos de ruido urbano bajo varias condiciones de aislamiento acústico de fachadas. Los resultados de esta prueba permitieron no sólo evaluar la representatividad de las magnitudes globales de aislamiento acústico (SNQs) actuales, sino también proponer una mejora de éstas mediante la aplicación de un algoritmo de optimización automático basado en Programación Cuadrática Secuencial (SQP), utilizando como parámetros de entrada los resultados de la prueba analizados mediante modelos Thurstonianos. La aplicación del algoritmo de optimización permitió obtener un espectro de referencia para el cálculo de un SNQ más representativo de sonidos urbanos (Lopt urban) que cualquiera de los existentes a día de hoy. Por otro lado, en el área de acústica de recintos se llevó a cabo un listening test con la finalidad de evaluar el poder operacional de siete protocolos de testeo de las diferencias generales, algunos de ellos comúnmente utilizados para realizar listening tests en este área y otros potencialmente aplicables a acústica pero, hasta la fecha, habitualmente aplicados en otros campos de la evaluación sensorial. Este listening test, en el que una amplia muestra de 134 participantes evaluó mediante estos protocolos la diferencia perceptual entre diversas auralizaciones confundibles de un mismo recinto, permitió la comparación del poder operacional de los diversos protocolos mediante el uso de modelos Thurstonianos. Esta comparación permitió determinar y proponer como recomendado aquel protocolo para el que se obtuvo un mejor poder operacional y una menor influencia de las diversas fuentes de sesgo. Por último, en el área de paisaje sonoro, se desarrollaron dos tareas noveles de listening test también basadas en testeo de las diferencias para la determinación de la similitud perceptual entre distintos paisajes sonoros. La utilidad de estas tareas se comprobó mediante la realización de un listening test sobre una pequeña población de 17 participantes que comparó paisajes sonoros urbanos con diferentes características arquitectónicas. Estos paisajes sonoros también fueron clasificados objetivamente mediante algoritmos de clasificación automáticos (K-means y clasificación jerárquica) en base a percentiles de los indicadores psicoacústicos Loudness (N5, N50 y N95), Sharpness (S5, S50 y S95 ), Roughness (R10, R50 y R95) y Fluctuation Strength (FS10, FS50 y FS95). Posteriormente, los resultados de esta clasificación se compararon con los obtenidos mediante el listening test, encontrándose una buena correlación, en la mayoría de las ocasiones, y poniéndose de relieve no solo la aplicabilidad de las tareas de listening test desarrolladas sino también la utilidad de los indicadores psicoacústicos para valorar la similitud perceptual de paisajes sonoros urbanos con características arquitectónicas similares. ----------ABSTRACT---------- In the different areas of acoustics, various measures and indicators are used nowadays to assess the acoustic behaviour of environments and their impact on the lifes of human beings. Although the metrics used in the different areas have been described over the decades attempting to take into account the human perception of sound, in recent years a paradigm shift is becoming more evident, focusing on developing better parameters, as well as improving existing ones, in order to ensure that they are as representative as possible of the subjective perception of sound. To this end, subjective tests are being carried out in which samples of the population are consulted about their subjective perception of different sound stimuli. The purpose of these tests, which can be carried out in real environments (in situ surveys) or in a laboratory (listening tests), is to find out from their responses how the human auditory system behaves in order to assess the adequacy of current indicators and to make improvements when necessary. The main obstacle for these tests to satisfactorily achieve this goal is the high heterogeneity of methodologies used to perform them, which leads to different investigations being subject to different sources of bias and analysis methods, hindering the comparison of their results. This fact reduces the relevance of their conclusions and makes it difficult to carry out meta-analyses based on the results of different tests, which would enable to obtain improvements in the indicators, making them representative of all the acoustic situations assessed by the different perceptual tests. The main objective of this thesis is to provide methodological contributions that facilitate the definition of homogeneous, accurate and minimally biased methodologies with highly informative analysis tools for the performance of perceptual tests in laboratory environments (listening tests) in the areas of sound insulation, room acoustics and soundscapes. These methodological contributions were identified after a detailed study of the types of listening tests currently employed in each of these areas, evaluating their advantages, disadvantages and main sources of bias, as well as studying in depth the state of the art in other areas of sensory evaluation where these types of tests have a greater background and where the quality of the different methodologies has, to date, been more thoroughly studied. Accordingly, specific methodological contributions were described for the design, performance and analysis of listening tests particularly appropriate for the most relevant purposes in each of the areas. These contributions, based on comparative difference testing methods, not only focused on a methodological homogenization in each of the three areas, but also on a transversal homogenization, which could facilitate the description of a common methodological framework based on difference testing that would allow the use of highly informative analysis methods barely employed so far in acoustics such as the Thurstonian models. These contributions were evaluated through the performance of three listening tests, one in each of the study areas. In the area of sound insulation, a listening test following an attribute-related 2-AC difference testing protocol was carried out on a large sample of 119 participants with the aim of assessing the annoyance perceived by them in the presence of different types of urban noise under different façade sound insulation conditions. The results of this test allowed not only to evaluate