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Search Results: 1 - 10 of 340860 matches for " E. Casta?ón "
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The confined two-dimensional hydrogen atom in the linear variational approach
N. Aquino,E. Casta?o
Revista mexicana de física , 2005,
Abstract: En este trabajo analizamos el problema de un átomo de hidrógeno bidimensional confinado al interior de una región circular de paredes impenetrables. Estudiamos los efectos de tama o sobre los valores propios de la energía como función del radio del círculo. Usamos el método variacional lineal con la base de la partícula libre en un círculo. Comparamos nuestros resultados con los obtenidos mediante la teoría de perturbaciones y el método Rayleigh-Ritz que habían sido reportados previamente.
Analysis of some meteorological variables recorded at 4000 m in the Argentinean subtropical Andean region
CASTA?EDA, M. E.;RATTO, N.;
Atmósfera , 2009,
Abstract: an automated weather station was installed in january 2004 for the first time at the destacamento las grutas of gendarmería nacional, province of catamarca (26°52'35"s, 68°18'37"w, 4000 masl). from april to december, meteorological conditions on the mountain were observed in order to better understand the high-altitude subtropical meteorology. this article documents the design, installation, and operation of the weather station, and presents a discussion of the collected measurements. the analyzed variables were air temperature, maxima and minima temperatures, humidity, precipitation, wind, as well as the occurence of snow, registered by the staff at gendarmería. large daily variability was recorded in most variables, which is not unexpected given the geographical location. daily fields of the ncep /ncar reanalysis relate the dates of large variability to cold surges affecting the region. hourly wind direction measurements show preferential directions of sw-nw, with the largest variability occurring during november and december, indicating that moisture enters the region from different sources.
Asociacion de leveduras del genero Cryptococcus con especies de Eucalyptus en Santafe de Bogota
Duarte, A.;Ordo?ez, N.;Casta?eda, E.;
Revista do Instituto de Medicina Tropical de S?o Paulo , 1994, DOI: 10.1590/S0036-46651994000200006
Abstract: environmental isolation of cryptococcus neoformans var. gattii was first made in australia in 1989 by ellis. he established a specific association with the tree species eucalyptus camaldulensis and e. tereticornis. based on his findings, ellis proposed that the fungus could be exported from australia to others regions, including colombia, by means of infected seeds. the purpose of this study was to isolate and identify cryptococcus sp., associated with eucalyptus trees; this is the first ecological evaluation of c. neoformans var. gattii in our country. a total of 100 eucalyptus trees, distributed among 13 zones, located in the center, northeast, east and west of santafé de bogotá, were studied. flowers, fruits, leaves, barks and eucalyptus debris were collected. the samples were processed by extraction with saline solution containing antibiotics, cultured in selective media and the isolates were identified by morphological and biochemical characteristics. twenty-seven isolates of 9 cryptococcus sp. were recovered from 21 eucalyptus trees, from 5 zones. one c. neoformans var. neoformans serotype a was recovered. the cryptococcus associated with eucalyptus is important because this is the first study done in our country.
