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Sample records for calor del verano

  1. Valoración del impacto de la ola de calor del verano de 2003 sobre la mortalidad Evaluation of the impact of the heat wave in the summer of 2003 on mortality

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    Gonzalo López-Abente

    2004-05-01

    Full Text Available Las altas temperaturas experimentadas en Europa durante el verano de 2003 tuvieron un efecto en la mortalidad en varios países, incluido el nuestro. En este capítulo se describe la mortalidad registrada durante el período comprendido entre el 1 de junio al 31 de agosto de 2003, y se comenta el impacto de las olas de calor sufridas. El número de defunciones se obtuvo de los registros civiles de las capitales de provincia y de una muestra aleatoria de 107 municipios rurales. Esto se comparó con la mortalidad esperada, estimada mediante un modelo de regresión de Poisson sobre series históricas de defunciones, corregido por la tendencia ascendente y la estacionalidad de la mortalidad. La información meteorológica la proporcionó el Instituto Nacional de Meteorología. España experimentó tres períodos de temperaturas elevadas. El exceso de defunciones asociado fue del 8% (43.212 observadas por 40.046 esperadas. El exceso de mortalidad afectó exclusivamente a las personas mayores de 65 años (15%. Este incremento también se observó en el medio rural. Este fenómeno es un problema de salud pública emergente por su riesgo atribuible creciente debido al envejecimiento de la población. Frente a ello, se pueden plantear sistemas de alerta y respuesta basados en el control de riesgos naturales, las demandas médicas de urgencia y las defunciones, así como en el fortalecimiento de la capacidad de respuesta de los servicios sociales y sanitarios.The effect of the elevated temperatures experimented in Europe during the summer 2003 on mortality was observed in several countries. This study, carried out in Spain, describes the mortality between the 1st June and the 31st August and evaluates the effect of the heat wave on mortality. Observed deaths were obtained from official vital Registers of the capital city of the 50 provinces. Deaths from 107 randomly selected rural villages were also obtained from the same source. Observed deaths were

  2. Critical analysis of the daylight saving time; Analisis critico al horario del verano

    Energy Technology Data Exchange (ETDEWEB)

    Romero Paredes Rubio, Hernando [Universidad Autonoma Metropolitana Ciudad-Ixtapalapa, Mexico, D.F., (Mexico)

    2001-07-01

    The critical analysis is presented as a synthesis of the problem untied since the implementation of the daylight saving time. The often related history is retaken to introduce the reader into the context of the causes of a such program. The geometric aspect of the solar trajectories is discussed and the length of the day as a function of the latitude and the time of the year to have technical elements for the time displacement in a certain region. The technical implementation of the daylight saving time based on three elements is justified: time of dawn and the decline (length of the day), national economic motivation and tourism industry. Stands out that although the daylight saving time schedule has a set of social and economic benefits it is not centered in the individual but in the society as a whole. The errors in handling the information and the misinformation are pointed out as the main causes of the controversy, the discord and the political manipulation of competing groups. [Spanish] El analisis critico se presenta como una sintesis del problema desatado desde la implementacion del horario de verano. La historia muchas veces contada se retoma para introducir al lector en el contexto de las causas de un tal programa. Se discute el aspecto geometrico de las trayectorias solares y la longitud del dia como una funcion de la latitud y de la epoca del ano para tener elementos tecnicos para el desplazamiento horario en una region determinada. Se justifica la implementacion tecnica del horario de verano en funcion de tres elementos: hora de alba y del ocaso (longitud del dia), motivacion economica nacional e industria turistica. Se destaca que si bien el horario de verano tiene un conjunto de beneficios sociales y economicos no se centra en el individuo sino en la sociedad en su conjunto. Se senalan los errores de manejo de la informacion y la desinformacion como los principales causantes de la polemica, el desacuerdo y la manipulacion politica de grupos

  3. Elementi di trasmissione del calore

    CERN Document Server

    Guglielmini, Giovanni

    1990-01-01

    Introduzione ; concetti fondamentali di conduzione termica ; conduzione termica in regime stazionario ; conduzione termica in regime variabile ; analisi numerica nei problemi do conduzione ; concetti fondamentali di convezione termica ; convezione forzata ; convezione naturale ; scambio termico in ebollizione e condensazione ; concetti fondamentali di radiazione termica ; scambio termico per radiazione ; scambiatori di calore ; problemi termici negli edifici.

  4. Helena o el mar del verano (1952 y la novela lírica

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    Casas, Ana

    2008-12-01

    Full Text Available After analysing the reception and context of Julián Ayesta’s Helena o el mar del verano (1952, this paper examines the diverse formal resources that connect this work to the genre of lyrical novel. From this perspective, it puts special attention to the subjectivity of the text, which particularly shows the consciousness of the child who progressively becomes an adult, rather than the objective representation of the world. Thus, the circular structure, the fragmentarism, the division of the story in scenes or the descriptive stillness are part of the narrator’s internalization of time and space, whose experience of the past has not concluded, for it continues to be alive for him.Tras reseñar la recepción de Helena o el mar del verano (1952, de Julián Ayesta, y enmarcarla en su contexto, el presente trabajo analiza los diversos recursos formales que relacionan esta obra con el género de la novela lírica. Desde esta perspectiva, se interesa por el subjetivismo del relato, el cual se afana en plasmar la conciencia del niño que deviene progresivamente adulto, y no tanto en representar el mundo de manera objetiva. Así, la estructura circular, el fragmentarismo, la división del relato en escenas o el estatismo descriptivo participan de la interiorización del tiempo y el espacio por parte de un narrador cuya experiencia del pasado no ha concluido, pues para él sigue estando viva.

  5. Daylight saving time (summer 2001) for a culture of energy care; Horario de verano 2001 por una cultura del cuidado de la energia

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-09-01

    As in other headings, such as the care of water and the environment, in what corresponds to energy care, we must take a foresighted attitude so that in a near future we not only can continue covering our energy needs, but also that we do not lack of it, because it is an indispensable service for modern life, practically in any field of the human activity. In this article it is mentioned how the daylight saving time works, the impact in the consumption and demand of electrical energy, resulting from the daylight saving time program 1996-2000. Energy impact, certification of the energy impact due to the application of the program in Mexico, the environmental impact, how the organism adapts harmonically to the summer schedule, the daylight saving program in the world, the daylight saving time program in Mexico, the adjustment in the period of application, and the accumulated results 1996-2000 by the establishment of the daylight saving time program. [Spanish] Al igual que en otros rubros, tales como el cuidado del agua y del medio ambiente, en lo que corresponde al cuidado de la energia, debemos tomar una actitud previsora para que en un futuro cercano no solo podamos continuar cubriendo nuestras necesidades de energia, sino para que esta no nos falte, porque se trata de un servicio indispensable para la vida moderna, practicamente en cualquier campo de la actividad humana. Este articulo se habla sobre como funciona el horario de verano, el impacto en el consumo y la demanda de energia electrica, resultados del horario de verano 1996-2000, Impacto energetico, certificacion del impacto energetico debido a la aplicacion del horario de verano en Mexico, el impacto ambiental, el organismo se adapta armonicamente al horario de verano, el horario de verano en el mundo, el horario de verano en Mexico, el ajuste en el periodo de aplicacion, y resultados acumulados 1996-2000 por el establecimiento del horario de verano.

  6. Variaciones interanuales de la precipitación de verano y el rendimiento del cultivo de la vid en Mendoza

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    Eduardo Andrés Agosta

    2010-12-01

    Full Text Available La producción de vid es la fuente económica agroindustrial principal en Cuyo (28°S-36°S / 65°W-70°W, siendo la región de más elevado desarrollo vitivinícola del país. Uno de los factores climáticos de mayor impacto en la producción de vid es la destrucción del cultivo por granizo, como resultado de la convección severa desarrollada en época estival. La violencia con que se desarrollan las tormentas estivales de granizo genera un impacto importante en el rendimiento de los viñedos afectados, logrando la disminución parcial o total de parcelas enteras. Durante el período 1979-2008, la precipitación de verano presenta fluctuaciones de la escala 7-8 años al igual que la producción total de vid y ambas se encuentran inversamente correlacionadas intradecádicamente. Asimismo, veranos húmedos (secos pueden presentar mayor (menor probabilidad de ocurrencia de daños por granizo en la temporada actual que se pueden asociar a menor (mayor producción de vid en la temporada del año siguiente debido a cambios en la disponibilidad de yemas fértiles. También una fracción de la variación de la producción de vid en el verano actual puede estar asociada a cambios en la precipitación de ese verano por daño directo (intensidad de la precipitación o indirecto (anegamiento relativamente prolongado ya que la desfoliación y asfixia radicular parecen afectar el rendimiento de las plantas. La clara dependencia climática de cultivo muestra que la producción total anual de vid está modulada por las variaciones de la precipitación en escalas decádicas, la cual está vinculada a factores de escala global del sistema climático. Se derivan potenciales resultados para el pronóstico de la producción de vid bajo futuros escenarios de cambio climático para la región.The grape production is the main economic source in the agro-industry of Cuyo (28°S-36°S / 65°W- 70°W, becoming the most developed region for wine production in Argentina

  7. Apuntes de Transmisión del Calor

    OpenAIRE

    Martín Domingo, Agustín

    2013-01-01

    Esta publicacion está basada en unos apuntes para la parte de Transmisión del Calor de las asignaturas de la ETSAM. Sin embargo, con el tiempo se ha añadido otro material extra que excede ampliamente el contenido del curso.

  8. The daylight saving time in Mexico; El cambio de horario durante la epoca del verano en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Covarrubias Ramos, Rogelio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1996-12-31

    The daylight saving time in Mexico for energy saving is analyzed; such a change is made forwarding the clocks one hour in all Mexico the first Sunday of April and backing them an hour the last Sunday of October. Mention is made the reasons why Mexico adopted this measure, the social-economic impact that brings along and the benefits of this daylight saving time. The case of countries that also apply this measure is analyzed. It is expected that this measure attains benefits for the society either collectively or individually through the ecology and the economy. [Espanol] Se analiza el cambio de horario en la epoca de verano en Mexico para ahorrar energia; dicho cambio se realiza al adelantar una hora al reloj en todo el territorio de Mexico el primer domingo de abril y retrazarlo una hora el ultimo domingo de octubre. Se mencionan las razones por las cuales Mexico adopto esta medida, el impacto socio-economico que traera consigo y los beneficios del cambio de horario. Se aborda la situacion de los paises que tambien aplican esta medida. Se espera que esta medida logre beneficios para la sociedad, ya sea en modo colectivo o individual, para la ecologia y para la economia.

  9. Persistencia del herbicida Imazapir en el suelo y efectos fitotóxicos sobre cultivos de invierno y de verano

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    GIANELLI, V.

    2011-04-01

    Full Text Available Imazapir es un herbicida de amplio espectro de control, perteneciente al grupo químico de las imidazolinonas. En Argentina es aplicado a gran escala en los cultivos de girasol y maíz Clearfield. Debido a su acción residual en el suelo, resulta de gran importancia determinar su persistencia fitotóxica. El objetivo de este trabajo fue determinar la persistencia fitotóxica sobre cultivos de invierno y de verano, de dos dosis de imazapir aplicado en un cultivo de girasol Clearfield. El ensayo se realizó en un suelo franco-arcilloso de Balcarce (Pcia. de Buenos Aires, siguiendo un diseño experimental en bloques completos aleatorizados con cuatro repeticiones. Los tratamientos consistieron en la aplicación de imazapir en dosis de 80 y 160 g de ingrediente activo (i.a/ha, incluyéndose un testigo sin tratar. Luego de la cosecha del girasol (marzo de 2003, se obtuvieron muestras de suelo mensualmente. Posteriormente, se efectúo un bioensayo en cámara de crecimiento con trigo, colza, girasol y maíz no tolerantes. Paralelamente, se sembró a campo maíz y girasol no tolerantes a imidazolinonas y papa, determinándose el rendimiento. Los resultados fueron analizados mediante un análisis de la varianza (p = 0.05. La persistencia fitotóxica en el bioensayo siguió el orden trigo > colza > girasol = maíz. A campo, ninguno de los cultivos evaluados mostró efectos negativos, indicando que no existió efecto residual sobre ellos.

  10. Cursos INDEM de verano: aprendiendo a interpretar las claves del mundo financiero

    OpenAIRE

    Mayoral, Silvia; Gómez Jorge, Fabiola; Alonso Ferreiro, Ignacio

    2015-01-01

    El Instituto para el Desarrollo Empresarial (INDEM), vinculado al Departamento de Economía de la Empresa de la Universidad Carlos III de Madrid ha organizado varios cursos y talleres, orientados a estudiantes de grado y profesionales del sector económico y financiero. Dichos cursos han sido dirigidos por expertos en finanzas, marketing, contabilidad y management. Contiene: Entrevista a Silvia Mayoral Blaya, Profesora titular en el Departamento de Economía de la Empresa de la UC3M y vicedec...

  11. EFECTO DEL PASTOREO DE VERANO DE TRÉBOL VIOLETA SOBRE EL CONTENIDO EN OMEGA-3 DE LA LECHE DE VACUNO

    OpenAIRE

    Flores, G.; RESCH, C.; Fernández-Lorenzo, B.; González-Arráez, A.; Valladares, J.; Dagnac, T; Latorre, A.; AGRUÑA, M. J.; Pereira, S; N. Díaz; Giménez, R.; RODRÍGUEZ-DIZ, X.

    2012-01-01

    Se presentan resultados de un ensayo en el que se evaluó el efecto del pastoreo de praderas de trébol violeta y de raigrás inglés durante el verano sobre la producción y composición de ácidos grasos (AG) de la leche de vacuno. El experimento se realizó entre el 25 de julio y el 26 de septiembre de 2010, con tiempo seco y caluroso. La calidad nutricional del pasto se redujo conforme avanzaba la estación de pastoreo en ambos tratamientos, de forma menos marcada para el pasto de trébol violeta, ...

  12. The methodology for the evaluation of the energy saving by the daylight saving time in Mexico; Metodologia para la evaluacion del ahorro de energia debido al cambio de horario durante la epoca del verano

    Energy Technology Data Exchange (ETDEWEB)

    Ramos Niembro, Gaudencio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1996-12-31

    A description is made of the methodology for the evaluation of energy saving by the daylight saving time in Mexico. A mathematical model was developed that would allow the quantitative evaluation of the energy saving by the daylight saving time, through measurements of the consumption of different users from the domestic commercial and industrial sector, considering the various variables that impact the consumption [Espanol] Se describe la metodologia para la evalucion del ahorro de energia por el cambio de horario de verano en Mexico. Se desarrollo un modelo matematico que permitiera evaluar cuantitativamente el ahorro de energia debido al cambio de horario durante la epoca de verano, atraves de mediciones de consumos de los diferentes usuarios de los sectores domestico, comercial e industrial, considerando las diversas variables que impactan en el consumo

  13. Efecto del calor aportado en recargues nanoestructurados base hierro

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    Agustín Gualco

    2013-12-01

    Full Text Available En los últimos años se han desarrollado consumibles de soldadura que depositan recubrimientos duros de aleaciones base hierro nanoestructuradas de gran resistencia al desgaste abrasivo. Las resistencias al desgaste erosivo y abrasivo están controladas principalmente por la composición química y la microestructura. A su vez, la microestructura del metal depositado puede presentar variaciones con el procedimiento de soldadura empleado, especialmente en relación al aporte térmico. Los parámetros operativos que definen el aporte térmico (tensión, corriente y velocidad de soldadura afectan aspectos como la geometría del cordón (ancho, penetración y sobremonta y la dilución con el material base. El propósito de este trabajo fue estudiar el efecto del calor aportado sobre las características geométricas del cordón, la dilución y la evolución microestructural de una aleación nanoestructurada base hierro, depositada por FCAW. Se soldaron muestras con aportes térmicos de entre 0,5 y 3,5 kJ/mm. Sobre cada cupón soldado se realizó un relevamiento dimensional, se analizó la composición química y se caracterizó la microestructura usando microscopías óptica y electrónica de barrido y difracción de rayos X. También se midieron la microdureza del depósito, el tamaño de cristalita y el grado de dilución. Se observó una gran influencia de las condiciones de proceso sobre la geometría del cordón. La dilución varió entre un 30 y un 40%, la microdureza del depósito se encontró entre 800 y 870 HV1 y el tamaño de cristalita osciló entre 105 y 130 nm, en función de las variables de proceso empleadas. Las mayores durezas y los menores tamaños de cristalita se obtuvieron con el menor aporte térmico, asociado a una menor dilución.

  14. Perturbaciones de los fuegos de verano en la palma mas austral del mundo (Jubaea Chilensis (mol. Baillon en microcuencas costeras de la Zona Mediterranea de Chile

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    Víctor Quintanilla Pérez

    2013-01-01

    Full Text Available Uno de los principales factores de degradación de las microcuencas costeras de la región de Valparaíso corresponde a los incendios forestales, como también a la expansión urbana y a las obras de infraestructura, que han implicado una importante disminución de la superficie vegetal nativa y que posee especies de un alto valor geobotánico y endémico, como es el caso de la palma chilena (Jubaea chilensis. Esta palmera se encuentra en la formación del bosque esclerófilo de Chile central (30o-37oS., área en la cual ocurren la mayor parte de los fuegos vegetales durante el vera- no en el país. A través de los registros de incendios que comprende el período 2000-2012, se han definido en el área de estudio los sectores críticos con mayor impacto de los fuegos; información que es complementada con la aplicación de índices de vegetación (NDVI a partir de imágenes satelitales Landsat e imágenes Theos-I de diferentes temporadas de verano.

  15. Cartagena de Indias. Verano de 2007

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    Santiago Rosero

    2013-09-01

    Las monjas junto a ellos, que han esperado su turno para tomarse una fotografía, hacen pensar en los registros que dan cuenta del paso del Instituto Lingüístico de Verano por varios países de América Latina y en la forma en que los misioneros de esa institución posaban junto a los pobladores autóctonos, en una proyección de supuesta empatía. En ese sentido, esta fotografía, que capta un momento surgido de manera completamente espontánea, sugiere dos formas de performance.

  16. Coeficientes de transferencia de calor y pérdida de eficiencia en intercambiadores de calor de placas durante el enfriamiento del licor amoniacal

    OpenAIRE

    Enrique Torres-Tamayo; Luís E. Quintana-Charlot; Orlando Vega-Arias; Yoalbys Retirado-Mediaceja

    2011-01-01

    En la planta de Recuperación de Amoniaco de la empresa niquelera Ernesto Che Guevara la pérdida de eficiencia del proceso de enfriamiento del licor amoniacal, mediante el uso de intercambiadores de calor de placas, se asocia a la incorrecta estimación de los coeficientes de transferencia de calor y la acumulación de incrustaciones en la superficie de intercambio; lo anterior incrementa el consumo de agua, la energía disponible en el sistema y los costos de mantenimiento. Se realizó una invest...

  17. Determinación del calor de fraguado de cemento por icrocalorimetría

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    Liliana Girlado G.

    2010-07-01

    Full Text Available Se determina el calor de fraguado del cemento Río Claro tipo III (Río Claro, Antioquia, Colombia por microcalorimetría de conducción de calor; así como también los efectos de la glucosa y de la sacarosa en el proceso de fraguado de este material. Al emplear 0,15 y 0,05% ( % en peso de estos aditivos en la preparación de las pastas, se observan retardos considerables en el fraguado de las mismas. Los aditivos también modifican el calor de fraguado: la pasta libre de estos presenta un valor de 38,03 J/g en tanto que la adición de glucosa y sacarosa producen valores menores, excepto en el caso de la sacarosa al 0,05% donde se observa un efecto térmico de 55.80 J/s,

  18. Temas de Física para Ingeniería: Temperatura y propagación del calor

    OpenAIRE

    Beléndez Vázquez, Augusto

    1992-01-01

    Acústica, fluidos y termodinámica: "Temperatura y propagación del calor". Introducción. Descripciones macroscópica y microscópica de un sistema. Equilibrio térmico y principio cero de la termodinámica. Termómetros y escala de temperaturas del gas ideal. Dilatación térmica. Propagación del calor.

  19. EVALUACIÓN DEL ESTRÉS TÉRMICO DURANTE EL VERANO 2015 EN LOS AMBIENTES DE UNA FÁBRICA DE CHOCOLATES EN LA CIUDAD DE LIMA

    OpenAIRE

    Arakaki Kiyán, Julio Alfonso; Universidad Nacional Agraria La Molina (Perú).; Tang Cruz, Oscar Enrique; Universidad Nacional Agraria La Molina (Perú).; Yaringaño Limache, Roxani; Universidad Nacional Agraria La Molina (Perú).

    2016-01-01

    El presente trabajo de investigación tuvo como objetivo evaluar el riesgo de estrés térmico en trabajadores de una planta de fabricación de chocolate ubicada en la ciudad de Lima durante la época de verano, usando el método denominado Índice WBGT de acuerdo a la norma NTP RM 375 -2008 y la guía 2 del DS 055-1010 evaluándose paralelamente el gasto metabólico de cada trabajador. La evaluación fue efectuada en 2 etapas del proceso de fabricación en caliente denominados Tostado - Secado y Confita...

  20. Raúl Pepe Verano Montesinos

    OpenAIRE

    José Luis Luque

    2013-01-01

    El 31 de enero de 2005 falleció en Lima el doctor Raúl Verano. Nacido el 12 de julio de 1940 en Cajatambo, realizó sus estudios superiores en la Universidad Nacional Mayor de San Marcos, graduándose en 1971 de bachiller en Educación y en 1972 obtuvo el grado de bachiller en Biología con la tesis Foraminíferos del litoral del departamento de Lima; optando la profesión de Biólogo en 1973. Empezó sus actividades docentes en 1965 como Ayudante de Prácticas en las cá- tedras de zoología y desde 19...

  1. Islas de calor urbano en Tampico, México. Impacto del microclima a la calidad del hábitat

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    Carlos Alberto Fuentes Pérez

    2014-01-01

    Full Text Available De todas las modificaciones climáticas por causa urbana, las térmicas son las más conocidas por los propios ciudadanos. La acción transformadora del espacio natural sobre el que se realiza el emplazamiento de la ciudad, llega a ser productora en gran medida de sus condiciones ambientales, incluida la climatología urbana. Todo proceso de urbanización sustituye los suelos y áreas naturales por superficies construidas, cuyos materiales se caracterizan por una baja reflectividad, con disminución de la capacidad de absorción de agua y un comportamiento térmico propicio para el almacenamiento y la emisión de calor. Estos elementos coadyuvan a realzar la temperatura atmosférica de la ciudad en relación con su entorno menos urbanizado a través de un fenómeno conocido como efecto de islas de calor urbano, produciendo un impacto del microclima a la calidad del hábitat. La presente investigación experimental aplicada tiene como objetivo, demostrar la metodología de investigación adoptada, para realizar las islas de calor urbanas en Tampico, México.

  2. Coeficientes de transferencia de calor y pérdida de eficiencia en intercambiadores de calor de placas durante el enfriamiento del licor amoniacal

    Directory of Open Access Journals (Sweden)

    Enrique Torres-Tamayo

    2011-10-01

    Full Text Available En la planta de Recuperación de Amoniaco de la empresa niquelera Ernesto Che Guevara la pérdida de eficiencia del proceso de enfriamiento del licor amoniacal, mediante el uso de intercambiadores de calor de placas, se asocia a la incorrecta estimación de los coeficientes de transferencia de calor y la acumulación de incrustaciones en la superficie de intercambio; lo anterior incrementa el consumo de agua, la energía disponible en el sistema y los costos de mantenimiento. Se realizó una investigación en un intercambiador de calor de placas, con el objetivo de determinar los coeficientes de transferencia y la influencia de las incrustaciones en la pérdida de eficiencia de la instalación. Mediante un procedimiento iterativo se determinó la ecuación del número de Nusselt y su dependencia con el Reynolds y Prandtl, para ello se utilizó un diseño experimental multifactorial y mediciones de los parámetros de trabajo de la instalación en función del tiempo. Los resultados predicen el conocimiento de los coeficientes para el cálculo del número de Nusselt, con los valores de Reynolds y Prandtl, para ambos fluidos (licor amoniacal y agua. Los valores de los coeficientes del licor son inferiores, ello se debe a la presencia de componentes gaseosos. La comparación con resultados de otros autores muestra correspondencia con los de Thonon. Se recomienda la limpieza y mantenimiento de la instalación en un período de 27 días debido a la reducción de la eficiencia térmica hasta valores inferiores al 70 %.

  3. Assessment methodology of the summer time schedule change (CHV) in Mexico: 10 years of application; Metodologia de evaluacion del cambio de horario de verano (CHV) en Mexico: 10 anos de aplicacion

    Energy Technology Data Exchange (ETDEWEB)

    Maqueda Zamora, Martin Roberto; Perez Rebolledo, Hugo [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2008-07-01

    The Summer Time is strongly bound to the rational use of the natural resources, since it is a measure that contributes to the care of the country energy resources and the improvement of the environment. This measure consists of advancing the clock one hour in the months that have greater insolation in the country and when doing it, the electrical energy demand is reduced, a saving in the consumption of the same is obtained, resulting in a reduction of the fossil fuel consumption that is needed to generate electric energy and also the emission of polluting agents to the environment is detained. It is to emphasize that the sustainable development and the environment depend on the energy efficient use. With the application of the Summertime Schedule, the entire country participate in the care of the energy resources that are derived from their application and generates in the population a culture of the care of the energy and the environment. This program is applied to world-wide level, including the industrialized countries. In this paper the methodology implemented by the Instituto de Investigaciones Electricas (IIE) is presented, to realize the calculations of saving in electrical power consumption and the quantification of the avoided demand, as well as the main results obtained in 10 years of application of the measure in Mexico. [Spanish] El horario de verano esta fuertemente ligado al uso racional de los recursos naturales, ya que es una medida que contribuye al cuidado de los recursos energeticos del pais y la mejora del medio ambiente. Esta medida consiste en adelantar el reloj una hora en los meses que se tiene mayor insolacion en el pais y al hacerlo, se reduce la demanda de energia electrica, se tiene un ahorro en el consumo de la misma y como resultado se reduce el consumo de combustibles fosiles que se necesitan para generar la energia electrica y tambien se dejan de emitir contaminantes al medio ambiente. Cabe resaltar que el desarrollo sustentable y el

  4. Estudio y optimización de los sistemas de intercambio de calor en generación termoeléctrica aplicada al aprovechamiento del calor residual

    OpenAIRE

    Aranguren Garacochea, Patricia

    2015-01-01

    La presente tesis doctoral estudia el aprovechamiento del calor residual mediante generación termoeléctrica para la obtención de potencia eléctrica generada gracias al efecto Seebeck. Dos son las aproximaciones empleadas, la simulación computacional, empleando variables obtenidas experimentalmente y la experimentación de escenarios reales. Ambas dos han obtenido valores muy prometedores para la generación eléctrica a través de los gases residuales. Con el desarrollo de esta tesis doctoral,...

  5. Raúl Pepe Verano Montesinos

    Directory of Open Access Journals (Sweden)

    José Luis Luque

    2013-05-01

    Full Text Available El 31 de enero de 2005 falleció en Lima el doctor Raúl Verano. Nacido el 12 de julio de 1940 en Cajatambo, realizó sus estudios superiores en la Universidad Nacional Mayor de San Marcos, graduándose en 1971 de bachiller en Educación y en 1972 obtuvo el grado de bachiller en Biología con la tesis Foraminíferos del litoral del departamento de Lima; optando la profesión de Biólogo en 1973. Empezó sus actividades docentes en 1965 como Ayudante de Prácticas en las cá- tedras de zoología y desde 1971 fue Jefe de Prácticas. Ascendiendo a Auxiliar en 1974, para luego ocupar diversos cargos en la administración universitaria, siendo los más destacados el de Director del Instituto de Investigaciones Antonio Raimondi entre 1981 y 1985 y Decano de la Facultad de Ciencias Biológicas de la Universidad Nacional Mayor de San Marcos en el período 1988 a 1991. Sus actividades de investigación estuvieron alrededor de la ictioparasitología, obteniendo el grado de Doctor en Ciencias Biológicas en 1987 con la tesis Kudoa peruviana Mateo, 1972, redescripción y ultraestructura; Kudoa sarmientae sp. n y Kudoa estela sp. n en peces de la costa peruana

  6. Comportamiento espacio-temporal de la nube estratocúmulo, productora de niebla en la costa del desierto de Atacama (21° lat. S., 70° long. W., durante un mes de invierno y otro de verano

    Directory of Open Access Journals (Sweden)

    Martín Farías Salvador

    2012-02-01

    Full Text Available Se muestran los resultados de la utilización de imágenes satelitales GOES, cada 90 minutos, para estudiar el comportamiento espacio-temporal de la nube estratocúmulo, productora de niebla advectiva, en un sector costero del desierto de Atacama. Este potencial recurso hidrológico, muy influyente en los ecosistemas de desierto, se investiga además con la intención de abastecer de agua potable a pequeños poblados rurales, para agricultura, bebederos en predios ganaderos y reforestación. A través de la comparación del comportamiento de este tipo de nube, entre un mes de invierno y otro de verano, se determinan sus ciclos diario y mensual, la frecuencia de su presencia, los corredores por donde penetra desde el océano hacia el interior, potenciales lugares para captación de agua y una gran diferencia existente entre los meses seleccionados.

  7. Distribución del fitoplancton en el Estrecho Bransfield, Bahía Chile y Paso Drake, durante el verano austral 1998 (Antártida)

    OpenAIRE

    Tapia, M.E.; Torres Ch., G.

    1998-01-01

    El principal objetivo fue de conocer la disponibilidad de la reserva alimenticia (fitoplancton), como un factor que puede influenciar la distribución y abundancia del krill antártico, registrados durante la VII Expedición Ecuatoriana a la Antártida en enero/1998 en el B/I ORION (INOCAR). La biomasa fitoplanctónica en el Estrecho Bransfield, registró altas concentraciones hacia el sur oeste del estrecho dominado principalmente por Cryptomonas spp. entre 1000.000 a 2200.000 cel/l, las menore...

  8. La tateana de Yasujirō: sobre El fin de la primavera (1949) y El comienzo del verano (1951), de Ozu

    OpenAIRE

    García Roig, Manuel

    2011-01-01

    La primera morada de que se tiene constancia en la cultura japonesa es una sencilla cabaña, la tateana-jûkyo. En su arquitectura tradicional las técnicas de la carpintería alcanzaron una elevada perfección, aplicándose a la construcción del teatro Nô. En el Paisaje haboku de Sesshu Toyó, artista suibokuga, las veladuras de la tinta china transforman la montaña, cabaña y barcaza en elementos de un espacio vacío donde flota la nada, Mu, expresión Zen del todo. Como el Nô, la vivienda japonesa e...

  9. Perturbaciones de los fuegos de verano en la palma mas austral del mundo (Jubaea Chilensis (mol.) Baillon) en microcuencas costeras de la Zona Mediterranea de Chile

    OpenAIRE

    Víctor Quintanilla Pérez; Mauricio Morales Constanzo

    2013-01-01

    Uno de los principales factores de degradación de las microcuencas costeras de la región de Valparaíso corresponde a los incendios forestales, como también a la expansión urbana y a las obras de infraestructura, que han implicado una importante disminución de la superficie vegetal nativa y que posee especies de un alto valor geobotánico y endémico, como es el caso de la palma chilena (Jubaea chilensis). Esta palmera se encuentra en la formación del bosque esclerófilo de Chile central (30o-37o...

  10. Isla de calor en Toluca, México

    Directory of Open Access Journals (Sweden)

    Carlos Constantino Morales Méndez

    2007-01-01

    Full Text Available El clima de la ciudad de Toluca y del mundo ha sido modificado como consecuencia del crecimiento de su población y el aumento de las dimensiones de su distribución territorial. Las variaciones atmosféricas son más acusadas entre los espacios urbanos y rurales a medida que las ciudades son más grandes y su mancha urbana es más extensa,así como de la reducción de la vegetación, el aumento en la calefacción en casas y edificios y por la contaminación del aire. Para identificar los espacios con calor más intenso por la infraestructura urbana, se propone una metodología que consiste en la determinación de los valores de temperatura que se registraron en dos días típicos de invierno y verano, durante el día y la noche,mostrando la distribución de la isla de calor en la zona de estudio, a partir de los datos delas estaciones de la Red Automática de Monitoreo Ambiental (RAMA. Asimismo, se considera el comportamiento y variación de algunas variables atmosféricas como humedad relativa, precipitación y viento, para mostrar su comportamiento relativamente anómalo en la zona urbana.

  11. Humedad de equilibrio y calor latente de vaporización del ajonjolí. Sésamun indicum L.

    Directory of Open Access Journals (Sweden)

    Julio E. Ospina M.

    2011-06-01

    Full Text Available El ajonjolí (Sésamun indicum L., es una oleaginosa originaria de África y cultivada en las regiones tropicales y subtropicales de Asia y América. A los 110 días de sembrada se cosecha la semilla la cual se utiliza como materia prima especialmente en la industria de grasas y aceites comestibles. Actualmente se pierden en Colombia, un alto porcentaje de semillas durante el proceso de secado natura en el campo. Debido a la falta de información técnica, científica en secado y almacenamiento del grana de ajonjolí se procedió a estudiar la metodología para determinar, el contenido de humedad por el método de la estufa, las curvas y modelo para cuantificar la humedad de equilibrio y el calor latente de vaporización.

  12. Análisis de la incertidumbre del poder calorífico en un motor de combustión interna alternativo

    OpenAIRE

    YILMAZ SOÑORA, NARIN

    2017-01-01

    [ES] Dentro del marco del diagnóstico de la combustión, es interesante el análisis de la incertidumbre del poder calorífico en un motor de combustión interna alternativo. Con ello, se pretende conocer con mayor certeza la energía aprovechable de la cual se dispone en un proceso de combustión. El objetivo de este trabajo es observar la influencia del fenómeno de la disociación sobre el poder calorífico en un motor de combustión interna alternativo. Para ello, a través de las herram...

  13. Convertidor termoeléctrico para el aprovechamiento del calor disipado por el cuerpo humano

    OpenAIRE

    Hilinger Pelegrín, Esther

    2008-01-01

    Este documento presenta un diseño de generador termoeléctrico para el aprovechamiento de la energía térmica del cuerpo humano. El sistema se compone de tres etapas: cuerpo humano, célula Peltier y un circuito acondicionador de señal. Los resultados de los ensayos de caracterización de cada una de las etapas se encuentran detallados en la memoria, así como las conclusiones a las que se llega del estudio de las pruebas realizadas. Los componentes que forman parte del diseño...

  14. Efectos de la intensidad y evolución a corto plazo de las propiedades físicas, erosionabilidad, humedad y temperatura del suelo

    OpenAIRE

    Llinares Palacios, Josep Vicent

    2001-01-01

    RESUMEN El impacto del fuego en el suelo y en los procesos ecológicos que operan en las laderas con matorrales mediterráneos depende de la elevación de temperaturas y de la duración del calor durante el incendio. A pesar de su importancia en nuestros ecosistemas forestales, hay pocos estudios en que se hayan medido de forma experimental, bajo condiciones ambientales típicas del verano, y condiciones controladas de combustible y estado del suelo y de la vegetación. El objetivo de esta...

  15. Energía termofotovoltaica: la conversión fotovoltaica del calor y su aplicación en sistemas de almacenamiento de energía

    OpenAIRE

    Datas Medina, Alejandro

    2015-01-01

    Del mismo modo que una célula solar convierte la luz del sol en electricidad, una célula termofotovoltaica convierte en electricidad la radiación térmica que emiten objetos incandescentes. Es decir, realizan una conversión directa del calor en electricidad, sin necesidad de emplear partes móviles ni fluidos. Entre las muchas aplicaciones de esta tecnología, en el Instituto de Energía Solar de la UPM estamos trabajando en un nuevo concepto de almacenamiento de energía térmica que utiliza silic...

