University of Extremadura
Dehesa. Repositorio Institucional de la Universidad de ExtremaduraNot a member yet
24789 research outputs found
Sort by
Isopods in the Bioremediation of Invasive Seaweeds? First Experience with the Seaweed Rugulopteryx okamurae Mass Dumped on Beaches
No full textEste artículo pertenece a la Sección de Contaminación MarinaDesde 2015, el alga invasora Rugulopteryx okamurae ha desencadenado la invasión de macrófitos marinos más grave de Europa. Su enorme biomasa costera vertida en las playas genera problemas de salud, olores fuertes, impactos en el turismo y altos costos de limpieza, pero también constituye un nuevo recurso marino potencial que ofrece importantes perspectivas de explotación. En este sentido, como estrategia de economía circular, se experimentó por primera vez con la biorremediación de algas marinas con isópodos (Isopoda, Crustacea, Arthropoda). Los especímenes de Porcellio laevis (isópodo terrestre nativo) se obtuvieron de parques urbanos y se mantuvieron en terrarios con un adecuado control de humedad y temperatura. Una muestra de 150 ejemplares adultos se dividió en seis lotes de 25 animales. Se alimentaron tres lotes con 100 g de mantillo de hojas de Quercus pyrenaica (testigo) y tres con una dieta compuesta por 100 g de mantillo de algas (tratamiento). P. laevis consumió hasta 1,5 veces su peso por día en la dieta de algas, con poca o ninguna pérdida de peso y tasas de reproducción adecuadas. El peso promedio de los isópodos fue de 1,6 g en el grupo de algas y de 2,5 g en el grupo de control. Sin embargo, se observó una alta mortalidad tanto en las mancas como en los adultos del grupo de tratamiento. En este sentido, el número medio de mancas por cm2 fue de 0 en el grupo de algas y de 325 en el grupo de control. A pesar de ello, los resultados son prometedores y, en consecuencia, proponemos fomentar la investigación con isópodos debido a su alta voracidad, alta prolificidad y resistencia al reciclaje de algas invasoras. El trabajo futuro debería explorar qué porcentaje de R. okamurae previene la mortalidad por diterpenos de isópodos y otros invertebrados. Este es un paso preliminar hacia la biorremediación masiva de las floraciones de primavera y verano de R. okamurae. Este trabajo contribuye a poner en valor este abundante recurso marino.Since 2015, the invasive seaweed Rugulopteryx okamurae has triggered the most serious marine macrophyte invasion in Europe. Its huge coastal biomass dumped on beaches generates health problems, strong odors, impacts on tourism, and high clean-up costs, but it also constitutes a new potential marine resource that offers significant prospects for exploitation. In this sense, as a circular economy strategy, seaweed bioremediation with isopods (Isopoda, Crustacea, Arthropoda) was experimented on for the first time. Specimens of Porcellio laevis (native terrestrial isopod) were obtained from urban parks and kept in terrariums with adequate humidity and temperature control. A sample of 150 adult specimens was divided into six batches of 25 animals. Three batches were fed with 100 g of mulch of Quercus pyrenaica leaves (control) and three with a diet composed of 100 g of mulch of algae (treatment). P. laevis consumed up to 1.5 times their weight per day on the algae diet, with little or no weight loss and adequate reproduction rates. The weight of the isopods averaged 1.6 g in the seaweed group and 2.5 g in the control group. However, high mortality was observed in both mancas and adults in the treatment group. In this sense, the average number of mancas per cm2 was 0 in the algae group and 325 in the control group. Despite this, the results are promising, and consequently, we propose to encourage research with isopods due to their high voracity, high prolificacy, and resistance to invasive algal recycling. Future work should explore what percentage of R. okamurae prevents diterpene mortality of isopods and other invertebrates. This is a preliminary step towards the massive bioremediation of spring and summer blooms of R. okamurae. This work contributes to highlighting this abundant marine resource.Financial assistance was obtained from the Autoridad Portuaria de la Bahía de Algeciras
(APBA), Fundación CEPSA y Red Eléctrica de España (REE).peerReviewe