Hematoma epidural secundario a anestesia espinal: Tratamiento conservador Epidural hematoma secondary to spinal anesthesia: Conservative treatment
M. Bermejo,E. Casta?ón,P. Fervienza,F. Cosío
Revista de la Sociedad Espa?ola del Dolor , 2004,
Abstract: Introducción: El hematoma epidural secundario a una anestesia neuroaxial es una complicación poco frecuente, pero de gran trascendencia tanto por sus implicaciones clínicas como por las médico legales; según algunos autores su incidencia puede oscilar entre 1/190.000-1/200.000 para las punciones peridurales y 1/320.000 en el caso de las espinales. El aspecto prioritario en su manejo terapéutico es el del diagnóstico y tratamiento precoz, antes de las 6-12 primeras horas. No obstante, en determinados pacientes como en el caso que presentamos puede no ser precisa la cirugía, resolviéndose el cuadro con tratamiento conservador. Caso clínico: Varón de 73 a os, ASA IV, con antecedentes de cirrosis con hipertensión portal, hiperesplenismo, EPOC, obesidad, cardiopatía hipertensiva e insuficiencia tricuspídea. Se programa para alcoholización prostática al haber sido desechada la cirugía. En la analítica preoperatoria destacaba una actividad de protrombina del 80% y 90.000 plaquetas. Se realizaron varios intentos fallidos de punción espinal, finalmente fue precisa una anestesia general con ventilación espontánea mediante mascarilla laríngea, propofol, fentanilo y sevoflurano. A las 36 horas, comienza la clínica en forma de dolor intenso lumbar, sin irradiación y arreflexia cutáneo plantar, confirmándose en la RMN la presencia de un hematoma epidural de L1 a L4. Ante la ausencia de paraparesia flácida, afectación esfinteriana u otros signos sensitivo-motores y tras consulta con la Unidad de Raquis y con el Servicio de Neurología se decide tratamiento conservador y actitud expectante en forma de analgesia y monitorización neurológica estricta, clínica y radiológica. Evolucionando favorablemente en los siguientes días. Discusión: Determinadas condiciones clínicas pueden influir en la aparición de un hematoma tras la realización de un bloqueo regional central: heparinas de bajo peso molecular, punciones dificultosas, cirugía vertebral previa, hepatopatías, fármacos, etc. El tratamiento quirúrgico en forma de laminectomía descompresiva realizada de forma precoz suele ser necesario y es el tratamiento de elección en muchas ocasiones, pero en determinadas condiciones como la que nos ocupa, sin síntomas compresivos, sin un carácter progresivo o bien que estos disminuyan rápidamente, puede optarse por un tratamiento conservador en forma de analgesia y corticoterapia, siempre bajo un estricto control que permita actuar de forma rápida ante cualquier eventualidad negativa en su evolución. Introduction: Epidural hematoma secondary to neuroaxial anesthesia is a rare complicat
Sleep quality, sleep patterns and consumption of energy drinks and other caffeinated beverages among Peruvian college students  [PDF]
Sixto E. Sanchez, Claudia Martinez, Raphaelle A. Oriol, David Yanez, Benjamín Casta?eda, Elena Sanchez, Bizu Gelaye, Michelle A. Williams
Health (Health) , 2013, DOI: 10.4236/health.2013.58A2005
Abstract:

Objectives: To evaluate sleep quality in relation to lifestyle characteristics including consumption of energy drinks and other caffeinated beverages among Peruvian college students. Methods: A total of 2458 college students were invited to complete a self-administered questionnaire that collected information about a variety of behaviors including consumption of energy drinks, caffeinated and alcoholic beverages. The Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality. Logistic regression procedures were used to estimate odds ratios (OR) and 95% confidence intervals (95% CI) for poor sleep quality in relation to lifestyle characteristics. Results: A total of 965 males and 1493 female students were enrolled in the study. 52.0% of males and 58.4% of females experienced poor sleep quality (p = 0.002). Females (OR = 1.28; 95% CI 1.08-1.51) and those who reported consuming ≥3 stimulant beverages per week (OR = 1.88; 95% CI 1.42-2.50) had higher odds of poor sleep quality. Students who consumed 1-19 alcoholic beverages monthly (OR = 1.90; 95% CI 1.46-2.49) had a higher odds of long sleep latency. Consumption of ≥3 stimulant beverages per week was associated with daytime dysfunction due to sleep loss (OR = 1.45; 95% CI 1.10-1.90), short sleep duration (OR = 1.49; 95% CI 1.14-1.94), and use of sleep medication (OR = 2.10; 95% CI 1.35-3.28). Conclusions: Consumption of energy drinks, other caffeinated beverages and alcoholic beverages are risk factors of poor sleep quality. Increased awareness of these associations should promote interventions to improve students’ lifestyle habits, including consumption of alcoholic and caffeinated beverages, and overall health.

