On the Trail of Spatial Patterns of Genetic Variation

[EN] The accurate determination of the spatial trends on the variability of a species' gene pool is essential to elucidate the underlying demographic-evolutionary events, thus helping to unravel the microevolutionary history of the population under study. Herein we present a new software called GenoCline, mainly addressed to detect genetic clines from allele, haplotype, and genome-wide data. This program package allows identifying the geographic orientation of clinal genetic variation through a system of iterative rotation of a virtual coordinate axis. Besides, GenoCline can perform complementary analyses to explore the potential origin of the genetic clines observed, including spatial autocorrelation, isolation by distance, centroid method, multidimensional scaling and Sammon projection. Among the advantages of this software is the ease in data entry and potential interconnection with other programs. Genetic and geographic data can be entered in spreadsheet table formatting (.xls), whereas genome-wide data can be imported in Eigensoft format. Genetic frequencies can also be exported in a format compatible with other programs dealing with population genetic and evolutionary biology analyses. All illustrations of results are saved in.svg format so that there will be high quality and easily editable vectorial graphs available for the researcher. Being implemented in Java, GenoCline is highly portable, thus working in different operating systems.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature

Sistema de extracción de derivadas en régimen dinámico para dispositivos de RF/microondas

This paper presents a novel measurement system for derivative extraction under dynamic conditions based on the utilization of pulsed signals. This kind of characterization avoids both heating and trapping effects, making possible to realize the extraction process under conditions as close as possible to the device RF behaviour. The system principles and set-up are presented and described in order to provide reliable device modelling. Moreover, results of derivative extraction for a FLL177ME MESFET are presented with the aim of highlighting differences between pulsed and traditional DC characterization

Análisis de la distorsión de intermodulación en amplificadores/mezcladores FET usando estadísticos de orden superior

In this paper, a simplified memoryless FET model is used to relate the output power spectral density function (PSD) to the excitation statistics, when the device is employed either in a small-signal amplifier or gate mixer. General closed form expressions are obtained for narrowband modulated signals (Gaussian or not). Furthermore, simulation and measurement results are presented with the aim of highlighting the differences in IMD behaviour when signals with different statistics are handled, or different working conditions are established

Neolithic expansion and the 17q21.31 inversion in Iberia: an evolutionary approach to H2 haplotype distribution in the Near East and Europe

The chromosomal region 17q21.31 harbors a 900 kb inversion polymorphism named after the microtubule-associated protein tau (MAPT) gene. Since no recombination occurs, two haplotypes are recognized: a directly oriented variant (H1) and an inverted variant (H2). The H2 haplotype features a distribution pattern with high frequencies in the Near East and Europe, medium levels in South Asia and North Africa, and low levels elsewhere. Studies of this genomic region are relevant owing to its likely association with numerous neurodegenerative diseases. However, the causes underlying the geographic distribution of the haplotype frequencies remain a bone of contention among researchers. With this work, we have intended to outline a plausible hypothesis on the origin of the high European H2 frequencies. To that end, we have analyzed an extensive population database (including three new Iberian populations) to explore potential clinal variations of H2 frequencies. We found a sigmoidal frequency cline with an upward trend from South Asia to Europe. The maximum value was detected in the Basques from Gipuzkoa province (0.494) with the curve’s inflection point in the Near East. From our results, we suggest that the most likely scenario for high H2 frequencies in Europe would be a founding event in the Near East during the late Paleolithic or early Neolithic. Subsequently, such H2 overrepresentation would have reached Europe with the arrival of the first Neolithic farmers. The current frequencies and geographic distribution of the 17q21.31 inversion suggest that the founding events mainly affected the H2D subhaplotype.This study was funded by the Basque Government (Grant for consolidated research groups, IT-833-13, and SAIOTEK Program, S-PE10UN54

Diseño de un amplificador de alta eficiencia clase-E @ 2GHz

Class-E power amplifiers have 100% theoretical efficiency, due to switched-mode operation. This concept has traditionally been applied to VHF and UHF frequency ranges. In this paper we propose its application to microwave frequencies, designing and characterizing a class-E power amplifier at 2 GHz based on a HEMT solid state device and microstrip technology

