Aplicación de un enfoque metodológico proveniente de la geografia de la población al estudio comparativo de los rasgos generales de la emigración exterior de los naturales de los archipiélagos del atlántico centrooriental (Azores, Madeira, Canarias y Cabo Verde) en los siglos XIX y XX

[...]. Desde una perspectiva geográfica, la que vamos a desarrollar, la emigración supone la existencia previa de unos factores de repulsión en el foco de partida, al tiempo que unos atractivos en el país de destino. En medio de esos estímulos objetivos que le impulsan a partir o a permanecer se sitúan los posibles emigrantes con su personal potencial emigratorio y con su percepción subjetiva y/o grupal de esa realidad. Pero la valoración positiva de nuevos lugares a donde emigrar no determina todavía el movimiento o viaje, pues deben superarse aun ciertos obstáculos para que la emigración sea efectiva. Barreras como la lengua o la religión y , entre otras mas, las legislaciones restrictivas o selectivas. Todavía queda al emigrante otras dos decisiones cruciales, la de porqué permanecer en la sociedad de acogida, y la de retornar al pais originario, en su caso. [...

Computer access, social interaction and learning in a bilingual/multicultural setting.

This study examined the nature of social interactions taking place between students working with computers in three inner-city school classrooms. Its main objective is to present a descriptive analysis of the impact of computers on the social relations between students in a bilingual/multicultural setting. The social interactions between students in the classroom are assumed to be an important dimension of their learning experience, especially for students from subordinate cultures. It is further assumed that student-student interactions take place within the context established by the teacher and the school, and within the general context of the society. The micro context (student-student interactions) can not be analyzed in isolation from the macro context (the society). Student interactions were defined as a verbal or non-verbal transaction between two students. These interactions were analyzed by using three major categories of interaction: (1) type of interaction, (2) form of interaction, and (3) mode or expressive style. Classroom sessions were videotaped for a period of 4 weeks near the end of the school year. In addition, fieldnotes were taken to complement the videotaped material. A crosstabulation analysis was conducted to examine the relationship between the categories of interaction and the demographic characteristics of the students initiating or receiving those interactions. Data on the students\u27 demographic characteristics, such as ethnicity, socioeconomic status, sex, and ability level, were gathered through the use of a questionnaire. It was found that all of the determinants of access to the computers and learning tended to favor Anglo students and did not facilitate the success of Hispanic and other minority students. On the other hand, Anglos usually assumed the dominant role in the interactions with Hispanic students. In general, the social interactions between students was determined by a combination of factors, including socioeconomic status, ethnicity, ability level, and sex. These factors played an important role in determining the type, form and mode of social interaction between students, but they should not be seen in isolation from each other. The powerless status of Hispanics in the school and the city, and the generalized presence of Anglos in positions of authority are additional factors that contribute to explain this phenomenon

Analysis of the rooftop photovoltaic potential in a real case: Energy community of the music school in Adeje

Rooftop photovoltaic emerges as an essential resource to promote the energy transition. It opens up the possibility to create energy communities and share the generated electricity within a neighbourhood, aiding to confront the energy crisis. However, low voltage distribution grids where originally designed radially, with a mainly one-directional power flow in mind. As such, a high penetration of distributed generation such as rooftop photovoltaic will negatively impact the grid, increasing the voltage profile and causing reverse power-flows. Thus, it is key to determine the limits set by the applicable regulation and analyze the effects of rooftop photovoltaic on the grid performance. This work aims to determine the impact on the distribution grid of an intense deployment of rooftop photovoltaic in a real case scenario, the surroundings of the music school in Adeje, Tenerife (Spain). For this purpose, the current statutory limits, as well as the network topology, the rooftop area and real consumption data of the vicinity are taken into account. A simulation is performed using the software OpenDSS, and the influence on the grid is estimated for different penetration scenarios. The results show that the transformer capacity limitation allows the integration of 420kWp. Setting this limitation aside, this value could be increased up to 579kWp without surpassing voltage limits, while the maximum photovoltaic potential in the vicinity according to available rooftop area is estimated at 1859,21kWp, but it would breach the current grid codes. To allow higher penetration limits, solutions such as the Volt-Var and Volt-Watt techniques as well as distribution static synchronous compensators are required

Influence of boron content on the fracture toughness and fatigue crack propagation kinetics of bainitic steels