Classical wave equation scalar normal modes and Green functions for confocal hyperboloidal electrodes
N. Aquino,E. Casta?o,E. Ley Koo,S. E. Ulloa
Revista mexicana de física , 2004,
Abstract: Se construyen expl′ citamente los modos normales y las funciones de Green escalares para la ecuaci′on de onda cl′asica sujetas a condiciones de frontera de Dirichlet y de Neumann en superficies hiperboloidales confocales, las cuales modelan las formas de los electrodos en un microscopio de tunelaje y barrido, y en juntas conductor-aislante-conductor. Estos modos y funciones son de inter′es como posibles puntos de partida para el estudio del efecto Casimir entre los electrodos de tales dispositivos.
Effects of recombinant growth hormone (GH) replacement and psychomotor and cognitive stimulation in the neurodevelopment of GH-deficient (GHD) children with cerebral palsy: a pilot study
Devesa J, Alonso B, Casteleiro N, Couto P, Casta ón B, Zas E, Reimunde P
Therapeutics and Clinical Risk Management , 2011, DOI: http://dx.doi.org/10.2147/TCRM.S21403
Abstract: ts of recombinant growth hormone (GH) replacement and psychomotor and cognitive stimulation in the neurodevelopment of GH-deficient (GHD) children with cerebral palsy: a pilot study Original Research (3924) Total Article Views Authors: Devesa J, Alonso B, Casteleiro N, Couto P, Casta ón B, Zas E, Reimunde P Published Date May 2011 Volume 2011:7 Pages 199 - 206 DOI: http://dx.doi.org/10.2147/TCRM.S21403 Jesús Devesa1,2, Bego a Alonso1, Nerea Casteleiro1, Paula Couto1, Beatriz Casta ón1, Eva Zas1, Pedro Reimunde1,2 1Medical Center “Proyecto Foltra”, Cacheiras (Teo), A Coru a, Spain; 2Department of Physiology, School of Medicine, University of Santiago de Compostela, Spain Abstract: Cerebral palsy (CP) is the main cause of physical disability in childhood and is an important health issue that has a strong socioeconomic impact. There is no effective treatment for CP and therapeutic approaches report only partial benefits for affected people. In this study we assessed the effects of growth hormone (GH) treatment combined with psychomotor and cognitive stimulation in the neurodevelopment of children with CP and GH deficiency (GHD). The study was carried out in 11 patients (7 boys and 4 girls; 4.12 ± 1.31 years) with GHD and CP who were treated with recombinant GH (rGH) and psychomotor and cognitive stimulation during 2 months. Battelle Developmental Inventory Screening Test (BDIST) was performed 2 months before commencing GH treatment, just before commencing GH administration, and after 2 months of combined treatment involving GH and cognitive stimulation. Psychomotor and cognitive status did not change during the period in which only cognitive stimulation was performed; however, significant improvements in personal and social skills, adaptive behavior, gross motor skills and total psychomotor abilities, receptive and total communication, cognitive skills and in the total score of the test (P < 0.01), and in fine motor skills and expressive communication (P < 0.02) were observed after the combined treatment period. Therefore, GH replacement together with psychomotor and cognitive stimulation seem to be useful for the appropriate neurodevelopment of children with GHD and CP.
Combining Artificial Intelligence and Advanced Techniques in Fault-Tolerant Control
Vargas-Martínez, A;Garza-Casta?ón, L. E.;
Journal of applied research and technology , 2011,
Abstract: we present the integration of artificial intelligence, robust, nonlinear and model reference adaptive control (mrac) methods for fault-tolerant control (ftc). we combine mrac schemes with classical pid controllers, artificial neural networks (anns), genetic algorithms (gas), h∞ controls and sliding mode controls. six different schemas are proposed: the first one is an mrac with an artificial neural network and a pid controller whose parameters were tuned by a ga using pattern search optimization. the second scheme is an mrac controller with an h∞ control (h∞). the third scheme is an mrac controller with a sliding mode controller (smc). the fourth scheme is an mrac controller with an ann. the fifth scheme is an mrac controller with a pid controller optimized by a ga. finally, the last scheme is an mrac classical control system. the objective of this research is to generate more powerful ftc methods and compare the performance of above schemes under different fault conditions in sensors and actuators. an industrial heat exchanger process was the test bed for these approaches. simulation results showed that the use of pattern search optimization and anns improved the performance of the ftc scheme because it makes the control system more robust against sensor and actuator faults.