Centella Moyano, M. y Chaves Carrillo, M.M. (2025). Attitudes towards active retirement. The case of an aging region with moderate economic development. International Journal of Human Sciences Research, 5 (3), 1-9. https://doi.org/10.22533/at.ed.558532523018
No full textThe aging of the population is a structural demographic trend that affects many developed countries. This phenomenon puts pressure on social protection systems, especially pensions, due to the increase in life expectancy and the extension of retirees' residual life. In this context, active retirement emerges as an option to prolong working life and alleviate the pressure on pension systems, as it allows people who have reached retirement age to continue participating in the labor market, either full-time or part-time, while receiving a percentage of their pension. Hence, it is important to analyze the assessment that workers close to retirement or already retired make of this instrument. The study focuses on the region of Extremadura, one of the most aged and with the lowest activity rates in Spain. Through a survey of people over 54 years old, the motivations and attitudes towards active retirement are identified. The results show that the predisposition to combine retirement and work varies according to age, economic situation, and perceived health. While low income and a poor economic situation increase the willingness to continue working, deteriorating health and the perception of having worked enough time are the main reasons for not opting for active retirement.peerReviewe
El cambio de lado de balón como indicador de rendimiento en baloncesto femenino
No full textEl objetivo de este estudio fue determinar si el cambio de lado de balón podría servir como un indicador de rendimiento en el baloncesto femenino. Se analizó el efecto del cambio de lado de balón en diversas variables de rendimiento en el juego (tiros, rebotes, nivel de oposición, etc.). Se analizaron un total de 6007 posesiones de balón de 64 partidos de la temporada 2020/2021 de la Liga Femenina Endesa, organizada por la Federación Española de Baloncesto (FEB). Se empleó la metodología observacional para definir y registrar las variables, y el análisis de datos se realizó mediante estadísticas descriptivas, la prueba de Chi-Cuadrado y ANOVA de un factor. Los resultados revelaron que el cambio de lado de balón tuvo un efecto significativo en las finalizaciones de las posesiones (p < 0.001). Específicamente, se asoció con un mayor número de intentos de lanzamientos y puntos anotados, un incremento en rebotes ofensivos y una reducción en pérdidas de balón. Incorporar el cambio de lado de balón durante las posesiones aumenta la probabilidad de éxito, lo que se traduce en un mayor número de puntos por posesión. Por lo tanto, el cambio de lado de balón puede considerarse un indicador de rendimiento en el baloncesto femenino.The aim of the study was to determine whether ball reversal is a performance indicator in women’s basketball. Its influence on various in-game performance variables (shots, rebounds, opposition, etc.) was analysed. A total of 6007 ball possessions from 64 games in the 2020/2021 season of the Liga Femenina Endesa, organized by the Spanish Basketball Federation (FEB), were analysed. Observational methodology was employed for defining and recording variables, and data analysis was conducted using descriptive statistics, the Chi-Square test, and one-way ANOVA. The results revealed that ball reversal had a significant impact on possession outcomes (p < 0.001). Specifically, it was associated with a higher number of shot attempts and points scored, an increase in offensive rebounds, and a reduction in turnovers. Incorporating ball reversal during possessions enhances the probability of success, translating into a greater number of points per possession. These findings suggest that ball reversal can thus be considered a performance indicator in women's basketball.This study was supported by grants awarded by the Spanish Ministry of Science, Innovation and Universities: Grant FPU19/06224peerReviewe
To Someone With Only a Hammer, Everything Looks Like a Nail: A Discussion on Interest Rate Policy in Light of the Recent Inflationary Episode.