  16. Study of the internal heat transfer of the water flow in nucleate boiling; Estudio de la transferencia de calor del flujo interno de agua en ebullicion nucleada

    Energy Technology Data Exchange (ETDEWEB)

    Payan Rodriguez, Luis Alfredo

    2003-09-01

    In this paper the development of a research project oriented to the analysis of the heat transfer of the water flow in nucleate boiling is presented. Here a mathematical model is described to characterize the water flow in boiling condition in vertical tubes by means of which the temperature distributions in the tube wall and in the water flow are obtained, including the calculation of the pressure drop throughout the tube. In addition, a mechanistic model focused to the prediction of the critical heat flow in vertical tubes uniformly heated was modified to be applied in non-uniform heat flow conditions. The proposed mathematical models were used in a case study derived from a real problem in a thermoelectric power plant, where it was required to simulate the process of boiling in fireplace tubes of the steam generator to determine the causes of the faults that happened in a considerable number of tubes. With the obtained results it was possible to establish that the faults in the tubes of the analyzed steam generator were originated because the heat transfer rate in the fireplace reached critical values that caused the deviation of the nucleate boiling to film boiling, causing the diminution of the heat transfer coefficient with the consequent sudden increase in the tube wall temperature. [Spanish] En este trabajo se presenta el desarrollo de un proyecto de investigacion orientado al analisis de la transferencia de calor en flujo de agua en ebullicion nucleada. Aqui se describe un modelo matematico para caracterizar el flujo de agua en ebullicion en tubos verticales mediante el cual se obtienen las distribuciones de temperatura en la pared del tubo y en el flujo de agua, incluyendo el calculo de la caida de presion a lo largo del tubo. Ademas, un modelo mecanistico enfocado a la prediccion del flujo de calor critico en tubos verticales uniformemente calentados fue modificado para aplicarlo en condiciones de flujo de calor no uniforme. Los modelos matematicos

  17. Transmisión del calor por conducción

    OpenAIRE

    Luis y Luis, Pedro

    1983-01-01

    Este libro es fruto de las actividades docentes, investigadoras y profesionales del autor en el Departamento de Físico Química de los procesos Industriales de la Facultad de Ciencias Químicas de la Universidad Complutense de Madrid, Escuela Técnica Superior de Ingenieros de Minas de Madrid y Junta de Energía Nuclear y por su contenido parece adecuado para los alumnos de los últimos cursos de las Universidades, Centros de Investigación y Profesionales del campo de la energía. El gran número...

  18. Determinación del requerimiento de frío y de calor en duraznero [Prunus persica (L. Batsch.] mediante un modelo de correlación

    Directory of Open Access Journals (Sweden)

    CHAAR, J

    2012-11-01

    Full Text Available Los árboles frutales de hoja no persistente poseen un período de reposo entre los ciclos vegetativos. Para salir de reposo invernal, las yemas deben acumular primero frío (endodormancia y luego calor (ecodormancia.El objetivo de este trabajo fue determinar el requerimiento de frío y de calor en cinco cultivares de duraznero mediante un método de correlación, con datos de fecha de plena floración y temperatura del aire de siete años, en el este de Mendoza. El requerimiento de frío varió entre 914 y 1262 unidades de frío, mientras que el de calor fluctuó entre 2177 y 6490 horas grado de crecimiento. Excepto en cv. “Prima”, la variabilidad entre años del requerimiento de frío (coeficiente de variación, CV: 18,3 a 18,9% fue mayor que la correspondiente al requerimiento de calor, (CV: 6,9 a 13,9%. Los requerimientos de calor disminuyeron en años de mayor acumulación de frío e indicaron una compensación. El modelo utilizado, permite disponer de información más precisa sobre los requerimientos térmicos de los cultivares, y así poder realizar una zonificación que racionaliceel cultivo y maximice su aprovechamiento, en las áreas agroclimáticamente adecuadas.

  19. Manejo prehospitalario de las lesiones causadas por el calor

    OpenAIRE

    Gómez Ruano, Juan Carlos

    2017-01-01

    Una de las mayores causas de morbilidad y mortalidad de personas cada verano en nuestro país y en todo el mundo son las enfermedades producidas por el calor, en especial el golpe de calor. Estas enfermedades son ocasionadas por exposiciones prolongadas al sol o a altas temperaturas que junto a otras causas como un consumo disminuido de líquidos, abuso de alcohol, utilización de demasiada ropa o ejercicio físico intenso pueden conducirnos a la muerte. Los primeros signos y síntomas de las e...

  20. Determinación del calor isostérico para pulpa de plátano (musa paradisiaca) por isotermas de sorción

    OpenAIRE

    CIRO, HÉCTOR; OSORIO, JAIRO ALEXANDER; CORTÉS, ELKIN ALONSO

    2008-01-01

    Las isotermas de sorción para ser usadas en la simulación y diseño de procesos de secado y almacenamiento de alimentos deben ser representadas por modelos válidos dentro de las condiciones encontradas en la práctica industrial. Usando el modelo de Chung–Pfost y ajustado por desorción el calor isostérico neto y total para pulpa de plátano fueron determinados. El calor neto isotérico neto decreció con el contenido de humedad del producto variando desde 1670 kJ/kg (5%.d.b) a 215 kJ/kg (26%.d.b...

  1. Estudio de la influencia del número de módulos termoeléctricos en la potencia calorífica disipada por un sistema de auto-refrigeración termoeléctrica

    OpenAIRE

    Conde Olazábal, Igor

    2014-01-01

    En el desarrollo del presente trabajo de fin de grado se expone un estudio sobre una de las múltiples aplicaciones de aprovechamiento de calor residual mediante termoelectricidad. Se trata de una aplicación novedosa y de creciente interés conocida por el nombre de “autorrefrigeración termoeléctrica” (ARTE). Dado un dispositivo cualquiera que genera calor, bien puedan ser transistores IGBT para el caso de electrónica de potencia o cualquier otra aplicación con generación de calor en el proceso...

  2. La recuperación termoeléctrica del calor residual, una fuente de energía ambientalmente amigable

    OpenAIRE

    Rodríguez, Julio E.

    2012-01-01

    El incremento del precio de los combustibles fósiles acompañado por el deterioro medioambiental asociado al calentamiento global generó un incremento en la actividad científica dirigida a identificar y desarrollar fuentes de potencia eléctrica no contaminantes. En este sentido, la conversión directa de energía térmica en eléctrica mediante dispositivos termoeléctricos utilizando calor residual como fuente de calentamiento, podría contribuir a solucionar los problemas energéticos de la socieda...

  3. Perfiles de temperatura generados por fuentes esféricas de calor durante el tratamiento del cáncer por hipertermia local

    OpenAIRE

    Giordano, Mauricio A.; Gutiérrez, Gustavo; Massa, Julio C.

    2011-01-01

    En este trabajo se derivan soluciones analíticas para el modelo de Pennes de difusión de calor en medios biológicos usando funciones de Green. El objetivo es predecir los perfiles de temperatura que se pueden obtener en tumores de forma esférica durante el tratamiento del cáncer por hipertermia usando fluidos magnéticos. El dominio matemático consta de dos regiones, la interna se corresponde con el tejido canceroso de dimensión finita; y la externa con tejido sano que se extiende ...

  4. Quinientos scudos: Tiziano en el verano de 1553, entre Carlos V y Felipe II

    OpenAIRE

    Munari, Isabella

    2016-01-01

    En el presente trabajo llevamos a cabo una reconstrucción documental, En el presente trabajo llevamos a cabo una reconstrucción documental, crítica y filológica de una Memoria de Francisco de Vargas, conservada en el Archivo General de Simancas. La lectura integral, la transcripción del documento - testimonio de un pago al pintor Tiziano Vecellio de quinientos escudos -, y sobre todo su conexión con otras fuentes, permiten datarlo en el verano de 1553. Más allá de reflejar la recompensa econó...

  5. Results of the study on the impact of the daylight saving time in Mexico that was coordinated by the Universidad Nacional Autonoma de Mexico; Resultados del estudio sobre el impacto del horario de verano en Mexico que fue coordinado por la Universidad Nacional Autonoma de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Velez Ocon, Carlos [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    2001-07-01

    Due to the multiple discussions that were raised in ample sectors of the society on the occasion of the implantation of the daylight saving last year, the Federal Government offered to make an integral study of the impact that causes this measure in the Mexican society. Later, the Secretariat of Energy asked for this study to Universidad Nacional Autonoma de Mexico (UNAM). In talks with the representatives of that Secretariat, it was determined that the study had to cover the largest number of sectors and activities of the society in which it could exist a suspicion of impact by this change, and which in addition had an important relevance in the life of the society. These areas were eighteen, that are listed in alphabetical as follows: agriculture, commerce, education, energy, family, finances, cattle raising, individual, industry, environment, mass media, health, public security, telecommunications, free time, transport, tourism, border zones. Altogether 70 institutions, 121 professors and investigators participated, 36 of which pertain to 15 dependencies of the UNAM; 46% belong to institutions in the Federal District and 54% to private institutions. It is worth to clarify that the time that was granted to make the study was of three months as of 1 May, which gave little margin to make specific studies with the purpose of successfully obtaining new information. Most of the analysis was made with already existing information in the corresponding sectors. [Spanish] Debido a las multiples discusiones que se suscitaron en amplios sectores de la sociedad con motivo de la implantacion del horario de verano el ultimo anos, el Gobierno Federal ofrecio realizar un estudio integral del impacto que causa esta medida en la sociedad mexicana. Posteriormente, la Secretaria de Energia le solicito este estudio a la Universidad Nacional Autonoma de Mexico (UNAM). En platicas con los representantes de esa Secretaria, se determino que el estudio debia cubrir el mayor numero de

  6. Thermal analysis of the heat recuperator of a combined cycle thermoelectric central; Analisis termico del recuperador de calor de una central termoelectrica de ciclo combinado

    Energy Technology Data Exchange (ETDEWEB)

    Romero Paredes, Hernando; Sanchez, I.; Lazcano, L. C.; Ambriz, Juan Jose; Alvarez, M. [Universidad Autonoma Metropolitana-Iztapalapa, Mexico, D. F. (Mexico); Gonzalez, O. [Comision Federal de Electricidad, Tula (Mexico)

    1996-12-31

    The thermoelectric centrals of the combined cycle type (Brayton Cycle and Rankine Cycle) present a series of opportunities to increase the efficiency of the combined cycle or of the generated power. This paper shows the methodology for the performance of energy balances in a heat recuperator (H. R.), typically employed in the combined cycle stations operating in Mexico, for the assessment of the energy harnessing in the different sections conforming a H. R. The effect of the installation of evaporative coolers and/or an absorption cooling system at the gas turbine compressor intake on the steam generation in the heat recuperator, is evaluated. This extra generation of steam is quantified for its potential use in the same absorption refrigeration system. From the assessment, it follows up that the steam generation in the H.R. is inversely proportional to the ambient temperature and that, although the increased amount of steam generated can not be harnessed in total by the steam turbine, the remaining fraction is good enough to cover the heat demand for the operation of the refrigeration system. [Espanol] Las centrales termoelectricas del tipo ciclo combinado (ciclo Brayton y ciclo Rankine) presentan un conjunto de oportunidades para incrementar la eficiencia del ciclo combinado o bien la potencia generada. En el presente trabajo se expone la metodologia para realizar los balances de energia en un recuperador de calor (R.C.) tipicamente utilizado en las Centrales de Ciclo Combinado (CCC) que operan en Mexico, para evaluar el aprovechamiento de la energia en las diferentes secciones que conforman un R.C. Se evalua el efecto que tiene la instalacion de enfriadores evaporativos y/o un sistema de enfriamiento por absorcion en la succion del compresor de la turbina de gas sobre la generacion de vapor en el recuperador de calor. Se cuantifica esta generacion extra de vapor para su posible utilizacion en el mismo sistema de refrigeracion por absorcion. De la evaluacion se

  7. Modelamiento y simulación del efecto de la entrada de calor en la penetración de una junta soldada

    Directory of Open Access Journals (Sweden)

    Lina Gómez

    2003-01-01

    Full Text Available En esta investigación se realizó el simulador SimVol, en el cual se experimentó con el fin de encontrar una relación entre la entrada de calor y la penetración de la junta soldada. SimVol se basó en un modelo en 2D, que describe el flujo de calor y el flujo de metal líquido en el charco de una soldadura realizada con el proceso GTAW (Gas Tungsten Arc Welding. En el modelo matemático se incluyen las ecuaciones de Navier-Stokes y la ecuación de energía, las cuales constituyen un sistema de ecuaciones diferenciales parciales de segundo orden, no-lineales, no homogéneas y transitorias. El modelo numérico se desarrolla en Volúmenes Finitos en un esquema totalmente implícito, con malla regular y escalonada; además, debido al desconocimiento del campo de presión es necesario utilizar el algoritmo SIMPLE (Semi-Implicit Method for Pressure-Linked Equations. La investigación también incluye una serie de experimentos que permitieron validar el modelo planteados.

  8. Validación de un ciclo de despirogenización por calor seco con el empleo del ensayo del lisado de amebocitos de limulus

    Directory of Open Access Journals (Sweden)

    Rolando Perdomo Morales

    2003-12-01

    Full Text Available Para el cumplimiento de las buenas prácticas de laboratorio y de fabricación de parenterales, una de las exigencias es la validación de los ciclos de despirogenización que se emplean. En el presente trabajo se describe la validación de un ciclo de despirogenización por calor seco en un horno de convección. En la primera etapa se estudiaron características físicas del equipo como el tiempo requerido para alcanzar la temperatura establecida, su distribución, estabilidad, y la influencia de la carga en el patrón de calentamiento. Considerando los resultados de esta fase se estableció un proceso total de 7 h a 180 ºC. La segunda etapa consistió en la determinación del grado de despirogenización retando el proceso con bioindicadores de endotoxinas. La concentración de endotoxinas en los bioindicadores control y sometidos al proceso de despirogenización se cuantificó con el empleo del ensayo del lisado de amebocitos de limulus método de gelificación. La diferencia entre el contenido de endotoxinas en el control y los tratamientos fue de 2 400 U de endotoxinas, por lo que el proceso rindió una reducción logarítmica mínima de 4,6 log, la cual es mayor que el límite de 3 log establecido por la Farmacopea de los Estados Unidos.To fullfill the good laboratory and parenteral drugs manufacturing practices, one of the demands is the validation of the depyrogenation cycles that are used. In this paper, it is described the validation of a depyrogenation cycle by dry heat in a convection oven. The physical features of the equipment, such as the time required to reach the established temperature, its distribution, stability, and the influence of the charge on the heating pattern, were studied in the first stage. Taking into account the results of this phase, it was established a total process of 7 h at 180 °C. The second stage consisted in the determination of the degreee of depyrogenation, challenging the process with endotoxin

  9. Mastitis de Verano en terneras (Summer Mastitis in veals).

    OpenAIRE

    García Lara. Tomás José; Hernández Ferro Sergio C; Silva Lugo Luís

    2012-01-01

    ResumenEn el presente trabajo se brindan algunas consideraciones clínicas, anatomopatológicas y epizootiológicas sobre un brote de Mastitis de Verano Arcanobacterium pyogenes (Corynebacterium pyogenes) sensible a la Penicilina, Cloranfenicol, Kanamicina y Propóleo en solución oleosa.Abstract The present paper gives some clinical, anatomopathological and epizootiological considerations on an outbreak of Summer Mastitis Arcanobectarium pyogenes (Corynebacterium pyogenes) sensitive to Penicillin...

  10. VI Verano de la Investigación Científica de la Universidad de Guanajuato

    Directory of Open Access Journals (Sweden)

    Luis Fernando Anaya Velázquez

    2012-02-01

    Full Text Available La sexta edición del Programa Institucional “Verano de la Investigación Científica de la Universidad de Guanajuato”, se llevó a cabo del 3 de julio al 4 de agosto del año 2000 en el cual se compilaron los resultados de investigación de 32 estudiantes de licenciatura, 6 de ellos, pertenecen al Estado de Tabasco, financiados por el Consejo de Ciencia y Tecnología del Estado de Tabasco, y 26 son estudiantes inscritos a nuestra Casa de Estudios y apoyados por la misma. Los estudiantes seleccionados pertenecen a las siguientes áreas del conocimiento: Ciencias Sociales y Humanidades: 6, Salud: 4, Ingenierías: 5, Ciencias Naturales y Exactas: 16 y Económico-Administrativas: 1. The sixth edition of the institutional program "Verano de la Investigación Científica de la Universidad de Guanajuato" (Scientific Research Summer of the University of Guanajuato was held from July 3 to August 4, 2000, in which research results were compiled of 32 undergraduate students, 6 from State of Tabasco, financed by the Consejo de Ciencia y Tecnología del Estado de Tabasco (Sciences and Technology Council of Tabasco and 26 from the Universidad de Guanajuato, supported by the University. The students selected belong to the following areas of learning: Social Sciences and Humanities, 6; Health, 4; Engineering, 5; Natural Sciences, 16; Economic Administration, 1.

  11. Revisión del cálculo de poder calorífico y punto de rocío del gas natural, y de la estimación de sus incertidumbres

    OpenAIRE

    Elizabeth Ayala Blanco; Adriana Alexandra Aparicio Ariza; Carlos Eduardo García Sánchez

    2016-01-01

    El gas natural debe cumplir ciertos requisitos que garanticen que su producción, transporte, distribución y consumo se realiza de forma segura. Estos requisitos corresponden a los parámetros de calidad de gas dentro de los cuales se encuentran el poder calorífico y el punto de rocío de hidrocarburo. Su correcta medición es de vital importancia, especialmente en los puntos de transferencia de custodia, ya que tanto quien entrega como quien recibe está interesado en conocer la calidad del gas c...

  12. CONCEPCIONES ALTERNATIVAS SOBRE LOS CONCEPTOS DE ENERGÍA, CALOR Y TEMPERATURA DE LOS DOCENTES EN FORMACION DEL INSTITUTO PEDAGÓGICO EN SANTIAGO, PANAMÁ

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    Viterbo Rodríguez

    2012-01-01

    Full Text Available El artículo presenta los resultados de una investigación realizada en el año 2009 en el Instituto Pedagógico Superior Juan Demóstenes Arosemena. La metodología utilizada en el estudio es del tipo descriptiva cuantitativa y se utilizó una prueba de elección múltiple para recoger los datos. Cada ítem de la prueba centraba la atención en las concepciones alternativas sobre energía, calor y temperatura. Dicha prueba, después de su validación y pilotaje, fue desarrollada por 241 estudiantes de licenciatura de este Instituto. Luego de analizar las respuestas de los ítems, se obtuvo suficiente evidencia para concluir, significativamente, que los docentes en formación tienen concepciones alternativas: el 63.8% sobre el concepto de energía; 69% sobre el concepto de calor, y el 70.7% sobre el concepto de temperatura y movimiento (p=0.05. Las respuestas proporcionadas por los estudiantes demuestran que un elevado número considera que las transformaciones de energía ocurren sin ningún tipo de intercambio ni degradación de la misma. Esto revela su falta de comprensión de las leyes de la termodinámica. Las concepciones alternativas sobre el concepto de energía sugieren tres áreas o líneas principales de problemas: el concepto mismo de energía, los procesos que implican la transferencia de energía y el principio de conservación de la energía.

  13. Utilización de las escorias de incineración de RSU para el incremento del poder calorífico del biogás generado por digestión anaerobia de la FORSU

    OpenAIRE

    Valle Zermeño, Ricardo del

    2013-01-01

    La utilización de las escorias provenientes de la incineración de residuos sólidos urbanos (RSU) para absorber CO2 y H2S del biogás obtenido por digestión anaerobia de la Fracción Orgánica de los RSU (FORSU) tiene un doble beneficio. Por un lado la optimización energética al incrementar el poder calorífico del gas y por otro la estabilización de las escorias para una posterior reutilización. Tanto la FORSU como las escorias forman parte de la gestión integral de los RSU en los denominados ...

  14. Análisis de aprovechamiento de calores residuales de los gases de escape del motor térmico mediante efecto Seebeck en una unión Cu-Al

    OpenAIRE

    Fernández Juncà, Joan

    2014-01-01

    El presente documento pretende estudiar la posibilidad de recuperar parte de la energía térmica expulsada (calor residual) por un motor térmico, en su paso por el sistema de escape. Analizar la viabilidad de poder cargar baterías y/o alimentar sistemas electrónicos del vehículo, a partir del flujo térmico de los gases de escape. Se pretende analizar con detalle el flujo térmico así como los efectos electromagnéticos asumibles en un transformador de una sola espira de sección gene...

  15. Crecimiento y características de canal en corderas tratadas con clorhidrato de zilpaterol durante primavera y verano

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    Ulises Macías-Cruz

    2013-01-01

    Full Text Available Se utilizaron 44 corderas Dorper x Pelibuey con peso vivo promedio de 24.56±0.70 kg para evaluar el efecto del clorhidrato de zilpaterol (CZ sobre el comportamiento productivo y algunas características de canal en épocas de primavera (n=24 y verano (n=20, bajo condiciones áridas del noroeste de México. En cada época, las corderas fueron colocadas en corraletas individuales y divididas en dos grupos para ser alimentadas sin CZ (SCZ o con 10 mg de CZ/ animal/día (CCZ durante 32 días. Posteriormente, todas las corderas fueron sacrificadas. La información se sometió a un análisis de varianza con un diseño de bloques completamente al azar con arreglo factorial 2x2. Las corderas CCZ de primavera presentaron mayor (P0.05 por efecto del CZ; contrariamente, el peso de canal caliente y fría, y la área del músculo Longissimus dorsi fueron mayores (P<0.05 en corderas CCZ. Solamente consumo de alimento y área del músculo Longissimus dorsi fueron afectados (P<0.01 por época. En conclusión, las altas temperaturas registradas en verano limitan el funcionamiento de CZ para mejorar el crecimiento y la eficiencia alimenticia de corderas de pelo finalizadas en corral, pero no las características de canal.

  16. Efecto de la Composición Química del Metal de Aporte y del Calor Aportado Sobre la Microestructura y las Propiedades Mecánicas de Juntas Soldadas de Aceros Inoxidables Dúplex

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    Sebastián Zappa

    Full Text Available Resumen Los aceros inoxidables dúplex poseen una microestructura dual (ferrita y austenita con contenidos aproximadamente iguales y se caracterizan por tener buena soldabilidad, buenas propiedades mecánicas y una alta resistencia a la corrosión generalizada y localizada. Gracias a estas características, estos aceros son los principales materiales a emplear en cañerías con altas exigencias, ampliamente utilizados en varias industrias, principalmente la petroquímica. Dichas propiedades están controladas por la composición química, el equilibrio microestructural y la ausencia de compuestos intermetálicos. El objetivo de este trabajo fue estudiar la influencia de la composición química del metal de aporte y el calor aportado sobre la microestructura y las propiedades mecánicas en juntas soldadas de cañerías de acero inoxidable dúplex. El metal base utilizado fue un acero inoxidable dúplex UNS S31803 de 8” de diámetro y 8,18 mm de espesor y los metales de aporte fueron dos alambres tubulares que depositan aceros inoxidables dúplex y lean dúplex (AWS A5.22: E2209T1-1 y E2209T1-G, mediante el proceso de soldadura semi-automático bajo protección gaseosa, soldados con alto y bajo calor aportado. De cada probeta se extrajeron muestras donde se determinó la composición química, se realizó la caracterización microestructural y se determinaron las propiedades mecánicas (dureza, tracción y Charpy-V.

  17. Diferencias entre las ondas gripales de verano y de otoño durante la pandemia de gripe (H1N1 2009 en Navarra

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    Jesús Castilla

    2011-01-01

    Full Text Available Fundamento: La gripe (H1N1 2009 produjo en Navarra una onda en verano y otra en otoño de 2009. El objetivo de este trabajo es comparar las características de ambas ondas epidémicas. Métodos: Analizamos la notificación individualizada de gripe, las confirmaciones virológicas en la red centinela de atención primaria, y los casos hospitalizados con confirmación de gripe en Navarra y comparamos los periodos de verano (semanas 21 a 39 de 2009 y otoño-invierno (semanas 40 de 2009 a 20 de 2010. Resultados: Durante 2009 hubo dos ondas de gripe A(H1N12009, con picos en julio y noviembre. En verano (semana 21 a 39 se notificaron 4.389 casos de síndrome gripal, siendo los más afectados los adultos jóvenes (58! entre 15 y 44 años. La mayor incidencia se registró tras las fiestas de San Fermín (92 casos por 100.000 en la semana 29 con retorno inmediato a niveles basales. En otoño se produjo una segunda onda que alcanzó tasas 7 veces mayores (667 casos por 100.000 en la semana 45 y se mantuvieron 9 semanas por encima del umbral epidémico, siendo el grupo de edad más afectado el de niños de 5 a 14 años (111 por 1000. En el pico de las dos ondas el porcentaje de frotis confirmados para gripe superó el 60!. Durante el verano se produjeron 66 ingresos con confirmación de gripe (H1N12009, y en otoño 158. La proporción de casos que requirieron ingresos en hospital fue mayor en verano (1,5! que en otoño (0,8!; p<0,0001. Conclusión: La circulación de la gripe fue mucho menor en verano. La aparición de casos graves se produjo tanto en momentos con alta como con baja incidencia de síndromes gripales.

  18. El documental de los años sesenta como arte: consideraciones de la película Crónica de un verano

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    José Alejandro López

    2011-01-01

    Full Text Available En la década de los sesenta del siglo pasado emergieron nuevas formas de cine documental, entre ellas el cinema verité, el direct cinema y el free cinema. Diversos estudios consideran estas propuestas una consecuencia directa de los avances tecnológicos, al restar importancia a otras condiciones. El objetivo de este texto es observar otras influencias, como la que tuvo el performance. Para esto, se realiza un análisis del documental Crónica de un verano, de Jean Rouch y Edgar Morin, como un performance.

  19. Determinación del grado de actividad física e intención de cambio en niñas y niños que participaron en las Escuelas Deportivas y Recreativas del Verano del 2005 de la Universidad de Costa Rica

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    Yamileth Chacón-Araya

    2006-06-01

    Full Text Available El propósito del estudio fue determinar el grado de actividad física y la intención de cambio en las niñas, niños y adolescentes matriculados en un programa de actividad física en la Universidad de Costa Rica. Las y los participantes (113 sujetos con edades comprendidas entre los 8 y 16 años respondieron un cuestionario relacionado con la intención de cambio de su actividad física, sus hábitos actuales y las posibilidades de práctica de la actividad física. Los resultados mostraron que 80.5% de las y los niños, realizaba ejercicio regularmente, al menos durante tres meses consecutivos. Se determinó que el 50.4% de las y los participantes no tienen la oportunidad de salir a jugar solos, si no los acompañan sus padres o encargados, y el 91.2% consideraba importante realizar ejercicio junto a sus progenitores. El 94.7% de los encuestadas(os recibe clases de Educación Física formales, pero sólo entre una y dos clases semanales, situación que repercute en su salud física y mental futura y en su posibilidad de incorporar el hábito de ejercitarse en su estilo de vida. Con base en el modelo de las etapas de cambio, se clasificó al 67.3% de las niñas y las(os niños, de los cuales un 55.8 % se ubicó en la etapa de mantenimiento. Este es el primer intento que se realiza en Costa Rica para clasificar a las niñas y los niños utilizando un modelo teórico, y los resultados son congruentes con los reportados en estudios efectuados en otros países. En conclusión, se recomienda el uso de este modelo transteórico para detectar la disponibilidad para el cambio en niñas, niños y adolescentes hacia hábitos y estilos de vida saludables. Es necesario ampliar los parámetros para realizar otras investigaciones al respecto.

  20. Transferencia de calor a lechos empacados

    OpenAIRE

    Beltrán Feged, Alvaro; Bonilla Melendez, Alberto; Cancelado Arias, Miguel

    2012-01-01

    Consideremos el lecho de solidos granulados de la figura 1.El lecho esta a una temperatura u (z,t), y tiene un calor especifico  cs, que se toma constante. z es la altura del lecho, y t es el tiempo. A este lecho entran G unidades de masa de fluido por unidad de tiempo y de área de sección de lecho(1)(2)

  1. Prácticas de Física: Calor de fusión

    OpenAIRE

    Beléndez,Augusto; Bernabeu, Guillermo; Vera Guarinos, Jenaro; Pastor Antón, Carlos; Martín García, Agapito

    1988-01-01

    El objetivo de esta práctica de laboratorio es la determinación del calor latente de fusión del hielo mediante el método de las mezclas así como el aprendizaje del manejo del calorímetro como instrumento de trabajo en experiencias térmicas, fundamentalmente de calorimetría. Para desarrollar la experiencia se introduce en un calorímetro una cierta cantidad de líquido a una temperatura superior a la del ambiente y luego añadir una cantidad de hielo a su temperatura de fusión. Es necesario conoc...

  2. Calore e termodinamica

    CERN Document Server

    Zemansky, Mark W

    1970-01-01

    Temperatura ; sistemi termodinamici semplici ; lavoro ; il calore e il primo principio ; gas ideali ; teoria cinetica dei gas ideali ; il secondo principio della termodinamica ; reversibilità e temperatura Kelvin ; entropia ; meccanica statistica sostanze pure ; transizioni di fase, elio liquido ed elio solido ; sistemi particolari ; paramagnetismo, fisica delle basse temperature, temperature negative e terzo principio ; superfluidità e superconduttività ; equilibrio chimico ; reazioni con gas ideali ; sistemi eterogenei.

  3. Estudio experimental de la conducción del calor en el maquinado de materiales endurecidos con altas velocidades de corte. // Experimental study of heat conduction in mechanization with high cutting speeds of hardened materials.

    Directory of Open Access Journals (Sweden)

    L. Cardoso Brandão

    2006-01-01

    Full Text Available El trabajo trata del estudio teórico-experimental de la conducción del calor en los materiales endurecidos, usados para laproducción de moldes y matrices, al maquinarlos con altas-velocidades del corte. Los materiales utilizados son los acerosAISI P20 y AISI D2. Los ensayos se realizaron con fresas de punta esférica (Ball Nose con revestimiento (TiAlN y lasprobetas para los ensayos tienen la forma de una ¼ parte de un tubo de 28 mm de diámetro con una longitud de 100 mm.Las pruebas realizadas demuestran la variación de la temperatura en función de los diferentes sistemas de refrigeración. Seutilizo aire comprimido y aire comprimido frío, comparándose las temperaturas de las probetas con el sistema sinrefrigeración de ningún tipo. Fueron también evaluadas las deformaciones sufridas por la superficie maquinada, debido alas variaciones de temperatura teniendo en cuenta la influencia de los sistemas de refrigeración empleados.Palabras claves: Temperatura; conducción del calor; alta velocidad de corte, moldes y matrices._________________________________________________________________________Abstract.This paper deals with the theoretical-experimental study of heat conduction in hardened materials for the production ofmolds and dies using high speed cutting. The employed materials were the AISI P20 and AISI D2 steels, being the testscarried out with (TiAlN coated ball nose in a work piece with the shape of a 1/4 tube with 28 mm diameter and 100 mmlength. This investigation demonstrates the variation of temperature as a function of different cooling systems, that is,compressed air and compressed cold air. Possible geometric deformation of the machined surfaces due to these variationsin temperature for distinct cooling systems was also evaluated.Keywords: Temperature, heat exchange; high cutting speed, dies.

  4. Predicción Climática Estacional de Precipitación Acumulada en Primavera y Verano en el Sur de Uruguay

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    Matilde Ungerovich

    Full Text Available Resumen Se desarrollan diferentes modelos pre-operativos de pronóstico dinámico-estadístico de precipitación estacional en el sur de Uruguay para primavera y verano. Para ello se utilizan regresiones lineales entre predicciones de variables dinámicas y observaciones de precipitación. Los pronósticos se inicializan en Agosto y Noviembre para los trimestres de Setiembre-Noviembre y Diciembre-Febrero, respectivamente. Las predicciones de las variables dinámicas son salidas de un ensamble del modelo de circulación general de la atmósfera ICTP MCGA forzado con condiciones de borde de temperatura de superficie del mar (TSM pronosticadas por NCEP-CFSv2. Las observaciones de precipitación provienen de 10 estaciones meteorológicas ubicadas al sur del Río Negro. Los mejores índices predictores se encuentran mediante validación cruzada, utilizando ventanas de un año, con las variables dinámicas. Se concluye que el mejor índice predictor es el viento meridional en 200 hPa promediado en una región que incluye el Sudeste de Sudamérica y es tal que anomalías de componente norte están asociadas a lluvias por encima de lo normal en el sur del país. Se encuentra que para todo el sur del país los pronósticos tienen habilidad únicamente en primavera mientras que para la zona metropolitana de Montevideo los pronósticos muestran habilidad para ambas estaciones y principalmente para verano.

  5. Análisis comparativo del aprendizaje de los conceptos de calor y temperatura utilizando una simulación digital interactiva y un texto ilustrado

    Directory of Open Access Journals (Sweden)

    Cimenna Chao Rebolledo

    2014-06-01

    Full Text Available Esta investigación analizó las diferencias que subyacen al aprendizaje de los conceptos de calor y temperatura en relación a los conceptos de energía térmica y energía cinética, a través de dos modalidades instruccionales: mediante la lectura de un texto ilustrado y a través de una simulación digital interactiva. Se trabajó con alumnos de dos grados escolares : 48 alumnos de segundo de secundaria sin instrucción previa sobre dichos fenómenos y 48 alumnos de tercero de secundaria con conocimientos académicos previos sobre los temas revisados. Se observaron diferencias significativas en la resolución de problemas asociados a los conceptos estudiados siendo mejor el desempeño de los participantes que utilizaron la simulación digital interactiva durante el aprendizaje y significativamente mejor en los alumnos con instrucción previa sobre dichos conceptos. El desempeño de los grupos que utilizaron el texto ilustrado fue significativamente mejor que su contraparte en problemas orientados a la definición literal de los fenómenos estudiados.

  6. Universidad de verano en El Cabañal

    OpenAIRE

    MUSHLIN, EYAL KOBY

    2014-01-01

    El proyecto se basa en cinco aspectos: creación de un eje de carácter público que comunica el barrio con la playa, relación entre dicho eje y las actividades de la universidad, fomento de zonas de actividad, apertura de vistas y recuperación del espacio verde, y generación de un microclima en el campus de la universidad. El programa incluye aulas, talleres y laboratorios, salas polivalentes, biblioteca, cafetería y viviendas temporales para estudiantes y profesores. Mushlin, EK. (2011). Un...

  7. MODELADO DE LAS ISOTERMAS DE SORCIÓN Y DEL CALOR ISOSTÉRICO DE SORCIÓN EN PULPA DE MANGO cv. TOMMY ATKINS MODELAGEM DE ISOTERMAS DE SORÇÃO E CALOR ISOSTÉRICO DE SORÇÃO DE POLPA DE MANGA cv. TOMMY ATKINS MODELING SORPTION ISOTHERMS AND ISOSTERIC HEAT OF SORPTION OF MANGO PULP cv. TOMMY ATKINS

    Directory of Open Access Journals (Sweden)

    JOSÉ BON

    2012-12-01

    Full Text Available El mango es un producto agrícola de gran importancia para diferentes países en vías de desarrollo, el cual ha incrementado su demanda por sus propiedades nutricionales y características exóticas. La relación entre el contenido de humedad y la actividad de agua suministra información útil para el procesamiento del mango, especialmente en las operaciones de secado y almacenamiento. La actividad de agua y el contenido de humedad de la pulpa de mango (Mangifera indica L. cv. Tommy Atkins fue analizada para determinar las isotermas de sorción. La actividad de agua fue medida utilizando un higrómetro eléctrico a cinco diferentes temperaturas (10, 20, 30, 40 y 50 °C y amplios rangos de contenido de humedad (2.829-0.031 kg kg-1 b.s. y actividad de agua (0.977-0.215. Un modelo teórico (GAB y cuatro ecuaciones empíricas (Oswin, Henderson, Halsey y Ratti fueron utilizados para representar las isotermas de sorción. Después de considerar diferentes criterios, el modelo de GAB fue evaluado como la mejor opción para representar el equilibrio higroscópico de la pulpa de mango (RMSE = 0.057, VAR = 0.996. Las isotermas mostraron un comportamiento acorde a los materiales agroalimentarios y similar al reportado para pulpa de mango de otras variedades. El calor isostérico de sorción fue calculado utilizando la ecuación de Clausius-Clapeyron a partir del modelo de GAB. Se observó una disminución en el calor isostérico de sorción al aumentar el contenido de humedad de equilibrio, con gran efecto de la humedad a valores por debajo de 0.8 kg kg-1 (b.s..A manga é um produto agrícola em países de desenvolvimento econômico, com grande aceitação devido a suas propriedades nutricionais e características exóticas. A relação entre o conteúdo de umidade e atividade de água proporciona informação útil para o processamento do mango, especialmente nas operações de secagem e armazenamento. A atividade de água e o conteúdo de umidade da

  8. Determinación del coeficiente global de transferencia de calor en secaderos rotativos de cáscara de limón Determination of global heat transfer coefficient in lemon peel rotary dryers

    Directory of Open Access Journals (Sweden)

    Marcos A. Golato

    2005-12-01

    Full Text Available En la bibliografía consultada no se encontraron trabajos de secado de cáscara de limón en secaderos rotativos. Se realizaron ensayos de medición en secaderos rotativos de cáscara de limón en una instalación agroindustrial del noroeste argentino. Se desarrolló un modelo matemático semiempírico mediante la resolución de los balances de materia y energía. Se obtuvo una correlación estadística para la predicción de los coeficientes globales volumétricos de transferencia de calor aparentes para secaderos rotativos de cáscara de limón.No papers on lemon peel drying in rotary dryers were actually found in the sources consulted. Measurement tests were carried out in the assessment of rotary dryer systems used to dehydrate lemon peel in an agroindustrial plant of Northwestern Argentina. A semiempirical mathematic model was developed solving mass and energy balances. A statistical correlation for predicting global heat transfer coefficient in rotary dryer lemon peel dehydration was obtained.

