1,022 research outputs found
The Socio-Environmental Survey: a tool for an integrated study of protected areas. The case of Sierra Sur de Sevilla and Sierra de Cádiz
La declaración de Espacios Naturales Protegidos ha producido con frecuencia conflictos con las poblaciones locales en la gestión de la conservación de la naturaleza. En respuesta a esta realidad han surgido nuevos métodos y estrategias que buscan una mejor integración de la componente social en las áreas protegidas. Este artículo presenta los resultados de una Encuesta Socio-Ambiental (ESA) realizada durante la elaboración de una propuesta de Espacio Natural Protegido para la Red de Espacios Naturales Protegidos de Andalucía en la campiña agrícola del Subbético, entre las provincias de Sevilla y Cádiz (sur de España). A partir de los datos obtenidos se propone y discute la aplicación de la figura de Paisaje Protegido (tipo Categoría V de UICN) asociada a un modelo de gestión participativa abierta.The declaration of Protected Areas has frequently led to conflicts with local populations because of nature conservation management. In response to this reality new methods and strategies are emerging that are looking for a better integration of the social component in Protected Areas. This article shows the results of a Socio-Environmental Survey (SES) conducted during the elaboration of a Protected Area proposal for the Andalusian Protected Areas Network in the Subbetic agricultural “campiña”, between Seville and Cádiz provinces (Southern Spain). Based on the data obtained, the application of the Protected Landscape figure (type Category V of IUCN) associated to an open participatory management model is proposed and discussed
Mitigation of Distortions in Radio-Over-Fiber Systems Using Machine Learning
Introducción: El constante crecimiento de usuarios conectados a internet por medio de dispositivos móviles ha conllevado a incrementar la investigación en el paradigma de las redes híbridas conocido como Radio-sobre-Fibra. Estas redes aprovechan las ventajas del ancho de banda de la fibra óptica y la movilidad de las transmisiones inalámbricas, evitando el cuello de botella que se da por la conversión óptico a eléctrico. No obstante, la dispersión cromática propia de la fibra óptica genera distorsiones en la señal de radiofrecuencia modulada ópticamente, lo cual limita su alcance.
Objetivo: Mejorar el desempeño de un sistema de radio sobre fibra en términos de la tasa de error de bit, usando demodulación no simétrica por medio del algoritmo de aprendizaje automático Máquina de Soporte Vectorial.
Metodología: Se simula un sistema de Radio-sobre-Fibra en el software especializado VPIDesignSuite. Se transmiten señales de radiofrecuencia moduladas en formatos 16 y 64-QAM con diferentes anchos de línea de láser sobre fibra óptica. Se aplica el algoritmo Máquina de Soporte Vectorial para la demodulación de la señal.
Resultados: La implementación del algoritmo de aprendizaje automático para la demodulación de la señal mejora significativamente el desempeño de la red permitiendo alcanzar los 30 km de transmisión por fibra óptica. Esto implica una reducción de la tasa de error de bit hasta en dos órdenes de magnitud en comparación con la demodulación tradicional.
Conclusiones: Se demuestra que con el uso de umbrales asimétricos usando algoritmo de Máquina de Soporte Vectorial se logran mitigar distorsiones en términos de la tasa de error de bit. Así, esta técnica se hace atractiva para futuras redes de acceso de alta capacidad.
Introduction: The ever-growing number of users connected to internet via mobile devices has driven to increase the research in the paradigm of hybrid optical networks called Radio-over-Fiber. These networks take advantages of the bandwidth given by the optical fiber and the mobility given by wireless transmissions, avoiding the bottleneck of optical-to-electrical conversion interfaces. However, the chromatic dispersion of the optical fiber generates distortions in the radiofrequency signals optically modulated, limiting the reach of transmission.
Objective: To improve the performance of a Radio-over-Fiber system in terms of bit-error-rate, using nonsymmetrical demodulation by means of the machine learning algorithm Support Vector Machine.
Methodology: A Radio-over-Fiber System is simulated in the specialized software VPIDesignSuite. The radiofrequency signals are modulated at 16 and 64-QAM formats with different laser linewidths and transmitted over optical fiber. The Support Vector Machine algorithm is applied to carry out nonsymmetrical demodulation.
