On the interplay among ambient temperature basal metabolic rate and body mass

One of the most generalized conclusions arising from studies analyzing the ecological variation of energy metabolism in endotherms is the apparent negative correlation between ambient temperature and mass-independent basal metabolic rate (residual BMR). As a consequence, ambient temperature has been considered the most important external factor driving the evolution of residual BMR. It is not clear, however, whether this relationship is size dependent, and artifacts such as the biased sampling of body masses in physiological data sets could cause us to overstate the ubiquity of the relationship. Accordingly, here we used published data on body mass (mb), BMR, and annual mean temperature (Tmean) for 458 mammal species (and/or subspecies) to examine the size dependence of the relationship between temperature and BMR. We found a significant interaction between mb and Tmean as predictors of residual BMR, such that the effect of Tmean on residual BMR decreases as a function of mb. In line with this, the amount of residual variance in BMR explained by Tmean decreased with increasing mb, from 20%–30% at body sizes of less than 100 g to almost 0 at body sizes greater than 1,000 g. These data suggest that our current understanding of the importance of broad-scale variation in ambient temperature as a driver of metabolic evolution in endotherms probably is affected by the large number of small species in both nature and physiological data sets

Developing a Simulation Model for Autonomous Driving Education in the Robobo SmartCity Framework

Abstract: This paper focuses on long-term education in Artificial Intelligence (AI) applied to robotics. Specifically, it presents the Robobo SmartCity educational framework. It is based on two main elements: the smartphone-based robot Robobo and a real model of a smart city. We describe the development of a simulation model of Robobo SmartCity in the CoppeliaSim 3D simulator, implementing both the real mock-up and the model of Robobo. In addition, a set of Python libraries that allow teachers and students to use state-of-the-art algorithms in their education projects is described too.Ministerio de Ciencia, Innovación y Universidades of Spain/FEDER; t RTI2018-101114-B-I00 Erasmus+ Programme of the European Union; 2019-1-ES01-KA201-065742, Centro de Investigación de Galicia “CITIC”; ED431G 2019/01

A Novel Hybrid Approach to Improve Performance on Frequency Division Duplex Systems with Linear Precoding

The final publication is available http://dx.doi.org/DOI: 10.1007/978-3-642-13803-4_31[Abstrtact] Linear precoding is an attractive technique to combat interference in multiple-input multiple-output systems because it reduces costs and power consumption in the receiver equipment. Most of the frequency division duplex systems with linear precoding acquire the channel state information at the receiver by using supervised algorithms. Such algorithms make use of pilot symbols periodically sent by the transmitter. In a later step, the channel state information is sent to the transmitter side through a limited feedback channel. In order to reduce the overhead inherent to the periodical transmission of training data, we propose to acquire the channel state information by combining supervised and unsupervised algorithms, leading to a hybrid and more efficient approach. Simulation results show that the performance achieved with the proposed scheme is clearly better than that with standard algorithms.Consellería de Economía e Industria; 09TIC008105PRMinisterio de Educación y Ciencia; TEC2007-68020-C04-0

The effect of food availability on phenotypic plasticity and phenotypic integration in the hylid frog Hypsiboas pulchellus

Background: Changes in food availability usually have an effect on the fitness-related traits of anuran larvae, such as body shape, developmental rate, and body size. Organism: Hypsiboas pulchellus, the South American common tree frog. Aim: Analyse the effect of food availability on larval survival, developmental rate (Gosner stage at the end of the experiment), body size (body mass and total length), body shape (the ratio between body length and total length), and intestine size (gut dry mass and gut length). Methods: We exposed tadpoles of H. pulchellus, all from a single clutch, to different levels of food availability. We set up eight food availability groups of five individuals each. After 39 days, we measured all phenotypic variables studied. We used linear and logistic regressions to analyse the data. We also used a structural equation modelling approach to evaluate the likelihood of ten causal models of covariation among the phenotypic traits (derived from four major biological hypotheses). Results: Three traits were observed to vary positively with food availability: developmental stage, body size, and gut size. Tadpole survival did not change with food availability. The results of structural equation modelling indicate that: (1) food availability acts directly on body size and gut size, (2) body size directly affects developmental rate, and (3) developmental rate acts directly on body shape. Conclusions: The present study supports the idea that anuran larvae are strongly affected by food availability. It also illustrates how structural equation modelling can increase our understanding of phenotypic integration among several traits that respond to changes in food availability

DASBE: Decision-Aided Semi-Blind Equalization for MIMO Systems with Linear Precoding

[Abstract] Multiple-Input Multiple-Output (MIMO) digital communications standards usually acquire Channel State Information (CSI) by means of supervised algorithms, which implies a loss of performance since pilot symbols do not convey information. We propose to obtain this CSI by using the so-called semi-blind techniques, which combine both supervised and unsupervised (blind) methods. The key idea consists in introducing a decision criterion to determine when the channel has suffered a significant change. In such a case, transmission of pilot symbols is required. The use of this criterion also allows us to determine the time instants in which CSI has to be sent to the transmitter from the receiver through a low-cost feedback channel.Ministerio de Ciencia e Innovación; 09TIC008105PRMinisterio de Ciencia e Innovación; TEC2007-68020-C04-01Ministerio de Ciencia e Innovación; CSD2008-0001