  9. Análisis de los medallistas de los juegos olímpicos de verano (1896-2012

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    Svetlana Molkov

    2017-09-01

    Full Text Available Los juegos olímpicos son uno de los eventos deportivos más seguidos y celebrados de todo el planeta, y conseguir una medalla olímpica es la máxima aspiración en la carrera de un deportista. En la presente investigación se analizan los medallistas de los juegos olímpicos modernos de verano (1896-2012, y se presta especial atención a su sexo y procedencia. A lo largo del estudio, se analizaron 14670 medallistas olímpicos de 140 países que compitieron en 52 especialidades deportivas durante 27 olimpiadas. De acuerdo con los resultados, EEUU es el país con el mayor número de deportistas premiados en este evento, seguido por la URSS y la Gran Bretaña. En cuanto al continente de procedencia de los medallistas, Europa abarca el mayor número de galardonados, seguido por América del Norte y Central y Asia. Considerando la modalidad deportiva, Europa es el continente con el mayor número de medallistas en la totalidad de las modalidades, seguido por América del Norte y Central en los deportes individuales y de cooperación, y por Asia en las modalidades de oposición y cooperación-oposición. En relación con el sexo, la participación de las mujeres en los juegos olímpicos fue escasa hasta la olimpiada de Ámsterdam, en 1928, y, a pesar de su aumento considerable en las competiciones olímpicas posteriores, el número de las medallistas nunca ha alcanzado la cantidad de los deportistas masculinos en los podios.

  10. Heat losses estimation associated with the physical state of the thermal insulation of pipes vaporductos network in Cerro Prieto geothermal field; Estimacion de perdidas de calor asociadas al estado fisico del aislamiento termico de las tuberias de la red de vaporductos del campo geotermico Cerro Prieto

    Energy Technology Data Exchange (ETDEWEB)

    Ovando Castelar, Rosember; Martinez Estrella, Juan Ignacio; Garcia Gutierrez, Alfonso [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: rovando@iie.org.mx; jime@iie.org.mx; aggarcia@iie.org.mx; Canchola Felix, Ismael; Miranda Herrera, Carlos; Jacobo Galvan, Paul [Campo Geotermico de Cerro Prieto, Comision Federal de Electricidad, Mexicali, B.C. (Mexico)

    2010-11-15

    The Cerro Prieto Geothermal Field (CPGF) steam transportation network is constituted by 140 km of pipes with diameters ranging from 8 to 48 inches, which transport the steam of 165 producing wells to 13 power plants which have a total installed capacity of 720 MWe. Originally, the pipes are thermally insulated with a mineral wool or fiber glass layer and an external aluminum or iron cover. Due to the insulation material has been exposed to weather conditions during the field operation it shows nowadays different grades of wear-out, or even it is lacking in some parts of the network, causing higher heat losses from the pipes to the environment. In this work, the magnitude of the heat losses related with the present condition of the thermal insulation throughout the pipeline network is assessed. This involved determining the longitude and diameter, as well as the insulation condition of each single pipeline section, and the calculation of the heat transfer coefficients for the different thermal insulation conditions defined for this study. [Spanish] La red de transporte de vapor del campo geotermico Cerro Prieto (CGCP) esta constituida por aproximadamente 140 km de tuberias de 8 a 48 pulgadas de diametro, las cuales conducen el vapor producido por 165 pozos hacia 13 plantas generadoras, cuya capacidad instalada es de 720 MWe. Originalmente, estas tuberias son aisladas termicamente con una capa de 2 pulgadas de material aislante a base de lana mineral o fibra de vidrio, y una proteccion exterior de aluminio o hierro. Debido principalmente al impacto de las condiciones meteorologicas durante el tiempo de operacion del campo, en algunas porciones de la red el aislante presenta actualmente distintos grados de deterioro, o incluso se encuentra ausente, lo cual se traduce en una mayor perdida de calor desde las tuberias hacia el medio ambiente. En el presente trabajo se evalua la magnitud de las perdidas de calor asociadas al estado fisico del aislamiento termico de las

  11. Determination of heat losses in the Cerro Prieto, Baja California, geothermal field steam transportation network based on the thermal insulation condition of the steam pipelines; Determinacion de perdidas de calor en la red de transporte de vapor del campo geotermico de Cerro Prieto, Baja California, con base en el estado fisico del aislamiento termico de vaporductos

    Energy Technology Data Exchange (ETDEWEB)

    Ovando Castelar, Rosember; Garcia Gutierrez, Alfonso; Martinez Estrella, Juan Ignacio [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: rovando@iie.org.mx; Canchola Felix, Ismael; Jacobo Galvan, Paul; Miranda Herrera, Carlos; Mora Perez, Othon [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia General de Cerro Prieto, Mexicali, B.C. (Mexico)

    2011-07-15

    In Cerro Prieto Geothermal Field (CPGF), the steam from producing wells is transported to power plants through a large and complex system of pipes thermally insulated with a 2 inches thick mineral wool or a fiber glass layer and an external aluminum or iron cover. The insulation material has been exposed to weather conditions during the field operation and has suffered density and thickness changes. In some cases the insulation has been lost completely, increasing heat transfer from the pipes to the environment. This paper analyzes the impact of the conditions of thermal insulation on heat losses in the CPGF steam-pipeline network. The heat losses are calculated by applying an iterative method to determine the surface temperature based on a heat balance calculated from the three basic mechanisms of heat transfer: conduction, convection, and radiation. Finally, using length and diameter data corresponding to the condition of the thermal insulation of each pipeline-and field operation data, the overall heat losses are quantified for steam lines throughout the pipeline network in the field. The results allow us to evaluate the magnitude of the heat losses in comparison with the overall energy losses occurring during steam transport from wells to the power plants. [Spanish] En el Campo Geotermico de Cerro Prieto (CGCP), BC, el transporte de vapor desde los pozos hasta las plantas generadoras de electricidad se lleva a cabo mediante un extenso y complejo sistema de tuberias que tipicamente se encuentran aisladas termicamente con una capa de 2 pulgadas de material aislante a base de lana mineral o fibra de vidrio, y una proteccion mecanica de aluminio o hierro galvanizado. Debido a la exposicion a las condiciones meteorologicas a traves del tiempo de operacion del campo, el aislamiento ha experimentado cambios en su densidad y espesor y en ocasiones se ha perdido por completo, lo cual repercute en una mayor transferencia de calor de las tuberias hacia el medio ambiente

  12. Influencia del Calor Aportado y Metal de Aporte Sobre las Propiedades Mecánicas y la Microestructura de Juntas Soldadas por FCAW de Acero Microaleado de Alta Resistencia

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    César Marconi

    2015-06-01

    Full Text Available ResumenActualmente, los aceros microaleados son ampliamente utilizados en reemplazo de los aceros al C y C-Mn por sus ventajas en cuanto a propiedades mecánicas, resistencia a la corrosión y soldabilidad, permitiendo una reducción de peso de los vehículos y estructuras sin detrimento de su resistencia. Cuando estos aceros son soldados, el ciclo térmico de la soldadura provoca cambios microestructurales que modifican sus propiedades originales. El calor aportado (HI: heat input es una de las principales variables a tener en cuenta cuando se evalúan estas modificaciones. Las propiedades finales de la unión soldada también se definen por el tipo de consumible utilizado. El objetivo de este trabajo es analizar las propiedades mecánicas y la microestructura de juntas soldadas a tope de un acero microaleado con dos grados de metal de aporte y diferentes HI. Como resultado del trabajo se observó un aumento considerable de tamaño de grano en la ZAC adyacente a la línea de fusión para todas las condiciones, siendo este efecto más marcado cuando se soldó con alto HI; y un ablandamiento en la ZAC de grano fino. Prácticamente se mantuvieron los valores de resistencia a la tracción al soldar con ambos consumibles, con un mejor desempeño cuando se soldó con bajo HI. La tenacidad en la ZAC mejoró con la disminución del HI.

  13. Manifestaciones músculo-articulares, y no las oleadas de calor, es el síntoma más prevalente en mujeres climatéricas del Caribe colombiano

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    Álvaro Monterrosa Castro

    2010-01-01

    Full Text Available Objetivo: Evaluar con Menopause Rating Scale la frecuencia y severidad de síntomas menopáusicos presentes en un conjunto global de mujeres saludables en edad media que son originarias y residen en distintas comunidades del Caribe colombiano. Materiales y métodos: Estudio transversal con formulario y escala MRS aplicada entre noviembre de 2006 y enero de 2009 a mujeres saludables entre 40 y 59 años de edad, tomadas de comunidades de la Costa Caribe colombiana: afrodescendientes, indígenas e hispánicas. Se determinó la frecuencia de presentación de los síntomas y su severidad. Resultados: Las molestias músculo-articulares fueron el síntoma más frecuente en un 72.9% de las mujeres, seguido de las oleadas de calor, en un 70.4%. La irritabilidad y el cansancio físico y mental fueron síntomas frecuentes, y se presentaron en más del 60% de las participantes. Las molestias músculo-articulares tienen la mayor puntuación promedio (1,6 +/- 1,3, lo cual revela que contribuyen en mayor proporción al deterioro de la calidad de vida. Al considerar la severidad de los síntomas en quienes manifestaron molestias músculo-articulares, los síntomas fueron severos o muy severos en un 29.6%, seguido de los problemas de vejiga, con un 23.2%. Conclusión: Para mejorar la calidad de vida de la mujer en la menopausia es importante caracterizar los síntomas climatéricos en cada población para brindar una mejor atención en salud, descubrir estrategias para el manejo de los síntomas y promover estilos de vida que contribuyan a disminuir su incidencia y severidad.

  14. ESTIMACIÓN DE LAS ISOTERMAS DE ADSORCIÓN Y DEL CALOR ISOSTÉRICO EN HARINA DE YUCA ESTIMAÇÃO DAS ISOTERMAS DE ADSORÇÃO E DO CALOR ISOSTÉRICO EM FARINHA DE MANDIOCA ADSORPTION ISOTHERMS AND ISOSTERIC HEAT ESTIMATION IN CASSAVA FLOUR

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    ALFREDO AYALA-APONTE

    2011-06-01

    Full Text Available Se determinaron las isotermas de adsorción de humedad en harina de yuca a 20, 25, 30 y 35°C mediante el método gravimétrico en el intervalo de actividad de agua entre 0.111 y 0.901. Los valores experimentales de adsorción se ajustaron mediante los modelos de GAB, BET, Oswin, Smith, Henderson y Chung and Pfost. El calor isostérico de sorción (Qst se determinó mediante la ecuación de Clausius-Clapeyron. Las isotermas obtenidas presentaron una forma sigmoidea (Tipo II. El contenido de humedad de equilibrio (CHE disminuyó con el aumento de la temperatura para un valor constante de actividad de agua. Los modelos de sorción GAB, Oswin y Smith fueron los que mejor ajustaron los valores experimentales. El Qst disminuyó con el aumento del CHE obteniéndose un valor máximo y un mínimo entre 118.84 y 45.20 kJ/mol para humedades entre 5 y 35 (g agua/g ms respectivamente.Se determinaram as isotermas de adsorção de humidade dafarinha de mandioca, 20, 25, 30 e 35°C utilizando-se o método estático gravimétrico numa faixa de atividade de água entre 0.111 e 0.90. Os valores experimentais de adsorção foram ajustados pelos modelos de GAB, BET, Oswin, Smith, Henderson e Chung, e Pfost. O calor isostérico de adsorção (Qst foi determinado pela ecuação de Clausius-Clapeyron. Os resultados mostraram que as isotermas obtidas foram de forma sigmoidal (Tipo II. O teor de humidade de equilibrio (CHE apresentou dependência com a temperatura, diminuindo com o aumento desta a um valor constante de atividade de água. Os Modelos de adsorção GAB, Oswin e Smith foram os que presentaram melhor ajuste aos valores experimentais. O Qst diminuío com o aumento de CHE, obténdo-se um máximo e um mínimo entre 118,84 e 45,20 kJ / mol de humidade entre 5 e 35 (g de água/g bs, respectivamente.Moisture adsorption isotherms of cassava flour were determined using a gravimetric static method at 20,25, 30 and 35°C in the range of water activity from 0.111 to 0

  15. Presentación clínica del golpe de calor en niños menores de 2 años en Lima - Perú

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    Reyner Loza Munarriz

    2001-10-01

    Full Text Available Objetivo: Describir el cuadro clínico de lactantes con golpe de calor (GC durante El Fenómeno de El Niño de 1998. Material y métodos: Se incluyeron 13 lactantes con criterios de GC, que acudieron a Emergencia Pediátrica del Hospital Cayetano Heredia entre el 1º de enero y el 31 de marzo de 1998. Se registró hematocrito, pruebas de coagulación, función hepática y renal, gasometría, electrolitos séricos y urinarios. Asimismo el flujo urinario, tipo de solución endovenosa utilizada para la rehidratación y la condición final del paciente al alta. Resultados: De los 13 lactantes, 4 fallecieron y 4 quedaron con secuelas neurológicas graves al alta. Los hallazgos clínicos relevantes fueron convulsiones (77%, dificultad respiratoria (85%, deshidratación (77%, shock (61%, diarrea aguda (85% y poliuria (75%. En el laboratorio general: anemia (84%, leucocitosis (60% tiempo de protrombina prolongado (53%, hiperglicemia (53% elevación de transaminasas (83%. En las alteraciones del medio interno; hiponatremia (84%, hipokalemia (70%, creatinina elevada (84%, urea elevada (53% y acidosis metabólica (100%. En el análisis sólo hubo asociación estadística entre el tiempo de protombina prolongado y el manejo inicial de fluidos con la condición final desfavorable. Conclusión: El GC es una enfermedad de pronóstico grave, donde el tiempo de protrombina prolongado, y el uso de soluciones hipertónicas en el manejo inicial, se asociaron a riesgo de muerte o secuelas neurológicas graves. Consideramos importante dar a conocer el comportamiento clínico y los factores asociados con un final catastrófico. (Rev Med Hered 2001; 12: 113-119.

  16. Current status of the second generation of parabolic trough solar concentrator for heat generation process designed at the IIE; Estado actual de la segunda generacion del concentrador solar de canal parabolico para generacion de calor de proceso disenado en el IIE

    Energy Technology Data Exchange (ETDEWEB)

    Ramos Berumen, Carlos; Ramirez Benitez, Juan Rafael; Beltran Adan, Jose [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: cramos@iie.org.mx; rramirez@iie.org.mx; jose.beltran@iie.org.mx

    2010-11-15

    The transformation industry normally uses thermal energy within its process, it obtains this energy burning fossils fuel, a new option is to use new technologies like the thermal solar technology like the parabolic trough, this is a long parabolic mirror used to reflect the sunlight and focused on an absorber tube with a heat-conducting fluid inside. The Instituto de Investigaciones Electricas (IIE) developed a prototype of parabolic trough that is operating in different industries, in this article are showing some improvements to the design, giving like result the second generation of the prototype of parabolic trough of the IIE. [Spanish] La industria de la transformacion normalmente utiliza energia termica dentro de su proceso, los medios convencionales para obtener esta energia es el quemar combustibles fosiles, una opcion que aplica nuevas tecnologias es el uso de la tecnologia termosolar a concentracion que le permitira a la industria utilizar el sol como fuente de energia primaria. El uso de esta tecnologia permitira a las empresas generar calor de proceso sin contaminar el ambiente, lo que dara como resultado empresas competitivas y autosuficientes. Para alcanzar temperaturas utiles a estas aplicaciones se requiere concentrar la energia solar en un area mas pequena, siendo la tecnologia mas extendida la de canal parabolico, el principio de operacion de esta tecnologia es la de concentrar la radiacion solar en el eje receptor preparado con una pintura especial para una mejor absorcion del calor y una cubierta de vidrio para evitar perdidas termicas, dentro del tubo circula un fluido caloportador el cual lleva el calor util hacia el proceso. El Instituto de Investigaciones Electricas (IIE) desarrollo un prototipo de canal parabolico, actualmente estan operando en diferentes industrias, resultado de estas aplicaciones se llevo a cabo una evaluacion del prototipo, se detectaron algunos puntos de mejoras al diseno, los cuales se exponen en este articulo, dando

  17. El clima de las ciudades: isla de calor de Salamanca

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    Mª Salud Alonso García

    2004-12-01

    Full Text Available En este trabajo se ha determinado la existencia de la isla de calor urbana (ICU, en una ciudad de tamaño medio, con un clima extremado y focos industriales de poca actividad. Con lo que se puede comprobar cómo afecta el calentamiento urbano a ciudades de estas características, pudiendo influir en los seres vivos de la zona. La existencia del fenómeno isla de calor, y su evolución en el tiempo, se han observado comparando los datos de temperatura registrados en una estación meteorológica situada en la ciudad, con los de otra estación fuera del radio de acción de la urbe, durante el período 1996-1998. Se han detectado dos fenómenos: la isla de calor nocturna, cuando la diferencia térmica entre la ciudad y la zona rural es positiva, que presenta sus valores más altos en otoño, y la isla de calor diurna, cuando la diferencia es negativa, que presenta sus valores más altos en primavera. Realizando un estudio estadístico de la evolución anual de la isla de calor nocturna en Salamanca, podemos definir isla de calor débil si su intensidad es inferior a 2 oC, moderada si se encuentra entre 2 oC y 4 oC e intensa si supera los 4 oC.

  18. Automatización y optimización del diseño de intercambiadores de calor de tubo y coraza mediante el método de Taborek//Automatization and optimization of shell and tube heat exchangers design using the method of Taborek

    Directory of Open Access Journals (Sweden)

    Maida Bárbara Reyes‐Rodríguez

    2014-01-01

    Full Text Available Los intercambiadores de calor del tipo de coraza y tubo constituyen la parte más importante de los equipos de transferencia de calor sin combustión en las plantas de procesos químicos. Existen en la literatura numerosos métodos para el diseño de Intercambiadores de calor de tubo y coraza. Entre los más conocidos se encuentran el Método de Kern, el Método de Bell Delaware, el Método de Tinker, elMétodo de Wills and Johnston y el Método de Taborek. El presente trabajo tiene como objetivo describir y automatizar el método de Taborek. Se realiza además la optimización del Costo del Intercambiador de Calor mediante el método de Recocido Simulado y el método de los algoritmos genéticos. Se puede concluir que la optimización por ambos métodos arroja resultados similares, disminuyendoapreciablemente el costo del intercambiador optimizado.Palabras claves: optimización, intercambiadores de calor, método de Taborek, algoritmos genéticos.______________________________________________________________________________AbstractShell and tube heat exchangers are the most important equipment for heat transfer without combustion in plants of chemical processes.There are many methods for designing shell and tube heat exchangers in literature. Among the most known are the Kern´s Method, the Method of Bell Delaware, the Method ofTinker, the Method of Wills and Johnston and the Method of Taborek. The objective of this paper is to describe and automate the Taborek´s method. It is also realized and optimization of the heat exchanger cost using the genetic algorithm and Simulated Annealing. It can be concluded that the optimization usingboth methods conduces to similar results, diminishing considerably the optimized exchanger cost.Key words: optimization, Heat Exchangers, Taborek, Genetic Algorithms.

  19. Análisis de la máxima intensidad de la isla de calor urbana nocturna de la ciudad de Rancagua (Chile y sus factores explicativos.

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    Pablo Sarricolea

    2008-12-01

    Full Text Available Las ciudades constituyen el hábitat por excelencia de los seres humanos, y pese a su diversidad presentan características ambientales (clima urbano comunes en muchas partes del mundo, como por ejemplo la presencia de la Isla de Calor Urbana (ICU, que corresponde a un aumento de origen antrópico de las temperaturas de la ciudad en comparación con su entorno inmediato de carácter natural y rural, siendo más intensa dicha diferencia en las noches. Por ello, el propósito de esta investigación es analizar la Máxima Intensidad de la Isla de Calor Urbana (MIICU de Rancagua a partir de mediciones de las temperaturas con transectos móviles y estaciones meteorológicas fijas. Se ha determinado que la máxima intensidad de la isla de calor urbana de Rancagua bordea los 6°C en verano y primavera, y 3°C para invierno y otoño. Los factores que explican las distribuciones de las temperaturas urbanas de Rancagua corresponden a las distancias a fuentes húmedas (río Cachapoal y las densidades poblacionales; y en menor medida las características topográficas del emplazamiento de la ciudad y las áreas verdes urbanas medidas a partir del índice normalizado de diferencias vegetales (NDVI. La principal conclusión de esta investigación indica que la ausencia de parques urbanos en Rancagua explica la distribución de las temperaturas y la elevada intensidad de la isla de calor, y también la no significativa relación entre temperaturas y NDVI. De no revertirse esta situación, la sostenibilidad ambiental futura de la ciudad de Rancagua se verá muy amenazada por el crecimiento urbano.Cities are the environment for excellence in human beings, and despite their diversity, environmental features (urban climate are common in many parts of the world, such as the presence of the Urban Heat Island (UHI. This corresponds to a temperature increase due to human activities in the city compared with its immediate natural and rural surroundings, the difference

  20. Concepciones alternativas de los docentes en formación del Instituto Pedagógico Superior Juan Demóstenes Arosemena sobre los conceptos de energía, calor y temperatura

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    Rodríguez, Viterbo

    2012-09-01

    Full Text Available Resumen: El artículo presenta los resultados de una investigación realizada en el año 2009 en el Instituto Pedagógico Superior Juan Demóstenes Arosemena. La metodología utilizada en el estudio es del tipo descriptiva cuantitativa y se utilizó una prueba de elección múltiple para recoger los datos. Cada ítem de la prueba centraba la atención en las concepciones alternativas sobre energía, calor y temperatura. Dicha prueba, después de su validación y pilotaje, fue desarrollada por 241 estudiantes de licenciatura de este Instituto. Luego de analizar las respuestas de los ítems, se obtuvo suficiente evidencia para concluir, significativamente, que los docentes en formación tienen concepciones alternativas: el 63.8% sobre el concepto de energía; 69% sobre el concepto de calor, y el 70.7% sobre el concepto de temperatura y movimiento (p=0.05. Las respuestas proporcionadas por los estudiantes demuestran que un elevado número considera que las transformaciones de energía ocurren sin ningún tipo de intercambio ni degradación de la misma. Esto revela su falta de comprensión de las leyes de la termodinámica. Las concepciones alternativas sobre el concepto de energía sugieren tres áreas o líneas principales de problemas: el concepto mismo de energía, los procesos que implican la transferencia de energía y el principio de conservación de la energía.Abstract: This article presents the results of research conducted in 2009 in the Instituto Pedagógico Superior Juan Demóstenes Arosemena. The methodology used in the study is descriptive research with a predominantly quantitative approach. A test was used with multiple-choice questions to collect data. Each item of the test was focused on alternative conceptions about energy, heat and temperature. The test, after validation and Piloting, was solved by 241 undergraduate students from the teaching training programs at Instituto Pedagógico. After analyzing the answers of the items, we

  1. Prácticas de Física: Equivalente en agua de un calorímetro

    OpenAIRE

    Beléndez,Augusto; Bernabeu, Guillermo; Vera Guarinos, Jenaro; Pastor Antón, Carlos; Martín García, Agapito

    1988-01-01

    Esta práctica de laboratorio tiene como objetivo el cálculo del equivalente en agua de un calorímetro con su error, familiarizarse con el uso del mismo y del termómetro. Para el desarrollo de esta práctica se dispone de un calorímetro lleno de agua en el que se ha colocado una resistencia interna. Se hace circular una corriente por la resistencia, de manera que la potencia que disipa la resistencia se convierte en potencia calorífica, por efecto Joule, calentando por un lado el agua en el int...

  2. Aplicación del Método de la Colonia de Hormigas Mixto a la optimización de intercambiadores de calor de tubo y coraza//Application of the Mixed Ant Colony Method to the optimization of tube and shell heat exchangers

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    Maida Bárbara Reyes‐Rodríguez

    2014-05-01

    Full Text Available Los procesos de transferencia de calor sonuno de los problemas más importantes a resolver en el campo de la Ingeniería. Entre los equipos más usados en la industria para realizar la transferencia de calor están los intercambiadores de calor de tubo y coraza. En el presente trabajo se desarrolla el procedimiento para la optimización del diseño de estos equipos utilizando el método de Kern y aplicando el algoritmo de la colonia de hormigas. Se aplica el mismo a tres ejemplos concretos y los resultados obtenidos se comparan con los obtenidos aplicando otros métodos de la inteligencia artificial. Se optimizan los principales parámetros geométricos de los intercambiadores de calor de tubo y coraza para lograr un menor costo de los mismos. Se demuestra la eficacia del nuevo procedimiento MACO (Mixed Ant Colony Optimization, en el proceso de optimización desde el punto de vista económico utilizando diferentes casos de estudios.Palabras claves: intercambiadores de calor, colonia de hormigas, método de Kern.______________________________________________________________________________AbstractHeat transfer processes are one of the most important problems to be solved in the field of Engineering. Among the most widely used equipment for heat transfer in the industry are the shell and tube heat exchangers. This paper develops the procedure for optimizing the design of shell and tube heat exchangers using the method of Kern and applying the ant colony algorithm. The procedure has been applied to three specific examples and the results obtained are compared with those obtained by applying other methods of artificial intelligence. The main geometric parameters of shell and tube heat exchangers are optimized, to achieve a lower cost of the exchanger. The efficacy of the new procedure MACO (Mixed Ant Colony Optimization for the optimization process from economically point of view was demonstrated, using different case studies.Key words: heat

  3. Dificultades y estrategias en el manejo del régimen terapéutico en el paciente renal crónico en hemodiálisis

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    António Filipe Cristóvão

    Full Text Available Objetivo: identificar las dificultades de los pacientes de hemodiálisis en el manejo del régimen terapéutico, las estrategias para hacer frente a estas dificultades e identificar factores que influyen en la gestión del tratamiento. Pacientes y métodos: se realizaron entrevistas semiestructuradas a una muestra intencional de 20 pacientes adultos, de dos centros de hemodiálisis, sometidas a análisis de contenido temático. Resultados: la mayor parte de las dificultades es en el área psicosocial: restricción de líquidos; dieta restrictiva; tener que realizar hemodiálisis; duración del tratamiento; tomar la medicación; limitaciones de vacaciones. Para hacer frente a las dificultades, los participantes utilizan más las estrategias de resolución de problemas que las estrategias para el control de las emociones. Conclusiones: el equipo de salud, la familia y la función renal residual, facilitan el manejo del tratamiento, mientras que el calor del verano y el humo son factores de complicación. Las enfermeras han de entender cómo los pacientes controlan el régimen de tratamiento, para promover mejor su autonomía.

  4. Impacto ecológico de los intercambiadores de calor de tubo y coraza

    OpenAIRE

    Reyes–Rodríguez, Maida Bárbara; Moya Rodríguez, Jorge Laureano; Cruz Fonticiella, Oscar Miguel

    2014-01-01

    Los intercambiadores de calor del tipo de coraza y tubo constituyen uno de los equipos más importantes en las plantas de procesos químicos. El diseño de los intercambiadores de calor desde el punto de vista termodinámico se basa en dos aspectos fundamentales, el coeficiente global de transferencia de calor y la caída de presión total. En el año 2007 el Científico chino Guo estableció una nueva propiedad termodinámica denominada “Entransía”, la cual expresa la capacidad de un cuerpo de transfe...

  5. El erotismo de el sueño de una noche de verano

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    Antonio PRIETO MARTÍNEZ

    2009-11-01

    Full Text Available RESUMEN: A partir de las fuentes de la comedia shakesperiana y teniendo en cuenta las aportaciones más significativas sobre la comedia de Shakespeare en el siglo XX, se trata en este estudio de aportar un enfoque nuevo, avalado por algunos investigadores, sobre El Sueño de una noche de verano. Muchos de los críticos y directores de teatro se resisten todavía a entender la obra —especialmente la experiencia de los amantes en el bosque— en otro sentido que no sea asumir el error aristotélico que sólo se subsana cuando los personajes aceptan finalmente la estructura social establecida. Proponemos que El Sueño de una noche de verano es una obra fundamentalmente erótica y que, a través de un lenguaje ambiguo y simbólico, Shakespeare aboga por la libertad sexual.ABSTRACT: Taking as a starting point the sources of Shakespeare in comedy and bearing in mind the most significant XXth Century contributions to the study of this comedy, this essay attempts to bring forward a new approach (endorsed by some critics to A midsummer night's dream. Many critics and theatre directors still refuse to fully comprehend the play —in particular the experience of the lovers in the wood—, making the mistake of imposing an aristotelian pattern in which the characters fully accept the established social structure. This essay asserts that A midsummer night's dream is fundamentally an erotic work and that, through the medium of an ambiguous and symbolic language, Shakespeare is advocating sexual liberty.

  6. Heat waves, intense droughts and desertification. summer 1994 in Southeast of Spain; Olas de calor, sequias intensas y desertificacion, durante el verano 1994 en el Sureste espanol (Murcia)

    Energy Technology Data Exchange (ETDEWEB)

    Avila, F.

    2009-07-01

    The South-East of spain, which has semiarid climate, is one of the hottest and dries areas in Europe. This region is specialized in irrigated agricultures and citrus fruits (lemons). the drought can last a long period, sometimes two or three years. The lack of water is becoming the biggest problem, especially since the development of irrigated cultures. Drought and heat waves are the major climatic risks and they cause most of the economic losses in agricultural activity. 1994 summer was exceptional in this region of Spain: heat waves and drought. A major disaster that revealed a crisis that began many years ago. The need of water is growing while the volume of available water tends to go down. 1994 summer and its disasters (fire, burnt crops by heat) generated social and politic tensions. Desertification is threatening the region. This situation is not new the drought is a normal phenomenon in a semiarid area, but the accumulation of drought, aridity and human actions worsening desertification. After 1994, new droughts and heat waves increased the lack of water because agriculture needs more and more water. Nonetheless this cultural method is compacting soil by the reduction of organic matter and by the heavy falls of rain. No solution has been found yet, they have to find new resources of water or change agricultural irrigation methods to save water and build up a sustainable development of this semiarid area. (Author) 12 refs.

  7. Análisis estructural de un intercambiador de calor de un reactor avanzado

    OpenAIRE

    García Merino, Carlos

    2008-01-01

    El objetivo fundamental de este proyecto consiste en el estudio estructural de un intercambiador de calor de un reactor avanzado de Generación VI. Este intercambiador de calor es el condensador PCCS (Passive Containment Cooling System), sistema de seguridad de una central nuclear ESBWR. El análisis estructural del condensador se ha realizado analítica y numéricamente. El cálculo analítico utiliza expresiones obtenidas del código ASME, para determinar tensiones por presiones internas. Y el cál...

  8. Carnot to Clausius: Caloric to Entropy

    Science.gov (United States)

    Newburgh, Ronald

    2009-01-01

    This paper discusses how the Carnot engine led to the formulation of the second law of thermodynamics and entropy. The operation of the engine is analysed both in terms of heat as the caloric fluid and heat as a form of energy. A keystone of Carnot's thinking was the absolute conservation of caloric. Although the Carnot analysis was partly…

  9. Higher Unsaturation and Peroxidizability Indices in Caloric ...

    African Journals Online (AJOL)

    In this report, Drosophila melanogaster were maintained on caloric restricted and normal diets for varying periods, mitochondrial phospholipid fatty acids were extracted and analyzed. Whilst 10 days and 20 days of caloric restriction did not cause any significant change in mitochondrial phospholipid fatty acid composition, ...

  10. Tolerancia al calor y humedad atmosférica de diferentes grupos raciales de ganado bovino

    Directory of Open Access Journals (Sweden)

    Ariel Guillén T

    2011-04-01

    Full Text Available Objetivo. Comparar algunas respuestas fisiológicas al calor y humedad atmosférica entre bovinos Chinampos (Bos taurus; Ch, ½ Charolais ½ Brahman (CB, Holstein (H y Jersey (J. Materiales y métodos. Se realizó un estudio en La Paz, México. Se utilizaron 12 vacas H, 10 J, 15 Ch y 8 CB. Durante el verano se midieron cada semana (a las 0600 y 1600 horas la frecuencia respiratoria (FR y temperatura rectal (TR. Se registraron las variables climáticas para calcular el índice de temperatura-humedad (ITH. Resultados. Durante todo el verano, la FR en los cuatro grupos estuvo por encima de los valores fisiológicos para el ganado bovino, siendo superior en H y J que en Ch y CB (p<0.01. En todos los grupos, la TR estuvo dentro de los límites fisiológicos de la especie estudiada. El grupo racial más afectado fue H (p<0.05. Cuando las constantes fisiológicas fueron analizadas dentro de cada una de tres categorías de ITH (<72, ≥72<78, y ≥78, las vacas H y J mostraron FR superior a las Ch y CB (p<0.01. La TR aumentó conforme se elevó el ITH siendo más marcado en J y H. El incremento de la FR entre la mañana y la tarde de cada día de medición fue mayor en H y J que en Ch y CB (p<0.05. La TR se incrementó más en H que en Ch (p<0.05. Conclusiones. Los grupos raciales más tolerantes al estrés por calor, determinado con base en FR y TR fueron Ch y CB.

  11. Efecto de las cubiertas ajardinadas sobre el microclima urbano de verano

    OpenAIRE

    Saiz Alcázar, Susana

    2016-01-01

    El cambio climático y sus efectos requieren con urgencia el desarrollo de estrategias capaces no solo de mitigar pero también permitir la adaptación de los sistemas afectados por este fenómeno a los cambios que están provocando a nivel mundial. Olas de calor más largas y frecuentes, inundaciones, y graves sequías aumentan la vulnerabilidad de la población, especialmente en asentamientos urbanos. Este fenómeno y sus soluciones potenciales han sido ampliamente estudiados en las últimas décadas ...

  12. Caloric beverage consumption patterns in Mexican children

    Directory of Open Access Journals (Sweden)

    Rivera Juan A

    2010-10-01

    Full Text Available Abstract Background Mexico has seen a very steep increase in child obesity level. Little is known about caloric beverage intake in this country as well as all other countries outside a few high income countries. This study examines overall patterns and trends in all caloric beverages from two nationally representative surveys from Mexico. Methods The two nationally representative dietary intake surveys (1999 and 2006 from Mexico are used to study caloric beverage intake in 17, 215 children. The volume (ml and caloric energy (kcal contributed by all beverages consumed by the sample subjects were measured. Results are weighted to be nationally representative. Results The trends from the dietary intake surveys showed very large increases in caloric beverages among pre-school and school children. The contribution of whole milk and sugar-sweetened juices was an important finding. Mexican pre-school children consumed 27.8% of their energy from caloric beverages in 2006 and school children consumed 20.7% of their energy from caloric beverages during the same time. The three major categories of beverage intake are whole milk, fruit juice with various sugar and water combinations and carbonated and noncarbonated sugared-beverages. Conclusion The Mexican government, greatly concerned about obesity, has identified the large increase in caloric beverages from whole milk, juices and soft drinks as a key target and is initiating major changes to address this problem. They have already used the data to shift 20 million persons in their welfare and feeding programs from whole to 1.5% fat milk and in a year will shift to nonfat milk. They are using these data to revise school beverage policies and national regulations and taxation policies related to an array of less healthful caloric beverages.

  13. Oxytocin reduces caloric intake in men

    National Research Council Canada - National Science Library

    Lawson, Elizabeth A; Marengi, Dean A; DeSanti, Rebecca L; Holmes, Tara M; Schoenfeld, David A; Tolley, Christiane J

    2015-01-01

    .... Oxytocin effects on nutrition and metabolism in humans are not well defined. It was hypothesized that oxytocin would reduce caloric intake and appetite and alter levels of appetite-regulating hormones...

  14. Epigenetic regulation of caloric restriction in aging

    National Research Council Canada - National Science Library

    Li, Yuanyuan; Daniel, Michael; Tollefsbol, Trygve O

    2011-01-01

    .... The aging process is frequently affected by environmental factors, and caloric restriction is by far the most effective and established environmental manipulation for extending lifespan in various animal models...