Results: The implementation of the machine learning algorithm for signal demodulation significantly improves the network performance, reaching transmissions up to 30 km. It implies a reduction of the bit-error-rate up to two
Introduction: The ever-growing number of users connected to internet via mobile devices has driven to increase the research in the paradigm of hybrid optical networks called Radio-over-Fiber. These networks take advantages of the bandwidth given by the optical fiber and the mobility given by wireless transmissions, avoiding the bottleneck of optical-to-electrical conversion interfaces. However, the chromatic dispersion of the optical fiber generates distortions in the radiofrequency signals optically modulated, limiting the reach of transmission.
Objective: To improve the performance of a Radio-over-Fiber system in terms of bit-error-rate, using nonsymmetrical demodulation by means of the machine learning algorithm Support Vector Machine.
Methodology: A Radio-over-Fiber System is simulated in the specialized software VPIDesignSuite. The radiofrequency signals are modulated at 16 and 64-QAM formats with different laser linewidths and transmitted over optical fiber. The Support Vector Machine algorithm is applied to carry out nonsymmetrical demodulation.
Results: The implementation of the machine learning algorithm for signal demodulation significantly improves the network performance, reaching transmissions up to 30 km. It implies a reduction of the bit-error-rate up to two orders of magnitude in comparison with conventional demodulation.
Conclusions: Mitigation of distortions in terms of bit-error-rate is demonstrated in a Radio-over-Fiber system using nonsymmetrical demodulation by using the Support Vector Machine algorithm. Thus, the proposed technique can be suitable for future high-capacity access networks.
 
Reducción de la resistencia al avance de un buque mediante la aplicación de pinturas especiales al casco
La crisis económica, el impacto medioambiental y el consumo continuado de los combustibles fósiles propician cualquier iniciativa que conlleve un ahorro de energía. En el mundo de los buques, uno de los objetivos ha sido siempre el alcanzar un casco hidrodinámicamente óptimo que con un mínimo de potencia proporcione la velocidad deseada. Esta resistencia al avance se debe esencialmente a dos razones: a la fricción entre el agua y el casco del buque y a la generación de olas debido a la presencia de la interfase aireagua. El presente trabajo recoge las labores llevadas a cabo para evaluar la posibilidad de minimizar la resistencia debida a la fricción mediante la aplicación de pinturas especiales al casco del buque. El análisis se ha aplicado a un buque de cooperación en materia de pesca que ha sido estudiado hidrodinámicamente en el Canal de Ensayos Hidrodinámicos de la E.T.S.I. Navales. Para el estudio de la reducción de la resistencia de fricción se han ensayado dos planchas con una superficie mojada equivalente al modelo utilizado en los ensayos hidrodinámicos con dos tipos diferentes de pintura. También se han llevado a cabo cálculos numéricos con un código comercial de tipo viscoso con la posibilidad de evaluar la rugosidad. Se pretende también con ello proceder a la validación de dicho código para la consideración de la rugosidad
Proposal for a provisional protocol for the care and identification of dental transmission routes of COVID-19 in Latin America : a Literature review
The new coronavirus called COVID-19 originated in the city of Wuhan, China and has currently spread to different continents, leading the World Health Organization (WHO) to declare a ?pandemic?. Therefore, the aim of this review was to present a new proposal for a care protocol in Peruvian Dentistry: Provisional review of the diagnosis, treatment, epidemiological characteristics, routes of transmission and recommendations of COVID-19. A search of digital scientific literature was made in the databases: Science Direct, Pubmed and Google Scholar. The Boolean operators AND, OR and NOT: ?Covid-19? ?Dental? ?Routes of transmission. They were included Scientific articles published in English between December 2019 - March 2020. Different studies were found mainly of epidemiological, observational and experimental design. On March 6, 2020, the President of the Republic of Peru confirmed and declared in Peru the beginning of the first case of coronavirus. According to reports from the Ministry of Health (MINSA) as of July 30, there are: PCR (+) 108, 299; Rapid test (+) 292, 384 positive cases and 18, 816 deceased with a lethality of 4.7%. Within the limitations of this literature review, the presence of the virus is inevitable in dental practice. The dentist must understand the evolution of this microorganism like all vulnerable professionals in the health sciences
Biloma secondary to blunt liver trauma in a pediatric patient: case report
Liver is the organ most frequently injured after blunt or penetrating abdominal trauma, being in pediatrics a pathology that has an increasing incidence; Non-operative management is the hallmark of treatment, however cases of secondary biliary leakage have been described, which may affect the intrahepatic or extrahepatic track. A male 8 years old, with blunt trauma in the right hypochondrium, presenting acute abdomen and hemodynamic instability, requiring exploratory laparotomy with a grade III liver injury in VI and VII hepatic segments. Four weeks after discharge, he presented as a complication a giant biloma in VII and VIII hepatic segments, performing percutaneous drainage guided by ultrasound. The incidence of biliary complications related to hepatic trauma is low, 4% in pediatric patients, dividing into bilomas or biliary fistulas; the presentation of biliary leakage is very non-specific and early diagnosis difficult; in the bilomas, the tomography allows to define precisely its size, nature, distribution and regional anatomy in relation to adjacent structures, as well as underlying cause. The approach of choice is percutaneous or endoscopic drainage, with surgical management being the last option
ORIGINAL ARTICLES Influence of Prepartum Chronic Ultramild Stress on Maternal Pup Care Behavior in Mice
Synthesis and Biological Evaluation of a-Tubulin-Binding Pironetin Analogues with Enhanced Lipophilicity
The preparation of four new lipophilic analogues of the natural pyrone pironetin is described. The nine-carbon side chain of the latter has been replaced in one analogue by a 4-phenylbutyl chain and in the other three analogues by long aliphatic chains of thirteen and sixteen carbons, all of them bearing two stereogenic centers.
