Desarrollo de aprendizajes activos en primeros cursos universitarios: Workshop cónica.

Como ya es conocido, los profesores de Matemáticas utilizamos los ejemplos como recursos de aprendizaje para enseñar algún contenido matemático concreto, de modo que las generalizaciones y abstracciones sean más fácilmente entendidas por los alumnos, pasando de lo concreto a lo abstracto, como otra forma de enseñar y practicar en Matemáticas. Esta metodología de trabajo se ve potenciada por el uso de dispositivos móviles llamados mobile-learning (m-learning) o educación móvil (educación-m), en español. Siguiendo esta línea de trabajo, se ha realizado el workshop de cónicas que se presenta en este artículo, empleando estas nuevas tecnologías (TIC) y con el objetivo de desarrollar aprendizajes activos en Geometría a través de la resolución de problemas en los primeros cursos de Grado en las ingenierías. ABSTRACT: As it is already known, math teachers, use examples as learning resources, to teach some specific math contents, so that generalizations and abstractions are more easily understood by students, from concrete to abstract, as another way of Mathematics teaching and training. This methodology is enhanced by the use of mobile devices, called mobile-learning (m-learning) o “educación móvil” (educación-m), in Spanish. Following this strategy, the workshop of conic sections shown in this paper has been carried out, using these new technologies (ICT) and in order to develop active learning in Geometry through problem-solving at the first years of engineering degrees

The landscape as a palliative resource for the conditions derived from home confinement by COVID-19.

During the weeks of confinement in Spain due to the COVID-19 pandemic, the population that was locked up stopped feeling, living and shaping their daily landscape. This abnormal situation generated lack of well-being and discomfort in frequent cases and even states of stress, mental fatigue, etc. The hypothesis put forward is that the two-level connection with the landscape that was left outside the walls of the houses helped to alleviate the deficits in physical and mental well-being; either through contact with the basic biophysical elements: direct light, air, vegetation, etc., (through different kinds of openings and windows on the façade), or through the observation of the extrinsic landscape through those same openings.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Apparent diffusion coefficient in the analysis of prostate cancer

The multiparametric magnetic resonance imaging (MPMRI) approach, has allowed the diagnostic performance in the detection and characterization of prostate cancer (PCa). Diffusion-weighted imaging (DWI), is an important technique in the MPMRI, that provides qualitative and quantitative biological information regarding water diffusivity in a non-invasive manner. The apparent diffusion coefficient (ADC) measures water mobility and can be quantified from the signal intensity loss between two or more b-values. Different studies reported that ADC values are directly associated with microvessel density and cellularity. One of the main aspects that is in discussion is the b-values that must be used in the DWI sequence in order to compute ADC.info:eu-repo/semantics/publishedVersio

A community approach to the Neotropical ticks-hosts interactions

The relationships between ticks and hosts are relevant to capture the ecological background driving the evolution of these parasites. We used a set of 4,764 records of ticks of the genera Amblyomma, Ixodes, and Haemaphysalis and their hosts in the Neotropics to approach the tick-host relationships using a network-based construct. The network identified 9 clusters of interacting hosts and ticks partially connected by 22 tick species that switch their host range according to their life cycle stage. These links among clusters do not confer an extra resilience to the network following removal of hosts and subsequent cascade extinctions of ticks: the robustness of the network slightly changed when these inter-clusters links are considered. Phylogenetic clustering of ticks to hosts at cluster level was not significant (p > 0.15) but if examined individually 63 tick species/stages (59%) displayed such clustering, suggesting that their hosts have a related phylogenetic background. We interpreted these results under an ecological perspective in which ticks could track its environmental niche associating to vertebrates that would maximize tick survival under the range of abiotic traits. We encourage these integrated analyses to capture the patterns of circulation of tick-transmitted pathogens, a topic still unaddressed in the Neotropical region.EEA RafaelaFil: Estrada-Peña, Agustin. Universidad de Zaragoza. Facultad de Veterinaria. Departamento de Patología Animal; EspañaFil: Nava, Santiago. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Tarragona, Evelina Luisa. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: de la Fuente, José. SaBio, Instituto de Investigación en Recursos Cinegéticos (IREC-CSIC-UCLM-JCCM); España. Oklahoma State University. Center for Veterinary Health Sciences. Department of Veterinary Pathobiology; Estados UnidosFil: Guglielmone, Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Regional Agropecuaria Rafaela; Argentin