  15. Fasting or caloric restriction for healthy aging.

    Science.gov (United States)

    Anton, Stephen; Leeuwenburgh, Christiaan

    2013-10-01

    Aging is associated with a host of biological changes that contribute to a progressive decline in cognitive and physical function, ultimately leading to a loss of independence, and increased risk of mortality. To date, prolonged caloric restriction (i.e., a reduction in caloric intake without malnutrition) is the only non-genetic intervention that has consistently been found to extend both mean and maximal life span across a variety of species. Most individuals have difficulty sustaining prolonged caloric restriction, which has led to a search for alternative approaches that can produce similar to benefits as caloric restriction. A growing body of evidence indicates that fasting periods and intermittent fasting regimens in particular can trigger similar biological pathways as caloric restriction. For this reason, there is increasing scientific interest in further exploring the biological and metabolic effects of intermittent fasting periods, as well as whether long-term compliance may be improved by this type of dietary approach. This special will highlight the latest scientific findings related to the effects of both caloric restriction and intermittent fasting across various species including yeast, fruit flies, worms, rodents, primates, and humans. A specific emphasis is placed on translational research with findings from basic bench to bedside reviewed and practical clinical implications discussed. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Determinación experimental mediante DSC de las estabilidades térmicas y las capacidades caloríficas: quinua, kiwicha y cañihua

    OpenAIRE

    Romero Carrión, Violeta; Tirado Rengifo, Arminda; Dávalos Prado, Juan

    2015-01-01

    El objetivo fue determinar mediante Calorímetría diferencial de barrido (“Differential Scanning Calorimetry”, DSC) el calor específico y los parámetros termofísicos de la descomposición completa y la gelatinización, de la quinua (Chenopodium quinoa, kiwicha (Amaranthus caudatus) y la cañihua (Chenopodium pallidicaule). Para la determinación del calor específico se usaron cápsulas de aluminio y tomando de referencia el c.e del zafiro, observándose picos en el termograma, entre 50 y 60°C y calo...

  17. Identificación de incrustaciones en ciclones recuperadores de calor de hornos DOPOL

    Directory of Open Access Journals (Sweden)

    Triviño Vázquez, Fernando

    1979-12-01

    Full Text Available Not avaible

    En un ciclón recuperador de calor, situado a la entrada del horno de clinquerización tipo DOPOL, se producían unas incrustaciones sedimentarias que terminaban produciendo la obstrucción del ciclón. Simultáneamente aparecían dificultades de marcha durante el crecimiento, por sedimentación- fusión, de dichas incrustaciones. Finalmente era necesaria la parada del horno para la limpieza del ciclón.

  18. Coeficientes de transferencia de calor en enfriadores de mineral laterítico a escala piloto

    OpenAIRE

    Ángel Legrá-Legrá; Yudmila Spencer-Rodríguez; Yoalbys Retirado-Mediaceja; Ángel O. Columbié-Navarro; Marbelis Lamorú-Urgellés; Ever Góngora-Leyva

    2009-01-01

    En la Planta de Hornos de Reducción de la empresa niquelera Ernesto Guevara las elevadas temperaturas del mineral reducido a la salida de los enfriadores (coolers) afectan el desarrollo eficiente del proceso de lixiviación. Se realizó una investigación, a escala piloto, en los enfriadores de mineral reducido con el fin de evaluar el comportamiento de los parámetros de transferencia de calor que caracterizan el proceso; para ello se registraron los valores de temperatura del agua y del flujo y...

  19. Anti-inflammatory and antioxidant activity of polyphenolic extracts from Lactuca sativa (var. Maravilla de Verano) under different farming methods.

    Science.gov (United States)

    Adesso, Simona; Pepe, Giacomo; Sommella, Eduardo; Manfra, Michele; Scopa, Antonio; Sofo, Adriano; Tenore, Gian Carlo; Russo, Mariateresa; Di Gaudio, Francesca; Autore, Giuseppina; Campiglia, Pietro; Marzocco, Stefania

    2016-09-01

    Besides their nutritional value, vegetables are a source of health-promoting compounds, such as polyphenols, and their content can be influenced by the particular farming method. In this study polyphenolic extracts from Lactuca sativa (var. Maravilla de verano) plants cultivated with different farming methods were chemically characterised and tested in vitro and ex vivo inflammation models. The tested extacts (250-2.5 µg mL(-1) ) were able to reduce both the inflammatory and oxidative stress in LPS-stimulated J774A.1 murine monocyte macrophage cells, by lowering the release of nitric oxide (NO) and reactive oxygen species (ROS) and promoting nuclear translocation of nuclear factor (erythroid-derived 2)-like 2; (Nrf2) and nuclear factor-κB (NF-κB). In this regard, quantitative profiles revealed different amounts of polyphenols, in particular quercetin levels were higher in plants under mineral fertilised treatment. Those extract showed an enhanced anti-inflammatory and antioxidant activity. Our data showed the anti-inflammatory and antioxidant potential of Maravilla de Verano polyphenolic extracts. The effect of farming methods on polyphenolic levels was highlighted. The higher reduction of inflammatory mediators release in extracts from plants cultivated under mineral fertilisation treatment was correlated to the higher amount of quercetin. These results can be useful for both nutraceutical or agronomic purposes. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  20. Diseño experimental, construcción y calibración de un sensor de flujo de calor para aplicaciones HVAC/R

    OpenAIRE

    Fonseca Díaz, Néstor; Burbano Jaramillo, Juan Carlos

    2007-01-01

    Este artículo presenta los resultados del estudio para el diseño experimental, construcción y calibración de un sensor de flujo de calor de utilidad en la detección de flujos de calor muy pequeños en Calefacción, Ventilación, Acondicionamiento de aire y Refrigeración (HVAC/R). Se propone el diseño de un sensor para medir flujos de calor en paredes de edificios y cuartos fríos del orden de 2 a 30 W/(m2K) con una incertidumbre total máxima de 5 % del flujo de calor medido. Actualmente, para ot...

  1. Ciclo espermatogénico del lacertilio Sceloporus mucronatus (Reptilia: Phrynosomatidae)

    OpenAIRE

    Víllagrán-Santa Cruz, Maricela; Méndez-De la Cruz, Fausto R.; Parra-Gámez, Leticia

    2016-01-01

    El ciclo espermatogénico anual del lacertilio Sceloporus mucronatus de la localidad de Acocomulco, Hidalgo, México, fue clasificado en siete estadios. Tiene una larga recrudescencia (6.5 meses), iniciándose en el invierno con proliferación de espermatogonias; el máximo número de espermatocitos primarios y secundarios se observa en la primavera y verano respectivamente; la espermiogénesis ocurre a ftnes del verano y es completada durante los meses otoñales, denotando con esto un ciclo reproduc...

  2. Cambios institucionales para preservar la cantidad y la calidad del agua en la cuenca del Lago de Tota

    OpenAIRE

    Chaparro Valderrama, Jairo

    2013-01-01

    Diversos estudios realizados durante las últimas décadas en la cuenca del lago de Tota, han identificado, por una parte, un crecimiento de la demanda de agua acompañado de una reducción en su oferta -especialmente durante el verano-, y, por la otra, procesos crecientes, aunque focalizados, de contaminación del agua en los afluentes del lago y en el lago mismo.

  3. Daylight-saving time: Consumption and demand saving and pollutants emission reduction; El cambio de horario de verano: Ahorros en consumo y demanda, y reduccion de contaminantes

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Gaudencio; Diaz, Rodrigo; Fiscal, Raul; Alquicira, Claudia; Martinez, Serafin; Maqueda, Martin [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1997-12-31

    This paper presents some of the saving obtained in demand and in fuels with the daylight-saving time, as well as the main aspects considered to make an evaluation of it. [Espanol] Se presentan los ahorros obtenidos en consumo, demanda y combustibles con el cambio de horario de verano, asi como los principales aspectos considerados para efectuar la evaluacion de los mismos.

  4. Oxytocin reduces caloric intake in men.

    Science.gov (United States)

    Lawson, Elizabeth A; Marengi, Dean A; DeSanti, Rebecca L; Holmes, Tara M; Schoenfeld, David A; Tolley, Christiane J

    2015-05-01

    Preclinical studies indicate that oxytocin is anorexigenic and has beneficial metabolic effects. Oxytocin effects on nutrition and metabolism in humans are not well defined. It was hypothesized that oxytocin would reduce caloric intake and appetite and alter levels of appetite-regulating hormones. Metabolic effects of oxytocin were also explored. A randomized, placebo-controlled crossover study of single-dose intranasal oxytocin (24 IU) in 25 fasting healthy men was performed. After oxytocin/placebo, subjects selected breakfast from a menu and were given double portions. Caloric content of food consumed was measured. Visual analog scales were used to assess appetite, and blood was drawn for appetite-regulating hormones, insulin, and glucose before and after oxytocin/placebo. Indirect calorimetry assessed resting energy expenditure (REE) and substrate utilization. Oxytocin reduced caloric intake with a preferential effect on fat intake and increased levels of the anorexigenic hormone cholecystokinin without affecting appetite or other appetite-regulating hormones. There was no effect of oxytocin on REE. Oxytocin resulted in a shift from carbohydrate to fat utilization and improved insulin sensitivity. Intranasal oxytocin reduces caloric intake and has beneficial metabolic effects in men without concerning side effects. The efficacy and safety of sustained oxytocin administration in the treatment of obesity warrants investigation. © 2014 The Obesity Society.

  5. Higher Unsaturation and Peroxidizability Indices in Caloric ...

    African Journals Online (AJOL)

    The biochemical processes involved in ageing are poorly understood. One of the general approaches to understanding the mechanism of ageing is to study the effect of experimental manipulations on life-span and the properties that are affected by them. Some of these experimental manipulations are caloric restriction and ...

  6. Epigenetic regulation of caloric restriction in aging

    Directory of Open Access Journals (Sweden)

    Daniel Michael

    2011-08-01

    Full Text Available Abstract The molecular mechanisms of aging are the subject of much research and have facilitated potential interventions to delay aging and aging-related degenerative diseases in humans. The aging process is frequently affected by environmental factors, and caloric restriction is by far the most effective and established environmental manipulation for extending lifespan in various animal models. However, the precise mechanisms by which caloric restriction affects lifespan are still not clear. Epigenetic mechanisms have recently been recognized as major contributors to nutrition-related longevity and aging control. Two primary epigenetic codes, DNA methylation and histone modification, are believed to dynamically influence chromatin structure, resulting in expression changes of relevant genes. In this review, we assess the current advances in epigenetic regulation in response to caloric restriction and how this affects cellular senescence, aging and potential extension of a healthy lifespan in humans. Enhanced understanding of the important role of epigenetics in the control of the aging process through caloric restriction may lead to clinical advances in the prevention and therapy of human aging-associated diseases.

  7. Coeficientes de transferencia de calor en enfriadores de mineral laterítico a escala piloto

    Directory of Open Access Journals (Sweden)

    Ángel Legrá-Legrá

    2009-03-01

    Full Text Available En la Planta de Hornos de Reducción de la empresa niquelera Ernesto Guevara las elevadas temperaturas del mineral reducido a la salida de los enfriadores (coolers afectan el desarrollo eficiente del proceso de lixiviación. Se realizó una investigación, a escala piloto, en los enfriadores de mineral reducido con el fin de evaluar el comportamiento de los parámetros de transferencia de calor que caracterizan el proceso; para ello se registraron los valores de temperatura del agua y del flujo y la temperatura del mineral, tanto a la entrada como a la salida de la instalación, para valores de flujos de 10 y 19 l/min. Como resultado se obtuvo el procedimiento de cálculo para determinar los coeficientes superficiales de transferencia de calor por unidad de longitud. Se encontró que en los enfriadores de mineral reducido predominan la conducción y radiación del mineral a la pared interior del cilindro cubierta por el sólido así como la convección y evaporación del agua al medio que permite dirigir las acciones hacia estos elementos para aumentar la eficiencia de la instalación.

  8. Calidad de agua de la bahía interior de Puno, lago Titicaca durante el verano del 2011

    NARCIS (Netherlands)

    Farfán, Diana Beltrán F.; Calli, Rocio Palomino P.; Terrazas, Edmundo Moreno G.; Peralta, Cesar G.; Montesinos, Daniel

    2015-01-01

    Water quality of the inner Puno Bay was evaluated; we established 12 stations, and were assessed monthly from December 2010 to April 2011. Physicochemical water parameters were determined with EPA and APHA standard methods. Nutrients were determined spectrophotometrically. The parameters of

  9. Intake of calorically sweetened beverages and obesity

    DEFF Research Database (Denmark)

    Olsen, N J; Heitmann, B L

    2009-01-01

    The prevalence of obesity has increased in the past 30 years, and at the same time a steep increase in consumption of soft drinks has been seen. This paper reviews the literature for studies on associations between intake of calorically sweetened beverages and obesity, relative to adjustment...... for energy intake. Conclusions from previous reviews have been inconsistent, but some included many cross-sectional studies or studies supported by sugar industry. A literature search was performed for prospective and experimental studies using Medline and Scirus. Fourteen prospective and five experimental...... not find effects. Eight prospective studies adjusted for energy intake. Seven of these studies reported associations that were essentially similar before and after energy adjustment. In conclusion, a high intake of calorically sweetened beverages can be regarded as a determinant for obesity. However...

  10. Caracterización hidrográfica del estuario del río Valdivia, centro-sur de Chile

    Directory of Open Access Journals (Sweden)

    José Garcés-Vargas

    2013-03-01

    Full Text Available La costa sureste del Océano Pacífico entre 37° y 41°S, se caracteriza por la presencia de un gran número de estuarios micromareales (rango mareal menor a 2 m. Uno de los estuarios más importantes dentro de estas latitudes es el estuario del río Valdivia, cuya estructura y dinámica termal y halina es poco conocida. Mediante mediciones hidrográficas de temperatura y salinidad tomadas durante un ciclo estacional anual y el análisis de sus principales forzantes (marea, caudal del río, vientos y radiación solar se explica la variabilidad así como sus cambios en la estratificación vertical. El análisis de la estructura termohalina de la columna de agua reveló que el estuario varió estacionalmente comportándose como un estuario de cuña salina en invierno y primavera producto del mayor caudal de los ríos afluentes, mientras que en verano y otoño se comportó como parcialmente mezclado, producto del menor caudal de los ríos. En invierno y primavera la columna de agua presentó inversión térmica, la cual fue asociada a pérdida de calor superficial y a la advección sub-superficial de aguas cálidas desde el océano adyacente hacia el interior del estuario que no se mezclaron con las de la superficie debido a la intensa estratificación salina. El cambio en el régimen estuarino de cuña salina a parcialmente mezclado según la estación del año y presencia de la inversión térmica estacional, son características hidrográficas necesarias tanto para la implementación de esfuerzos de conservación de hábitat vulnerables presentes en la zona (áreas de crianza de juveniles de especies explotadas, como para la utilización de este sistema para actividades de acuicultura y manejo de recursos marinos.

  11. Analysis of the astronomical elements and its impact in the daylight saving time in Mexico; Analisis de los elementos astronomicos y su repercusion en el horario de verano en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Torres, Juan M; Navarrete Padilla, Roberto [Universidad de Guanajuato, Guanajuato, Guanajuato (Mexico)

    2000-07-01

    The analysis of the denominated daylight time is presented in Mexico, starting from the consideration of the astronomical elements that they determine the conformation of the day. In a principle we contemplates that only variable but along the process others were included that are decisive of the process of this change in the time. With the above-mentioned like reference is contemplated the analyses starting from the following general variable: a) astronomical variable, b) economic variable c) variable bio-environmental. The analysis for the astronomical part is developed starting from including the elements that determine the concept by day Astronomical and Civil day and its starting from statements and approaches outlined by the official sources and the bio-environmental (in specific the biological rhythms) for some results of investigators' studies in the matter. [Spanish] Se presenta el analisis del denominado Horario de Verano (H. de V.) en Mexico, a partir de la consideracion de los elementos astronomicos que determinan la conformacion del dia. En un principio se contemplo esa unica variable pero a lo largo del proceso se incluyeron otras que son determinantes del proceso de cambio en el tiempo. Con lo anterior como referencia se contempla el analisis a partir de las siguientes variables generales: a) variable astronomica, b) variable bio-ambiental c) variable economica. El analisis de la parte astronomica se desarrolla a partir de incluir los elementos que determinan el concepto de dia Astronomico y dia Civil y su relacion, por otro lado la parte economica se revisa a partir de afirmaciones y criterios planteados por las fuentes oficiales y la bio-ambiental (en especifico los ritmos biologicos) por algunos resultados de estudios de investigadores en la materia.

  12. Transferencia molecular de calor, masa y/o cantidad de movimiento

    OpenAIRE

    Betancourt Grajales, Ramiro

    2008-01-01

    Este texto fue diseñado para proveer un tratamiento integrado de las tres áreas del transporte: impulso, calor y masa. Las similitudes entre las leyes de flujo permiten aplicar directamente analogías en el cálculo del transporte haciendo una economía en el esfuerzo docente–discente acorde con las pedagogías intensivas. Muchas de las ecuaciones básicas son matemáticamente idénticas cuando se expresan en términos de las variables y densidades de flujo generalizadas. El texto comienza con tra...

  13. La era Solís y la Organización Internacional del Trabajo : 1964-1966

    OpenAIRE

    Abdón Mateos

    1995-01-01

    A partir del verano de 1964 la diplomacia franquista logró una cierta mejora de sus relaciones con los directivos de la Organización Internacional del Trabajo (OIT). La tormenta exterior del trienio 1961-1963 provocada por la represión de huelguistas, miembros del Movimiento Europeo y activistas de la izquierda había remitido y parecía que se imponía una apertura al diálogo.

  14. CONCENTRACIONES PLASMÁTICAS DE 25-OH-VITAMINA D EN SANGRE DE CORDÓN UMBILICAL TRAS LOS MESES DE VERANO

    Directory of Open Access Journals (Sweden)

    Cristina Manzano Varo

    2017-01-01

    Full Text Available Los niveles de vitamina D (25(OHD del recién nacido dependen de los depósitos maternos. En los últimos años se han publicado estudios que muestran una elevada prevalencia de deficiencia de vitamina D en mujeres embarazadas, viéndose en algunos diferencias estacionales. El objetivo del presente estudio fue determinar los valores de 25(OHD en sangre de cordón después de los meses de verano y determinar su relación con diferentes variables. Métodos: Se seleccionó a 103 mujeres en el momento del parto durante los meses de octubre, noviembre y principios de diciembre, cuyas gestaciones tuvieron lugar durante meses de máxima exposición solar. Se determinaron las concentraciones de 25(OHD en sangre de cordón umbilical y se recogieron datos perinatales, ingesta de vitamina D y calcio y exposición solar mediante cuestionario. Se realizó el análisis estadístico mediante el programa SPSS. Las comparaciones se realizaron mediante test de Kruskal- Wallis y U de Mann-Whitney, aplicando corrección por comparaciones múltiples de Bonferroni. Se consideró estadísticamente significativa una p<0,05 y de 0,0083 para comparaciones múltiples. Resultados: El valor medio de 25(OHD en sangre de cordón fue 12,36±7,2 ng/ml. El 83,4% de las mujeres presentaron niveles deficitarios. Se observó una correlación estadísticamente significativa entre los niveles bajos de vitamina D y la baja ingesta de vitamina D (coeficiente de correlación 0,29; la etnia, presentando el valor más alto la etnia caucásica (17,9 ± 5,83 ng/ml y el menor la etnia indopakistaní (6,68 ± 4,2 ng/ml; el uso de indumentaria tradicional (5,64 ± 3,09 ng/ml; la baja exposición solar y el fototipo cutáneo oscuro con un coeficiente de correlación de 0,67 y -0,48 respectivamente. Conclusiones: Existe una elevada prevalencia de deficiencia de vitamina D en sangre de cordón umbilical independiente de la exposición solar. Se observó una correlación entre niveles bajos de

  15. Use of non-caloric edulcorants in children

    OpenAIRE

    Calzada León Raúl; Altamirano Bustamante Nelly

    2014-01-01

    We analyze the health normativity for the denomination of non caloric edulcorants in Mexico, and the authorization for the use of natural and synthetic non caloric edulcorants in newborn and until puberty. Special emphasis was given to the consecutive points of safety required in order to assure that they are free of secondary effects. For each non caloric edulcorant available in Mexico, we looked into the studies which mention their side effects in terms of growth and overall.

  16. Use of non-caloric edulcorants in children

    Directory of Open Access Journals (Sweden)

    Calzada León Raúl

    2014-07-01

    Full Text Available We analyze the health normativity for the denomination of non caloric edulcorants in Mexico, and the authorization for the use of natural and synthetic non caloric edulcorants in newborn and until puberty. Special emphasis was given to the consecutive points of safety required in order to assure that they are free of secondary effects. For each non caloric edulcorant available in Mexico, we looked into the studies which mention their side effects in terms of growth and overall.

  17. Modeling microscale heat transfer using Calore.

    Energy Technology Data Exchange (ETDEWEB)

    Gallis, Michail A.; Rader, Daniel John; Wong, Chung-Nin Channy; Bainbridge, Bruce L.; Torczynski, John Robert; Piekos, Edward Stanley

    2005-09-01

    Modeling microscale heat transfer with the computational-heat-transfer code Calore is discussed. Microscale heat transfer problems differ from their macroscopic counterparts in that conductive heat transfer in both solid and gaseous materials may have important noncontinuum effects. In a solid material, three noncontinuum effects are considered: ballistic transport of phonons across a thin film, scattering of phonons from surface roughness at a gas-solid interface, and scattering of phonons from grain boundaries within the solid material. These processes are modeled for polycrystalline silicon, and the thermal-conductivity values predicted by these models are compared to experimental data. In a gaseous material, two noncontinuum effects are considered: ballistic transport of gas molecules across a thin gap and accommodation of gas molecules to solid conditions when reflecting from a solid surface. These processes are modeled for arbitrary gases by allowing the gas and solid temperatures across a gas-solid interface to differ: a finite heat transfer coefficient (contact conductance) is imposed at the gas-solid interface so that the temperature difference is proportional to the normal heat flux. In this approach, the behavior of gas in the bulk is not changed from behavior observed under macroscopic conditions. These models are implemented in Calore as user subroutines. The user subroutines reside within Sandia's Source Forge server, where they undergo version control and regression testing and are available to analysts needing these capabilities. A Calore simulation is presented that exercises these models for a heated microbeam separated from an ambient-temperature substrate by a thin gas-filled gap. Failure to use the noncontinuum heat transfer models for the solid and the gas causes the maximum temperature of the microbeam to be significantly underpredicted.

  18. Current and future employment of the heat pumps; Pompe di calore. Presente e futuro

    Energy Technology Data Exchange (ETDEWEB)

    Cassitto, L. [Milan Politecnico, Milan (Italy). Dipt. di Energetica

    2001-12-01

    Heat pumps, mainly the compression type, grant high energy savings together with environment protection because of the free low temperature energy from environment or wasted heat they use. Their large employment depends on the appreciation of the above properties that are will be done. To grant economic savings on using heat pumps, electric energy and natural gas should have fixed and predictable prices. [Italian] Le pompe di calore, in particolare quelle a compressione, hanno elevate prestazioni energetiche e ambientali, grazie all'utilizzo di fonti di calore gratuite a bassa temperatura, naturali o residue di altri processi. La loro diffusione e' legata alla percezione di queste potenzialita' rinunciando alle caldaie tradizionali. Sono indispensabili prezzi dell'energia elettrica e del metano stabili e comunque prevedibili per garantire anche la loro convenienza economica.

  19. A Dissociation between Recognition and Hedonic Value in Caloric and Non-caloric Carbonated Soft Drinks

    Directory of Open Access Journals (Sweden)

    Franco eDelogu

    2016-01-01

    Full Text Available Consumption of sugar-sweetened beverages (SSBs is considered to be a contributor to diabetes and the epidemic of obesity in many countries. The popularity of non-caloric carbonated soft drinks as an alternative to SSBs may be a factor in reducing the health risks associated with SSBs consumption. This study focuses on the perceptual discrimination of SSBs from artificially sweetened beverages (ASBs. 55 college students rated 14 commercially available carbonated soft drinks in terms of sweetness and likeability. They were also asked to recognize if the drinks contained sugar or a non-caloric artificial sweetener. Overall, participants showed poor accuracy in discriminating drinks’ sweeteners, with significantly lower accuracy for SSBs than ASBs. Interestingly, we found a dissociation between sweetener recognition and drink pleasantness. In fact, in spite of a chance-level discrimination accuracy of SSBs, their taste was systematically preferred to the taste of non-caloric beverages. Our findings support the idea that hedonic value of carbonated soft drinks is dissociable from its identification and that the activation of the pleasure system seems not to require explicit recognition of the sweetener contained in the soft drink. We hypothesize that preference for carbonated soft drinks containing sugar over non-caloric alternatives might be modulated by metabolic factors that are independent from conscious and rational consumers’ choices.

  20. Caloric versus low-caloric sweeteners: Can the body be fooled?

    NARCIS (Netherlands)

    Smeets, P.A.M.

    2010-01-01

    Low-caloric artificial sweeteners have been around for several decades now. Still, the debate over their usefulness in decreasing energy intake is ongoing. In principle, replacing sugar-containing foods with 'light' versions will lead to decreased energy intake. However, the reality of food intake

  1. Nutrigenetics and nutrigenomics of caloric restriction.

    Science.gov (United States)

    Abete, Itziar; Navas-Carretero, Santiago; Marti, Amelia; Martinez, J Alfredo

    2012-01-01

    Obesity is a complex disease resulting from a chronic and long-term positive energy balance in which both genetic and environmental factors are involved. Weight-reduction methods are mainly focused on dietary changes and increased physical activity. However, responses to nutritional intervention programs show a wide range of interindividual variation, which is importantly influenced by genetic determinants. In this sense, subjects carrying several obesity-related single-nucleotide polymorphisms (SNPs) show differences in the response to calorie-restriction programs. Furthermore, there is evidence indicating that dietary components not only fuel the body but also participate in the modulation of gene expression. Thus, the expression pattern and nutritional regulation of several obesity-related genes have been studied, as well as those that are differentially expressed by caloric restriction. The responses to caloric restriction linked to the presence of SNPs in obesity-related genes are reviewed in this chapter. Also, the influence of energy restriction on gene expression pattern in different tissues is addressed. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Caloric testing by continuous automatic alternating irrigation.

    Science.gov (United States)

    Reker, U

    1980-01-01

    Quantitative caloric test results show a high variability. They were described as questionable by Frenzel (1955) and a review of the test was recommended by Hood (1973). Thus, we developed a new method: continuous automatic alternating irrigation. An irrigator is connected to two water-baths of 30 degrees C and 44 degrees C. A time-relays switches over from one bath to the other every 60 s. The continuous, but alternating, irrigations produce subsequently alternating exponential temperature waves in the temporal bone. The mathematical model shows a quasi-periodicity and sufficient symmetry of the alternating thermal gradient across the canal, except for the first stimulus. After 11 irrigations of 60 s, a short (20 s) "washout" irrigation terminates the sequence. By the five repetitions of each stimulus and the additional possibility of correlating the response to the paper-marked stimulus periodicity the judgement is far more reliable and therefore, in doubtful cases, despite the five-fold data, quicker. The technical device is simple enough for routine use and inexpensive. The results of the caloric test are now much more clear-cut and the correlation to a known clinical pathology is remarkably high.

  3. Automobilismo: no calor da competição Automovilismo: en el calor de la competición Car racing: in the heat of competition

    Directory of Open Access Journals (Sweden)

    Luiz Oswaldo Carneiro Rodrigues

    2004-06-01

    ções ambientais do autódromo no dia de sua morte.El presente artículo cuestiona el papel del calor como un factor de riesgo adicional para el accidente que sufrió Ayrton Senna. El automovilismo de competición constituye un desafío biológico, una situación estresante desde el punto de vista mental y físico. El mantenimiento de la performance depende de la disponibilidad de los carbohidratos y del oxígeno, hidratación adecuada y temperatura interna constante entre 37 y 38 grados centígrados. La disipación de calor producido por el metabolismo que ocurre a través del aumento del flujo de sangre para mantener la temperatura cerebral constante constituye un problema permanente. Se ha verificado experimentalmente que la energía requerida para conducir un auto de carrera es similar a la requerida para practicar un deporte como el voleibol. Durante una carrera, el individuo está expuesto a un microambiente caliente dentro de la cabina que puede llegar hasta los 50 grados centígrados generado por fuentes de calor como las mecánicas y las ambientales. El bloque del sudor por el mameluco resulta en humedad y disconfor personal, lo que implica un mayor esfuerzo personal para conducir el auto. Las medidas contra el calor comienzan antes de la carrera, cuidando el estado nutricional, la hidratación y principalmente el acondicionamiento físico a través de ejercicios aeróbicos regulares y adecuados, que permitan aumentar la capacidad de trabajo y la tolerancia al calor, lo que resulta en una menor fatiga durante la carrera. Otro procedimiento importante debería ser la aclimatación de los pilotos en ambientes calientes y húmedos. Se debe realizar lo posible en el acondicionamiento del vehículo para respetar el sistema de banderas de advertencia para los riesgos de hipertermia. En conclusión, si ahora Ayrton Senna fuera un individuo con mayor riesgo de desarrollar hipertermia, independientemente de otras causas, no parece haber habido tiempo suficiente en la carrera para

  4. The reno-protective effects of dietary caloric restriction against ...

    African Journals Online (AJOL)

    This study has demonstrated that these pathophysiological alterations caused by disturbed glucose homeostasis are reversed by caloric restriction and thus CR may have therapeutic/preventive potential towards the development of diabetic nephropathy. Keywords: dietary caloric restriction; lipid peroxidation; oxidative ...

  5. Nueva especie del género Arctosa (Araneae, Lycosidae del sur de Brazil

    Directory of Open Access Journals (Sweden)

    Estevam Luís Cruz da Silva

    2008-12-01

    Full Text Available Se describe e ilustra una nueva especie del género Arctosa C. L. a Koch, 1848, en base a material procedente de Sapiranga, sur del Brasil. Los miembros de este género por lo general excavan refugios pequeños en los bordes arenosos de los lagos, sin embargo, esta nueva especie se encuentra debajo de rocas en los bordes de rios pequeños. Se puede encontrar hembras con ootecas y machos durante todo el año, aunque son más abundantes en el período del verano.

  6. Heat pump for purification of geothermal brines; Bomba de calor para purificacion de salmuera geotermica

    Energy Technology Data Exchange (ETDEWEB)

    Santoyo-Gutierrez, S; Barragan-Reyes, R.M; Holland, F.A [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: rmb@iie.org.mx

    2007-01-15

    Integrated use of geothermal resources is one of the most important goals for the future. Presently geothermal heat pumps offer two benefits: using heat from residual brines and converting these brines into very pure water. Designs and descriptions are presented of an experimental system to purify geothermal brines integrated to an adsorption heat-pump. The system was constructed and tested in the IIE (Institute for Electrical Research) facilities. During the experimental stage, pure water was obtained. Maximum capacity for pure water was 4.3 kg per hour, presenting an Actual Coefficient of Performance (COP)A of 1.4. The results are encouraging to project units at an industrial level for operating with geothermal and/or solar heat. [Spanish] El aprovechamiento integral de los recursos geotermicos en todas sus formas es una de las metas importantes a lograr en los proximos anos. Hoy en dia, el uso de las bombas de calor en la geotermia ofrece un doble beneficio: aprovechan el calor de los fluidos de desecho y tienen la capacidad de transformar la salmuera geotermica en agua de alta pureza. Se presenta el diseno y descripcion de un sistema experimental para purificacion de salmuera geotermica integrado a una bomba de calor por absorcion, el cual fue construido y probado en el Instituto de Investigaciones Electricas. En toda la etapa de experimentacion se obtuvo agua pura. La capacidad maxima alcanzada de produccion de agua pura de este sistema fue de 4.3 kg por hora, mostrando un rendimiento en terminos del Coeficiente Real de Rendimiento (COP)A de 1.4. Estos resultados se consideran alentadores para la proyeccion de unidades a escala industrial que puedan ser operadas con calor geotermico y/o solar.

  7. Efectos no-newtonianos en un cambiador de calor comercial de doble tubo para aplicaciones alimentarias

    OpenAIRE

    Molina Sánchez, Alberto Aurelio

    2006-01-01

    El objetivo del presente proyecto es evaluar la importancia que los efectos no newtonianos de los productos alimentarios ejercen sobre el flujo y la transferencia de calor en procesos industriales. En concreto, el estudio se basa en el comportamiento reológico seudoplástico mostrado por el cremogenado de melocotón durante un proceso de enfriamiento. El proyecto consta de una primera parte de recopilación bibliográfica en la que se exponen los conocimientos necesarios para poder llevar a cabo ...

  8. Tecnologías emergentes para la conservación de alimentos sin calor

    OpenAIRE

    Fernández Molina, Juan José; Barbosa-Cánovas, Gustavo V.; Swanson, Barry G.

    2001-01-01

    Not available

    Se han investigado los principios básicos de tres tecnologías emergentes para pasteurizar y esterilizar alimentos sin empleo del calor Mediante numerosos estudios se ha comprobado la efectividad de los campos eléctricos pulsantes de alta intensidad (CEPAI), los pulsos de luz (PL) y los campos magnéticos oscilantes (CMO) en la destrucción de microorganismos y enzimas de sistemas alimentarios. En la inactivación microbiana por CEPA!, el blanco principal es la me...

  9. Analysis of caloric test responses in sudden hearing loss.

    Science.gov (United States)

    Shih, Cheng-Ping; Chou, Yu-Ching; Chen, Hsin-Chien; Lee, Jih-Chin; Chu, Yueng-Hsiang; Wang, Chih-Hung

    2017-02-01

    Sudden sensorineural hearing loss is characterized by a rapid-onset hearing loss that develops within 3 days. Vertigo may also be present. We conducted a retrospective study to investigate whether the severity of a loss of caloric function is associated with the initial hearing loss and with hearing recovery. Our study population was made up of 135 patients-67 men and 68 women, aged 25 to 71 years (mean: 50.9)-with sudden sensorineural hearing loss who had undergone bithermal caloric testing. We compared various patient factors according to patients' hearing level and their response to caloric testing. We also analyzed the canal paresis (CP) value in patients with an abnormal caloric response according to three factors: disease severity, vertigo, and hearing recovery, and we evaluated the correlation between the loss of caloric function and hearing outcomes. We found that an abnormal caloric response was significantly associated with a profound hearing loss at presentation, the presence of vertigo, and poor hearing recovery. Among patients with an abnormal caloric response, the CP value was significantly correlated with hearing recovery (r = 0.503, p = 0.001). Poor hearing recovery was seen in 80% of patients with a CP value of ≥40% but in only 25% of patients with a value of hearing recovery was worse in the patients with a CP value of ≥40% (p = 0.002). We conclude that a CP value of ≥40% is a significant prognostic factor for an unfavorable treatment outcome.

  10. Transferencia de Calor y Materia durante la Fritura de Trozos de Ñame (Dioscórea alata) Heat and Mass Transfer during the Frying of Slices of Yam (Dioscórea alata)

    OpenAIRE

    Armando Alvis; Luis E Cortés; Manuel Páez

    2009-01-01

    En el presente trabajo se analizó la transferencia de calor y materia durante el freído de trozos de ñame en aceite de soya a 140, 160, 180°C. Los coeficientes de transferencia de calor y materia fueron determinados a partir de las gráficas de las relaciones adimensionales de temperatura y concentración de humedad versus tiempo. Los coeficientes de transferencia de calor y materia se incrementaron al aumentar la temperatura del aceite. Para la variedad de ñame llamada Pico de Botella, la pérd...

  11. [Caloric restriction: about its positive metabolic effects and cellular impact].

    Science.gov (United States)

    Ortiz-Bautista, Raúl Julián; Aguilar-Salinas, Carlos Alberto; Monroy-Guzmán, Adriana

    2013-01-01

    Caloric restriction, as a 30 to 60% decrease of ad libitum balanced caloric intake, without malnutrition, is the non-genetic strategy that has consistently extended the average and maximum lifespan of most living beings, and it has been tested from unicellular organisms like yeast Saccharomyces cerevisiae to Rhesus primates. In addition, various genetic and pharmacological caloric restriction models have shown to protect against cancer, cardiovascular and neurodegenerative diseases. Primate studies suggest that this intervention delays the onset of age-related diseases; in humans, it has physiological, biochemical and metabolic effects decreasing diabetes and cardiovascular disease risk factor. Although currently the mechanism by which caloric restriction has its positive effects at the cellular level is unknown, it has been reported to decrease oxidative stress and increase in mitochondrial biogenesis.

