Coherent states on the circle

We present a possible construction of coherent states on the unit circle as configuration space. In our approach the phase space is the product Z x S^1. Because of the duality of canonical coordinates and momenta, i.e. the angular variable and the integers, this formulation can also be interpreted as coherent states over an infinite periodic chain. For the construction we use the analogy with our quantization over a finite periodic chain where the phase space was Z_M x Z_M. Properties of the coherent states constructed in this way are studied and the coherent states are shown to satisfy the resolution of unity.Comment: 7 pages, presented at GROUP28 - "28th International Colloquium on Group Theoretical Methods in Physics", Newcastle upon Tyne, July 2010. Accepted in Journal of Physics Conference Serie

Sedentarism impact on cardio-respiratory response in college students

La vida universitaria constituye una etapa crítica para la adquisición de hábitos saludables, por ello sería conveniente establecer medidas para la detección del riesgo de desarrollar patologías en un futuro. Los objetivos de esta investigación son conocer cuál es el nivel de sedentarismo y la repercusión del mismo en la función pulmonar y en la respuesta cardiorrespiratoria, estudiada a través de las presiones respiratorias máximas en boca y la prueba de 6 minutos marcha. La población de estudio fueron estudiantes del Grado de Fisioterapia de la Universidad de Vigo, durante los cursos académicos 2012-2013 y 2013-2014, un total de 104 sujetos. La muestra la formaron un total de 71 estudiantes. Los resultados muestran un nivel bajo de sedentarismo. Se establecen relaciones negativas entre los hábitos sedentarios y las pruebas de función pulmonar y cardiorrespiratorias, lo cual sugiere que los hábitos adquiridos en la juventud tienen repercusiones sobre el organismo ya desde edades tempranasHigher education is a critical period for the acquisition of healthy habits. The measures to detect the risk of developing diseases in the future are necessary. The objective of this research is to understand the impact of physical inactivity on lung function and cardiorespiratory response, studied through maximal respiratory pressures and 6-minute walk tests. The study was done with the students of Degree of Physiotherapy of Pontevedra faculty in Vigo University throughout the academic courses 2012-2013 and 2013-2014, with a total of 104 subjects. The sample comprised a total of 71 students. The results show low levels of physical inactivity. Negative relationships between sedentary habits and cardiorespiratory tests and pulmonary function are established, suggesting that habits acquired in youth have implications on the body from an early ag

An experimental model of mixing processes generated by an array of top-heavy turbulent plumes

The mixing process of two fluids of unequal density generated by the evolution of an array of forced turbulent plumes is studied in the laboratory. The corresponding qualitative conclusions and the quantitative results based on measures of the density field and of the height of the fluid layers are described. The partial mixing process is characterized and analyzed, and the conclusions of this analysis are related to the mixing efficiency and the volume of the final mixed layer as functions of the Atwood number, which ranges from 0.010 to 0.134. An exponential fit is used to evaluate the mixing efficiency versus the Atwood showing the role of initial conditions on mixing efficiency variability

Thorpe method applied to planetary boundary layer data

Turbulence affects the dynamics of atmospheric processes by enhancing the transport of mass, heat, humidity and pollutants. The global objective of our work is to analyze some direct turbulent descriptors which reflect the mixing processes in the atmospheric boundary layer (ABL). In this paper we present results related to the Thorpe displacements dT , the maximum Thorpe displacement (dT )max and the Thorpe scale LT , the Ozmidov scale and their time evolution in the ABL during a day cycle. A tethered balloon was used to obtain vertical profiles of the atmospheric physical magnitudes up to 1000m. We discuss the vertical and horizontal variability and how different descriptors are related to atmospheric mixing

A Course of Thermodynamics for an Industrial Engineering Degree using New Methodologies and Technologies

This paper presents the experience carried out at the Industrial Engineering School (ETSII) of the Universidad Politécnica de Madrid (UPM) for teaching Thermodynamics science using new methodologies and technologies. During the last two years a special course on Thermodynamics has been given to those students who failed to pass the ordinary examination. This group was made of around thirty students with some level of knowledge of the subject. Nontraditional teaching methodologies have been applied to this group stretching the potential of new technologies to the maximum possible extent. A complete e-learning system developed by our University called Aula Web was used to produce a weekly schedule for each individual student. Aula Web consists of several modules. News and Forum channel the communications with the student.“Contents” is a repository holding various types of learning material such us presentations, theoretical texts and problems with solutions. “Activities” assigns homework to the student who can submit it electronically. Finally, “Self-assessment” composes bespoke self-assessment tests resorting to a wide database of questions and short problems. A totally personalized long problem was programmed using MATLAB. The problem is structured in ten steps that help the student to progress towards his/her learning target. Upon conclusion of the learning program the student should have acquired all foreseen knowledge of the subject. Observed results are very satisfactory. Throughout the whole process the level of motivation of the students has been very high. The Universidad Politécnica de Madrid supports education innovation experiences through special programs whose main target is the convergence at the European Higher Education Space