EHEA Adaptation of the Exercises of Electricity and Electronics at the University of A Coruña Using a Design Based on Competences

[Summary] The adaptation to the European Higher Education Area (EHEA) of the subject of Electricity and Electronics at the Escuela Técnica Superior de Náutica y Máquinas of the University of A Coruña requires important modifications not only in the methodology to be used but also in the evaluation system. The objective is that the students acquire the specific competences and cross-competences identified for this subject. As a consequence of the process of adaptation to the new EHEA, a great improvement in the quality of the learning process has been obtained. Moreover, the necessity of such improvements have been confirmed by the results presented in this work, based on the teaching experience acquired during the last three years. However, the required improvements in the learning process also demand important changes in the relationship between professor and students.[Resumen] La adaptación al Espacio Europeo de Educación Superior (EEES) de la asignatura de Electricidad y Electrónica impartida en la E.T.S. de Náutica y Máquinas de la Universidade da Coruña requiere importantes modificaciones tanto en la metodología a usar como en el sistema de evaluación. El objetivo es que los estudiantes adquieran las competencias tanto específicas como transversales que han sido identificadas para esta asignatura. Como consecuencia del proceso de adaptación al EEES, se obtiene una importante mejora en la calidad del proceso de aprendizaje. Además, la necesidad de dichas mejoras queda claramente demostrada por los resultados presentados en este trabajo, basados en la experiencia adquirida a lo largo de los últimos tres años. Sin embargo, las mencionadas modificaciones en el proceso de aprendizaje también implican cambios importantes en la relación existente entre el profesor y los alumnos

Mueble in mueble: encuentro entre arquitectura y mobiliario

El presente trabajo versa sobre el estudio del mobiliario fijo en el espacio interior doméstico. Se desarrolló un estudio genealógico, a partir del análisis de la obra de autores que han establecido categorías de esta tipología de mobiliario con relación íntima y comprometida con la estructura espacial arquitectónica. Relevamos y documentamos, a esos efectos, casos de estudio desde a la segunda mitad del s. XX hasta la actualidad, tanto a nivel internacional como nacional. Desde el punto de vista metodológico, incorporamos la consulta a diversos actores nacionales, vinculados al diseño de equipamiento y el proyecto de arquitectura, para así colaborar con la definición del estado del arte del tema de estudio. Además proponemos una taxonomía propia como instrumento de reconocimiento de esta categoría de disposit

Channel estimation techniques for linear precoded systems: Supervised, unsupervised, and hybrid approaches

The final publication is available at Springer via http://dx.doi.org/10.1016/j.sigpro.2011.01.001[Abstract] Linear precoding is an attractive technique to combat interference in multiple-input multiple-output systems because it reduces cost and power consumption at the receiver. Frequency division duplex systems with linear precoding acquire the channel state information at the receiver side by using supervised algorithms. Such methods make use of pilot symbols periodically provided by the transmitter. Next, this channel state information is sent to the transmitter side through a low-cost feedback channel. Thus, the available channel information allows the transmitter to adapt signals to the channel conditions. Given that pilot symbols do not convey user data, they penalize throughput, spectral efficiency, and transmission energy consumption of the system. In this work, we propose to mitigate the aforementioned limitations by combining both supervised and unsupervised algorithms to acquire the channel state information needed by the transmitter. The key idea consists in introducing a simple criterion to determine whether the channel has suffered a significant variation which requires the transmission of pilot symbols. Otherwise, when small fluctuations happen, an unsupervised method is used to track these channel variations instead. This criterion will be evaluated by considering two types of strategies for the design of the linear precoders: Zero-Forcing and Wiener criteria.Consellería de Economía e Industria; 10TIC105003PR.Consellería de Economía e Industria; 09TIC008105PRMinisterio de Ciencia e Innovación; TEC2010-19545-C04-01Ministerio de Ciencia e Innovación; CSD2008-00010

A comparison between Poisson and zero-inflated Poisson regression models with an application to number of black spots in Corriedale sheep

Dark spots in the fleece area are often associated with dark fibres in wool, which limits its competitiveness with other textile fibres. Field data from a sheep experiment in Uruguay revealed an excess number of zeros for dark spots. We compared the performance of four Poisson and zero-inflated Poisson (ZIP) models under four simulation scenarios. All models performed reasonably well under the same scenario for which the data were simulated. The deviance information criterion favoured a Poisson model with residual, while the ZIP model with a residual gave estimates closer to their true values under all simulation scenarios. Both Poisson and ZIP models with an error term at the regression level performed better than their counterparts without such an error. Field data from Corriedale sheep were analysed with Poisson and ZIP models with residuals. Parameter estimates were similar for both models. Although the posterior distribution of the sire variance was skewed due to a small number of rams in the dataset, the median of this variance suggested a scope for genetic selection. The main environmental factor was the age of the sheep at shearing. In summary, age related processes seem to drive the number of dark spots in this breed of sheep