  12. South Pacific quasi-stationary waves and anomalously cold summers in the northernmost Antarctic Peninsula Ondas cuasi-estacionarias en el Pacífico sur y veranos fríos anómalos en el extremo norte de la Península Antártica

    Directory of Open Access Journals (Sweden)

    Alfredo J Costa

    2012-12-01

    presente trabajo tiene como objetivo analizar la circulación troposférica en el Hemisferio Sur (HS asociada a veranos (Dic-Feb anómalamente fríos (VAF en el período 1981-2010 sobre el extremo norte de la Península Antártica (PA mostrando que el verano de 2010 es singularmente frío, razón por la cual este verano es estudiado por separado. De ahí que el verano de 2010 es comparado con la composición de los VAFs previos a 2010. Se utiliza el criterio del cuartil para identificar VAFs y un flujo de actividad de onda para perturbaciones estacionarias cuasi-geostróficas (CG embebidas en un flujo básico que varía zonalmente como herramienta de diagnóstico para estudiar la propagación de trenes de ondas desde el Pacífico. Los VAFs previos a 2010 se caracterizan por un tren de ondas cuasi-estacionarias (OCE - del tipo patrón PSA (Pacífico-Sudamericano - extendido barotrópicamente en tropósfera hasta baja estratósfera, propagándose sobre el Pacífico Sur desde una región de convección anómala sobre Nueva Zelanda. Este tren de ondas da lugar a un centro ciclónico estacionario anómalo al noroeste de la PA. La componente anómala inducida de viento del Este junto a anomalías de alta nubosidad se encuentran asociadas a los VAFs sobre el norte de la PA. El singular verano de 2010 no sólo muestra un centro ciclónico estacionario anómalo al noroeste de la PA sino que también muestra uno anticiclónico en latitudes medias sobre el sudeste del Pacífico Sur. Desde ahí, hay propagación de OCE, localizada regionalmente, atravesando el sur de Sudamérica ya que no se observa una estructura de onda del tipo PSA sobre el Pacífico Sur. La propagación emana desde una zona de anomalías positivas de latemperatura de superficie del mar (TSM en el Pacífico Sur a través de la generación local de baroclinicidad del flujo medio. De ahí que esta propagación de OCE está asociada a actividad transiente anómala. A su vez, estas anomalías en la TSM podrían estar

  13. Olas de calor e influencia urbana en Madrid y su área metropolitana

    Directory of Open Access Journals (Sweden)

    Fernández García, F.

    2008-12-01

    Full Text Available The frequency and duration of the warmest temperature episodes, a common phenomenon under the continental Mediterranean conditions of the Spanish Southern Meseta, has increased in the Madrid area since the 80´s, although their magnitude remains unchanged. The effect of the urban environment on those extreme events has exacerbated the heat load due to the persistence of the high temperatures along the night time hours. Nevertheless, the diversity of the urban morphology introduces a spatial variability on the strength of this nocturnal heat load, aggravating it in the densely urbanized areas and mitigating it in the vicinities of the green areas.

    La frecuencia y duración de los episodios cálidos extremos, un fenómeno habitual en el clima mediterráneo continental de la Meseta Meridional, ha aumentado en el área de Madrid desde los años noventa, aunque su magnitud permanece constante. En el interior de la aglomeración urbana, el efecto general de la ciudad sobre estos eventos climáticos extremos ha supuesto una exacerbación del calor, no tanto por un aumento de la temperatura máxima, como por una persistencia del calor en las horas nocturnas. No obstante, la diversidad de la morfología urbana introduce variaciones espaciales en la intensidad de este calor nocturno, agravando sus efectos en las áreas densamente urbanizadas y mitigándolos en las proximidades de las áreas verdes.

  14. Characteristics of non caloric dulcorants and their use in children

    OpenAIRE

    Calzada León Raúl; Altamirano Bustamante Nelly

    2014-01-01

    This is a descriptive review of the elaboration routes, the physical and chemical characteristics, metabolism and clearance, sweetener level, residual flavor, maximal recommended ingestion, security levels and the assessment of growth and development problems in children (from newborns, including prematures, to the end of puberty), of the main no caloric edulcorants used in Mexico. The no caloric edulcorants included in this review are: aspartame, acesulfame-K, sucralose, sacarin, ciclamates,...

  15. Characteristics of non caloric dulcorants and their use in children

    Directory of Open Access Journals (Sweden)

    Calzada León Raúl

    2014-07-01

    Full Text Available This is a descriptive review of the elaboration routes, the physical and chemical characteristics, metabolism and clearance, sweetener level, residual flavor, maximal recommended ingestion, security levels and the assessment of growth and development problems in children (from newborns, including prematures, to the end of puberty, of the main no caloric edulcorants used in Mexico. The no caloric edulcorants included in this review are: aspartame, acesulfame-K, sucralose, sacarin, ciclamates, thaumatin, D- tagatose, estevia and alitame.

  16. Modificaciones en la distribución espacial de la temperatura y la humedad relativa como resultado del crecimiento urbano: el caso de la ciudad de Bahía Blanca, Argentina

    Directory of Open Access Journals (Sweden)

    F. Ferrelli

    2016-04-01

    Full Text Available El crecimiento de las ciudades genera modificaciones en la atmósfera local que pueden afectar la confortabilidad y calidad de vida de la población. El objetivo del presente trabajo fue comparar la evolución de la isla de calor de verano e invierno entre los años 1985 y 2014 en Bahía Blanca (Argentina. Esta ciudad ha sufrido un importante aumento de la población y de las actividades industriales en los últimos años. Se estudió el aumento de la zona urbana construida, las variaciones espaciales de temperatura y humedad relativa y el crecimiento de la población. Se calcularon índices de confort climático (Humidex, Termohigrométrico y Temperatura Equivalente. La zona urbana construida se extendió más de 110 km² y el incremento de la población fue de 22,4 %. Las modificaciones en el espacio urbano, junto con una mayor densidad de edificios, generaron cambios en las temperaturas de verano de 1985 y 2014. En la primera el centro de la ciudad fue más cálido que las zonas periféricas. La zona más confortable fue la costera. En 2014, en el centro de la ciudad se presentaron las temperaturas más altas y las zonas más confortables fueron las periféricas y los parques. Las mediciones de invierno no registraron diferencias considerables entre sí en las mediciones nocturnas. Los resultados demostraron que el crecimiento de las edificaciones y el incremento de la población de Bahía Blanca modificaron la distribución espacial de la temperatura y la humedad relativa y generaron situaciones de desconfort. Estos resultados generaron información necesaria para futuros planes de desarrollo urbano.

  17. Role of caloric homeostasis and reward in alcohol intake in Syrian golden hamsters

    OpenAIRE

    Gulick, Danielle; Green, Alan I.

    2010-01-01

    The Syrian golden hamster drinks alcohol readily, but only achieves moderate blood alcohol levels, and does not go through withdrawal from alcohol. Because the hamster is a model of caloric homeostasis, both caloric content and reward value may contribute to the hamster’s alcohol consumption. The current study examines alcohol consumption in the hamster when a caloric or non-caloric sweet solution is concurrently available and caloric intake in the hamster before, during, and after exposure t...

  18. Transferencia de calor en la colada continua de aceros. I parte. El molde

    Directory of Open Access Journals (Sweden)

    Cicutti, C.

    1997-10-01

    Full Text Available The continuous casting mold plays the important role of receiving the liquid steel and allowing an uniform and defect free solidified skin to be developed. In this work, the different heat transfer mechanisms which are present from the liquid steel to the mold cooling water are reviewed. The effect of operating variables on heat extraction and the relationship between global and distributed heat flux are also analyzed.

    El molde de colada continua cumple la importante función de recibir el acero líquido y permitir que se desarrolle una capa solidificada uniforme y libre de defectos. En este trabajo se revisan los distintos mecanismos implicados en el proceso de transferencia de calor, desde el acero líquido hasta el agua de refrigeración del molde. Se analiza también el efecto de las distintas variables de funcionamiento en la extracción calórica producida y la relación entre el flujo global de calor y su distribución a lo largo del molde.

  19. Use of caloric and non-caloric sweeteners in US consumer packaged foods, 2005–9

    Science.gov (United States)

    Ng, Shu Wen; Slining, Meghan M.; Popkin, Barry M.

    2012-01-01

    Our understanding of the use of caloric (CS) and non-caloric sweeteners (NCS) in the US food supply is limited. This study utilizes full ingredient list and nutrition facts panel (NFP) data from Gladson Nutrition Database, and nationally representative purchases of consumer packaged foods from Nielsen Homescan in 2005 through 2009 to understand the use of CS (including FJC) and NCS in CPG foods. Of the 85,451 uniquely formulated foods purchased during 2005–2009, 75% contain sweeteners (68% with CS only, 1% with NCS only, 6% with both CS and NCS). CS are in >95% of cakes/cookies/pies, granola/protein/energy bars, ready-to-eat cereals, sweet snacks, and sugar-sweetened beverages. NCS are in >33% of yogurts and sports/energy drinks, 42% of waters (plain or flavored), and most diet sweetened beverages. Across unique products, corn syrup is the most commonly listed sweetener, followed by sorghum, cane sugar, high fructose corn syrup and FJC. Also, 77% of all calories purchased in the US in 2005–2009 contained CS and 3% contained NCS, while 73% of the volume of foods purchased contained CS and 15% contained NCS. Trends during this period suggest a shift towards the purchase of NCS-containing products.Our study poses a challenge toward monitoring sweetener consumption in the US by discussing the need and options available to improve measures of CS and NCS, and additional requirements on NFPs on CPG foods. PMID:23102182

  20. Estudio sobre los efectos de campo acústico en la transmisión de calor de un calentador de aire de admisión

    OpenAIRE

    RAMÍREZ CARDONA, MARÍA ISABEL

    2015-01-01

    Se ha documentado que la presencia de ondas acústicas puede influir sobre la transferencia de calor, a través de las modificaciones producidas por las ondas en la capa límite. Esta opción presenta a priori ventajas sobre otras formas de mejora de la transferencia de calor, como la corrugación de superficies, ya que su influencia sobre la pérdida de carga es menor y el requerimiento energético es marginal comparado con el del calentador mismo. Se pretende por ello estudiar el potencial de mejo...

  1. Modelación de la transferencia de calor y masa en el absorbedor de una máquina de refrigeración por absorción. Resultados para un banco de tubos. // Heat and mass transference modeling in the absorbent of an absorbator cooling machine.( Results for a bank

    OpenAIRE

    C. A. Cisneros Ramírez

    2002-01-01

    En este artículo se presenta el comportamiento de la temperatura, la concentración y el coeficiente de traspaso de calor,tanto local como promedio, durante el proceso de absorción sobre un banco de tubos. Además se presenta la ecuaciónobtenida a partir del modelo presentado en artículos anteriores, que caracteriza el comportamiento del producto delcoeficiente global de traspaso de calor (U) por el área de traspaso de calor (A) para el banco de tubos.Palabras claves: Modelación, absorbedores, ...

  2. Transferencia de calor incrementada en espacios anulares con elementos helicoidales insertados//Review of augmentation techniques for heat transfer coefficient in annular spaces using helical elements

    Directory of Open Access Journals (Sweden)

    Josué Imbert‐González

    2014-08-01

    Full Text Available La transferencia de calor incrementada por métodos pasivos se emplea en diversosintercambiadores de calor de alta efectividad. El objetivo del trabajo presentado fue la evaluación del estado de las investigaciones en el campo de la transferencia de calor mejorada en espacios anulares, a partir del empleo de elementos turbulizadores helicoidales como técnicas pasivas. La revisión se centró en el empleo de láminas helicoidales y espirales, la obtención de ecuaciones de correlación del coeficiente de transferencia de calor incrementado, el coeficiente de fricción y la evaluación que se realiza de este proceso por parte de diferentes autores. El análisis crítico permitió realizar valoraciones integradas y recomendar sobre los aspectos que podrían ser analizados en el futuro en esta temática.Palabras claves: transferencia de calor incrementada, láminas helicoidales, espirales, espacios anulares, métodos pasivos._______________________________________________________________________________AbstractThe transfer enhancement by passive methods is used in several heat exchanger of high effectiveness. The objective of the presented work was the evaluation of the state of the investigations in heat transfer enhancement in annular spaces, from the employment of elements helical. The revision was centered in the employment of twisted tape and wire coil in spiral, the equations of correlation obtained of the coefficient of transfer of increased heat, the coefficient of friction and the evaluation that was carried out of this process on the part of different authors. From the critical analysis of the published results, the authors recommend on the topics that can be analyzed in the future in this area.Key words: heat transfer enhancement, twisted tape, helical springs, annular spaces, passive methods.

  3. Calidad nutritiva de láminas de festuca alta (Festuca arundinacea Schreb en rebrotes de verano y otoño

    Directory of Open Access Journals (Sweden)

    INSUA, J.R.

    2013-12-01

    Full Text Available Se evaluó el efecto de la morfogénesis y estructura foliar en la calidad de las láminas de rebrotes de verano y otoño de Festuca arundinacea Schreb. Se utilizó un diseño completamente aleatorizado (n=3 en 250 macetas al aire libre sin limitantes hídricas de N y P. En los rebrotes de cada estación se realizaron tres cosechas de 300 macollos/repetición para obtener láminas en tres estados de desarrollo (recientemente expandida,adulta y pre-senescencia, correspondientes a tres generaciones consecutivas de hojas.

  4. Las clases de Educación Física en escuelas rurales primarias con modalidad de régimen de verano en la Provincia de Salta

    OpenAIRE

    Tannenbaum, Germán Alfredo

    2017-01-01

    149 p. il. La investigación llevada a cabo durante el año/periodo lectivo 2012-2013 y 2013-2014 sigue una línea cualitativa explicativa, dirigida a explicar que la metodología empleada por el profesor de educación física se debe adaptar a las características propias de las clases de educación física en escuelas rurales primarias con modalidad de régimen de verano en la provincia de Salta. En la actualidad el interés por estudiar e investigar en la escuela rural no ha sido un tema centra...

  5. Modeling and design aspects of active caloric regenerators

    Science.gov (United States)

    Engelbrecht, Kurt

    2015-03-01

    A cooling device based on a solid caloric material using, for example, the elastocaloric, magnetocaloric, barocaloric or electrocaloric effect has the potential to replace vapor-compression based systems for a variety of applications. Any caloric device using a solid refrigerant may benefit from using a regenerative cycle to increase the operating temperature span. This presentation shows how all active caloric regenerators can be modeled using similar techniques and how they are related to passive regenerator performance. The advantages and disadvantages of using a regenerative cycle are also discussed. The issue of hysteresis in caloric materials is investigated from a system/thermodynamic standpoint and the effects on cooling power and efficiency are quantified using a numerical model of an active regenerator using model caloric materials with assumed properties. The implementation in a working device will be discussed for elastocaloric and magnetocaloric cooling devices. It is shown that demagnetization effects for magnetocaloric systems and stress concentration effects in elastocaloric system reduce the overall effect in the regenerator and care must be taken in regenerator design for both technologies. Other loss mechanisms outside the regenerator such as heat leaks are also discussed. Finally, experimental results for active magnetic regenerative cooler are given for a range of operating conditions. The most recently published device uses a regenerator consisting of Gd and three alloys of GdY and has demonstrated a COP over 3.

  6. Effect oflight reduction, surnmerpruning and nitro gen supply on the vegetative and generative growth of 'Golden Delicious' apples Efecto de la reducción de la luz, la poda de verano y el suministro de nitrógeno sobre el crecimiento vegetativo y reproductivo de los arboles de manzano ‘Golden delicious’

    Directory of Open Access Journals (Sweden)

    Casierra Posada Fanor

    2000-12-01

    Full Text Available In order to study the effect of a black mesh protection net (33% light reduction capacity on the vegetative and reproductive growth of 'Golden Delicious' apple trees in Berlin (Germany, three different nitrogen levels and summer pruning at two different times were used. The results of shoots growth, trunk growth, shootlroot ratio, leafarea, early leaffall, numberofflowers perplant, flowers density per branch, fruit set and dry matter production are presented and discussed. In general, shade did not affect vegetative growth, but leaf area and fruit set. Winter pruning induced the greatest number of flowers per plant. Winter pruning along with surnmer pruning in June, increased fruit seto High levels of nitrogen increased number of flowers per plant and shoot growth, but reduced fruit set.En un sistema de lisímetros, se realizó un ensayo para determinar el efecto de una red negra antigranizo con una capacidad reductora de la luz del 33%, con tres diferentes niveles de fertilización nitrogenada y poda de verano en dos diferentes épocas sobre el crecimiento vegetativo y reproductivo de árboles. de manzano 'Golden Delicious' en Berlín (Alem.. Se discuten los resultados del crecimiento de las ramas, diámetro del tallo, la relación ramas/raíz, el área foliar, caída prematura de hojas, el número de flores por
    planta, la densidad de flores por rama, el amarre de frutos y la producción de materia seca. En términos generales, la sombra no afectó considerablemente el crecimiento vegetativo, pero sí redujo el área foliar y el amarre de
    frutos. La poda de invierno indujo un mayor número de flores por planta y la poda de invierno con poda de verano en junio favoreció el mejor amarre de frutos. Con el incremento en la dosis de nitrógeno se presentó un mayor número de flores por planta, y un mayor crecimiento de las ramas, pero se redujo el amarre de frutos.

  7. Construcción de un calorímetro isoperibolico de inmersión de precisión

    Directory of Open Access Journals (Sweden)

    Liliana Giraldo G.

    2010-07-01

    Full Text Available Se diseña y construye un calorímetro isoperibólico tipo submarino para la medida de calores de inmersión de sólidos en líquidos. La celda calorimétrica, de una capacidad aproximada de 85 mi, se fabrica en vidrio Pyrex y va sumergida dentro de una chaqueta submarina construida en bronce cromado. El conjunto se introduce dentro de un termostato de agua estabilizado a 25 ±0,001 °C. El sensor de temperatura está constituido por termisiores NTC colocados en un puente de Maier transpuesto y provisto de una Fuente de intensidad constante. La sensibilidad del termómetro es del orden de 5 * I O' °C/p V cuando la corriente de medida en el puente es del orden de 1 mA.

  8. Caloric restriction and exercise "mimetics'': Ready for prime time?

    Science.gov (United States)

    Handschin, Christoph

    2016-01-01

    Exercise and diet are powerful interventions to prevent and ameliorate various pathologies. The development of pharmacological agents that confer exercise- or caloric restriction-like phenotypic effects is thus an appealing therapeutic strategy in diseases or even when used as life-style and longevity drugs. Such so-called exercise or caloric restriction "mimetics" have so far mostly been described in pre-clinical, experimental settings with limited translation into humans. Interestingly, many of these compounds activate related signaling pathways, most often postulated to act on the common downstream effector peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) in skeletal muscle. In this review, resveratrol and other exercise- and caloric restriction "mimetics" are discussed with a special focus on feasibility, chances and limitations of using such compounds in patients as well as in healthy individuals. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Análisis de la dispersión axial de masa y calor en reactores de lecho fijo

    Directory of Open Access Journals (Sweden)

    Rangel Jara Hermes Augusto

    1997-01-01

    Full Text Available Dentro del espíritu investigativo a nivel teórico del estudio de los reactores químicos, el presente trabajo desarrolla e implementa un análisis conceptual y numérico de los fenómenos de dispersión axial de calor y masa en reactores de lecho fijo. Se pretende disponer de una alternativa numérica que permita en una forma rápida y precisa la solución de las ecuaciones diferenciales junto con las respectivas condiciones de frontera del modelo matemático. Para la simulación del reactor de lecho fijo se empleó un modelo unidimensional pseudohomogeneo con parámetros aglomerados.

  10. Análisis de la dispersión axial de masa y calor en reactores de lecho fijo

    Directory of Open Access Journals (Sweden)

    Rangel Jara Hermes Augusto

    2011-06-01

    Full Text Available Dentro del espíritu investigativo a nivel teórico del estudio de los reactores químicos, el presente trabajo desarrolla e implementa un análisis conceptual y numérico de los fenómenos de dispersión axial de calor y masa en reactores de lecho fijo. Se pretende disponer de una alternativa numérica que permita en una forma rápida y precisa la solución de las ecuaciones diferenciales junto con las respectivas condiciones de frontera del modelo matemático. Para la simulación del reactor de lecho fijo se empleó un modelo unidimensional pseudohomogeneo con parámetros aglomerados.

  11. Constrained caloric curves and phase transition for hot nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Borderie, B., E-mail: borderie@ipno.in2p3.fr [Institut de Physique Nucléaire, CNRS-IN2P3, Université Paris-Sud 11, F-91406 Orsay Cedex (France); Piantelli, S. [INFN Sezione di Firenze, 50019 Sesto Fiorentino (Italy); Rivet, M.F. [Institut de Physique Nucléaire, CNRS-IN2P3, Université Paris-Sud 11, F-91406 Orsay Cedex (France); Raduta, Ad.R. [National Institute for Physics and Nuclear Engineering, RO-76900 Bucharest-Magurele (Romania); Ademard, G. [Institut de Physique Nucléaire, CNRS-IN2P3, Université Paris-Sud 11, F-91406 Orsay Cedex (France); Bonnet, E. [GANIL, (DSM-CEA/CNRS-IN2P3), F-14076 Caen Cedex (France); Bougault, R. [LPC Caen, ENSICAEN, Université de Caen, CNRS-IN2P3, F-14050 Caen Cedex (France); Chbihi, A.; Frankland, J.D. [GANIL, (DSM-CEA/CNRS-IN2P3), F-14076 Caen Cedex (France); Galichet, E. [Institut de Physique Nucléaire, CNRS-IN2P3, Université Paris-Sud 11, F-91406 Orsay Cedex (France); Conservatoire National des Arts et Métiers, F-75141 Paris Cedex 03 (France); Gruyer, D. [GANIL, (DSM-CEA/CNRS-IN2P3), F-14076 Caen Cedex (France); Guinet, D.; Lautesse, P. [Université Claude Bernard Lyon 1, Institut de Physique Nucléaire, CNRS-IN2P3, F-69622 Villeurbanne Cedex (France); Le Neindre, N.; Lopez, O. [LPC Caen, ENSICAEN, Université de Caen, CNRS-IN2P3, F-14050 Caen Cedex (France); Marini, P. [GANIL, (DSM-CEA/CNRS-IN2P3), F-14076 Caen Cedex (France); and others

    2013-06-10

    Simulations based on experimental data obtained from multifragmenting quasi-fused nuclei produced in central {sup 129}Xe+{sup nat}Sn collisions have been used to deduce event by event freeze-out properties in the thermal excitation energy range 4–12 AMeV [S. Piantelli, et al., INDRA Collaboration, Nucl. Phys. A 809 (2008) 111]. From these properties and the temperatures deduced from proton transverse momentum fluctuations, constrained caloric curves have been built. At constant average volumes caloric curves exhibit a monotonic behaviour whereas for constrained pressures a backbending is observed. Such results support the existence of a first order phase transition for hot nuclei.

  12. Sistemas de transmisión de calor para hornos de vía seca en la fabricación de cemento

    Directory of Open Access Journals (Sweden)

    Tonry, J. Richard

    1961-12-01

    Full Text Available Not availableEn los últimos años se han puesto en marcha numerosos sistemas para mejorar la transmisión de calor en los hornos de vía seca y, en consecuencia, el consumo de combustible en la industria del cemento. El objetivo principal ha sido el ahorro de combustible y la obtención de mayores velocidades de producción en comparación con los hornos horizontales normales. Estos sistemas pueden dividirse en dos grupos: (1 externos, donde fluyen en contracorriente sólidos y gases calientes, 71 (2 internos, con exposición de superficie y radiación de la misma como medio de transmisión de calor. Esta tendencia a sistemas de este tipo puede compararse a la que hubo hace cuarenta años con las calderas de recuperación de calor en hornos de vía seca. El primer objetivo, tanto entonces como ahora, es la mejor utilización del calor en los gases de escape.

  13. Prevention of mammary tumorigenesis by intermittent caloric restriction: does caloric intake during refeeding modulate the response?

    Science.gov (United States)

    Cleary, Margot P; Hu, Xin; Grossmann, Michael E; Juneja, Subhash C; Dogan, Soner; Grande, Joseph P; Maihle, Nita J

    2007-01-01

    Chronic caloric restriction (CCR) prevents mammary tumorigenesis in rodents, but a protective effect for intermittent caloric restriction (ICR) is less well documented. We recently reported that ICR reduced mammary tumor (MT) incidence of mouse mammary tumor virus-transforming growth factor (MMTV-TGF)-alpha mice to a greater extent than did CCR. Here, we repeated this protocol and obtained serum and tissue samples. Ad libitum (AL) MMTV-TGF-alpha mice were fed AIN-93M diet. Beginning at 10 weeks of age, ICR mice received isocaloric AIN-93M-mod diet (2-fold increases in protein, fat, vitamins, and minerals) at 50% of ad libitum for 3 weeks followed by 3 weeks refeeding with AIN-93M diet. CCR mice were pair-fed AIN-93M:AIN-93M-mod (2:1) matching intakes for restriction/refeeding cycles. Mice were sacrificed for MT size, at 79 (end of 12th restriction) or at 80 (1 week after 12th refeeding) weeks of age. AL and ICR-80 mice had heavier body weights than ICR-79 and CCR mice (P food intakes of ICR and CCR mice were reduced 12% and 15% versus AL mice (P food than did AL mice during refeeding. MT incidence was 84%, 13%, and 27% for AL, ICR, and CCR mice, respectively. MT weight (P < 0.0011) and number (P < 0.01) were higher for AL mice compared with ICR and CCR mice. AL and ICR-80 mice had similar serum IGF-I levels, but only AL values were higher than those of ICR-79 and CCR mice (P < 0.0017). ICR mice had more MT DNA breaks compared with AL and CCR mice, suggesting enhanced apoptosis (P < 0.02). AL mice had higher mammary fat pad ObR and ObRb leptin receptor mRNA expression than did ICR and CCR mice (P < 0.001), but there was no effect on MTs. These results confirm that ICR prevents development of MTs to a greater extent than does CCR, although "overeating" during refeeding may compromise this protection.

  14. Transferencia de calor en la colada continua de aceros. II parte. Enfriamiento secundario

    Directory of Open Access Journals (Sweden)

    Cicutti, C.

    1997-12-01

    Full Text Available Once the strand leaves the mold, the solidification of steel progresses due to the heat extracted in the secondary cooling zone of the continuous casting machine. In this zone, heat is extracted mainly by: the incidence of water from sprays, radiation to surroundings contact with rolls and run out water accumulated between rolls and strand. In this work, all these mechanisms are evaluated and, when it is possible, they are quantified. Methods which are usually employed to measure solidification profiles in the continuous casting machine are also reviewed. Finally, the incidence of secondary cooling on the quality of cast products is discussed.

    La solidificación del acero iniciada en el molde continúa en la zona de enfriamiento secundario de la máquina donde el calor es extraído, principalmente por la incidencia del agua de los rociadores, la radiación al medio ambiente, el contacto con los rodillos y el agua acumulada en ellos. En este trabajo se revisa cada uno de estos mecanismos determinando, en los casos en que es posible, valores cuantitativos de los mismos. Además, se analizan los distintos métodos empleados para medir el avance del espesor solidificado en la máquina de colada continua. Por último, se discute la incidencia del enfriamiento secundario en la calidad final de los productos colados.

  15. Climatología urbana por modificación antropogénica. Alteración del balance de energía natural / Urban climatology by anthropogenic modification. Alteration of the natural energy balance

    Directory of Open Access Journals (Sweden)

    Fuentes Pérez, Carlos Alberto

    2015-09-01

    Full Text Available La investigación valora el análisis climático histórico para establecer la temperatura y humedad relativa media, en contraste con la climatología urbana por modificación antropogénica estudio de caso, y su contribución de consigna fijado para invierno y verano que son las estaciones críticas. El procedimiento metodológico a implementar, apoya a los planificadores urbanos a no tener que participar científicamente para evaluar el emplazamiento térmico de sus proyectos y por lo tanto se puede acelerar el proceso de diseño sin comprometer el énfasis en el contexto urbano sustentable. Con base a los resultados se establecen las islas de calor urbano y su huella térmica en el hábitat. El objetivo de la presente investigación es determinar la climatología urbana por modificación antropogénica y su alteración a la calidad del hábitat en Tampico, México. The research assesses the historical climate analysis to determine the average temperature and relative humidity, in contrast to urban anthropogenic weather modification case study, and their contribution setpoint set for winter and summer are the season’s criticism. The methodology to implement, procedure supports urban planners will not have to participate to scientifically evaluate the thermal construction projects and therefore can accelerate the design process without compromising the emphasis on sustainable urban context. Based on the results of urban heat islands and thermal footprint habitat established. The objective of this research is to determine the urban climate by anthropogenic modification and alteration of habitat quality in Tampico, Mexico.

  16. Dal calore all'entropia una introduzione alla termodinamica

    CERN Document Server

    Vicentini Missoni, Matilde

    1992-01-01

    Panta rei : processi ed equilibrio ; l'universo termodinamico : l'aspetto processuale ; il punto di vista dei processi come bilancio tra proprietà dell'equilibrio ; il fluire dell'energia ; automobili, frigoriferi e pompe di calore : informazioni tecnologiche ; e allora ? l'entropia ; la termostatica come teoria assiomatica ; la termodinamica dei processi.

  17. Índice de reflectancia solar de revestimientos verticales: potencial para la mitigación de la isla de calor urbana

    Directory of Open Access Journals (Sweden)

    Noelia Liliana Alchapar

    Full Text Available La condición artificial del medio urbano modifica el consumo de energía y el confort térmico. El incremento de las temperaturas de una ciudad en relación a las áreas periféricas conduce a la formación de una Isla de Calor Urbana. Es por ello, que trabajar sobre las propiedades termofísicas de los materiales (techos, pavimentos y fachadas es una estrategia de mitigación viable para disminuir las temperaturas de una ciudad. El objetivo principal de éste trabajo es estudiar la capacidad de 80 revestimientos para fachadas disponibles regionalmente para mitigar los efectos negativos de la Isla deCalor Urbana, mediante la determinación del Índice de Reflectancia Solar (SRI. El material que posee el comportamiento más eficiente es el Acrílico Rulato Travertino fino marfil (SRI = 100%, Temp. Sup.= 35 ºC, mientras el más ineficiente es el Acrílico Llaneado fino gris plomo (SRI = 29%, Temp. Sup.= 74 ºC. No obstante existen alternativas intermedias que resultan del efecto combinado de la composición del material, su color y textura. Esta situación demuestra que es posible mitigar el efecto de isla de calor a partir de una adecuada selección de revestimientos verticales.

  18. Modelo de transmisión de calor por radiación en una piscina de combustible gastado mediante TRACE

    OpenAIRE

    Sanchez Saez, Francisco; Carlos Alberola, Sofía; Martorell Alsina, Sebastián Salvador; Villanueva López, José Felipe

    2013-01-01

    El trabajo desarrollado consiste en la simulación termohidráulica de una piscina de combustible gastado al producirse un transitorio de pérdida de refrigerante con pérdida de refrigeración a través del canal de transferencia. La simulación se realiza con el código Best Estimate TRACE. Para seguir la evolución del comportamiento de la piscina, una variable importante a seguir es la temperatura de vaina, cuya evolución depende del calor que consiga emitir. En esta simulación se h...

  19. La equinoterapia en las distintas alteraciones del desarrollo del menor.

    OpenAIRE

    Chamorro González, Mireya

    2015-01-01

    La equinoterapia consiste en la utilización del caballo como un método terapéutico para rehabilitar a personas con discapacidad. Esta terapia es considerada una gran alternativa para aumentar el autoestima de los que sufren algún tipo de discapacidad, también a través de esta terapia se mejora y fortalece el estado emocional, así del mismo modo ayuda a mejorar la manera de desenvolverse en su entorno social. Esta terapia se realiza a través de la trasmisión del calor corporal del caballo, del...

  20. Isolated directional preponderance of caloric nystagmus: I. Clinical significance.

    Science.gov (United States)

    Halmagyi, G M; Cremer, P D; Anderson, J; Murofushi, T; Curthoys, I S

    2000-07-01

    To determine the clinical significance of an isolated directional preponderance (DP) on bithermal caloric testing. An isolated caloric DP was defined as a DP, calculated according to the standard Jongkees formula, of > or = 40%, with a spontaneous nystagmus (SN) in darkness of or = 40%. This was followed by a review of the clinical data on the 144 patients identified with such a result and then by a telephone or postal follow-up study of these patients. The study group eventually comprised 114 patients; these were patients in whom a clinical diagnosis could be made at the time the caloric test was done, or who responded to requests for follow-up information. The 34 patients in whom a clinical diagnosis could not be made at the time of the caloric test, and who did not respond to requests for follow-up information, were excluded. A balance disorders clinic in a tertiary referral hospital. All patients underwent standard bithermal caloric testing. Some of the patients also underwent rotational testing. A clinical diagnosis for the cause of the isolated DP, made either at the time of the caloric test or on the basis of information supplied at follow-up by the patient or by the referring physician. Of 114 patients, 39 had benign paroxysmal positioning vertigo, 14 had Ménière's disease, and 5 had migrainous vertigo. Five patients had central nervous system (CNS) disorders, and this was clinically apparent at the time of the caloric test in 4, so that only 1 patient with an isolated DP developed evidence of a CNS disorder after the caloric test was done. In the other 54 patients, no definite diagnosis could be made, but 41 of these 54 were either completely well or much better at follow-up. An isolated DP on caloric testing is usually a transient, benign disorder. About half the patients with an isolated DP have either Ménière's disease or benign paroxysmal positioning vertigo; in most of the other half, no definite diagnosis is made but most of these patients will

  1. Estudio de la concentración microbiana del aire en depósitos del Archivo Nacional de Cuba

    Directory of Open Access Journals (Sweden)

    Sofía Flavia Borrego Alonso

    2010-09-01

    Full Text Available Actualmente el estudio de la microbiota en ambientes interiores es de interés para los especialistas, pues los microorganismos pueden provocar afectaciones a la salud de las personas y causar el biodeterioro de colecciones valiosas. Los objetivos del trabajo fueron: determinar la concentración microbiana del aire en depósitos del Archivo Nacional de Cuba, realizar la identificación taxonómica de los hongos aislados y definir el riesgo potencial que ellos representan para el biodeterioro del patrimonio documental y la salud del personal. El muestreo microbiológico se realizó en verano e invierno y en 6 depósitos, empleando un método de sedimentación. Para aislar hongos y bacterias se emplearon placas de Petri con medios de cultivo adecuados que se colocaron por triplicado a 3m de altura. Se determinó cualitativamente la actividad celulolítica, la producción de pigmentos y de ácidos a los hongos aislados. La microbiota viable total fue mayor en invierno que en verano, siendo la concentración bacteriana significativamente superior en esta estación (sequía en tanto que la fúngica es más elevada en verano. Los géneros fúngicos que predominaron en invierno fueron Aspergillus, Cladosporium, Penicillium, Curvularia y Alternaria, mientras que en verano prevaleció Cladosporium y se aislaron los géneros Fusarium, Mucor y Chrysonilia que llegaron a alcanzar niveles significativos en algunos depósitos. Los hongos aislados degradaron celulosa, produjeron pigmentos y ácidos. Asimismo, se evidenció que pueden provocar estados alérgicos y enfermedades respiratorias a las personas. Con relación a las bacterias del aire, predominaron las Gram positivas y se identificaron los géneros Enterobacter, Hafnia, Serratia, Streptomyces, Bacillus, Streptococcus y Staphylococcus. De igual manera, se detectó que las bacterias identificadas son capaces de producir afectaciones a la salud del personal.

  2. EL CALOR DE LA TEORÍA

    Directory of Open Access Journals (Sweden)

    Fernando J. García Selgas

    2015-01-01

    Full Text Available Este trabajo es una reflexión crítica sobre la apuesta metateórica que Alfonso Pérez Agote hacepor lo que él denomina “teoría caliente” (TC. Empiezo analizando qué entiende por TC, cómoargumenta su preferencia por ella frente a la “teoría fría” y cómo la aplica de manera efectiva.Tras recordar que esta tesis resulta un salto en el vacío respecto a planteamientos previos mejorasentados, paso a cuestionar algunos de sus supuestos e implicaciones. Todo ello, más el hechode que la practica sociológica del propio Alfonso parece incumplir su propuesta, viene a mostrarque la tesis de la TC resulta ser una excusa innecesaria y perjudicial para quien, queriendoceñirse a la investigación empírica, no puede evitar tomar partido en los debates teóricos y ve larealidad social como una realidad predefinida.

