Tunable ring resonator filter for OFDM Transmission systems

A novel tunable filter is theoretically demonstrated. It is based on a ring resonator with an amplifier and a noise filter in the loop. This optoelectronic device has potential as a high-sensitivity receiver and as a tunable demultiplexer in OFDM transmission systems.Publicad

La descentralización del currículo de matemáticas en la educación obligatoria en España durante la década 1990-2000

La Constitución española de 1978 consagró el Estado de las Autonomías. Los respectivos Estatutos preveían la asunción de competencias educativas por parte de los gobiernos autonómicos; sin embargo no es hasta 1990, con la Ley de Ordenación General del Sistema Educativo (LOGSE), cuando se produce la transferencia efectiva de dichas competencias desde el gobierno central a las autonomías. Se promulgan a partir de ese momento los primeros desarrollos curriculares de carácter autonómico. En este trabajo se realiza la descripción y el estudio comparado de dichos currículos autonómicos en la educación obligatoria (6-16 años) en lo que se refiere a las matemáticas.The 1978 Spanish Constitution strengthened the Spanish Autonomous Communities. Articles comprehended in this Constitution foresaw the assumption of educative obligations by the Autonomies (Spanish regional governments). However, this assumption was not effective until 1990 with the enactment of the LOGSE (Spanish acronym for General Regulation Law of Educative System). Since then the first autonomic curriculum developments were established. This study conducts a comparative analysis among mathematics curriculum developments for Compulsory Education (from 6 to 16-year olds) in several Autonomous Communities

Regional decentralization of mathematics curriculum in primary and secondary spanish education during the nineties

La Constitución española de 1978 consagró el Estado de las Autonomías. Los respectivos Estatutos preveían la asunción de competencias educativas por parte de los gobiernos autonómicos; sin embargo no es hasta 1990, con la Ley de Ordenación General del Sistema Educativo (LOGSE), cuando se produce la transferencia efectiva de dichas competencias desde el gobierno central a las autonomías. Se promulgan a partir de ese momento los primeros desarrollos curriculares de carácter autonómico. En este trabajo se realiza la descripción y el estudio comparado de dichos currículos autonómicos en la educación obligatoria (6-16 años) en lo que se refiere a las matemáticas. .The 1978 Spanish Constitution strengthened the Spanish Autonomous Communities. Articles comprehended in this Constitution foresaw the assumption of educative obligations by the Autonomies (Spanish regional governments). However, this assumption was not effective until 1990 with the enactment of the LOGSE (Spanish acronym for General Regulation Law of Educative System). Since then the first autonomic curriculum developments were established. This study conducts a comparative analysis among mathematics curriculum developments for Compulsory Education (from 6 to 16-year olds) in several Autonomous Communities

Analysis of double-parallel amplified recirculating optical-delay lines

A novel method of analysis of double-parallel amplified recirculating optical-delay lines (DPAROD) is presented. The location of the maxima and the minima of the transfer function for this configuration is calculated and experimentally demonstrated. The influence of different parameters, such as the coupling coefficients, gains, lengths of the fiber loops and fractional losses of the directional couplers, on the shape of the transfer function are analyzed. Different measurements have been taken to verify this model. The potential application of these interconnected delay loops as filters is a reason for developing this method.Publicad

Multimode interference filter to solve degradation on coupler common-mode rejection

After quantifying degradation of a common mode rejection ratio (CMRR) 3dB-coupler due to excitation of TE01 mode, a novel compact circuit including multimode interference (MMI) coupler+bend+MMI+filter (CBF) is proposed. We show a CBF circuit has better CMRR at the expense of moderate loss. A complete tolerance analysis to main geometrical parameters has also been carried out.Publicad

Amplified Fiber-Optic Recirculating Delay Lines

Experimental and theoretical results on single- and double-amplified recirculating delay lines are presented. One of our aims is to emphasize their application as filters, showing a wide flexibility of design. Analysis of their performance in the spectral and time domains have been carried out. A novel method of understanding the behavior of double structures has been developed and successfully tested with experimental results employing Er-doped fiber amplifiers as delay lines.Publicad