No full textLos problemas logísticos ocasionados por las disrupciones de las cadenas globales de valor tras la Pandemia del COVID-19 han dado pie a un nuevo episodio de inflación. Basándonos en el análisis de literatura sobre el uso de la política monetaria convencional para gestionar este tipo de coyunturas, junto con la evidencia empírica expuesta, en este trabajo planteamos tres cuestiones: i) la necesidad de abordar qué elementos están causando este episodio de aumento de precios; ii) discutir la estrategia para efectuar un cambio de modelo energético dirigido por el mercado, donde los cuellos de botella, el incremento de los precios de la energía y ciertas materias primas escasas y la concentración de empresas es la norma y iii) exponerlas implicaciones políticas de este episodio transitorio para la política económica proponiendo un nuevo marco de coordinación monetario-fiscal para facilitar una restauración de la relación real de intercambio.The logistical problems caused by the disruptions of global value chains following the COVID-19 Pandemic have given rise to a new episode of inflation. Based on the analysis of the literature on the use of conventional monetary policy to manage this type of conjuncture, together with the empirical evidence presented, in this paper we raise three questions: i) the need to address what elements are causing this episode of price increase; ii) discuss the strategy to effect a market-led change of energy model, where bottlenecks, rising prices of energy and certain scarce commodities and the concentration of firms is the norm and iii) convey the political implications of this transitory episode for economic policy with a proposal for a new framework of monetary-fiscal coordination facilitating a restoration of the real terms of trade.Os problemas logísticos causados pelas rupturas nas cadeias globais de valor após a pandemia de COVID-19 deram origem a um novo episódio de inflação. Com base na análise da literatura sobre o uso da política monetária convencional para lidar com esse tipo de conjuntura, juntamente com as evidências empíricas apresentadas, neste artigo levantamos três questões: i) a necessidade de abordar quais elementos estão causando esse episódio de aumento de preços; ii) discutir a estratégia para implementar uma mudança no modelo energético liderado pelo mercado, onde gargalos, aumento dos preços da energia e de certas commodities escassas, além da concentração de empresas, são a norma; e iii) expor as implicações políticas desse episódio transitório para a política econômica, com uma proposta de um novo marco de coordenação monetário-fiscal que facilite a restauração dos termos reais de troca.peerReviewe
Localización de zonas emprendedores en América Latina: un análisis espacial
No full textEl objetivo de este trabajo es de analizar los patrones espaciales de la intención emprendedora de los estudiantes universitarios en el continente americano. Los estudios sobre el fenómeno emprendedor han omitido la posible asociación espacial, lo cual podría explicar la inconsistencia de los resultados y conclusiones de investigaciones anteriores. Los datos se han obtenido de la Encuesta GUESSS y contienen una muestra inicial de 70,337 participantes. El Análisis Exploratorio de Datos Espaciales demuestra patrones espaciales en Costa Rica y Panamá con una alta intención emprendedora (hot spots). Este estudio puede servir de base para el desarrollo de políticas públicas que promuevan y apoyen el emprendimiento; y, cuando sea pertinente, proponer iniciativas estratégicas articuladas y coordinadas entre países basadas en la ubicación se estos en los clústers identificados (hot/cold spots).This study analyzes spatial patterns in the entrepreneurial intention of university students in Latin America. Studies on the entrepreneurial phenomenon have paid little attention to possible spatial associations, which might explain the dissimilar results reported by prior work. The analysis uses a sample of 70,337 university students drawn from the GUESSS survey. The results of the exploratory spatial model reveal significant spatial patterns in Costa Rica and Panama with a high entrepreneurial intention (hot spots). This study can serve as a basis for developing public policies to promote entrepreneurship and, when appropriate, propose articulated and coordinated strategic initiatives between countries located in the identified clusters (hot/cold spots).peerReviewe
Organización de actividades de deporte inclusivo desde los centros educativos
No full textEn un mundo cada vez más consciente de la importancia de la inclusión, el deporte se presenta como una herramienta poderosa para derribar barreras y fomentar la igualdad. Este capítulo explora cómo los centros educativos pueden organizar actividades deportivas inclusivas, basándose en las experiencias y programas desarrollados en Extremadura. A través de la colaboración entre diversas entidades y la implementación de programas específicos, se busca crear un entorno donde todos los estudiantes, independientemente de sus capacidades, puedan participar y beneficiarse del deporte.peerReviewe
The Influence of Prefabricated Foot Orthosis Use on the Modification of Foot Posture in Adults with Pronated Feet: A Randomised Controlled Trial