  3. Ecosistema marino del estrecho de Bransfield, bahía Almirantazgo y alrededores de las islas Joinville y Elefante. ANTAR XXII, 2014

    OpenAIRE

    Espino, Marco; Ayón, Patricia; Cornejo, Rodolfo; Alarcón, Julio; Vásquez, Luis; Quiñones, Javier; Chang, Flor; Goya, Elisa; Villegas, Piero; Velazco, Federico; Quipuzcoa, Luis; Castillo, David; Quesquén, Roberto; Rivadeneyra, Sofia; Correa, Jonathan

    2016-01-01

    En el verano austral 2014, el Instituto del Mar del Perú desarrolló la XXII Campaña científica del Perú a la Antártida, ANTAR XXII, a bordo del BIC Humboldt. Los resultados de investigación sobre el ecosistema marino Antártico dan a conocer las interrelaciones entre el krill antártico (Euphausia superba), fauna y flora acompañantes, depredadores y condiciones oceanográficas imperantes en el medio. La temperatura superficial del mar varió entre -1,5 y 1,6 °C, asociada a aguas fr...

  4. Estudio estructural en instalaciones de bomba de calor : Structural study of heat pump´s installations

    Directory of Open Access Journals (Sweden)

    Oscar M. Cruz Fonticiella

    2013-06-01

    Full Text Available Se investigan las irreversibilidades de una bomba de calor, con análisis exergéticos y estructurales. Se utilizó una instalación experimental de una bomba de calor lográndose datos y cálculos de la eficiencia de la compresión, temperaturas medias de los focos caliente y frío del ciclo, diferencia de temperatura a la salida del condensador, media logarítmica del evaporador, caídas de presiones del condensador y el evaporador y un análisis exergético y estructural con las propiedades termodinámicas en los puntos clave del ciclo, coeficiente de comportamiento del ciclo, balances de masas, energías y entropía, entropía generada en cada componente, balance de exergía con las irreversibilidades en cada componente, eficiencia exergética, defecto de eficiencia y coeficientes de vínculos estructurales Se exploraron las potencialidades de mejora de cada componente para una posterior optimización termoeconómica.The irreversibility of a heat pump with exergy and structural analysis is investigated. An experimental installation of a heat pump and calculations achieving data compression efficiency, the average temperature of hot and cold spots in the cycle was used, The temperature difference output condenser, log mean evaporator , pressures drops condenser and evaporator and structural exergy analysis and thermodynamic properties at key points of the cycle, the cycle coefficient of performance, mass balances, energy and entropy, entropy generated in each component, the availability balance irreversibilities in each component , exergetic efficiency, default coefficients efficiency and structural links were obtained. The potential for improvement for each component for further thermoeconomic optimization were explored

  5. Estudio estructural en instalaciones de bomba de calor; Structural study of heat pump´s installations

    Directory of Open Access Journals (Sweden)

    Oscar M. Cruz Fonticiella

    2013-06-01

    Full Text Available Se investigan las irreversibilidades de una bomba de calor, con análisis exergéticos y estructurales. Se utilizó una instalación experimental de una bomba de calor lográndose datos y cálculos de la eficiencia de la compresión, temperaturas medias de los focos caliente y frío del ciclo, diferencia de temperatura a la salida del condensador, media logarítmica del evaporador, caídas de presiones del condensador y el evaporador y un análisis exergético y estructural con las propiedades termodinámicas en los puntos clave del ciclo, coeficiente de comportamiento del ciclo, balances de masas, energías y entropía, entropía generada en cada componente, balance de exergía con las irreversibilidades en cada componente, eficiencia exergética, defecto de eficiencia y coeficientes de vínculos estructurales Se exploraron las potencialidades de mejora de cada componente para una posterior optimización termoeconómica.  The irreversibility of a heat pump with exergy and structural analysis is investigated. An experimental installation of a heat pump and calculations achieving data compression efficiency, the average temperature of hot and cold spots in the cycle was used, The temperature difference output condenser, log mean evaporator , pressures drops condenser and evaporator and structural exergy analysis and thermodynamic properties at key points of the cycle, the cycle coefficient of performance, mass balances, energy and entropy, entropy generated in each component, the availability balance irreversibilities in each component , exergetic efficiency, default coefficients efficiency and structural links were obtained. The potential for improvement for each component for further thermoeconomic optimization were explored.

  6. Evaluación de un recuperador de calor en una industria frigorífica//Evaluation of waste heat recovery in frigorific industry

    Directory of Open Access Journals (Sweden)

    Josué Imbert‐González

    2014-01-01

    Full Text Available La recuperación de calor forma parte de las medidas propuestas para el empleo adecuado del amoniaco en países tropicales. Este artículo analiza un sistema de recuperación de calor instalado en una instalación de refrigeración industrial. En el análisis, que parte de las lecturas comparativas de parámetros de operación de la instalación, se determinó la efectividad del intercambio térmico, el incremento en laeficiencia del sistema de refrigeración, así como el combustible ahorrado por concepto de calentamiento del agua en la industria. Los resultados obtenidos reportaron que el diseño térmico basado en intercambio de calor en espacios anulares, permite un ahorro importante de recursos y un elevado índice de aprovechamiento térmico.Palabras claves: recuperación de calor, instalación frigorífica, ahorro de energía.________________________________________________________________________________AbstractThe waste heat recovery by heat pipes is accepted as an excellent way of saving energy and preventing global warming. This article assesses the impact of the use of a heat exchanger used as a heat recovery in the refrigeration industry. Elements are evaluated from the point of view of heat transfer, evaluating the quality of heat exchange process. Is calculated increase in the efficiency of the cooling system. The heated water is used in the steam generation system of the industry. Is calculated fuel consumption savings resulting from this warming. The findings provide elements that show the enormous potential of this technique in the refrigeration industry.Key words: waste heat recovery, Industrial refrigeration, saving energy.

  7. Evaluation of anti-inflammatory activity and fast UHPLC-DAD-IT-TOF profiling of polyphenolic compounds extracted from green lettuce (Lactuca sativa L.; var. Maravilla de Verano).

    Science.gov (United States)

    Pepe, Giacomo; Sommella, Eduardo; Manfra, Michele; De Nisco, Mauro; Tenore, Gian Carlo; Scopa, Antonio; Sofo, Adriano; Marzocco, Stefania; Adesso, Simona; Novellino, Tiziana; Campiglia, Pietro

    2015-01-15

    Fresh cut vegetables represent a widely consumed food worldwide. Among these, lettuce (Lactuca sativa L.) is one of the most popular on the market. The growing interest for this "healthy" food is related to the content of bioactive compounds, especially polyphenols, that show many beneficial effects. In this study, we report the anti-inflammatory and antioxidant potential of polyphenols extracted from lettuce (var. Maravilla de Verano), in J774A.1 macrophages stimulated with Escherichia coli lipopolysaccharide (LPS). Lettuce extract significantly decreased reactive oxygen species, nitric oxide release, inducible nitric oxide synthase and cycloxygenase-2 expression. A detailed quali/quantitative profiling of the polyphenolic content was carried out, obtaining fast separation (10 min), good retention time and peak area repeatability, (RSD% 0.80 and 8.68, respectively) as well as linearity (R(2)⩾ 0.999) and mass accuracy (⩽ 5 ppm). Our results show the importance in the diet of this cheap and popular food for his healthy properties. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. INDEPENDENCIA DE MALLA EN TUBOS TORSIONADOS PARA INTERCAMBIO DE CALOR: CASO DE ESTUDIO

    Directory of Open Access Journals (Sweden)

    Juan Gonzalo Ardila-Marín

    2016-01-01

    Full Text Available La dinámica de fluidos computacional (Computational Fluids Dynamics – CFD ha sido útil para la predicción del desarrollo dinámico y térmico en intercambiadores de calor de tubos curvados y torsionados, tal como lo hizo Záchar en 2010 cuando investigó la doble mejora del curvado y una vena corrugada helicoidal que simulaba la inserción de un resorte al interior del tubo, pero geometrías comerciales como Turbotec® no han sido investigadas. Además, varias herramientas comerciales para la generación de malla están disponibles, sin embargo, el efecto que la calidad y el número de elementos tienen en la solución y el aumento del costo de cómputo, obliga a equilibrar la precisión con los recursos computacionales disponibles. Esta investigación buscó la discretización del volumen de control de intercambiadores mejorados realistas, para su posterior uso en el desarrollo numérico de correlaciones para dimensionamiento y selección. Luego de una evaluación del estado del arte y del desarrollo geométrico de los volúmenes de control con las herramientas CAD SolidEdge® y DesignModeler®, se empleó la herramienta Meshing® de ANSYS Workbench® para el mallado, evaluando los métodos y las configuraciones globales y locales de malla, para su generación y la verificación de métricas; se desarrollaron estudios de independencia de malla para dos geometrías de intercambiadores, evaluando la incidencia de la calidad y el número de elementos en la convergencia del Número de Nusselt, y se validaron con resultados experimentales disponibles en la literatura. Como resultado principal se seleccionaron las mejores mallas para el estudio numérico de cada geometría y se validó la metodología propuesta. Los resultados de simulación son influenciados por la calidad del mallado, entre otros parámetros; todos deben ser evaluados antes de emplear dichos resultados en la toma de decisiones, y es necesario usar resultados experimentales para

  9. DESARROLLOS INSTRUMENTALES EN MICROCALORIMETRIA DE CONDUCCIÓN DE CALOR

    Directory of Open Access Journals (Sweden)

    Liliana Giraldo G.

    2010-09-01

    Full Text Available Se presentan aspectos generales de la microcalorimetría de conducción de calor. Se describe el diseño y la operación de microcalorímetros de conducción de calor estático y de flujo construidos en este laboratorio, los cuales fueron calibrados eléctrica y químicamente. Estos equipos se emplean en la caracterización de sólidos porosos por la técnica de calorimetría de inmersión y en la determinación de entalpias de transferencia de solutos; su uso se ilustra con algunos resultados típicos. Se mencionan además otras aplicaciones que se dan actualmente a estos aparatos.

  10. Coeficientes de transferencia de calor experimental para el enfriamiento de licor en intercambiadores de placas//Experimental heat transfer coefficients for the liquor cooling in plate heat exchanger

    Directory of Open Access Journals (Sweden)

    Enrique Torres‐Tamayo

    2014-01-01

    Full Text Available La pérdida de eficiencia del proceso de enfriamiento del licor amoniacal, mediante el uso de intercambiadores de calor de placas, está asociada a imprecisiones en la estimación de los coeficientes de transferencia de calor y la acumulación de incrustaciones en la superficie de intercambio. El objetivo de la investigación es determinar los coeficientes de transferencia de calor y la influencia de lasincrustaciones en la pérdida de eficiencia de la instalación. Mediante un procedimiento iterativo se estableció la ecuación del número de Nusselt y su relación con el número de Reynolds y Prandtl. Se utilizó un diseño experimental multifactorial. Los resultados predicen el conocimiento de los coeficientespara el cálculo del número de Nusselt en ambos fluidos. Los valores de los coeficientes del licor amoniacal son inferiores, ello se debe a la presencia de componentes gaseosos. La ecuación obtenida muestra correspondencia con el modelo de Buonapane, el error comparativo es del 3,55 %.Palabras claves: intercambiador de calor de placas, coeficientes de transferencia de calor, eficiencia térmica.______________________________________________________________________________AbstractThe loss of efficiency of the ammonia liquor cooling process, by means of the plate heat exchanger, is associated to the incorrect estimate of the heat transfer coefficients and the accumulation of inlays in the exchange surface. The objective of the investigation is to determine the transfer coefficients and the influence of the inlays in the efficiency loss of the installation. By means of an iterative procedure was obtained the Nusselt number equation and the relationship with the Reynolds and Prandtl number, for it was used it a design experimental multifactorial. The results predict the knowledge of the coefficients forthe calculation of the Nusselt number for both fluids. The ammonia liquor coefficients values are inferior, due to the presence of gassy

  11. Perspective food addiction, caloric restriction, and dopaminergic neurotransmission

    DEFF Research Database (Denmark)

    Stankowska, Arwen Urrsula Malgorzata; Gjedde, Albert

    2013-01-01

    for a reduced cognitive reward condition. The combination of caloric restriction and food addiction imparts a high risk of relapse as a result of further reduction of dopaminergic neurotransmission and the subsequent loss of reward. As with drugs of abuse, ingestion of large quantities of sugar in circumstances...... by the relationship between dopamine receptor availability in the striatum and sensation-seeking in the form of an inverted U, suggested by recent findings, consistent with two opposite states of hypodopaminergic and hyperdopaminergic neuromodulation....

  12. Macronutrients and caloric intake in health and longevity

    OpenAIRE

    Solon-Biet, Samantha M.; Mitchell, Sarah J.; de Cabo, Rafael; Raubenheimer, David; Le Couteur, David G.; Simpson, Stephen J.

    2015-01-01

    Both lifespan and healthspan are influenced by nutrition, with nutritional interventions proving to be robust across a wide range of species. However, the relationship between nutrition, health and aging is still not fully understood. Caloric restriction is the most studied dietary intervention known to extend life in many organisms, but recently the balance of macronutrients has been shown to play a critical role. In this review, we discuss the current understanding regarding the impact of c...

  13. Strenuous exercise with caloric restriction: effect on luteinizing hormone secretion.

    Science.gov (United States)

    Williams, N I; Young, J C; McArthur, J W; Bullen, B; Skrinar, G S; Turnbull, B

    1995-10-01

    To test whether strenuous exercise with and without caloric restriction alters LH secretion, and whether these changes are apparent in the immediate post-exercise period, LH pulse parameters were studied in four moderately trained eumenorrheic women over three successive menstrual cycles. Blood samples were obtained 5 h before and 5 h after 90 min of running at 74% VO2max. Each test was preceded by a 7-d treatment of controlled diet and exercise (74% VO2max). During CONTROL, subjects were eucaloric on days 1-7, and performed no exercise on days 5-7. During STTI (short-term training increase), subjects were eucaloric and completed 90 min runs on days 5-7. During DIET/STTI, subjects consumed 60% of the calories necessary to maintain weight on days 1-7, and exercised as in STTI. A significant decrease in overall (0700-1830 h) LH pulse frequency during DIET/STTI compared with CONTROL and STTI treatments was observed. No changes were found in mean serum LH levels or peak amplitude. These results suggest that high-volume training combined with caloric restriction may predispose one to exercise-induced changes in LH pulse frequency, while adequate caloric intake may prevent these changes.

  14. Calores de Solución y Propiedades Termodinámicas Relacionadas: Un método Gráfico General de Cálculo

    Directory of Open Access Journals (Sweden)

    Alfredo Gómez O.

    2009-07-01

    Full Text Available Se presenta un método gráfico de cálculo con el cual es posible evaluar a partir de datos de calor de solución. diferentes propiedades termodinámicas de interés tales como: caloresres diferenciales de solución del soluto y del solvente. A HD,P 2 V ^ HOIF.I • calor de solución a dilución infinita A tH°; entalpias molares parciales relativas del soluto y del solvente. Lj y L,. y la entalpia molar aparente relativa, L^. El método está basado en la representación gráfica del calor integral de solución expresado por mol de soluto, A H||,fr.2 en función de la relación entre el número de moles de solvente y soluto, n^/nj. Cuando k>s datos experimentales de calor de solución son tomados hasta alta dilución, puede obtenerse con precisión el vak>r de A H°, con to cual el diagrama propuesto corresponde también a la representación gráfica de(^L2 en función de n^/nj. Se discute el significado f fsk» de las propiedades consideradas así como las relaciones existentes entre ellas. El diagrama propuesto presenta ventajas ya que además de su carácter más general, resulta más preciso y conveniente que k>s métodos particulares comúnmente empleados, especialmente en la evaluación de las propiedades citadas para el caso del soluto en soluciones muy diluidas. de(^L2 en función de n^/nj. Se discute el signifteado f fsk» de las propiedades conskJeradas asi como las relaciones existentes entre ellas. El diagrama propuesto presenta ventajéis ya que además de su caráctermás general, resulta más preciso y conveniente que k>s métodos particulares comúnmente empleados, especialmente en la evaluackin de las propiedades citadas para el caso del soluto en soluctones muy diluidas.

  15. An In Vivo Magnetic Resonance Spectroscopy Study of the Effects of Caloric and Non-Caloric Sweeteners on Liver Lipid Metabolism in Rats

    NARCIS (Netherlands)

    Janssens, Sharon; Ciapaite, Jolita; Wolters, Justina C.; van Riel, Natal A.; Nicolay, Klaas; Prompers, Jeanine J.

    2017-01-01

    We aimed to elucidate the effects of caloric and non-caloric sweeteners on liver lipid metabolism in rats using in vivo magnetic resonance spectroscopy (MRS) and to determine their roles in the development of liver steatosis. Wistar rats received normal chow and either normal drinking water, or

  16. Efectos fisiológicos de la deshidratación. ¿Por qué los deportistas deben ingerir líquidos durante el ejercicio en el calor?

    OpenAIRE

    González-Alonso, José; F. Coyle, Edward

    1998-01-01

    Durante el ejercicio prolongado realizado en condiciones de calor ambiental, los deportistas incurren en niveles de deshidratación bastante acusados debido principalmente a las grandes pérdidas de agua a través del sudor (1-2 l/h). Datos recientes demuestran que esta deshidratación progresiva causa alteraciones significativas de los sistemas cardiovascular, metabólico, termorregulador y endocrino, que a su vez pueden anticipar la aparición de la fatiga, ocasionar un golpe de calor o incluso c...

  17. Modelado de la transferencia de calor e índices de calidad durante el escaldado convencional y asistido por ultrasonidos de champiñones.

    OpenAIRE

    LESPINARD, ALEJANDRO; Bon Corbín, José; Carcel Carrión, Juan Andrés; Benedito Fort, José Javier; Mascheroni, Rodolfo Horacio

    2013-01-01

    En la industria de los alimentos, el uso de ultrasonidos (US) en combinación con procesos convencionales ofrece nuevas posibilidades para la mejora de los procesos de alimentos, que van desde el ahorro de energía a aumentos en el rendimiento del proceso o la calidad del producto; en este sentido ha demostrado ser una tecnología emergente que permite mejorar la transferencia de calor y materia. No obstante, aún es necesario realizar estudios concretos para los diferentes procesos y/o productos...

  18. El fenómeno de la isla de calor en dos ciudades turísticas. Los casos de Ibiza y Lloret de Mar

    OpenAIRE

    Serra Pardo, Juan

    2016-01-01

    [spa] El estudio del clima urbano ha permitido analizar la modificación que las ciudades ejercen sobre el clima regional a escala local, especialmente la alteración térmica que supone. Esta alteración, conocida con el nombre de isla de calor urbana (ICU), es el elemento más significativo y mejor conocido del clima urbano. De este modo, desde diferentes disciplinas se ha estudiado el fenómeno, estableciendo sus características, causas, impactos y consecuencias, en primer lugar, para luego desa...

  19. Simulación numérica de flujo de aire y transferencia de calor en un enfriador vertical con puerta panorámica

    OpenAIRE

    Narváez Buestán, Freddy Eduardo

    2017-01-01

    En este proyecto de investigación se analizan los flujos de aire y transferencia de calor en el interior de un Enfriador vertical. El aire sale por el cobertor y se visualiza mediante el software Ansys Fluent como el diseño influye en la distribución de flujo. Se propone una mejora en el diseño del Cobertor optimizando la distribución del flujo. In this research project the air flows and heat transfer inside a Vertical Cooler are analyzed. The air comes out through the cover panel freez...

  20. Rendimiento y calidad de forraje del pasto ovillo (Dactylis glomerata L. al variar la frecuencia e intensidad de pastoreo

    Directory of Open Access Journals (Sweden)

    Jorge Armando Villareal González

    2014-01-01

    Full Text Available El objetivo fue determinar el rendimiento y calidad del pasto ovillo ( Dactylis glomerata L., al variar la frecuencia e intensidad de pastoreo. Se evaluaron tres frecuencias (2, 3 y 4 semanas en primavera y verano y 4, 5 y 6 semanas durante otoño y dos intensidades de pastoreo (severa: 3 a 5 cm y ligera: 6 a 8 cm de altura de forr aje residual. Se evaluó el rendimiento de forraje, tasa de acumulación neta de forraje (TANF, composición morfoló gica y calidad del forraje. El mayor rendimiento acumulado y TANF se presentaron con pastoreo severo cada 4 y 6 sem anas y en ambas intensidades cada 3 y 5 semanas. El mayor rendimiento estacional (7,844; 7,699; 7114 kg MS ha -1 se presentó en verano en las mismas frecuencias e intensidades de pastoreo, respectivamente ( P <0.05. Durante primavera no se observaron dife rencias en rendimiento y TANF entre frecuencias de pastoreo. En otoño la frecuencia de 5 semanas superó a la de 4 ( P <0.05, pero no diferente a la de 6 semanas. En todas las estaciones del año la intensidad de pastoreo severo superó a la ligera, siendo diferentes en primavera y verano ( P <0.05. En general, el contenido de proteína total y digestibilidad in vitro de la materia seca tendieron a disminuir conforme aumentó el intervalo de pastoreo, siendo en promedio de 20 y 65 %, respectivamente. Se concluye que para obtener el mayor re ndimiento y calidad de forraje, los pastoreos deben realizarse cada 4 semanas durante primavera-verano y cada 5 semanas en otoño, a una intensidad severa.

  1. Descripción de un brote de enfisema y edema pulmonar agudo del bovino (EPAB) en Parral (Chile)

    OpenAIRE

    H. URRUTIA; C. BREVIS; Quezada, M.; Donoso, S

    1997-01-01

    Se describe un brote de enfisema y edema alveolar agudo del bovino (EPAB) ocurrido en la zona centro-sur a fines del verano de 1995. Los animales Frisón negro, de aproximadamente 2 años de edad, fueron afectados después de cambiarse de una pradera fibrosa a una suculenta de alfalfa. La mortalidad por esta causa fue de un 23%. Las principales lesiones encontradas en la necropsia fueron enfisema y edema intersticial intenso del pulmón, lo cual fue corroborado histopatológicamente, encontrándose...

  2. Can we live longer by eating less? A review of caloric restriction and longevity.

    Science.gov (United States)

    Roth, Lauren W; Polotsky, Alex J

    2012-04-01

    Caloric restriction, decreasing caloric intake by 20-30%, was first shown to extend life in rats nearly 80 years ago. Since that time, limiting food intake for longevity has been investigated in species from yeast to humans. In yeast and lower animals, caloric restriction has repeatedly been demonstrated to lengthen the life span. Studies of caloric restriction in non-human primates and in humans are ongoing and initial results suggest prolongation of life as well as prevention of age-related disease. There is also data in rodents suggesting that short term caloric restriction has beneficial effects on fertility. Although caloric restriction has many positive effects on health and longevity, quality of life on a restricted diet as well as the ability to maintain that diet long term are concerns that must be considered in humans. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  3. The Lexicocalorimeter: Gauging public health through caloric input and output on social media

    CERN Document Server

    Alajajian, S E; Reagan, A J; Alajajian, S C; Frank, M R; Mitchell, L; Lahne, J; Danforth, C M; Dodds, P S

    2015-01-01

    We propose and develop a Lexicocalorimeter: an online, interactive instrument for measuring the "caloric content" of social media and other large-scale texts. We do so by constructing extensive yet improvable tables of food and activity related phrases, and respectively assigning them with sourced estimates of caloric intake and expenditure. We show that for Twitter, our naive measures of "caloric input", "caloric output", and the ratio of these measures---"caloric balance"---are all strong correlates with health and well-being demographics for the contiguous United States. Our caloric balance measure outperforms both its constituent quantities, is tunable to specific demographic measures such as diabetes rates, provides a real-time signal reflecting a population's health, and has the potential to be used alongside traditional survey data in the development of public policy and collective self-awareness. Because our Lexicocalorimeter is a linear superposition of principled phrase scores, we also show we can m...

  4. Biología reproductiva del Potoyunco peruano Pelecanoides Garnotii en isla La Vieja, Costa Central del Perú

    OpenAIRE

    Jahncke, Jaime; Goya, Elisa

    1998-01-01

    Se encontraron adultos reproductivos durante todo el año; sin embargo, se identificaron dos picos reproductivos. El primero, más sincrónico, ocurre en los meses de verano entre diciembre y marzo; el segundo, menos marcado, ocurre en invierno entre mayo y setiembre. La duración del período de incubación se ha estimado en 50 a 60 días. Los pichones que nacen requieren de 70 a 80 días para completar el desarrollo. Se observaron tasas de crecimiento mayores durante los meses de invierno, debido p...

  5. Macronutrients and caloric intake in health and longevity.

    Science.gov (United States)

    Solon-Biet, Samantha M; Mitchell, Sarah J; de Cabo, Rafael; Raubenheimer, David; Le Couteur, David G; Simpson, Stephen J

    2015-07-01

    Both lifespan and healthspan are influenced by nutrition, with nutritional interventions proving to be robust across a wide range of species. However, the relationship between nutrition, health and aging is still not fully understood. Caloric restriction is the most studied dietary intervention known to extend life in many organisms, but recently the balance of macronutrients has been shown to play a critical role. In this review, we discuss the current understanding regarding the impact of calories and macronutrient balance in mammalian health and longevity, and highlight the key nutrient-sensing pathways that mediate the effects of nutrition on health and ageing. © 2015 Society for Endocrinology.

  6. Horas frío y horas de calor en zonas climáticas de la España peninsular (2002-2011)

    OpenAIRE

    García Merayo, José Luis; Gallego Abaroa, Teresa; Martínez Núñez, Lourdes

    2015-01-01

    Esta publicación pretende dar una idea aproximada del número de horas frío y horas de calor que se dan en las distintas zonas climáticas peninsulares, así como la aproximación que, a esos valores, proporciona la fórmula de Crossa-Raynaud, la más utilizada para su cálculo. No se trata de proponer, justificar o refutar determinadas hipótesis o métodos para el cálculo de horas frío o de calor, sino simplemente de aceptar la utilidad en las aplicaciones climáticas de estas variables derivadas y h...

  7. The urban climate: urban heat island of Salamanca El clima de las ciudades: isla de calor de Salamanca

    Directory of Open Access Journals (Sweden)

    Mª Salud Alonso García

    2004-12-01

    Full Text Available We have determined the existence of the urban heat island (UHI in a medium-sized city, with an extreme climate and few important foci of industrial pollution. It was seen that urban warming can arise in cities of these characteristics, being able to influence in the alive beings of the zone. By comparing the temperature series in an urban area and those from a nearby rural area, we studied the temporal evolution of the intensity of the UHI for the three-year period between 1996 and 1998. We detected two phenomenons: nocturnal heat island, when the difference of temperature between city and rural zone is positive, and diurnal heat island, when is negative. The most intense nocturnal heat island was seen in autumn, and the most intense diurnal heat island was seen in spring. Statistical study of the annual series corresponding to the night-time heat island permits a definition for Salamanca: a weak island, such as the one showing an intensity lower than 2.0 oC, a moderate island, if the intensity lies between 2.0 oC and 4.0 oC, and an intense island when a values greater than 4.0 oC is passed.En este trabajo se ha determinado la existencia de la isla de calor urbana (ICU, en una ciudad de tamaño medio, con un clima extremado y focos industriales de poca actividad. Con lo que se puede comprobar cómo afecta el calentamiento urbano a ciudades de estas características, pudiendo influir en los seres vivos de la zona. La existencia del fenómeno isla de calor, y su evolución en el tiempo, se han observado comparando los datos de temperatura registrados en una estación meteorológica situada en la ciudad, con los de otra estación fuera del radio de acción de la urbe, durante el período 1996-1998. Se han detectado dos fenómenos: la isla de calor nocturna, cuando la diferencia térmica entre la ciudad y la zona rural es positiva, que presenta sus valores más altos en otoño, y la isla de calor diurna, cuando la diferencia es negativa, que

  8. Heat transfer study for convection and radiation in an open cavity; Estudio de de la transferencia de calor por convencion y radiacion en una cavidad abierta

    Energy Technology Data Exchange (ETDEWEB)

    Cabanillas Lopez, Rafael E [Universidad de Sonora, Hermosillo, Sonora (Mexico); Estrada Gasca, Claudio A [Centro de Investigacion en Energia-UNAM, Temixco, Morelos (Mexico); Alvarez Garcia, Gabriela S [CENIDET, Cuernavaca, Morelos (Mexico)

    2000-07-01

    Interaction of natural convection and radiation heat transfer in an open side square cavity has been simulated numerically. Previous studies have shown results of the simulation of heat transfer for convection on this geometry. This paper reports the effect of considering both the convection and the radiation mechanisms. Radiation was found to have a great influence on the total amount of heat lost by the cavity as well as on the pattern of flow and on the temperature field. Computations were performed within the domain of the cavity for two-dimensional laminar flow problem. The average of heat transfer coefficient was calculated for several values of the Grashof number for air (Pr = 0.7), with the bottom wall at 500 K (constant temperature) and the open side at 300 K. [Spanish] Se presenta el estudio de la interaccion conveccion natural-radiacion en una cavidad rectangular abierta. Algunos estudios anteriores han mostrado resultados sobre la transferencia de calor por el mecanismo de conveccion natural sobre cavidades abiertas. Aqui se presenta la influencia de considerar ambos mecanismos de transferencia de calor, la conveccion y la radiacion. Se demuestra que el intercambio radiactivo tiene una gran influencia tanto en la cantidad total de calor perdido por la cavidad al ambiente, como en el patron de flujo y de temperatura dentro de la cavidad. Se resuelven numericamente las ecuaciones gobernantes para flujo laminar en dos dimensiones y se calcula el coeficiente promedio de transferencia de calor para diferentes valores del Grashof en una cavidad llena de aire (Pr 0.7), teniendo la pared del fondo de la cavidad a 500 K y los alrededores a 300 K.

  9. Heat transfer in simple houses; Transferencia de calor en casas habitacion

    Energy Technology Data Exchange (ETDEWEB)

    Porta, Miguel Angel; Rubio, Eduardo; Fernandez, Jose Luis [Centro de Investigaciones Biologicas del Noroeste, Baja California Sur, (Mexico); Gomez Munoz, Victor [Centro Interdiciplinario de Ciencias Marinas, Baja California Sur (Mexico)

    2000-07-01

    habitacion bajo distintas combinaciones de factores geometricos, incluyendo la orientacion de la vivienda, los parteluces y otros protectores de la fachada, los materiales y los metodos constructivos. El articulo presenta el balance energetico del sistema, que aqui se representa mediante tres ecuaciones de equilibrio energetico, que describen cada una, la ventana, la obra de mamposteria y el aire interior. La solucion simultanea de las ecuaciones diferenciales se obtiene por el metodo de Kutta, de la que se despejan las temperaturas medias representativas de cada uno de los elementos anteriores, y se calcula el flujo de calor entre ellos a lo largo del dia, asi como los flujos de intercambio con el exterior.

  10. Material-based figure of merit for caloric materials

    Science.gov (United States)

    Griffith, L. D.; Mudryk, Y.; Slaughter, J.; Pecharsky, V. K.

    2018-01-01

    The efficient use of reversible thermal effects in magnetocaloric, electrocaloric, and elastocaloric materials is a promising avenue that can lead to a substantially increased efficiency of refrigeration and heat pumping devices, most importantly, those used in household and commercial cooling applications near ambient temperature. A proliferation in caloric material research has resulted in a wide array of materials where only the isothermal change in entropy in response to a handful of different field strengths over a limited range of temperatures has been evaluated and reported. Given the abundance of such data, there is a clear need for a simple and reliable figure of merit enabling fast screening and down-selection to justify further detailed characterization of those material systems that hold the greatest promise. Based on the analysis of several well-known materials that exhibit vastly different magnetocaloric effects, the Temperature averaged Entropy Change is introduced as a suitable early indicator of the material's utility for magnetocaloric cooling applications, and its adoption by the caloric community is recommended.

  11. High monetary reward rates and caloric rewards decrease temporal persistence.

    Science.gov (United States)

    Fung, Bowen J; Bode, Stefan; Murawski, Carsten

    2017-02-22

    Temporal persistence refers to an individual's capacity to wait for future rewards, while forgoing possible alternatives. This requires a trade-off between the potential value of delayed rewards and opportunity costs, and is relevant to many real-world decisions, such as dieting. Theoretical models have previously suggested that high monetary reward rates, or positive energy balance, may result in decreased temporal persistence. In our study, 50 fasted participants engaged in a temporal persistence task, incentivised with monetary rewards. In alternating blocks of this task, rewards were delivered at delays drawn randomly from distributions with either a lower or higher maximum reward rate. During some blocks participants received either a caloric drink or water. We used survival analysis to estimate participants' probability of quitting conditional on the delay distribution and the consumed liquid. Participants had a higher probability of quitting in blocks with the higher reward rate. Furthermore, participants who consumed the caloric drink had a higher probability of quitting than those who consumed water. Our results support the predictions from the theoretical models, and importantly, suggest that both higher monetary reward rates and physiologically relevant rewards can decrease temporal persistence, which is a crucial determinant for survival in many species. © 2017 The Authors.

  12. Role of sleep timing in caloric intake and BMI.

    Science.gov (United States)

    Baron, Kelly G; Reid, Kathryn J; Kern, Andrew S; Zee, Phyllis C

    2011-07-01

    Sleep duration has been linked to obesity and there is also an emerging literature in animals demonstrating a relationship between the timing of feeding and weight regulation. However, there is a paucity of research evaluating timing of sleep and feeding on weight regulation in humans. The goal of this study was to evaluate the role of sleep timing in dietary patterns and BMI. Participants included 52 (25 females) volunteers who completed 7 days of wrist actigraphy and food logs. Fifty-six percent were "normal sleepers" (midpoint of sleep ≥5:30 AM). Late sleepers had shorter sleep duration, later sleep onset and sleep offset and meal times. Late sleepers consumed more calories at dinner and after 8:00 PM, had higher fast food, full-calorie soda and lower fruit and vegetable consumption. Higher BMI was associated with shorter sleep duration, later sleep timing, caloric consumption after 8:00 PM, and fast food meals. In multivariate models, sleep timing was independently associated with calories consumed after 8:00 PM and fruit and vegetable consumption but did not predict BMI after controlling for sleep duration. Calories consumed after 8:00 PM predicted BMI after controlling for sleep timing and duration. These findings indicate that caloric intake after 8:00 PM may increase the risk of obesity, independent of sleep timing and duration. Future studies should investigate the biological and social mechanisms linking timing of sleep and feeding in order to develop novel time-based interventions for weight management.

  13. Tecnologías emergentes para la conservación de alimentos sin calor

    Directory of Open Access Journals (Sweden)

    Fernández Molina, Juan José

    2001-01-01

    Full Text Available Not available

    Se han investigado los principios básicos de tres tecnologías emergentes para pasteurizar y esterilizar alimentos sin empleo del calor Mediante numerosos estudios se ha comprobado la efectividad de los campos eléctricos pulsantes de alta intensidad (CEPAI, los pulsos de luz (PL y los campos magnéticos oscilantes (CMO en la destrucción de microorganismos y enzimas de sistemas alimentarios. En la inactivación microbiana por CEPA!, el blanco principal es la membrana celular que, al ser sometida a campos eléctricos de alta intensidad, se hace permeable formando huecos o poros cuyo tamaño se incrementa a medida que aumenta la intensidad del campo eléctrico o el tiempo de tratamiento o se reduce la resistencia iónica del medio de pulsación. Por otra parte, los PL inducen reacciones fotoquímicas y fototérmicas en los alimentos, causando la muerte de gran cantidad de microorganismos, especialmente en productos alimenticios envasados. Los CMO producen simulación o inhibición en el crecimiento y reproducción de los microorganismos, un simple pulso de intensidad de 5-10 teslas y frecuencias de 5-500 kHz es suficiente para reducir el número de microorganismos en un mínimo de 2 ciclos logarítmicos. Se ha comprobado que estas tecnologías alargan la vida de anaquel de diversos productos alimenticios y pueden ser consideradas como sustitutos parciales de los procesos convencionales de pasteurización y esterilización de alimentos por tratamientos térmicos.

  14. Organización de eventos deportivos: diseño de un proyecto de organización y gestión de un Campus de Tenis de Verano

    OpenAIRE

    Hernández Gimeno, Antonio

    2016-01-01

    Realización de un proyecto de gestión y organización de un Campus de verano de tenis en el polideportivo de Sant Joan d'Alacant, que también incluirá otro tipo de actividades principalmente deportivas. El proyecto contemplará la planificación, el marketing, recursos materiales, recursos humanos, permisos, seguros necesarios, presupuesto, estudio de mercado, etc. Es un proyecto perfectamente aplicable en la realidad y en otros polideportivos o lugares que gocen de las instalaciones necesarias...