Detección precoz de pacientes con degeneración macular asociada a la edad en farmacias comunitarias de la provincia de Pontevedra

OBJETIVOS Detección precoz de pacientes sospechosos de padecer DMAE. Cuantificar la respuesta del paciente en los casos de derivación. Establecer posibles factores de riesgo relacionados con la enfermedad en la población estudiada.MÉTODOS Estudio descriptivo en 25 farmacias de la provincia de Pontevedra, desde marzo a mayo de 2011. Sujetos: mayores de 50 años, no diagnosticados, sin problemas mentales y no dependientes. La muestra, aleatoria, se estratificó por grupos de edad. En caso de encontrar alteraciones visuales sospechosas de DMAE, se recomendaba la consulta al oftalmólogo. Al cabo de un mes se le llamaba por teléfono y se registraba el resultado. En caso de no haberla realizado, se le recordaba la importancia de dicha visita y se le llamaba transcurrido un mes más, registrándose entonces el resultado o la no visita.RESULTADOS Se hicieron 481 pruebas (48,4% hombres y 51,6% mujeres). Media de edad, 67,3 años (DE 9,5). Antecedentes familiares de alteraciones visuales en 125 (27,2%). Se derivaron al oftalmólogo 51 posibles positivos (10,6%), de los que tan sólo en 8 (15,7%) se obtuvo confirmación de su visita al médico. Ninguno resultó positivo. Las rela

Evolución histórica del concepto de límite funcional en los libros de texto de bachillerato y curso de orientación universitaria (COU) : 1940-1995

In this paper, we study the historical development of the concept of functional limit in the textbooks of bachillerato and COU during the last fifty years. We analyse twenty-seven books in three stages. In the last one, which gathers the results from the others, we consider three dimensions: conceptual, cognitive and phenomenologic that show us a wide perspective of the changes experimented in this development

Children’s improvement of a motor response during backward falls through the implementation of a safe fall program

The World Health Organization has warned that, in children, the second cause of death from unintentional injuries are falls. The objective of this study was to analyze the motor response of primary schoolchildren when a backwards fall occurs. These analyses occurred before and after interventions of the Safe Fall program, which aims to teach safe and protected ways of backward falling. A quasi-experimental research design was used, with a sample of 122 Spanish (Sevillian) schoolchildren in the 10–12 age bracket. The INFOSECA ad-hoc observation scale was used for data collection: this scale registers 5 essential physical reactions throughout the process of a safe and protected backwards fall. After that, a number of descriptive, correlational and contrast statistics were applied. The value used in the McNemar test to establish statistical significance was p < 0.05. Results showed that over 85% of students had developed the competence to correctly perform all five physical motions that allow for a safer backward fall. The teaching of safe and protected techniques for falling backwards in child population in Primary Education is possible through the implementation of the Safe Fall program in Physical Education classes, which can help making falls safer, diminishing the risk and severity of the injuries they cause

The concept of sustainable tourism in English for Tourism course books

2017 fue designado como el Año Internacional del Turismo Sostenible para el Desarrollo. El concepto de sostenibilidad turística está cada vez más vinculado a las nuevas formas de ocio. Los manuales de Inglés para Turismo deberían asimismo reflejar estas tendencias. El artículo muestra el análisis de contenido de 43 libros de inglés turístico universitario publicados a partir de 1992 para constatar la evolución del enfoque sobre sostenibilidad turística hasta convertirse en un tema habitual en la mayoría de los ejemplares actuales, así como los cambios en la terminología empleada.2017 is the International Year of Sustainable Tourism for Development. The current concept of tourism sustainability is increasingly linked to new trends of leisure. Course books of English for Tourism, likewise, should reflect these social changes. This article shows the content analysis of 43 textbooks used in teaching English for Tourism, published from 1992. Results verify the evolution of contents related to tourism sustainability, to become a common topic in most current course books, as well as the changes undergone in the terminology used