the representativeness of the current Single-Number Quantities of sound insulation (SNQs), but also to propose an improvement of these through the application of an automatic optimization algorithm based on Sequential Quadratic Programming (SQP), using as input parameters the results of the test analyzed by means of Thurstonian models. The application of the optimization algorithm enabled to obtain a reference spectrum for the calculation of a more representative SNQ of urban sounds (Lopt urban) than any of the existing ones. On the other hand, in the area of room acoustics, a listening test was carried out in order to evaluate the operational power of seven overall difference testing protocols, some of them commonly used for listening tests in this area and others potentially applicable to room acoustics but, to date, usually applied in other fields of sensory evaluation. This listening test, in which a large sample of 134 participants evaluated, using these protocols, the perceptual difference between different confusable auralizations of the same room, allowed a comparison of the operational power of the various protocols using Thurstonian models. This comparison allowed to identify and recommend the protocol with the best operational power and the least influence of the various sources of bias. Finally, in the area of soundscapes, two novel listening test tasks were developed, also based on difference testing, for the determination of perceptual similarity between different soundscapes. The usefulness of these tasks was tested by means of a listening test conducted on a small population of 17 participants who compared urban soundscapes with different architectural features. These soundscapes were also objectively classified using automatic clustering algorithms (i.e., K-means and hierarchical clustering) based on percentiles of the psychoacoustic indicators Loudness (N5, N50 and N95), Sharpness (S5, S50 and S95 ), Roughness (R10, R50 and R95) and Fluctuation Strength (FS10, FS50 and FS95). Subsequently, the results of this clustering were compared with those obtained by the listening test, finding a good correlation, in most cases, and highlighting not only the applicability of the listening test tasks developed but also the usefulness of psychoacoustic indicators to assess the perceptual similarity of urban soundscapes with similar architectural characteristics
Subjective and objective acoustic performance ranking of heavy and light weight walls
This study presents a comparison between heavyweight and lightweight walls, in terms of perceived
loudness of pink noise transmitted through 10 different walls. The objective is to investigate whether
the single number descriptor RA,50–5000 adequately reflects the subjective perception of the acoustic performance
of a wall and if the sound reduction index spectral behaviour affects the subjective rating. To
perform the experiment, a Matlab based digital tool was developed and a pairwise comparison listening
test was performed in laboratory conditions with thirty three subjects. The sound samples consisted of
only one stimulus – pink noise-, filtered by the sound reduction index spectrum of 5 heavy weight walls
and 5 corresponding lightweight walls with the same RA,50–5000 but different Rw.
The results were analysed and used to rank the walls from best to worst according to the perceived
loudness of the sound samples. It has been shown that lightweight walls are better ranked than heavy
walls, not only when compared to those with the same RA,50–5000, but in some cases also when the
RA,50–5000 of the heavy wall is higher than the RA,50–5000 of the lightweight one. Furthermore, the ranking
obtained from the listening test results matches very well with the ranking made according to
Rw + C, RA,100–3150.publisher: Elsevier
articletitle: Subjective and objective acoustic performance ranking of heavy and light weight walls
journaltitle: Applied Acoustics
articlelink: http://dx.doi.org/10.1016/j.apacoust.2016.03.008
content_type: article
copyright: © 2016 Elsevier Ltd. All rights reserved.status: publishe
Influencia del estímulo musical sobre la percepción de la claridad C80
La Claridad C80 ha sido ampliamente utilizada para la determinación de la claridad musical de recintos desde su definición en 1974. A pesar de lo extendido de su uso, no se ha investigado en profundidad que este índice tenga una buena correlación con la percepción subjetiva de la claridad para cualquier entorno acústico. En esta comunicación se presentan los resultados obtenidos del análisis de la correlación existente entre el C80 y la percepción subjetiva para distintos estímulos y recintos. La información sobre la percepción subjetiva de la claridad se ha obtenido mediante la realización de un test psicoacústico a un conjunto de 18 participantes. Se utilizaron cinco estímulos musicales y 18 respuestas al impulso obtenidas mediante la simulación de tres recintos acústicos. Los resultados obtenidos muestran que el estímulo musical constituye un factor significativo sobre la percepción que los oyentes tienen sobre la claridad de un recinto. De este modo se concluye que el C80 presenta posibilidades de mejora para mejorar su relación con la percepción subjetiva. ----------ABSTRACT---------- The acoustic parameter C80 has been widely used in the determination of the musical clarity of a venue since its definition in 1974. Despite its extended use, an exhaustive research has not been conducted which can conclude whether this index has a good correlation with the subjective perception of the musical clarity for certain kinds of music styles. This present communication shows the analysis of the correlation between the C80 and the subjective perception of the clarity for various musical stimuli and various venues. The information about the subjective perception of the clarity has been obtained from a listening test carried out by a set of 18 participants. The stimuli used were a total of five musical pieces and eighteen impulse responses obtained through the simulation of three acoustic halls. The obtained results show that the musical stimuli were a significant factor in the perception of the clarity of the hall. Therefore it can be concluded that the C80 presents room for improvement in order to enhance its correlation with the subjective perception
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