  15. Modelación y simulación de disipadores de calor para procesadores de computadora en COMSOL Multiphysics Modeling and simulation of heat sinks for computer processors in COMSOL Multiphysics

    Directory of Open Access Journals (Sweden)

    Sulin Garro Acón

    2012-11-01

    Full Text Available En este estudio se analizó la transferencia de calor en tres disipadores de calor utilizados para enfriar los procesadores de computadoras de escritorio. El objetivo de estos disipadores es evitar el sobrecalentamiento de la unidad de procesamiento y la consecuente reducción de la vida útil del computador. Los disipadores de calor se modelaron usando COMSOL Multiphysics con las dimensiones reales de los dispositivos y la generación de calor se modeló con una fuente puntual. Luego se modificaron los diseños de los disipadores para lograr una temperatura más baja en la zona más caliente del procesador. El resultado fue una reducción en la temperatura en el rango de 5-78 grados Kelvin, al rediseñarse el disipador de calor con variaciones feasibles como la reducción del grosor de las placas de intercambio de calor y el aumento de su número. Esto demuestra la posibilidad de desarrollar diseños optimizados para disipadores de calor que no requieran más materiales sino una mejor ingeniería. El trabajo se inició como parte del curso CM-4101 Modelización y Simulación.In this study, the heat transfer of three desktop- computer heat sinks was analyzed. The objective of using these heat sinks is to avoid overheating of the computer’s processing unit and in turn reduce the corresponding loss in the unit’s service time. The heat sinks were modeled using COMSOL Multiphysics with the actual dimensions of the devices, and heat generation was modeled with a point source. In the next step, the heat sink designs were modified to achieve a lower temperature in the higher temperature location on the heat sink. The results were temperature reductions in the range of 5-78 degrees Kelvin, by making feasible variations in design such as reducing the thickness of the heat exchanger fins and increasing their number. This paper demonstrates that there is room to develop improved designs that do not require more materials but rather a better engineering

  16. Modelo matemático de la transferencia de calor para predecir el perfil de durezas en probetas Jominy

    Directory of Open Access Journals (Sweden)

    López, E.

    2013-04-01

    Full Text Available The heat transfer coefficient was estimated at the bottom surface at Jominy bar end quench specimen by solution of the heat inverse conduction problem. A mathematical model based on the finite-difference method was developed to predict thermal paths and volume fraction of transformed phases. The mathematical model was codified in the commercial package Microsoft Visual Basic v. 6. The calculated thermal path and final phase distribution were used to evaluate the hardness distribution along the AISI 4140 Jominy bar.En el presente trabajo se estimó el coeficiente de transferencia de calor en la superficie que se encuentra en contacto con el chorro de agua en la probeta Jominy mediante la solución del problema inverso de conducción de calor. Con el objetivo de predecir los perfiles térmicos y las fracciones de fase transformadas se formuló un modelo matemático con el método de diferencias finitas y se codificó en el software comercial Microsoft Visual Basic v. 6. Los perfiles térmicos y las fracciones de fase calculadas se utilizaron para predecir el perfil de durezas en una probeta Jominy de acero AISI 4140 mediante el uso de correlaciones empíricas.

  17. Notas sobre la organización y ubicación del arte paleolítico en las cuevas del monte del Castillo (Puente Viesgo. Santander

    Directory of Open Access Journals (Sweden)

    Reynaldo GONZÁLEZ GARCÍA

    2009-10-01

    Full Text Available El presente artículo es un pequeño resumen de una parte de las conclusiones de los trabajos realizados en el transcurso del verano de 1985 en el Monte del Castillo. El propósito de los mismos se orientó en una total y exhaustiva revisión de la gran mayoría de figuras paleolíticas, tanto pintadas, grabadas, y en algún caso esculpidas, de las cuatro cuevas que forman este prestigioso y conocido conjunto troglodítico: La cueva de las Monedas, la cueva de la Pasiega, la cueva de las Chimeneas y la cueva del Castillo, en Puente Viesgo, Santander.

  18. Sensitivity of caloric test and video head impulse as screening test for chronic vestibular complaints

    Science.gov (United States)

    Mezzalira, Raquel; Bittar, Roseli Saraiva Moreira; do Carmo Bilécki-Stipsky, Marcia Maria; Brugnera, Cibele; Grasel, Signe Schuster

    2017-01-01

    OBJECTIVE: This study compared the results of the caloric test with those of the video head impulse test obtained during the same session and evaluated whether the former can be used to screen for non-acute vestibular dysfunction. METHODS: A total of 157 participants complaining of dizziness with vestibular characteristics of varying durations and clinical courses completed the caloric test and video head impulse test. RESULTS: Significantly more caloric test results than video head impulse test results were abnormal. CONCLUSIONS: The results of the caloric test and video head impulse test are distinct but complement each other. Within our sample, the caloric test was more sensitive for vestibular dysfunction. Therefore, the video head impulse test is not a suitable screening tool of the vestibular system in patients with chronic complaints. PMID:28954005

  19. Incorporación de los materiales de cambio de fase en placas de yeso para almacenamiento de energía térmica mediante calor latente": caracterización térmica del material mediante la técnica DSC

    OpenAIRE

    Oliver, A.; Neila, F. J.; García, A

    2011-01-01

    La Calorimetría Diferencial de Barrido es una técnica de análisis térmico, usada desde hace décadas, para medir la entalpía asociada al cambio de fase de un material como función del tiempo y de la temperatura. Otras técnicas menos utilizadas son la Calorimetría Convencional el Análisis Térmico Diferencial. Existe una gran incertidumbre en los valores de propiedades suministrados por los fabricantes (puesto que éstos se refieren a las sustancias puras) y es conveniente utilizar DSC para te...

  20. Fugas de calor y aprovechamiento de efluentes en la optimización de ciclos Brayton totalmente irreversibles

    National Research Council Canada - National Science Library

    Herrera, C. A; Rosillo, M.E; Castaño

    2008-01-01

    ... (maquinas irreversibles, flujos disipativos, consumo de potencia en todo trasiego de fluídos, transmisiones de calor a gradientes de temperatura finitos, fugas de calor, desaprovechamiento de efluentes, restricciones en caídas de presión...

  1. Caloric requirements in patients with inflammatory bowel disease.

    Science.gov (United States)

    Barot, L R; Rombeau, J L; Feurer, I D; Mullen, J L

    1982-01-01

    Measured resting energy expenditure (REE) was compared to predicted basal energy expenditure (BEE) in 35 consecutive patients with nonseptic inflammatory bowel disease (IBD) and 20 healthy volunteers. Patients with IBD were groups greater or less than 90% ideal body weight (IBW). The BEE in kcal/day was found to be equivalent to the measured REE in both patient groups. It is suggested that the BEE be used to determine caloric requirements in nonseptic patients with inflammatory bowel disease. Patients less than 90% IBW had significantly higher measured energy expenditure (26.4 +/- 1.0) per kg body weight than either controls (21.2 +/- 0.7) or patients greater than or equal to 90% IBW (21.2 +/- 0.8), p less than 0.001. It is suggested that this increased expenditure is due to a combined effect of weight loss and intrinsic disease. PMID:7055399

  2. Caloric Restriction Promotes Structural and Metabolic Changes in the Skin

    Directory of Open Access Journals (Sweden)

    Maria Fernanda Forni

    2017-09-01

    Full Text Available Caloric restriction (CR is the most effective intervention known to enhance lifespan, but its effect on the skin is poorly understood. Here, we show that CR mice display fur coat remodeling associated with an expansion of the hair follicle stem cell (HFSC pool. We also find that the dermal adipocyte depot (dWAT is underdeveloped in CR animals. The dermal/vennule annulus vasculature is enlarged, and a vascular endothelial growth factor (VEGF switch and metabolic reprogramming in both the dermis and the epidermis are observed. When the fur coat is removed, CR mice display increased energy expenditure associated with lean weight loss and locomotion impairment. Our findings indicate that CR promotes extensive skin and fur remodeling. These changes are necessary for thermal homeostasis and metabolic fitness under conditions of limited energy intake, suggesting a potential adaptive mechanism.

  3. Caloric restriction and the aging process: a critique.

    Science.gov (United States)

    Sohal, Rajindar S; Forster, Michael J

    2014-08-01

    The main objective of this review is to provide an appraisal of the current status of the relationship between energy intake and the life span of animals. The concept that a reduction in food intake, or caloric restriction (CR), retards the aging process, delays the age-associated decline in physiological fitness, and extends the life span of organisms of diverse phylogenetic groups is one of the leading paradigms in gerontology. However, emerging evidence disputes some of the primary tenets of this conception. One disparity is that the CR-related increase in longevity is not universal and may not even be shared among different strains of the same species. A further misgiving is that the control animals, fed ad libitum (AL), become overweight and prone to early onset of diseases and death, and thus may not be the ideal control animals for studies concerned with comparisons of longevity. Reexamination of body weight and longevity data from a study involving over 60,000 mice and rats, conducted by a National Institute on Aging-sponsored project, suggests that CR-related increase in life span of specific genotypes is directly related to the gain in body weight under the AL feeding regimen. Additionally, CR in mammals and "dietary restriction" in organisms such as Drosophila are dissimilar phenomena, albeit they are often presented to be the very same. The latter involves a reduction in yeast rather than caloric intake, which is inconsistent with the notion of a common, conserved mechanism of CR action in different species. Although specific mechanisms by which CR affects longevity are not well understood, existing evidence supports the view that CR increases the life span of those particular genotypes that develop energy imbalance owing to AL feeding. In such groups, CR lowers body temperature, rate of metabolism, and oxidant production and retards the age-related pro-oxidizing shift in the redox state. Copyright © 2014 The Authors. Published by Elsevier Inc. All

  4. Low Caloric Sweeteners for Diabetes and Obesity Care and Their

    Directory of Open Access Journals (Sweden)

    Mohammad Asif

    2015-10-01

    Full Text Available Diabetes and obesity are two common human disorders that affecting human health and invite various diseases and disorders in normal body functions. These diseases are very common worldwide. Diabetes occurs when high blood sugar levels develop. This happens when body can’t make and use all of the insulin it needs to blood sugar normally to keep blood sugar levels as normal as possible to control diabetes. Diabetic patients will need to follow a diet plan, do exercise and possibly take insulin injections. As part of eating plan, health care provider, and dietitian may ask to limit the amount of carbohydrates eat each day. Low-calorie sweeteners are one easy tool to help for follow eating plan. Obesity is more susceptible and often been associated with frequent ingestion of high energy food in high amount and high intake of sugars such as fermentable sugars such as sucrose, fructose, glucose, and maltose. Both diseases are may be genetically or due to hormonal imbalances. High energy sweeteners may causes caries in the teeth particularly susceptible to the children. Increased calorie intake associated with sugars and carbohydrates, especially when associated with physical inactivity, has been implicated in obesity. Fortunately, low calorie artificial and natural alternatives of sugars have been developed as alternatives to fermentable sugars and have shown promise in these health issues. Although there are only few artificial sweeteners (saccharin, aspartame, acesulfam potassium, sucralose, cyclamate that have been approved as food additives by the Food and Drug Administration and additional other low-caloric sweeteners (sugar alcohols, neotame, stevia, erythritol, xylitol, tagatose that have FDA-generally recognized as safe. Given the health impact of sugars and other carbohydrates, professionals should be aware of the marketed available low caloric sweeteners and both their benefits and potential risks.

  5. Combined Salt and Caloric Restrictions: Potential Adverse Outcomes.

    Science.gov (United States)

    Homma, Tsuyoshi; Homma, Mika; Huang, Yuefei; Mayurasakorn, Korapat; Rodi, Nurul Mahamad; Hamid, Anis Amalina Abdul; Hurwitz, Shelley; Yao, Tham; Adler, Gail K; Pojoga, Luminita H; Williams, Gordon H; Romero, Jose R

    2017-10-11

    We hypothesized that caloric restriction (CR) and salt restriction (ResS) would have similar effects on reducing cardiovascular risk markers and that combining CR and ResS would be synergistic in modulating these markers. To test our hypothesis, rats were randomized into 2 groups: ad libitum liberal salt diet (ad libitum/high-sodium, 1.6% sodium) or ResS diet (ad libitum/ResS, 0.03% sodium). CR was initiated in half of the rats in each group by reducing caloric intake to 60% while maintaining sodium intake constant (CR/high-sodium, 2.7% sodium or CR/ResS, 0.05% sodium) for 4 weeks. CR in rats on a high-sodium diet improved metabolic parameters, renal transforming growth factor-β and collagen-1α1 and increased plasma adiponectin and renal visfatin and NAD+ protein levels. Although CR produced some beneficial cardiovascular effects (increased sodium excretion and reduced blood pressure), it also was associated with potentially adverse cardiovascular effects. Adrenal zona glomerulosa cell responsiveness and aldosterone levels and activation were inappropriately increased for the volume state of the rodent. Like CR on HS, CR on a ResS diet also produced relative increased zona glomerulosa responsiveness and an increased blood pressure with no improvement in metabolic parameters. These results suggest that combining CR and ResS may decrease the beneficial effects of each alone. Furthermore, CR, regardless of dietary salt intake, inappropriately activates aldosterone production. Thus, caution should be used in combining ResS and CR because the combination may lead to increased cardiovascular risk. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  6. Influencia de condiciones ambientales sobre la presencia de bacterias en suelos urbanos del Monte Austral, Neuquén

    OpenAIRE

    Pezzullo, Silvina D.; Manacorda, Ana M.; García, Cintia C.; Alvarez, Anahí S.

    2012-01-01

    La ciudad de Neuquén se ubica en la Provincia Fitogeofráfica del Monte y los factores ambientales determinan la aridez del suelo. Un porcentaje de sus calles son de tierra mejoradas con ripio y sin cordón cuneta ni veredas construidas. Durante el verano algunos barrios son regados con aguas contaminadas con efluentes cloacales provenientes de un arroyo. El ingreso de partículas de suelo a las viviendas cercanas constituye un riesgo sanitario, por los organismos que van adheridos a las mismas,...

  7. Análisis exergético comparativo entre intercambiadores de calor // A comparative exergetic analysis of compact heat exchangers

    Directory of Open Access Journals (Sweden)

    Rubén Borrajo-Pérez

    2011-08-01

    Full Text Available Los intercambiadores de calor son equipos de importancia primordial en la industria y enaplicaciones domésticas en general. El trabajo está relacionado con el area de la intensificacion de latransferencia de calor en intercambiadores de calor compactos y la comparación entre diferentestipos de superficies intensificadas. La comparación es realizada a partir del análisis de la exergíadestruída por la superfície de intercambio como resultado de las perdidas por fricción y delintercambio térmico entre cuerpos con diferencia finita de temperaturas. El análisis de Segunda Leyde la Termodinámica permite identificar en que superfície de intercambio se genera mas entropía.Como resultado fundamental se obtiene la dependencia entre la exergía destruída y elespaciamiento transversal para una superfície formada por una fila de tubos elipticos a diferentesvalores del numero de Reynolds. Se identifica al intercambio térmico como la de mayor aporte a laentropía generada. Finalmente se demuestra la viabilidad de la intensificación de la transferencia decalor empleando generadores de vórtices en intercambiadores de calor.Palabras claves: generadores de vórtices, intecambiadores de calor compactos, tubos elípticos, exergía.__________________________________________________________________AbstractThe heat exchangers are important devices in both industry and household applications. This work isabout heat transfer enhancement in heat exchangers surface. Many heat transfer enhancementtechniques can be applied and then a comparative tool is needed to evaluate its performance.Thermodynamics is one of these tools and the exergetic analysis can be applied to heat exchangersurfaces. The exergy destroyed because both of thermal exchange between bodies with differenttemperatures and destroyed by friction drag is calculated. These results are used to compare heatexchanger surfaces. Heat exchanger surfaces in smooth configuration and the same surfaces

  8. A time-energy analysis of daytime surface activity in degus, Octodon degus Análisis del uso de tiempo y energía en la actividad superficial diaria en degus, Octodon degus

    Directory of Open Access Journals (Sweden)

    G.J. Kenagy

    2002-03-01

    ón de tiempo y energía en un roedor caviomorfo diurno el degu, Octodon degus, en Chile central. Cuantificamos los componentes de actividad superficial en el campo sobre una base diaria durante el solsticio de verano en condiciones de calor y aridez extrema, para contestar la siguiente pregunta: ¿el tiempo absoluto disponible para la actividad superficial limita el rendimiento? ¿la asignación de tiempo y energía a locomoción juega un limitación funcional significativa en el presupuesto de energía total y en el rendimiento? Los degus permanecen forrajeando cerca de 2/3 de su tiempo fuera de las cuevas; están estacionarios cerca de 88 % del tiempo, caminan cerca del 10 %, y corren rápidamente de un punto a otro solamente un 2 % del tiempo. Los costos netos de locomoción (caminando y corriendo fueron calculados en 2,2 % del gasto energético total. Esta baja asignación neta de tiempo y energía a locomoción, junto a la abundante distribución de alimento en un ámbito de hogar pequeño, sugieren que el rendimiento diario de los degus no está limitado por el tiempo absoluto disponible bajo condiciones normales en el solsticio de verano (extremo estacional de largo del día, calor y aridez. Las demandas de energía totales se lograrían con 4,5 h de actividad superficial por día. Las observaciones empíricas, junto a un modelo simple de gasto de energía y tiempo entregan una validación simple de la actividad del balance de energía total en roedores de vida libre. El bajo impacto de la locomoción sobre el presupuesto de energía total representa una economía en la conducta de estos animales, los rápidos modos de locomoción minimizarían el riego de predación. Postulamos que estos análisis cuantitativos de gasto de energía asociados con la conducta de campo contribuirían a la modelación teórica del uso de tiempo y energía

  9. Energy saving in heat exchangers of industrial refrigeration systems; Ahorro de energia en intercambiadores de calor en los sistemas de refrigeracion industrial

    Energy Technology Data Exchange (ETDEWEB)

    Padilla, A.; Romero Paredes, Hernando; Ambriz, Juan Jose [Universidad Autonoma Metropolitana-Iztapalapa, Mexico, D. F. (Mexico)

    1994-12-31

    This paper presents the energy losses of the heat exchangers utilized in industrial refrigeration systems . The effects of the different scaling products on the heat transfer rates are presented and the energy not transferred because of them is evaluated. A simplified method for the evaluation is developed and applied to the evaporators and condensers more frequently employed in the industrial refrigeration systems. The internal and external heat transfer coefficients are evaluated in different types of heat exchangers. The energy losses as a function of the scale thickness on the heat exchanger is shown. [Espanol] El trabajo presenta las perdidas energeticas que se tienen en los intercambiadores de calor usados en los sistemas de refrigeracion industrial. Se presentan los efectos que tienen los diferentes incrustantes en las tasas de transferencia de calor y se evalua la energia que no se transfiere causada por aquellos. Se desarrolla un metodo simplificado de evaluacion y se aplica a los evaporadores y condensadores mas comunes empleados en los sistemas de refrigeracion industrial. Se evaluan los coeficientes internos y externos en diferentes tipos de intercambiadores. Se muestran las perdidas energeticas en funcion del espesor del incrustante en la pared del intercambiador.

  10. INFLUENCIA DE LA ÉPOCA DE COSECHA EN LA CALIDAD DEL LICOR DE CACAO TIPO NACIONAL

    Directory of Open Access Journals (Sweden)

    Milton Alexis Ruíz Pinargote

    2014-12-01

    Full Text Available El objetivo de esta investigación fue evaluar la influencia de las épocas de cosecha (invierno y verano sobre las características físicas, sensoriales y bromatológicas del cacao nacional perteneciente al jardín clonal de la ESPAM MFL. Los análisis se efectuaron a partir de muestras de almendras secas evaluándose porcentaje de fermentación, almendras violetas, peso de semillas y testa, sabores básicos y específicos, pH, acidez, ceniza y grasa. Los datos fueron procesados mediante la prueba de T para encontrar diferencias entre épocas usando el programa estadístico INFOSTAT versión 2008. Los resultados muestran significación estadística para la fermentación entre las épocas del año, el mayor porcentaje de fermentación obtenido fue de 96.5 % del clon EET-19 en verano, mientras que en invierno sobresalió el clon EET-103. El perfil sensorial de los sabores específicos obtuvo mayores diferencias en el sabor floral con respecto al frutal y nuez, además de los sabores básicos con niveles medios y altos entre épocas; las propiedades bromatológicas acidez y ceniza fueron parecidas entre invierno y verano; contrario al pH y grasa que varían significativamente entre épocas. Se concluye que las épocas del año influyen sobre las propiedades físicas, sensoriales y bromatológicas del cacao nacional.

  11. Incorporación de materiales de cambio de fase en placas de yeso para almacenamiento de energía térmica mediante calor latente: caracterización térmica del material mediante la técnica DSC

    Directory of Open Access Journals (Sweden)

    Oliver, A.

    2011-06-01

    Full Text Available Differential Scanning Calorimetry (DSC is a thermal analysis technique which has been used for more than three decades to measure the temperatures and heat flows associated with transitions in materials as a function of time. Other techniques, are Differential Thermal Analysis DTA and Conventional Calorimetry. There is great uncertainty in the values supplied by the manufacturers (because they are referred to pure substances and the DSC should be used to get more accurate values. It will be analyzed the thermal storage capacity depending on temperature for several compound materials formed by some aggregates, mainly gypsum and phase change materials, in various proportions. The results have been compared with other building materials such as gypsum boards and brick layer. The suitability of the new construction material for thermal energy storage will be assessed in comparison with other materials traditionally used for this purpose.

    La Calorimetría Diferencial de Barrido es una técnica de análisis térmico, usada desde hace décadas, para medir la entalpía asociada al cambio de fase de un material como función del tiempo y de la temperatura. Otras técnicas menos utilizadas son la Calorimetría Convencional el Análisis Térmico Diferencial. Existe una gran incertidumbre en los valores de propiedades suministrados por los fabricantes (puesto que éstos se refieren a las sustancias puras y es conveniente utilizar DSC para tener valores más exactos. Se va a analizar la capacidad de almacenamiento térmico en función de la temperatura de varios materiales compuestos formados por los mismos agregados -principalmente yeso y material de cambio de fase- en distintas proporciones. Los valores obtenidos se comparan con otros materiales constructivos, yeso laminado y ladrillo. También se verifica la idoneidad del nuevo material constructivo para el almacenamiento de energía térmica frente a otros materiales utilizados

  12. Enfermedad de mano, pie y boca en un hospital del Callao, 2016

    Directory of Open Access Journals (Sweden)

    Milton José Max Rodríguez-Zúñiga

    Full Text Available La enfermedad de mano, pie y boca (EMPB es una enfermedad exantemática viral, causada principalmente por Coxsackie A16, con una sintomatología típica consistente en fiebre; exantema pápulo-vesicular en manos, pies y genitales; y un enantema ulceroso en boca. En el verano del 2016 se presentó una diversidad de casos en un hospital del Callao en niños y adultos, con una sintomatología compatible con EMPB; el diagnóstico fue clínico, se aplicó terapia de soporte con resolución final de síntomas. En la última década se han presentado reportes en algunos países con una afectación atípica causada por el Coxsackie A6, produciendo lesiones más extensas y en adultos. Sin embargo, el diagnóstico sigue siendo clínico, solo necesitando confirmación virológica en casos atípicos o cuando el diagnóstico no es claro. La importancia de este reporte radica en describir los casos del Callao ocurridos en el verano del 2016, para servir de apoyo a los profesionales de la salud en el diagnóstico y manejo de pacientes con similar sintomatología.

  13. Laboratório caseiro: calorímetro de baixo custo

    OpenAIRE

    Laburú, Carlos Eduardo; UEL - Párana; Rodrigues, Rogério; UEL - Paraná

    1998-01-01

    Este trabalho propõe a construção de um calorímetro de baixo custo, de montagem simples e com materiais facilmente encontrados. Objetiva- se com o calorímetro proposto substituir os normalmente utilizados nos laboratórios de física do secundário. Examina-se a capacidade térmica e o isolamento térmico do calorímetro proposto, comparando-o com um comercial muito utilizado nas escolas.

  14. Computational program to design heat pumps by compression (ciclo 1.0); Programa computacional para diseno de bombas de calor por compresion (ciclo 1.0)

    Energy Technology Data Exchange (ETDEWEB)

    De Alba Rosano, Mauricio [CIE, UNAM, Temixco, Morelos (Mexico)

    2000-07-01

    refrigerantes. La simulacion del condensador y del evaporador incluye la determinacion de su conductancia global (UA), y cuando alguno de estos es del tipo coraza y tubos, se indica el numero de pasos pares de tubos por coraza. Dadas las condiciones de entrada y de salida del fluido que se desea calentar, las condiciones del fluido que cede calor, y la eficiencia electrica del motor que impulsa al compresor; el programa determina la mejor combinacion de compresor y refrigerante, tomando como criterio el COP. Los resultados que brinda CICLO 1.0 son: condiciones de operacion del ciclo de compresion, es decir, presiones y temperaturas a la entrada y salida de cada uno de los componentes que constituyen la bomba de calor, flujo masico de refrigerante, COP, potencia requerida en el compresor, asi como su eficiencia volumetrica e isoentropica, conductancia global de los intercambiadores y otros datos. Se ha ejecutado CICLO 1.0 con datos de bombas de calor que operan actualmente, y los resultados obtenidos de la simulacion han sido muy similares con los reportados de la operacion de dichas instalaciones.

  15. Caloric intake and Alzheimer's disease. Experimental approaches and therapeutic implications.

    Science.gov (United States)

    Pasinetti, Giulio Maria; Zhao, Zhong; Qin, Weiping; Ho, Lap; Shrishailam, Yemul; Macgrogan, Donal; Ressmann, Wendy; Humala, Nelson; Liu, Xunxian; Romero, Carmen; Stetka, Breton; Chen, Linghong; Ksiezak-Reding, Hanna; Wang, Jun

    2007-01-01

    Alzheimer's disease (AD) is a rapidly growing public health concern with potentially devastating effects. Presently, there are no known cures or effective preventive strategies. While genetic factors are relevant in early-onset cases, they appear to play less of a role in late-onset sporadic AD cases, the most common form of AD. Due to the fact that the disease typically strikes very late in life, delaying symptoms could be as good as a cure for many people. For example, it is now widely accepted that if the onset of the disease could be delayed by even 5 years, the incidence could be cut in half. Both clinical and epidemiological evidence suggests that modification of lifestyle factors such as nutrition may prove crucial to AD management given the mounting experimental evidence suggesting that brain cells are remarkably responsive to "what somebody is doing". Among other nongenetic factors influencing AD, recent studies strongly support the evidence that caloric intake may play a role in the relative risk for AD clinical dementia. Indeed, the effect of diet in AD has been an area of research that has produced promising results, at least experimentally. Most importantly, as mechanistic pathways are defined and their biochemical functions scrutinized, the evidence supporting a direct link between nutrition and AD neuropathology continues to grow. Our work, as well as that of others, has recently resulted in the development of experimental dietary regimens that might promote, attenuate or even reverse features of AD. Most remarkably, while we found that high caloric intake based on saturated fat promotes AD type Beta-amyloidosis, conversely we found that dietary restriction based on reduced carbohydrate intake is able to prevent it. This evidence is very exciting and is, in part, consistent with current epidemiological studies suggesting that obesity and diabetes are associated with a >4-fold increased risk of developing AD. The clarification of the mechanisms

  16. Thermal and friction drop characteristic of heat exchangers with elliptical tubes and smooth fins//Caracterización térmica e hidráulica de intercambiadores de calor con tubos elípticos y aletas lisas

    Directory of Open Access Journals (Sweden)

    Rubén Borrajo-Pérez

    2012-09-01

    Full Text Available Pressure drop and heat transfer are the most important parameters in compact heat exchanger. There is a lack of information in the literature about heat exchanger with elliptical tube. The objective of this work was the experimental characterization of compact heat exchangers models using elliptical tube with eccentricity of 0,5 and smooth fins. The Reynolds numbers and the spacing were varied and always inside laminar regime. The experiments were conducted in an open wind tunnel using sublimation of naphthalene and the heat and mass transfer analogy. As results, the average and local Nusselt number and friction factor for 36 models were obtained. Correlations for Colburn and friction factors were presented. This correlations were obtained for 200calor son importantes parámetros en intercambiadores de calor. Existe falta de información cuando de intercambiadores de calor y tubos elípticos se trata. El objetivo del trabajo fue caracterizar experimentalmente modelos de intercambiadores de calor con tubos elípticos yaletas lisas. El numero de Reynolds y los espaciamientos fueron variados, dentro del régimen laminar. Los experimentos fueron desarrollados en un túnel de viento de circuito abierto usando la sublimación de naftaleno y la analogía calor y masa. Los números de Nusselt medio, locales y el factor de fricción fueronobtenidos en forma de correlaciones de Factores de Fricción y Colburn. Las correlaciones, validas para 200

  17. Diseño, Construcción y Calibración de un calorímetro de solución de precisión media

    Directory of Open Access Journals (Sweden)

    Alfredo Gómez O.

    2009-07-01

    Full Text Available Se descriten los criterios de diseño, la construcción y la calibración de un calorímetro isoperit> ólico de solución de precisión media y de bajo costo. Se miden los cambios térmicos mediante un termistor de 15.000 otimios a 293 K, cuya calibración permite encontrar la expresión AT = -52,495 log,o (Rf/Ri para el cambio de temperatura en función de la resistencia, en el rango de trabajo, 297 a 299 K, La sensibilidad termométríca es 0,00158 K/otimio. El error relativo máximo en las medidas calorimétricas con el sistema de calibración benceno-cíclotiexano es de 3%. el de la capacidad calorífica es de 2,74% y el correspondiente a la diferencia de temperatura es de 1,66%, Se encuentran problemas por la gran pendiente de pérdidas de calor, 0,048 K/mln. (valor máximo observado. El coeficiente de transferencia de calor de las paredes del vaso calorimétrico resultó elevado aunque cumple las especificaciones exigidas.

  18. Heat transfer coefficients obtainment by means of naphthalene sublimation in air; Obtencion de coeficientes de transferencia de calor por medio de la tecnica de sublimacion de naftalina en aire

    Energy Technology Data Exchange (ETDEWEB)

    Perez Galindo, Jose Arturo; Garcia Gutierrez, Alonso [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1985-12-31

    This work describes the experimental technique for the sublimation of naphthalene in air which measures heat transfer coefficients through the use of the analogy between the transference phenomena of heat and mass. The technique used to substitute the experimental measurements of heat transfer, in which it is difficult to control the border thermal conditions, when they are dimmed by the omnipresent problem of heat conduction through the walls of the transference surfaces. Two examples are included of the application technique and its potential is outlined. [Espanol] En este trabajo se describe la tecnica experimental de la sublimacion de naftalina en aire mediante la que se miden coeficientes de transferencia de masa. Los datos asi obtenidos pueden convertirse en coeficientes de transferencia de calor a traves del uso de la analogia entre los fenomenos de transferencia de calor y masa. La tecnica se utiliza para substituir las mediciones experimentales de transferencia de calor, en las que es dificil controlar las condiciones termicas de frontera, cuando las empana el problema omnipresente de la conduccion de calor a traves de las paredes de las superficies de transferencia. Se incluyen dos ejemplos de la aplicacion de la tecnica y se destaca su potencial.

  19. Líneas de investigación del Proyecto Oxkintok

    OpenAIRE

    Rivera Dorado, Miguel

    1998-01-01

    Not available.España recuperó en el año 1968 una vieja tradición. Equipos españoles viajaron a América para realizar investigaciones de campo sobre las culturas indígenas del Nuevo Mundo. Se enlazaba así con los cronistas que en la época de la colonia indagaron por doquier toda clase de pormenores sobre la realidad nativa contemporánea y sobre sus antecedentes precolombinos. En el verano de 1986, un grupo de arqueólogos de distintas instituciones emprendió la más ambiciosa de todas esas inves...

  20. Is contextual-potentiated eating dependent on caloric density of food?

    Directory of Open Access Journals (Sweden)

    Fernando Fernández-Aranda

    2009-01-01

    Full Text Available One experiment tested whether a specific context could elicit eating in rats as a result of Pavlovian conditioning and whether this effect depended on the caloric density of food. Thirty two deprived rats experienced two contexts. They had access to food in context A, but no food was available in context B. During conditioning, half of the animals received high density caloric food (HD groups whereas the other half, low density caloric food (LD groups. Then, half of the rats in each type of food group was tested in context A and the other half in context B. The results demonstrated an effect of context conditioning only in HD groups. These findings suggest the relevance of both contextual conditioning and caloric density of food in eating behaviour. Implications for the aetiology of binge eating will be discussed.

  1. Relationship between caloric intake and length of hospital stay for infants with bronchiolitis.

    Science.gov (United States)

    Weisgerber, Michael C; Lye, Patricia S; Nugent, Melodee; Li, Shun-Hwa; De Fouw, Kari; Gedeit, Rainer; Simpson, Pippa; Gorelick, Marc H

    2013-01-01

    Poor oral intake is a common presenting symptom among infants hospitalized with bronchiolitis. The prevalence, degree, and duration of iminished caloric intake in these infants have not been studied. Our goal was to determine the daily caloric intake among infants admitted with bronchiolitis and to evaluate the relationship between early hospital caloric intake and length of stay (LOS). We conducted a retrospective chart review of infants aged or =183 days. Caloric intake was diminished in the early course of hospitalization for infants who had bronchiolitis and slowest to normalize in infants with the longest LOS. Interventions aimed at decreasing LOS among infants admitted with bronchiolitis should consider the potential significance of nutrition for severely affected infants with this condition.

  2. Palatable Hyper-Caloric Foods Impact on Neuronal Plasticity.

    Science.gov (United States)

    Morin, Jean-Pascal; Rodríguez-Durán, Luis F; Guzmán-Ramos, Kioko; Perez-Cruz, Claudia; Ferreira, Guillaume; Diaz-Cintra, Sofia; Pacheco-López, Gustavo

    2017-01-01

    Neural plasticity is an intrinsic and essential characteristic of the nervous system that allows animals "self-tuning" to adapt to their environment over their lifetime. Activity-dependent synaptic plasticity in the central nervous system is a form of neural plasticity that underlies learning and memory formation, as well as long-lasting, environmentally-induced maladaptive behaviors, such as drug addiction and overeating of palatable hyper-caloric (PHc) food. In western societies, the abundance of PHc foods has caused a dramatic increase in the incidence of overweight/obesity and related disorders. To this regard, it has been suggested that increased adiposity may be caused at least in part by behavioral changes in the affected individuals that are induced by the chronic consumption of PHc foods; some authors have even drawn attention to the similarity that exists between over-indulgent eating and drug addiction. Long-term misuse of certain dietary components has also been linked to chronic neuroimmune maladaptation that may predispose individuals to neurodegenerative conditions such as Alzheimer's disease. In this review article, we discuss recent evidence that shows how consumption of PHc food can cause maladaptive neural plasticity that converts short-term ingestive drives into compulsive behaviors. We also discuss the neural mechanisms of how chronic consumption of PHc foods may alter brain function and lead to cognitive impairments, focusing on prenatal, childhood and adolescence as vulnerable neurodevelopmental stages to dietary environmental insults. Finally, we outline a societal agenda for harnessing permissive obesogenic environments.

  3. Fasting and Caloric Restriction in Cancer Prevention and Treatment.

    Science.gov (United States)

    Brandhorst, Sebastian; Longo, Valter D

    Cancer is the second leading cause of death in the USA and among the leading major diseases in the world. It is anticipated to continue to increase because of the growth of the aging population and prevalence of risk factors such as obesity, smoking, and/or poor dietary habits. Cancer treatment has remained relatively similar during the past 30 years with chemotherapy and/or radiotherapy in combination with surgery remaining the standard therapies although novel therapies are slowly replacing or complementing the standard ones. According to the American Cancer Society, the dietary recommendation for cancer patients receiving chemotherapy is to increase calorie and protein intake. In addition, there are no clear guidelines on the type of nutrition that could have a major impact on cancer incidence. Yet, various forms of reduced caloric intake such as calorie restriction (CR) or fasting demonstrate a wide range of beneficial effects able to help prevent malignancies and increase the efficacy of cancer therapies. Whereas chronic CR provides both beneficial and detrimental effects as well as major compliance challenges, periodic fasting (PF), fasting-mimicking diets (FMDs), and dietary restriction (DR) without a reduction in calories are emerging as interventions with the potential to be widely used to prevent and treat cancer. Here, we review preclinical and preliminary clinical studies on dietary restriction and fasting and their role in inducing cellular protection and chemotherapy resistance.