Noise analysis in distributed amplifiers with feedback-active load

This paper presents the noise analysis of amplifiers when the input line termination is implemented via an active load. The noise figure (NF) of distributed amplifiers is analysed to determine the effect of the gate and drain terminations. The noise of a transistor configured as a one-port device has been analysed and a lower noise temperature has been achieved as compared with a conventional resistor. In order to improve the noise performance of the overall amplifier, a parallel feedback has been added to the active load, and its effects are analysed in terms of noise. A distributed amplifier has been designed as a test vehicle of the analysis and characterised with a resistor as input line termination and with an active load to demonstrate the improvement in NF at frequencies below 2 GHz. The resulting amplifier exhibits 10.9 dB of small signal gain from 1 to 5 GHz, with a reduction of 0.6 dB in NF below 2 GHz when the input line termination is replaced by an active load.This work was supported by the Ministerio de Economía y Competitividad from Spain under the CONSOLIDER-INGENIO 2010 program CSD2010-00064 reference, and the research program FPI BES-2011-046199

Cryogenic performance of a 3-14 GHz bipolar SiGe low-noise amplifier

The performance of silicon-germanium (SiGe) transistors under cryogenic operation is analysed. The design and characterization of a 3–14 GHz low-noise amplifier (LNA) using SiGe transistors at 300 K and at 13 K are presented. A three stage amplifier is implemented with bipolar transistors model BFU910F from NXP commercially available with a plastic package. The amplifier exhibits 36.8 dB average gain with average noise temperature of 103 K and 42 mW DC power consumption at 300 K ambient temperature. Whereas cooled down to 13 K ambient temperature, it provides 32.4 dB average gain, 11.4 K average noise temperature with a minimum of 7.2 K at 3.5 GHz and a DC power dissipation of 5.8 mW. The presented LNA demonstrates an outstanding performance at cryogenic temperature for a commercial plastic packaged transistor.The authors would like to thank the Spanish Ministry of Economy, Industry and Competitiveness for the financial support provided under the grant ESP2015-70646-C2-2-R

¿Cómo afectó la crisis económica de 2008 a los temas de investigación de los bancos centrales? El caso de los asociados y colaboradores del CEMLA

Central banks play a fundamental role in a country"s monetary policy. This study has a twofold objective: a) to analyse the contribution to academic research made by the associates and collaborating members of the Center for Latin American Monetary Studies (CEMLA) and b) to analyse the evolution of research topics in the economic literature over the without economic crisis and with crisis. Eighteen banks were subjected to bibliometric analysis covering the period 2000-2019. The results show that, although the number of publications is higher for the collaborating members, the growth rate over time is higher in the associates. Associates collaborate less with other institutions in the crisis period than collaborating members. The evolution of topics reveals important differences between the two groups.Los bancos centrales juegan un papel fundamental en la política monetaria de un país. Este estudio tiene un doble objetivo: a) analizar la contribución a la investigación académica realizada por los miembros asociados y colaboradores del Centro de Estudios Monetarios Latinoamericanos (CEMLA) y b) analizar la evolución de los temas de investigación en la literatura económica a lo largo del Períodos de precrisis y crisis. Dieciocho bancos fueron sometidos a análisis bibliométrico cubriendo el período 2000-2019. Los resultados muestran que, aunque el número de publicaciones es mayor para los miembros colaboradores, la tasa de crecimiento en el tiempo es mayor en los asociados. Los asociados colaboran menos con otras instituciones en periodo de crisis que los miembros colaboradores. La evolución de los temas revela diferencias importantes entre los dos grupos

Calibration of a polarimetric microwave radiometer using a double directional coupler

This paper presents a built-in calibration procedure of a 10-to-20 GHz polarimeter aimed at measuring the I, Q, U Stokes parameters of cosmic microwave background (CMB) radiation. A full-band square waveguide double directional coupler, mounted in the antenna-feed system, is used to inject differently polarized reference waves. A brief description of the polarimetric microwave radiometer and the system calibration injector is also reported. A fully polarimetric calibration is also possible using the designed double directional coupler, although the presented calibration method in this paper is proposed to obtain three of the four Stokes parameters with the introduced microwave receiver, since V parameter is expected to be zero for the CMB radiation. Experimental results are presented for linearly polarized input waves in order to validate the built-in calibration system.The authors would like to thank The Spanish Ministry of Science and Innovation for financial support provided through the grants ESP2015-70646-C2-2-R, ESP2017-83921-C2-2-R and PID2019-110610RB-C2

Double square waveguide directional coupler for polarimeter calibration

A novel full-band square waveguide coupler design based on directional couplers which couple the TE10 and TE01 orthogonal modes in a square waveguide is presented. This waveguide coupler is aimed at the calibration of polarization receivers. This is composed of a pair of rectangular waveguide directional couplers, which are rotated 90° between them and both are coupled to the main square waveguide through each one of the square section walls. The coupler covers the full frequency band from 10 to 18.9 GHz. It has inherent low cross-polarization, which allows obtaining any known elliptically polarized wave at a square waveguide when a signal is applied to the couplers. The fabricated prototype of this coupler exhibits 31 dB of coupling, with flatness of ±3.8 dB and excellent cross polarization better than 50 dB over the whole band.This work was supported by the Spanish Ministry of Economy and Competitiveness under Grant ESP2015-70646-C2-2-R