No full textThe use of prefabricated orthoses resulted in a decreased FPI in adults, especially in those with highly pronated feet. However, the index minus presence nullified the effect of prefabricated orthoses on foot posture neutralisation.peerReviewe
Enhancing noise robustness of automatic Parkinson's disease detection in diadochokinesis tests using multicondition training
No full textDespite significant advances on automatic detection of Parkinson’s disease (PD) based on speech, several open challenges still need to be addressed before a validated computer-aided diagnosis system can be used practically. One of these challenges lies in considering the potential corruption of speech caused by environmental noises, which may be nonstationary and exhibit varied characteristics. Speech features automatically extracted from diadochokinetic (DDK) tests have shown utility in assessing articulatory aspects of speech impairment in PD. The authors propose an automatic PD detection system based on a multicondition training (MCT) framework. The approach considers various types of realistic acoustic noise in addition to DDK recordings and uses machine learning for feature selection and classification. For each experiment, the noise addition process did not artificially increase the dataset size, as each subject’s recordings were either affected by a single noise type or had no injected noise. To compare with this MCT-based approach, an alternative method is examined where training involves speech samples affected by uniform noise conditions. This method, referred to as single-condition training (SCT), involves training with features either from the original waveforms or from waveforms altered by noise addition, ensuring uniformity by using the same type of realistic noise across all the training samples. The benefit of the MCT approach is demonstrated by showing the results obtained in classification tests to discriminate patients affected by PD from healthy individuals. The experiments performed were based on an in-house voice recording database composed of 30 individuals diagnosed with PD and 30 healthy controls. The speech samples were recorded using a smartphone as a data collection device so that the samples were not affected by speech compression algorithms. Both approaches (SCT and MCT) were tested against each specific type of noise under consideration. The mean accuracy rates showed improvements of 1.68%, 5.18%, and 4.39% for/pa/,/ta/, and/ka/ syllables, respectively, when using MCT compared with SCT. To the best of the authors’ knowledge, this is the first strategy published in the literature to deal with the potential corruption of speech by environmental noise in automatic PD detection aid systems based on DDK tests.This research is part of R&D&I Project PID2021-122209OB-C32 funded by MCIN/AEI/10.13039/501100011033 and European Regional Development Funds (ERDF); Grants GR21057 and GR21072, funded by Junta de Extremadura and the ERDF; and Grant FPU18/03274 funded by Ministerio de Ciencia, Innovación y Universidades, Spain .peerReviewe
Análisis de la relación existente entre la globalizacion económica y la reaparición del ultranacionalismo en Europa occidental
No full textPrograma de Doctorado en Economía y EmpresaDurante las últimas décadas los partidos ultranacionalistas en Europa Occidental han experimentado un fuerte incremento electoral. De forma paralela, el mundo entero ha constatado la implementación de la globalización socioeconómica. Ante esta interacción de sucesos, la presente tesis doctoral se ha marcado como objetivo analizar la posible relación entre ambos fenómenos. Para ello, la investigación se disgrega en cuatro capítulos. El primero trata de situar la posición ideológica del ultranacionalismo en materia socioeconómica. En el segundo capítulo se lleva a cabo una revisión sistemática de la literatura académica para hallar posibles antecedentes en la relación entre la globalización económica y el respaldo al ultranacionalismo. El tercero de los capítulos tiene como propósito analizar la relación de las variables características de la globalización con el respaldo al ultranacionalismo utilizando España como un caso de estudio. Para cumplir con tal propósito se ha implementado un modelo autorregresivo espacial con datos de panel y desagregación municipal. Así mismo, este tercer capítulo pone de manifiesto la importancia del partido gobernante a nivel municipal sobre el bienestar económico de la ciudadanía midiendo tal bienestar como la variación de las rentas a lo largo de una legislatura. El cuarto capítulo complementa la tesis doctoral analizando el respaldo electoral al ultranacionalismo en otras áreas geográficas ajenas a Europa Occidental con el fin de tratar de captar posibles razones subyacentes similares a escala global. Concretamente, se ha optado por el estado de Iowa al tener ciertas particularidades que lo convierten en ilustrativo de la situación del ultranacionalismo estadounidense.Over the last few decades, ultranationalist parties in Western Europe have experienced a strong electoral growth. At the same time, the entire world has witnessed the spread of socioeconomic globalization. In view of this interaction of events, this doctoral thesis has aimed to analyze the possible relationship between the two trends. To this purpose, the research is divided into