Análisis de los factores determinantes del precio del activo vivienda

En el presente trabajo se analiza el comportamiento del mercado del activo-vivienda en el periodo 1978-2000 desde la perspectiva de los factores que influyen directamente en la formación de los precios de dicho activo. Los factores que individualmente mejor explican las variaciones en el precio de la vivienda son (por orden decreciente): el IPC corregido, los costes de la construcción, el PIB per capita, el precio de los alquileres, las VPO terminadas, el volumen de crédito disponible, el tipo de interés de referencia, las viviendas libres terminadas y la población en el intervalo 24-35 años. A nivel agregado, el grupo de variables que mejor explican conjuntamente las fluctuaciones del mercado hipotecario son: PIB per capita, el precio del alquiler de la vivienda y los tipos de interés de referencia. Las variables más representativas son tanto de tipo financiero como macroeconómico (estructurales), por lo que se observa que tanto el modelo anglosajón como el germánico explican, parcialmente, el comportamiento inversor en España

La metodología científica en economía de la empresa en la actualidad

[ES] Mientras la realidad se transforma a gran ritmo, las ideas de ciencia y de conocimiento científico entran en crisis. Esta crisis también se manifiesta en los estudios empresariales: muchos afirman que la Economía de la Empresa no es ciencia, sino un conjunto de conocimientos diversos, débilmente conectados entre sí. Otros se pierden en investigaciones alejadas de la realidad, y un último grupo no consigue remontar un enfoque meramente practicista. Por ello, estimamos que es un buen momento para recordar los fundamentos que sustentan una ciencia: su objeto formal y material y su método. Para ello se realizará una exposición sintética del pensamiento del profesor Soldevilla.[EN] While real life is changing, the idea of science and scientific knowledge enters in crisis. This crisis appear in the managerial studies too: many people affirm that business management is not a science, but a set of different knowledges, weakly interconnected. Another group is getting lost in investigations far away from the reality, and a last group does not overcome a practical approach. We think that this is a good moment to remember the foundations of a science: its formal and material object and its method

Métodos cuantitativos versus métodos cualitativos en la economía de los Negocios. ¿Es una metodología reconciliable?

Changes in the organizational environment over the last three decades have increasingly led to traditional theories being called into question, by stimulating the search for new models suited to the new realities of business economics, generating a crisis or scientific revolution that may result in the appearance of a new paradigm. The positivism-phenomenology duality provokes an “epistemological crisis” in research in management sciences. But the existence of both approaches does not imply the election of one scientific orientation in frontal opposition to the other. From these two conceptions of research procedure, the methods applied can be classed into groups, quantitative and qualitative. The quantitative methodologies places great confidence in the ability of data and measurement to represent opinions or concepts, while qualitative methodologies focus on words and relations to describe a reality or situation. While the diversity of methods contribute to its development and indicates the maturity of an area, the methods must be suitably implemented to obtain significant, valid results. The methodology to be used is not going to depend solely on the type of study or the reality under examination, but also on the stage the research process has reached

Indicadores utilizados en el aprendizaje virtual de Institutos Superiores Técnicos y Tecnológicos en Ecuador

El presente artículo tiene como objetivo estudiar existencia de indicadores utilizados en el aprendizaje virtual de los Institutos Superiores Técnicos y Tecnológicos (ISTT) en Ecuador, tomando en cuenta que las modalidad virtual es una alternativa para acceder a la educación superior, para ello fue necesario revisar los procesos de evaluación a los que han sido sometidos los ISTT. El diseño metodológico utilizado fue de tipo documental, fue necesario la lectura de varios trabajos e informes de evaluación realizados por los organismos de control, entre los principales resultados obtenidos se evidenció que la formación de nivel  técnica y tecnológica no ofrece carreras en modalidad virtual y por consiguiente los docentes han adquirido las destrezas tecnológicas requeridas; se concluyó que  los Institutos Superiores Técnicos y Tecnológicos no han desarrollado una cultura de calidad en función de los parámetros establecidos, solo se trata de cumplir las exigencias del CACES por obligación mas no por vocación, en este sentido al no existir indicadores sobre el aprendizaje virtual en este nivel de formación, no se han realizado los esfuerzos necesarios para promover la modalidad virtual como alternativa de accesibilidad y cubrir la demanda insatisfecha de los estudiantes