The relatively good combination of high strength and ductility makes bainitic steels a candidate to replace many other steels in industrial applications. However, in service, ductility and strength are not up to standard requirements. In many industrial components, toughness and fatigue performance are also very relevant. In the present study, bainitic steels with varying content of boron were fabricated, with the aim of analyzing the fracture toughness and changes in the fatigue life. The results show that a relatively small change in the boron content can cause a notable variation in the fracture toughness of bainitic steels. The maximum value obtained in fracture toughness was for the steel with the highest boron content. It was observed that the amount of interlath martensite constituents decreases in steels with the addition of boron, leading to the promotion of the presence of void coalescence and a remarkable rise in the toughness of bainitic steels. An increase on the fatigue life of the bainitic steels with an increase in the boron content was also observed, through analysis by means of Paris’ law. A comprehensive micrographic study was carried out in order to examine the mechanics of fatigue crack growth in the bainitic steels, revealing small longitudinal cracks in bainitic steels that lack boron. These cracks tend to disappear in bainitic steels that contain boron. To elucidate this behavior, micrographs of the surfaces generated by the crack growth process were taken, showing that several nano-cracks appeared between the bainite laths. It is finally argued that this high-energy consumption process of nano-crack nucleation and growth is the reason for the improved toughness and fatigue life observed in bainitic steels.Peer ReviewedPostprint (author's final draft

Síndrome de Yentl: ¿realidad actual en el síndrome coronario agudo sin elevación del segmento ST?

La enfermedad cardiovascular es la primera causa de mortalidad en países industrializados, independientemente del género del sujeto. Las mujeres que desarrollan un evento coronario agudo presentan un pronóstico más desfavorable en comparación con los hombres, explicado por una mayor comorbilidad asociada y un manejo diagnóstico y terapéutico más deficiente

Evaluation of the anti-angiogenic potential of hydroxytyrosol derivatives

Angiogenesis, a process which allows the formation of new vessels from pre-existing ones, is an essential phenomenon for tumor survival since it allows cancer cells to obtain nutrients and oxygen. This explains the increasing interest showed by many groups of research and pharmaceutical companies to find compounds with potential to disrupt at least one of the steps within the angiogenic process. Hydroxytyrosol (3,4-dihydroxyphenyl ethanol) has been identified as the most important health-related phenolic compound of virgin olive oil because of its pleiotropic effects on multiple targets. In 2012, our group identified hydroxytyrosol as an anti-angiogenic compound able to inhibit several key steps in the angiogenic process. In the present study, the potential effects of six hydroxytyrosol derivatives are tested and compared with those exhibited by hydroxytyrosol by making use of several in vitro and in vivo assays. Results indicate that these are candidate new anti-angiogenic compounds with potential utility in anti-tumor and anti-angiogenic therapies.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech [Our experimental work is supported by grants BIO2014-56092-R (MINECO and FEDER) and P12-CTS-1507 (Andalusian Government and FEDER) and funds from group BIO-267 (Andalusian Government). The "CIBER de Enfermedades Raras" is an initiative from the ISCIII (Spain)]. This communication has the support of a travel grant

Multimodal prosody: gestures and speech in the perception of prominence in Spanish

Multimodal communication cannot be properly understood without analyzing the natural interweaving of speech and gestures as it typically occurs in everyday spoken language, thus moving beyond studies that elicit gestures in the laboratory, most of which are also conducted for English. Therefore, this study addresses the effect of both visual and acoustic cues in the perception of prominence in Castilian Spanish using spontaneous speech from a TV talent-show. Four between-subjects experiments in each modality—audio-only and audiovisual—were conducted online, each including a different combination of manipulated cues: Exp1 (flat F0), Exp2 (flat intensity), and Exp3 (flat F0 + flat intensity), while all cues remained intact in the control experiment Exp0. Additionally, the capability of the different gesture phases to convey prominence was analyzed in their interaction with the acoustic cues. The results showed that, when prominence was perceived in manipulated stimuli, the effect of the visual information depended on the acoustic cues available in the signal and was also reduced when compared to non-manipulated stimuli, pointing to a strong integration of both modalities in prominence perception. In non-manipulated stimuli, all acoustic cues—except for spectral balance—played a role in the perception of prominence; however, when the visual information was added, it reduced the perceptual effect of the acoustic cues, and the main role played by duration was combined with that of the stroke phase of gestures

Harmonic Analysis of the Wind Energy Conversion System Connected with Electrical Network

A harmonic analysis for a wind energy conversion system (WECS) based in a doubly fed induction generator (DFIG) is presented. A back-to-back frequency converter as voltage source for excite to rotor winding is used whereas than the electrical network excites to stator winding. The analysis is based on the induction machine model and the steady-state frequency converter model. Additionally, dynamic-state and steady-state models are developed and compared validating the results of the simulations obtaining a harmonic model, in steady-state, clear, and precise of the wind energy conversion system