Sistema Inteligente de Detección y Orientación de usuarios en Bibliotecas
Casta?o, Bonifacio,E-Martín, Yolanda,R-Moreno, M. Dolores,Usero, Luis
Revista Espa?ola de Documentación Científica , 2013,
Abstract: Since the late nineties, Radio Frequency IDentification (RFID) manages library catalogs, loans, returns and security. RFID, with a moderate investment, improve the capabilities of both, librarian and user. This paper presents a new use for RFID to determine where a book is located and the shortest route to it in libraries with multiple levels and rooms. An application named SIGUEME (Sistema Inteligente de GUiado para Entornos Multiusuario Extensos; Intelligent System to Guide for Multiuser Extensive Environments) was implemented experimentally in the Meco’s public library (Madrid). The system allows people detection and customized guiding in the building thanks to different screen placed in strategic points. We have developed a wireless communications system based on Zigbee technology that eliminates the need of wires. Los dispositivos de identificación por radiofrecuencia (Radio Frequency IDentification, en adelante RFID) son usados desde finales de los a os noventa en el entorno de bibliotecas para la gestión del inventario, control de catálogos, seguridad, préstamo y devolución. Durante este tiempo han demostrado ser un componente que, con una inversión moderada, mejora multitud de capacidades tanto para el bibliotecario como para el usuario. En este artículo se expone una nueva funcionalidad con RFID para bibliotecas que ha sido implantada de forma experimental en la Biblioteca Municipal de Meco (Madrid). Su objetivo es abordar un problema común que sufren los usuarios en bibliotecas con diferentes alturas y múltiples espacios: la correcta localización de los libros y la orientación por el edificio. Para solventar este problema se ha desarrollado una aplicación bautizada como SIGUEME (Sistema Inteligente de GUiado para Entornos Multiusuario Extensos). El sistema permite la detección de las personas por el edificio y el guiado personalizado por el mismo gracias a la visualización de la información en pantallas. Para evitar el cableado, se ha utilizado un sistema de comunicaciones inalámbrico basado en la tecnología Zigbee.
Toxic Effects of Saccharosa and Ammonium Ion in Osteopilus septentrionalis larvae.
Trujillo Hernández J,Carballo Hondal O,Casta?eda León JM,álvarez Pérez E
RETEL : Revista de Toxicología en Línea , 2007,
Abstract: The culture media used in the production of bioproducts for agricultural purposes are rich in carbon hydrates. There are some organisms unable to assimilate these carbon hydrates. Formulations containing ammonium ions are potentially toxic. The objectives of this work are to record sings of toxicity or mortality in larvae of frogs (Osteospilus septentrionalis), macroscopic and histological damages in organs and tissues of larvae exposed to the culture medium and to ammonium sulphate. A static 96 hours study was carried out with healthy larvae, between the 25 - 26 stagets according to Gosner classification. The concentrations evaluated were: 0.1, 1.0, 10.0 and 100.0 mg/l for both culture medium and Ammonium Sulphate. Concentrations were calculated according to their proportion in the final formulation. Only under the 100.0 mg/l concentration, the 100 % of larvae died after 96 hours. Both groups showed signs of toxicity, evidenced by injury in organs and tissues (liver, vesicle, pancreas and intestines). An excessive ingestion of carbon hydrates (saccharosa) caused cell degeneration in liver and pancreas cells, this finding coincided with the reports of other authors. It is concluded that the excessive ingestion of saccharosa and ammonium caused death and damages to the frog larvae Osteospilus septentrionalis kept under pond conditions.
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