Their cytotoxic activity and their interactions with tubulin have been investigated. It has been found that all four are cytotoxic towards two either sensitive or resistant tumoral cell lines with similar IC50 values in each case, thus indicating that, like the parent natural compound, they also display a covalent mechanism of action. However, one of them operates in all likelihood through a mechanism very similar to pironetin whereas the other three seem to be cytotoxic via a different mechanism
A window onto the Eocene (Cenozoic): The palaeontological record of the Sobrarbe-Pirineos UNESCO Global Geopark (Huesca, Aragon, Spain)
The Sobrarbe-Pirineos UNESCO Global Geopark, located in the Central Pyrenees, is a region of remarkable geodiversity that includes extensive Eocene fossil-bearing sites and constitutes an important archive of paleobiodiversity. The Sobrarbe-Pirineos Geopark hosts outcrops of Eocene formations bearing an unusual abundance and diversity of fossils from marine and continental sedimentary environments, making the Sobrarbe-Pirineos Geopark a perfect window for learning about tropical ecosystems of the Eocene of southern Europe. These environments were in part tectonically controlled and offer a unique opportunity to understand how faunas changed in an active area. Here, we outline the main groups of fossils from the Sobrarbe-Pirineos Geopark, including popular examples such as the “Crocodile of Ordesa-Vio” and the sirenian Sobrarbesiren. The Geopark has been a major tool in the geoconservation of Eocene fossils
Synthesis and biological evaluation of truncated α-tubulin-binding pironetin analogues lacking alkyl pendants in the side chain or the dihydropyrone ring
The preparation of several new truncated analogues of the natural dihydropyrone pironetin is described. They differ from the natural product mainly in the suppression of some of the alkyl pendants in either the side chain or the dihydropyrone ring. Their cytotoxic activity and their interactions with tubulin have been investigated. It has been found that all analogues are cytotoxic towards two either sensitive or resistant tumoral cell lines with similar IC50 values in each case, thus strongly suggesting that, like natural pironetin, they also display a covalent mechanism of action. Their cytotoxicity is, however, lower than that of the parent compound. This indicates that all alkyl pendants are necessary for the full biological activity, with the ethyl group at C-4 seemingly being particularly relevant. Most likely, the alkyl groups cause a restriction in the conformational mobility of the molecule and reduce the number of available conformations. This makes it more probable that the molecule preferentially adopts a shape which fits better into the binding point in α-tubulin
Nitrogen, Iron, and Zinc Acquisition: Key Nutrients to Aspergillus fumigatus Virulence
Aspergillus fumigatus is a ubiquitous soil decomposer and an opportunistic pathogen that is characterized by its large metabolic machinery for acquiring nutrients from media. Lately, an ever-increasing number of genes involved in fungal nutrition has been associated with its virulence. Of these, nitrogen, iron, and zinc metabolism-related genes are particularly noteworthy, since 78% of them have a direct implication in virulence. In this review, we describe the sensing, uptake and regulation process of the acquisition of these nutrients, the connections between pathways and the virulence-implicated genes. Nevertheless, only 40% of the genes mentioned in this review have been assayed for roles in virulence, leaving a wide field of knowledge that remains uncertain and might offer new therapeutic and diagnostic targets.This research was funded by the Basque Government: grant number IT1362-19. U.P.-C. and S.C.-S. received a predoctoral fellowship from the University of the Basque Country and Basque Government, respectively
- …