four chapters. The first one tries to situate the ideological position of ultranationalism in socioeconomic issues. In the second chapter, a systematic review of the academic literature is conducted in order to find possible antecedents in the relationship between economic globalization and support for ultranationalism. The third chapter aims to analyze the relationship between the economic globalization and support for ultranationalism using Spain as a case study. In order to fulfill this purpose, a spatial autoregressive model with panel data and municipal disaggregation has been implemented. Likewise, this third chapter highlights the importance of the ruling party at the municipal level on the economic welfare of the citizens by measuring such welfare as the variation of incomes throughout a legislature. The fourth chapter complements the doctoral thesis by analyzing the electoral support for ultranationalism in other geographical areas outside Western Europe in order to try to capture possible similar underlying reasons on a global scale. Specifically, the state of Iowa has been chosen as it has certain particularities that make it illustrative of the situation of ultranationalism in the United States.Beca predoctoral Fulbright en Department of Political Science de University of Iowa bajo la supervisión de Prof. Frederick Solt. Beca europea de investigación y movilidad en estudios europeos Premio Europeo Carlos V” en su convocatoria 2022, Fundación Europea e Iberoamericana de Yust
Fuzzy Wavelet Neural Adaptive Finite-Time Self-Triggered Fault-Tolerant Control for a Quadrotor Unmanned Aerial Vehicle With Scheduled Performance
No full textVersión de artículo publicado en: Engineering Applications of Artificial Intelligence, Volume 131, 2024, 107832, ISSN 0952-1976, https://doi.org/10.1016/j.engappai.2023.107832.Este artículo se centra en el diseño de un control adaptativo auto-desencadenado resistente en tiempo finito basado en redes neuronales wavelet difusas con un rendimiento de seguimiento asegurado para un vehículo aéreo no tripulado quadrotor sujeto a fallos desconocidos del actuador. En primer lugar, se integra una función de rendimiento finito-temporal mejorada con el marco de control backstepping filtrado por comandos para garantizar el rendimiento de seguimiento programado, que puede limitar eficazmente las fluctuaciones transitorias del error de seguimiento en caso de fallo. A continuación, se desarrollan dos mecanismos de compensación para debilitar el impacto adverso inducido por los fallos del actuador y los errores del filtro. Además, se diseña un controlador adaptativo neuronal de ondículas difusas con rendimiento asegurado para mejorar la insensibilidad a los fallos y la precisión de seguimiento del vehículo controlado, en el que se emplean redes neuronales de ondículas difusas para aproximar las no linealidades desconocidas y se permite que las señales de control alcancen una actualización irregular sólo cuando se viola el protocolo de activación preespecificado. El análisis de estabilidad demuestra que el controlador diseñado garantiza que los subsistemas de actitud y posición son estables en tiempo finito, y que los errores de seguimiento están estrictamente confinados a una región preasignada y nunca cruzan sus límites permitidos. Por último, los resultados de la simulación confirman la validez del esquema de control desarrollado.This paper focuses on fuzzy wavelet neural networks-based adaptive finite-time self-triggered resilient control design with assured tracking performance for a quadrotor unmanned aerial vehicle subject to unknown actuator faults. First, an improved finite-time performance function is integrated with the command-filtered backstepping control framework to assure the scheduled tracking performance, which can effectively constrain the transient fluctuations of the tracking error at fault occurrence. Then, two compensation mechanisms are developed to weaken the adverse impact induced by actuator faults and filter errors. Further, a fuzzy wavelet neural adaptive self-triggered resilient controller with assured performance is designed to improve the fault insensitivity and tracking accuracy of the controlled vehicle, where the fuzzy wavelet neural networks are employed to approximate the unknown nonlinearities and the control signals is allowed to achieve irregular updating only when the pre-specified trigger protocol is violated. Stability analysis proves that the designed controller guarantees the attitude and position subsystems are finite-time stable, and the tracking errors are strictly confined to a preassigned region and never cross its allowed bounds. Finally, the validity of the developed control scheme is confirmed by the simulation results.This work was supported in part by the National Natural Science Foundation of China under Grant 62203153, 61976081, in part by Key Scientific Research Projects of Higher Education Institutions in Henan Province, China under Grant 22A413001, in part by Top Young Talents in Central Plains under Grant Yuzutong (2021) 44, in part by Technology Innovative Teams in University of Henan Province, China under Grant 23IRTSTHN012, and in part by the Serbian Ministry of Education, Science and Technological Development under Grant No. 451-03-68/2022-14/200108.PeerReviewe