Connexin-36 protects against suddent infant death syndrome

The sudden infant death syndrome (SIDS) is the main cause of postneonatal infant death; however the etiology of SIDS remains ill defined. The hypothesis that SIDS, or a subset of SIDS, is due to an abnormal brainstem mechanism is one of the current leading hypotheses on SIDS etiology. The brainstem is essential for cardiac and respiratory function, controlling autonomic and homeostatic responses including breathing, central chemosensitivity, heartbeat and blood pressure, all mechanisms that are thought to be involved in SIDS. Connexin-36 (Cx36), the principal component of neuron-to-neuron channels that form the electrical synapses, is present in the specific neural populations of brainstem region involved in the CO2 chemoreception and respiratory control, and its expression is unregulated during this critical period of life. Accordingly, we postulate that Cx36 would be a key element in the pathogenesis of SIDS. To address this issue we have studied how the genetic suppression of Cx36 expression affects to the respiratory pacemaker, central chemoreflexes, cardiorespiratory coupling, and risk for SIDS. Mice lacking Cx36 at postnatal day 14 showed in comparison with control wild-type greater variability in the respiratory rhythmicity, abnormally enhanced ventilatory responses to hypoxia and hypercapnia, more cardiorespiratory phase synchronization and less respiratory sinus arrhythmia. A combination of low O2 and high CO2 content in inspired air was used as exogenous stressor of SIDS; under these conditions all wild-type mice survived while the 40% of Cx36-knockout animals succumbed by respiratory failure

Meniscectomía por Cirugía Artroscópica

El propósito de este trabajo es presentar la experiencia y valoración estadística de 83 artroscopias de rodilla realizadas por los autores, durante el año 1988, describiendo la patología hallada, la técnica empleada, complicaciones per y postoperatorias así como la estancia media hospitalaria de estos pacientes.With this work, the authors showed their experience and statistic evaluation of 83 arthroscopies of the knee in 1988, describing the pathological findings, technical procedure used, complications during and after the arthroscopy as well as the average stay of these patients in the hospital

Las especies de Hyalopterus Koch, 1854 (Hemiptera, Aphididae), pulgones harinosos de los frutales de hueso, en España peninsular e Islas Baleares

Distribution of the genus Hyalopterus Koch, 1854 (Aphidinae, Aphidini, Rhopalosiphina) in Spanish mainland and Balearic Islands has been studied by the review of the bibliographic records, the material deposited in Universidad de León collection and the photographs stored in Insectarium virtual. The distribution of Hyalopterus species is updated and new records are reported. An identification key for the viviparous females of Hyalopterus species is also presented.Se ha estudiado la distribución de las especies del género Hyalopterus Koch, 1854 (Aphidinae, Aphidini, Rhopalosiphina) en España peninsular e Islas Baleares mediante la revisión de las citas bibliográficas, del material depositado en la colección de la Universidad de León y de las fotografías almacenadas en Insectarium virtual. Se actualiza la distribución de las especies y aportan citas en nuevas provincias. Además, se aporta una clave de identificación para las hembras vivíparas ápteras de las especies de Hyalopterus

Estudio de las emisiones de CO2 en una instalación de turbina de gas con diferentes combustibles

El uso de las turbinas de gas en ciclo combinado es una de las alternativas más aceptadas en los últimos tiempos. Existen muchas razones por las que se está investigando sobre la posibilidad de usar otro tipo de combustibles como alternativa al característico, gas natural (metano). Entre otras, se pueden citar: la evolución del precio y la disponibilidad en una zona de algún tipo de gas de síntesis [17] así como estrategias medioambientales y de emisiones [10], [18], [20]. En la bibliografía se encuentran estudios, en los que de forma rigurosa se establece la relación entre la eficiencia de una instalación, usando balances característicos del Segundo Principio de la Termodinámica, y aspectos muy diversos como análisis de los gases de combustión [14], posibilidad de recalentamiento de los gases [19], temperaturas de gasificación [23] y temperatura de llama [18] etc. Estos estudios siempre toman como combustible el metano. En este estudio se presenta un análisis de las emisiones de CO2 (toneladas emitidas) por energía eléctrica producida (MWh) en la instalación de turbina de gas en ciclo combinado usando como combustible los primeros elementos de los hidrocarburos alcanos desde el metano, que se toma como referencia, hasta el heptano. Esto permite la determinación de las emisiones para distintos combustibles con distintas composiciones. Como parámetros relacionados directamente con la eficiencia de la instalación, se han contemplado para cada combustible diferentes temperaturas de entrada a la turbina de gas y distintas relaciones de compresión. Finalmente se obtienen una serie de curvas que relacionan la eficiencia y las emisiones con el número de carbonos presentes en el combustible. El análisis realizado pretende ser un elemento de discusión, basado en aspectos puramente termodinámicos, para la toma de decisione

The histo structure of galls induced by aphids as a useful taxonomic character: the case of rectinasus (Hemiptera, Aphididae, Eriosomatinae)

P. 487-492Morphological differentiation of gall tissues induced on plants may play a role to characterize the real taxonomic position of the gall inducer. We verified this hypothesis with galls induced by Rectinasus buxtoni on Pistacia palaestina. There is controversy about the taxonomic localization of genus Rectinasus: in one classification it is situated with the genera Forda and Paracletus while in another it is linked to the genera Geoica and Baizongia. Histological examination of the walls of the galls reveals the presence of two opposed vascular bundles and an inner surface of the gall with cavities. These features place Rectinasus in the same group as Geoica and Baizongia, and not with Paracletus and Forda, whose galls have a different histological structure, as generally admitted.S