  4. Comportamentos das Famílias Portuguesas em Épocas de Calor e Durante a Onda de Calor de Agosto de 2003

    OpenAIRE

    Nogueira, Paulo; Paixão, Eleonora; Falcão, José Marinho

    2005-01-01

    Este estudo teve como principal objectivo a caracterização das atitudes e da adopção de medidas de protecção em períodos de calor e em particular conhecer aquelas que efectivamente foram adoptadas durante a onda de calor de Agosto de 2003 (29 de Julho a 15 de Agosto). Foi realizado um inquérito por via postal, aplicando um questionário aos indivíduos de 18 e mais anos das unidades de alojamento (UA), que constituem a amostra ECOS (Em Casa Observamos Saúde) do Observatório Nacional de Saúd...

  5. Comportamentos das famílias portuguesas em épocas de calor e durante a onda de calor de Agosto de 2003

    OpenAIRE

    Nogueira, Paulo Jorge; Paixão, Eleonora de Jesus; Falcão, José Marinho

    2005-01-01

    RESUMO - Este estudo teve como principal objectivo a caracterização das atitudes e da adopção de medidas de protecção em períodos de calor e em particular conhecer aquelas que efectivamente foram adoptadas durante a onda de calor de Agosto de 2003 (29 de Julho a 15 de Agosto). Foi realizado um inquérito por via postal, aplicando um questionário aos indivíduos de 18 e mais anos das unidades de alojamento (UA), que constituem a amostra ECOS (Em Casa Observamos Saúde) do ...

  6. Respuestas al estrés por calor en los cultivos. I. Aspectos moleculares, bioquímicos y siológicos.

    Directory of Open Access Journals (Sweden)

    Néstor Felipe Chaves-Barrantes

    2016-12-01

    Full Text Available El objetivo de esta revisión fue integrar los mecanismos por los cuales las plantas responden al estrés por calor a lo largo del continuo suelo-planta-atmósfera, desde una perspectiva agronómica. Esta revisión presenta las bases siológicas del estrés por calor, para lo cual se examinaron las temperaturas óptimas y los umbrales de estrés por calor en los cultivos, las metodologías para su estudio, y las respuestas moleculares, bioquímicas y siológicas de las plantas a altas temperaturas. Se describe el efecto de las altas temperaturas sobre la estructura y el metabolismo celular, la respiración y la aclimatación de la Q10, la estabilidad de las membranas, la acumulación de osmolitos compatibles, la producción de pigmentos y metabolitos secundarios, la producción de especies reactivas de oxígeno (ROS y enzimas antioxidantes, la producción de proteínas de estrés, y el efecto sobre la fotosíntesis y la partición de asimilados. Además, se discuten los cambios hormonales que regulan la respuesta de las plantas en el campo, su señalización y la aclimatación al estrés térmico.

  7. Use of caloric and noncaloric sweeteners in US consumer packaged foods, 2005-2009.

    Science.gov (United States)

    Ng, Shu Wen; Slining, Meghan M; Popkin, Barry M

    2012-11-01

    Our understanding of the use of caloric and noncaloric sweeteners in the US food supply is limited. This study uses full ingredient list and Nutrition Facts label data from Gladson Nutrition Database and nationally representative purchases of consumer packaged foods from Nielsen Homescan in 2005 through 2009 to understand the use of caloric sweeteners (including fruit juice concentrate) and noncaloric sweeteners in consumer packaged foods. Of the 85,451 uniquely formulated foods purchased during 2005 through 2009, 75% contain sweeteners (68% with caloric sweetener only, 1% with noncaloric sweetener only, 6% with both caloric and noncaloric sweeteners). Caloric sweetener are in >95% of cakes/cookies/pies, granola/protein/energy bars, ready-to-eat cereals, sweet snacks, and sugar-sweetened beverages. Noncaloric sweetener are in >33% of yogurts and sport/energy drinks, 42% of waters (plain or flavored), and most dietetic sweetened beverages. Across unique products, corn syrup is the most commonly listed sweetener, followed by sorghum, cane sugar, high-fructose corn syrup, and fruit juice concentrate. Also, 77% of all calories purchased in the United States in 2005-2009 contained caloric sweeteners and 3% contained noncaloric sweeteners, and 73% of the volume of foods purchased contained caloric sweetener and 15% contained noncaloric sweetener. Trends during this period suggest a shift toward the purchase of noncaloric sweetener-containing products. Our study poses a challenge toward monitoring sweetener consumption in the United States by discussing the need and options available to improve measures of caloric sweetener and noncaloric sweetener and additional requirements on Nutrition Facts labels on consumer packaged foods. Copyright © 2012 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

  8. Caloric restriction decreases orthostatic tolerance independently from 6° head-down bedrest.

    Directory of Open Access Journals (Sweden)

    John P Florian

    Full Text Available Astronauts consume fewer calories during spaceflight and return to earth with an increased risk of orthostatic intolerance. Whether a caloric deficiency modifies orthostatic responses is not understood. Thus, we determined the effects of a hypocaloric diet (25% caloric restriction during 6° head down bedrest (an analog of spaceflight on autonomic neural control during lower body negative pressure (LBNP. Nine healthy young men completed a randomized crossover bedrest study, consisting of four (2 weeks each interventions (normocaloric bedrest, normocaloric ambulatory, hypocaloric bedrest, hypocaloric ambulatory, each separated by 5 months. Muscle sympathetic nerve activity (MSNA was recorded at baseline following normocaloric and hypocaloric interventions. Heart rate (HR and arterial pressure were recorded before, during, and after 3 consecutive stages (7 min each of LBNP (-15, -30, -45 mmHg. Caloric and posture effects during LBNP were compared using two-way ANOVA with repeated measures. There was a strong trend toward reduced basal MSNA following caloric restriction alone (normcaloric vs. hypocaloric: 22±3 vs. 14±4 burst/min, p = 0.06. Compared to the normocaloric ambulatory, both bedrest and caloric restriction were associated with lower systolic blood pressure during LBNP (p<0.01; however, HR responses were directionally opposite (i.e., increase with bedrest, decrease with caloric restriction. Survival analysis revealed a significant reduction in orthostatic tolerance following caloric restriction (normocaloric finishers: 12/16; hypocaloric finishers: 6/16; χ2, p = 0.03. Caloric restriction modifies autonomic responses to LBNP, which may decrease orthostatic tolerance after spaceflight.

  9. The comparative effect of fasting with and without caloric restriction in Rat on oxidative stress parameters

    OpenAIRE

    Nurina Tyagita; Taufiqurrachman Nasihun; Titiek Sumarawati

    2016-01-01

    Introduction: Fasting, like Islamic Ramadan Fasting, has been associated with health benefits. Islamic Ramadan fasting, a form of caloric restriction (CR) or alternate day fasting that. Studies suggest a comparable effect of ADF and caloric restriction. Despite the fact that fasting can be considered as a form of dietary restriction, fasters tend to have difficulty to reduce their food intake during non-fasting period by overeating leading to the excessive calorie intake. To compare the effec...

  10. Weight Cycling and Cancer: Weighing the Evidence of Intermittent Caloric Restriction and Cancer Risk

    OpenAIRE

    Henry J. Thompson; McTiernan, Anne

    2011-01-01

    Overweight and obese individuals frequently restrict caloric intake to lose weight. The resultant weight loss, however, typically is followed by an equal or greater weight gain, a phenomenon called weight cycling. Most attention to weight cycling has focused on identifying its detrimental effects, but preclinical experiments indicating that intermittent caloric restriction or fasting can reduce cancer risk have raised interest in potential benefits of weight cycling. Although hypothesized adv...

  11. Postoral Glucose Sensing, Not Caloric Content, Determines Sugar Reward in C57BL/6J Mice

    Science.gov (United States)

    Zukerman, Steven; Ackroff, Karen

    2015-01-01

    Recent studies suggest that because of their energy value, sugars are more rewarding than non-caloric sweeteners. However, intragastric infusion data indicate that sugars differ in their postoral appetite-stimulating effects. We therefore compared the preference for isocaloric 8% sucrose, glucose, and fructose solutions with that of a non-caloric sweetener solution (0.8% sucralose) in C57BL/6J mice. Brief 2-bottle tests indicated that sucralose was isopreferred to sucrose but more preferred than glucose or fructose. Yet, in long-term tests, the mice preferred sucrose and glucose, but not fructose to sucralose. Additional experiments were conducted with a non-caloric 0.1% sucralose + 0.1% saccharin mixture (S + S), which does not have the postoral inhibitory effects of 0.8% sucralose. The S + S was preferred to fructose in brief and long-term choice tests. S + S was also preferred to glucose and sucrose in brief tests, but the sugars were preferred in long-term tests. In progressive ratio tests, non-deprived and food-deprived mice licked more for glucose but not fructose than for S + S. These findings demonstrate that the nutrient-specific postoral actions, not calories per se, determine the avidity for sugar versus non-caloric sweeteners. Furthermore, sweet taste intensity and potential postoral inhibitory actions must be considered in comparing non-caloric and caloric sweeteners. PMID:25715333

  12. COMPORTAMIENTO DEL VIENTO LOCAL DIURNO EN LA CUENCA DEL RÍO LLOBREGAT

    Directory of Open Access Journals (Sweden)

    Jordi Comalrena de Sobregrau Bailina

    2012-01-01

    Full Text Available El estudio de los datos meteorológicos de cinco estaciones representativas de la cuenca del río Llobregat (veranos de 2006, 2007 y 2009 para establecer patro- nes de comportamiento del viento local diurno que puedan ayudar a las tareas de prevención de incendios forestales ha revelado que la marinada es el elemento principal a tener en cuenta sólo en la zona costera y hasta la sierra Prelitoral. El patrón de la zona media y alta de la cuenca (interior responde, en cambio, a la influencia del viento de valle y los vientos de ladera. El sistema de vientos locales de la cuenca del Llobregat supone un factor añadido de riesgo meteoro- lógico de propagación de incendios forestales, dado que la velocidad más alta se detecta durante el período de mayor riesgo: a la temperatura elevada y a la baja humedad hay que sumar, por lo tanto, la velocidad del viento máxima diaria. Sin embargo, la previsibilidad del sistema, la velocidad media baja o moderada y la ausencia de cambios bruscos e imprevistos de velocidad y dirección descartan considerarlo un elemento de importante riesgo por sí mismo.

  13. Palatable Hyper-Caloric Foods Impact on Neuronal Plasticity

    Science.gov (United States)

    Morin, Jean-Pascal; Rodríguez-Durán, Luis F.; Guzmán-Ramos, Kioko; Perez-Cruz, Claudia; Ferreira, Guillaume; Diaz-Cintra, Sofia; Pacheco-López, Gustavo

    2017-01-01

    Neural plasticity is an intrinsic and essential characteristic of the nervous system that allows animals “self-tuning” to adapt to their environment over their lifetime. Activity-dependent synaptic plasticity in the central nervous system is a form of neural plasticity that underlies learning and memory formation, as well as long-lasting, environmentally-induced maladaptive behaviors, such as drug addiction and overeating of palatable hyper-caloric (PHc) food. In western societies, the abundance of PHc foods has caused a dramatic increase in the incidence of overweight/obesity and related disorders. To this regard, it has been suggested that increased adiposity may be caused at least in part by behavioral changes in the affected individuals that are induced by the chronic consumption of PHc foods; some authors have even drawn attention to the similarity that exists between over-indulgent eating and drug addiction. Long-term misuse of certain dietary components has also been linked to chronic neuroimmune maladaptation that may predispose individuals to neurodegenerative conditions such as Alzheimer’s disease. In this review article, we discuss recent evidence that shows how consumption of PHc food can cause maladaptive neural plasticity that converts short-term ingestive drives into compulsive behaviors. We also discuss the neural mechanisms of how chronic consumption of PHc foods may alter brain function and lead to cognitive impairments, focusing on prenatal, childhood and adolescence as vulnerable neurodevelopmental stages to dietary environmental insults. Finally, we outline a societal agenda for harnessing permissive obesogenic environments. PMID:28261067

  14. Cardioprotective Signature of Short-Term Caloric Restriction.

    Directory of Open Access Journals (Sweden)

    Hossein Noyan

    Full Text Available To understand the molecular pathways underlying the cardiac preconditioning effect of short-term caloric restriction (CR.Lifelong CR has been suggested to reduce the incidence of cardiovascular disease through a variety of mechanisms. However, prolonged adherence to a CR life-style is difficult. Here we reveal the pathways that are modulated by short-term CR, which are associated with protection of the mouse heart from ischemia.Male 10-12 wk old C57bl/6 mice were randomly assigned to an ad libitum (AL diet with free access to regular chow, or CR, receiving 30% less food for 7 days (d, prior to myocardial infarction (MI via permanent coronary ligation. At d8, the left ventricles (LV of AL and CR mice were collected for Western blot, mRNA and microRNA (miR analyses to identify cardioprotective gene expression signatures. In separate groups, infarct size, cardiac hemodynamics and protein abundance of caspase 3 was measured at d2 post-MI.This short-term model of CR was associated with cardio-protection, as evidenced by decreased infarct size (18.5±2.4% vs. 26.6±1.7%, N=10/group; P=0.01. mRNA and miR profiles pre-MI (N=5/group identified genes modulated by short-term CR to be associated with circadian clock, oxidative stress, immune function, apoptosis, metabolism, angiogenesis, cytoskeleton and extracellular matrix (ECM. Western blots pre-MI revealed CR-associated increases in phosphorylated Akt and GSK3ß, reduced levels of phosphorylated AMPK and mitochondrial related proteins PGC-1α, cytochrome C and cyclooxygenase (COX IV, with no differences in the levels of phosphorylated eNOS or MAPK (ERK1/2; p38. CR regimen was also associated with reduced protein abundance of cleaved caspase 3 in the infarcted heart and improved cardiac function.

  15. Validación de dos métodos analíticos: calor de combustión y azufre, en materiales combustibles que pueden ser quemados en hornos de clinker

    Directory of Open Access Journals (Sweden)

    Karen Hooker

    2010-10-01

    Full Text Available Se validaron dos métodos para llevar a cabo la evaluación fisicoquímica de materiales de desecho de diferentes empresas interesadas en tratar sus residuos, para utilizarlos como combustible alternativo para un horno de cemento, que calcina estos materiales a una temperatura máxima de 2000°C. Con este fin se optimizaron las figuras de mérito de la determinación del calor de combustión y del porcentaje de azufre.

  16. CONCENTRACIONES PLASMÁTICAS DE 25-OH-VITAMINA D EN SANGRE DE CORDÓN UMBILICAL TRAS LOS MESES DE VERANO

    National Research Council Canada - National Science Library

    Cristina Manzano Varo; Oscar García-Algar; Antonio Mur Sierra; Roser Ferrer Costa; Antonio Carrascosa Lezcano; Diego Yeste Fernández; Sandra Ortigosa Gómez

    2017-01-01

    Los niveles de vitamina D (25(OH)D) del recién nacido dependen de los depósitos maternos. En los últimos años se han publicado estudios que muestran una elevada prevalencia de deficiencia de vitamina D en mujeres embarazadas...

  17. REDUCCIÓN DE LA CANTIDAD DE Vibrio mimicus CON CALOR O ÁCIDO ACÉTICO EN HUEVO DE TORTUGA (Lepidochelys olivacea)

    OpenAIRE

    M\\u00F3nica Pereira-Zamora; Eric Wong-Gonz\\u00E1lez

    2010-01-01

    Este estudio se realizó en el Ce ntro Na cional de Cie ncia y Tecnología de Alimentos en el año 2000, con el fin de determinar la reducción de Vibrio mimicus en huevo de tortuga lora utilizando calor o ácido acético. Para ellos se determinó el tiempo de coagulación a diferentes temperaturas o niveles de pH con el fin de seleccionar los que podían utilizarse para la reducción del patógeno sin afectar las cualidades sensoriales del huevo crudo. Los huevos inoculados con Vibrio mimicus con carga...

  18. Replacing sweetened caloric beverages with drinking water is associated with lower energy intake.

    Science.gov (United States)

    Stookey, Jodi D; Constant, Florence; Gardner, Christopher D; Popkin, Barry M

    2007-12-01

    Reduced intake of sweetened caloric beverages (SCBs) is recommended to lower total energy intake. Replacing SCBs with non-caloric diet beverages does not automatically lower energy intake, however. Compensatory increases in other food or beverages reportedly negate benefits of diet beverages. The purpose of this study was to evaluate drinking water as an alternative to SCBs. Secondary analysis of data from the Stanford A TO Z intervention evaluated change in beverage pattern and total energy intake in 118 overweight women (25 to 50 years) who regularly consumed SCBs (>12 ounces/d) at baseline. At baseline and 2, 6, and 12 months, mean daily beverage intake (SCBs, drinking water, non-caloric diet beverages, and nutritious caloric beverages), food composition (macronutrient, water, and fiber content), and total energy intake were estimated using three 24-hour diet recalls. Beverage intake was expressed in relative terms (percentage of beverages). In fixed effects models that controlled for total beverage intake, non-caloric and nutritious caloric beverage intake (percentage of beverages), food composition, and energy expenditure [metabolic equivalent (MET)], replacing SCBs with drinking water was associated with significant decreases in total energy intake that were sustained over time. The caloric deficit attributable to replacing SCBs with water was not negated by compensatory increases in other food or beverages. Replacing all SCBs with drinking water was associated with a predicted mean decrease in total energy of 200 kcal/d over 12 months. The results suggest that replacing SCBs with drinking water can help lower total energy intake in overweight consumers of SCBs motivated to diet.

  19. Estudo do Sujamento da Superfície de Transferência de Calor do Evaporador de uma Bomba de Calor aquecido pelo efluente de uma fábrica de pasta para papel

    OpenAIRE

    Fernandes, Sofia Assunção

    2010-01-01

    O presente trabalho tem como principal objectivo a avaliação do sujamento da superfície de transferência de calor do evaporador de uma bomba de calor, quando se utiliza o efluente da fábrica de pasta e papel da Portucel Soporcel em Cacia como fluido de aquecimento. Para a realização deste estudo montou-se uma instalação, composta por uma bomba de calor, um circuito de água de arrefecimento do condensador da bomba de calor e um circuito de água residual quente para o aquecimento do evaporador ...

  20. Analytical model to describe the thermal behavior of a heat discharge system in roofs; Modelo analitico que describe el comportamiento termico de un sistema de descarga de calor en techos

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Gomez, V.H.; Contreras-Espinosa, J.J.; Gonzalez-Ortiz, G.; Morillon-Galvez, D.; Fernandez-Zayas, J.L. [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)]. E-mail: vichugo@servidor.unam.mx; jjuancon2000@yahoo.com.mx; gilberto_gonzalez25@hotmail.com; damg@pumas.iingen.unam.mx; JFernandezZ@iingen.unam.mx

    2012-01-15

    The present study proposes an analytical model which describes the thermal behavior of a heat discharge system in roof, when the surfaces that constitute it are not translucent. Such a model derives from a thermal balance carried out to a heat discharge system in roofs. To validate it, an experimental prototype that allows simulating the thermal behavior of a heat discharge system in wall and roof was used, and the results were compared to those obtained with the proposed analytical model. It was found that the thermal behavior of the analytical model is similar to the thermal behavior of the experimental prototype; a worthless variation was detected among their respective outcome (The difference of temperatures can be caused by the heat transfer coefficient, of which no studies defining its behavior accurately have been found). Therefore, it can be considered that the proposed analytical model can be employed to simulate the thermal behavior of a heat discharge system in roofs when the surfaces that constitute it are opaque. [Spanish] En el presente estudio se propone un modelo analitico que describe el comportamiento termico de un sistema de descarga de calor en techo, cuando las superficies que lo componen no son translucidos. Dicho modelo surge a partir de un balance termico realizado a un sistema de descarga de calor en techos. Para validarlo, se realizaron dos corridas experimentales en un prototipo que permite simular el comportamiento termico de un sistema de descarga de calor en techo y se compararon los resultados medidos con los calculados por el modelo analitico propuesto. Se encontro que, el comportamiento termico del modelo analitico es similar al comportamiento termico del prototipo experimental, se detecto una variacion despreciable entre los valores arrojados por ambos modelos (la diferencia de temperaturas puede estar ocasionada por la obtencion del coeficiente convectivo de transferencia de calor, del cual no se han encontrado estudios que

  1. Estudi comparatiu entre un sistema de climatització solar amb planta d’absorció geotèrmica i un sistema de climatització amb bomba de calor geotèrmica

    OpenAIRE

    Costillo Javier, Sergi

    2009-01-01

    Disseny i dimensionat d’una instal•lació de climatització, durant tot l'any, i comparació entre un sistema de climatització solar amb una planta d’absorció geotèrmica i un sistema de climatització mitjançant una bomba de calor geotèrmica, per al despatx de professors i becaris del nou laboratori d’ energia de l’EPS, mitjançant la utilització d’un sistema d’energia solar tèrmica de baixa temperatura, com a medi d’aportació de calor, i per energia geotèrmica per a la climatització integral...

  2. The Lexicocalorimeter: Gauging public health through caloric input and output on social media.

    Directory of Open Access Journals (Sweden)

    Sharon E Alajajian

    Full Text Available We propose and develop a Lexicocalorimeter: an online, interactive instrument for measuring the "caloric content" of social media and other large-scale texts. We do so by constructing extensive yet improvable tables of food and activity related phrases, and respectively assigning them with sourced estimates of caloric intake and expenditure. We show that for Twitter, our naive measures of "caloric input", "caloric output", and the ratio of these measures are all strong correlates with health and well-being measures for the contiguous United States. Our caloric balance measure in many cases outperforms both its constituent quantities; is tunable to specific health and well-being measures such as diabetes rates; has the capability of providing a real-time signal reflecting a population's health; and has the potential to be used alongside traditional survey data in the development of public policy and collective self-awareness. Because our Lexicocalorimeter is a linear superposition of principled phrase scores, we also show we can move beyond correlations to explore what people talk about in collective detail, and assist in the understanding and explanation of how population-scale conditions vary, a capacity unavailable to black-box type methods.

  3. Caloric Requirements of Patients With Brain Impairment and Cerebral Palsy Who Are Dependent on Chronic Ventilation.

    Science.gov (United States)

    Gale, Rena; Namestnic, Julia; Singer, Pierre; Kagan, Ilya

    2017-11-01

    Israeli law mandates chronic ventilator support for children and adolescents who are severely brain impaired and show minimal responses. Feeding protocols in these cases have been based on the caloric requirements of healthy children, deducting calories for lack of activity as well as an individual adjustment according to the cerebral palsy growth curves. However, patients are still inclined to gain excessive weight. Our objective was to determine the caloric requirements of these patients. Sixteen patients hospitalized in a dedicated unit who were ventilated through tracheostomies and fed via gastrostomies were included. Patients were aged 3-24 years; duration of ventilation was 1-7.5 years; and diagnoses included congenital genetic or brain malformations (n = 9), hypoxic accidents (n = 4), and postbacterial or postviral encephalitis (n = 3). Resting energy expenditure (REE) was determined by indirect calorimetry. REE values were compared with the caloric requirements of age-comparable healthy children and the calories actually delivered. Data were analyzed with paired t tests, Pearson correlations, and linear regression. The REE of our patients was 46% lower than the estimated caloric requirements of healthy children. In practice, patients received 32% more calories than that measured by REE. These findings were not affected by age, weight, diagnosis, or length of hospitalization. The caloric expenditure of these patients is very low. A diet guided by indirect calorimetry is proposed to aid in providing optimal nutrition support for this unique population to avoid overfeeding and obesity.

  4. Moldes de arcilla para fundir metales procedentes del Castro Hallstáttico de El Royo (Soria

    Directory of Open Access Journals (Sweden)

    Jorge Juan EIROA

    2009-12-01

    Full Text Available Durante los trabajos de la segunda campaña de excavaciones arqueológicas en el castro de la Virgen del Castillo de El Royo (Soria, que se desarrollaron durante el verano de 1979, apareció un lote de moldes de arcilla para fundir metales que, por su indudable interés para documentar aún más el desarrollo de la metalurgia en la Meseta, ofrecemos hoy, independientemente de la memoria oficial que sobre el yacimiento y su excavación preparamos.

  5. FLUJO INTERNO MIXTO CON DIFUSIÓN DOBLE DE CALOR Y MASA EN UNA CAVIDAD RECTANGULAR MIXED INTERNAL FLOW WITH DOUBLE DIFFUSION OF HEAT AND MASS

    Directory of Open Access Journals (Sweden)

    Carlos H Salinas Lira

    2008-09-01

    Full Text Available El presente trabajo muestra resultados de transporte de calor y masa (Doble al interior de una cavidad rectangular ocasionado por un flujo convectivo forzado y natural (Mixto. El modelo matemático consta de las ecuaciones de Navier-Stokes para describir el flujo laminar de un fluido incompresible. Además es modelado el transporte de calor y masa a través de dos ecuaciones diferenciales lineales de segunda orden, incorporando en forma lineal los efectos de los gradientes de concentración y de temperaturas. El modelo matemático es resuelto numéricamente a través del Método de Volúmenes Finitos descrito en coordenadas curvilíneas y variables colocalizadas, representando los términos difusivos a través de diferencia central y usando un esquema potencial para los términos convectivos. Se muestran resultados originales de patrones de flujo: Isotermas, isoconcentraciones y números de Nusselt y de Sherwood en regiones características para el problema de flujo interno mixto con difusión de calor y masa.The present work shows the relationship of the transport of heat and mass (double in a rectangular cavity caused by a forced and natural convection. The mathematical model consists of the Navier-Stokes equations to describe the incompressible laminar flow. The transport of heat and mass are modelled through two second order no-linear differential equations, incorporating in linear way the effects of gradients of concentrations and temperature. The mathematical problems is solved numerically through the Finite Volumes Method, in curvilinear coordinated and co-located variables, representing the diffusion through central difference and using a potential schemes for the convection terms. Original results of flow models are shown: Isotherms, isoconcentrations and numbers of Nusselt and Sherwood in characteristic regions for the mixed internal flow problem with heat and mass are shown.

  6. Caracterización estacional del hábitat fluvial del río Erro (Navarra

    Directory of Open Access Journals (Sweden)

    P.M. Leunda, R. Miranda, M.C. Escala

    2004-01-01

    Full Text Available Se presenta la descripción de catorce tramos representativos del río Erro (Navarra a partir de la caracterización del hábitat fluvial llevada a cabo en invierno, verano y otoño de 2002. Para este estudio se han considerado parámetros tanto del hábitat físico (profundidad, anchura del cauce, pendiente de las orillas, velocidad del agua, tipo de sustrato, vegetación acuática y sombreado como físico-químicos del agua (temperatura, pH, conductividad, sólicos disueltos y oxigeno disuelto. El análisis de las caracteristicas del rio Erro permite considerar su estado general como bueno, aunque se detecta la presencia de un tramo sensible aguas abajo de la localidad de Erro. Si bien este tramo sensible presenta niveles de conservación aceptables, es susceptible de deteriorarse si no de adoptan las medidas oportunas para su conservación. Se sugiere su inclusión en el Lugar de Interés Comunitario (Red Natura 2000 de Navarra de los "Sistemas Fluviales de lis Ríos Irati, Urrobi y Erro".

  7. Pensamiento y lenguaje: una propuesta de intervención en un programa de verano a través de rutinas de pensamiento

    OpenAIRE

    Bartolomé Álvarez, Andrea Aida

    2017-01-01

    Existe una gran relación entre el lenguaje y el pensamiento, ya que ambos dependen directamente entre ellos, aspecto fundamental a consideran sobre todo durante su periodo de desarrollo. Pretendemos profundizar en estos dos temas importantes, partiendo de bases teóricas sobre el pensamiento, para a continuación hablar del lenguaje y finalmente ver la relación que existe entre ellas. Lo fundamental cuando tratamos con niños es la intervención educativa, que debemos basar siempre en unos ...

  8. Comportamiento ecofisiológico de cultivares de coliflor (Brassica Oleracea Linn. Var Botrytis) de verano-otoño en clima templado

    OpenAIRE

    Dovis, Verónica Lorena

    2009-01-01

    El cultivo de la coliflor, que se encuentra presente en la mayoría de los planteos productivos del cinturón hortícola santafesino (Santa Fe, Argentina), presenta requerimientos ambientales que dificultan la obtención de un producto de buena calidad durante la época estival. Si bien existen cultivares recomendados para estas condiciones, aún existe incertidumbre acerca de los factores que influyen sobre la formación de la pella. El objetivo de este trabajo fue estudiar los efectos de la temper...

  9. SirT1 regulates energy metabolism and response to caloric restriction in mice.

    Directory of Open Access Journals (Sweden)

    Gino Boily

    Full Text Available The yeast sir2 gene and its orthologues in Drosophila and C. elegans have well-established roles in lifespan determination and response to caloric restriction. We have studied mice carrying two null alleles for SirT1, the mammalian orthologue of sir2, and found that these animals inefficiently utilize ingested food. These mice are hypermetabolic, contain inefficient liver mitochondria, and have elevated rates of lipid oxidation. When challenged with a 40% reduction in caloric intake, normal mice maintained their metabolic rate and increased their physical activity while the metabolic rate of SirT1-null mice dropped and their activity did not increase. Moreover, CR did not extend lifespan of SirT1-null mice. Thus, SirT1 is an important regulator of energy metabolism and, like its orthologues from simpler eukaryotes, the SirT1 protein appears to be required for a normal response to caloric restriction.

  10. Dietary restriction with and without caloric restriction for healthy aging [version 1; referees: 3 approved

    Directory of Open Access Journals (Sweden)

    Changhan Lee

    2016-01-01

    Full Text Available Caloric restriction is the most effective and reproducible dietary intervention known to regulate aging and increase the healthy lifespan in various model organisms, ranging from the unicellular yeast to worms, flies, rodents, and primates. However, caloric restriction, which in most cases entails a 20–40% reduction of food consumption relative to normal intake, is a severe intervention that results in both beneficial and detrimental effects. Specific types of chronic, intermittent, or periodic dietary restrictions without chronic caloric restriction have instead the potential to provide a significant healthspan increase while minimizing adverse effects. Improved periodic or targeted dietary restriction regimens that uncouple the challenge of food deprivation from the beneficial effects will allow a safe intervention feasible for a major portion of the population. Here we focus on healthspan interventions that are not chronic or do not require calorie restriction.

  11. Teoria Construtal e desempenho térmico de Trocadores de Calor Solo-Ar

    OpenAIRE

    Ruth da Silva Brum

    2016-01-01

    Trocadores de Calor Solo-Ar (TCSA) são dispositivos usados para melhorar o condicionamento térmico de ambientes construídos. Eles funcionam através da ventilação do ar por um ou mais dutos enterrados, utilizando o solo como fonte ou sumidouro de calor. Em virtude da defasagem entre as temperaturas do ar e das camadas superficiais da Terra, é possível resfriar o ar no verão e aquecê-lo no inverno. Seus princípios de operação baseiam-se na mecânica dos fluidos e transferência de calor, áreas on...

  12. La industria achelense del «Teso de San Francisco» (Ciudad Rodrigo, Salamanca

    Directory of Open Access Journals (Sweden)

    José Ignacio MARTÍN BENITO

    2009-12-01

    Full Text Available El conjunto arqueológico que aquí presentamos fue hallado por nosotros en el verano de 1982, dentro de una sistemática campaña de prospecciones que desde hace varios años venimos realizando en el valle del río Águeda, con el fin de poder conocer y establecer una secuencia de las industrias achelenses que nos permita tener un apoyo de base en el estudio de otros complejos similarmente culturales de otras áreas o regiones de la cuenca del Duero, y contribuir, de esta manera, a un mayor conocimiento del Paleolítico Inferior en la meseta duriense.

  13. Sex and race differences in caloric intake during sleep restriction in healthy adults.

    Science.gov (United States)

    Spaeth, Andrea M; Dinges, David F; Goel, Namni

    2014-08-01

    Evidence indicates that men and African Americans may be more susceptible to weight gain resulting from sleep loss than women and whites, respectively. Increased daily caloric intake is a major behavioral mechanism that underlies the relation between sleep loss and weight gain. We sought to assess sex and race differences in caloric intake, macronutrient intake, and meal timing during sleep restriction. Forty-four healthy adults aged 21-50 y (mean ± SD: 32.7 ± 8.7 y; n = 21 women, n = 16 whites) completed an in-laboratory protocol that included 2 consecutive baseline nights [10 or 12 h time in bed (TIB)/night; 2200-0800 or 2200-1000] followed by 5 consecutive sleep-restriction nights (4 h TIB/night; 0400-0800). Caloric intake and meal-timing data were collected during the 2 d after baseline sleep and the first 3 d after sleep restriction. During sleep restriction, subjects increased daily caloric intake (P sleep restriction, exhibited a greater increase in caloric intake during sleep restriction (d = 0.62), and consumed a higher percentage of daily calories during late-night hours (d = 0.78, Ps sleep restriction, or meal timing. However, African Americans consumed more carbohydrates, less protein, and more caffeine-free soda and juice than whites did during the study (Ps sleep loss than women due to a larger increase in daily caloric intake, particularly during late-night hours. These findings are relevant to the promotion of public health awareness by highlighting nutritional risk factors and modifiable behaviors for weight gain related to sleep-wake timing. © 2014 American Society for Nutrition.

  14. Moderate exercise training and chronic caloric restriction modulate redox status in rat hippocampus.

    Science.gov (United States)

    Santin, Katiane; da Rocha, Ricardo Fagundes; Cechetti, Fernanda; Quincozes-Santos, André; de Souza, Daniela Fraga; Nardin, Patrícia; Rodrigues, Letícia; Leite, Marina Concli; Moreira, José Cláudio Fonseca; Salbego, Christianne Gazzana; Gonçalves, Carlos Alberto

    2011-11-03

    Physical activity has been related to antioxidant adaptations, which is associated with health benefits, including those to the nervous system. Additionally, available data suggest exercise and a caloric restriction regimen may reduce both the incidence and severity of neurological disorders. Therefore, our aim was to compare hippocampal redox status and glial parameters among sedentary, trained, caloric-restricted sedentary and caloric-restricted trained rats. Forty male adult rats were divided into 4 groups: ad libitum-fed sedentary (AS), ad libitum-fed exercise training (AE), calorie-restricted sedentary (RS) and calorie-restricted exercise training (RE). The caloric restriction (decrease of 30% in food intake) and exercise training (moderate in a treadmill) were carried out for 3 months. Thereafter hippocampus was surgically removed, and then redox and glial parameters were assessed. Increases in reduced glutathione (GSH) levels and total antioxidant reactivity (TAR) were observed in AE, RS and RE. The nitrite/nitrate levels decreased only in RE. We found a decrease in carbonyl content in AE, RS and RE, while no modifications were detected in thiobarbituric acid reactive substances (TBARS). Total reactive antioxidant potential (TRAP), superoxide dismutase (SOD) activity, S100B and glial fibrilary acid protein (GFAP) content did not change, but caloric restriction was able to increase glutamine synthetase (GS) activity in RS and glutamate uptake in RS and RE. Exercise training, caloric restriction and both combined can decrease oxidative damage in the hippocampus, possibly involving modulation of astroglial function, and could be used as a strategy for the prevention of neurodegenerative diseases. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Postoral glucose sensing, not caloric content, determines sugar reward in C57BL/6J mice.

    Science.gov (United States)

    Sclafani, Anthony; Zukerman, Steven; Ackroff, Karen

    2015-05-01

    Recent studies suggest that because of their energy value, sugars are more rewarding than non-caloric sweeteners. However, intragastric infusion data indicate that sugars differ in their postoral appetite-stimulating effects. We therefore compared the preference for isocaloric 8% sucrose, glucose, and fructose solutions with that of a non-caloric sweetener solution (0.8% sucralose) in C57BL/6J mice. Brief 2-bottle tests indicated that sucralose was isopreferred to sucrose but more preferred than glucose or fructose. Yet, in long-term tests, the mice preferred sucrose and glucose, but not fructose to sucralose. Additional experiments were conducted with a non-caloric 0.1% sucralose + 0.1% saccharin mixture (S + S), which does not have the postoral inhibitory effects of 0.8% sucralose. The S + S was preferred to fructose in brief and long-term choice tests. S + S was also preferred to glucose and sucrose in brief tests, but the sugars were preferred in long-term tests. In progressive ratio tests, non-deprived and food-deprived mice licked more for glucose but not fructose than for S + S. These findings demonstrate that the nutrient-specific postoral actions, not calories per se, determine the avidity for sugar versus non-caloric sweeteners. Furthermore, sweet taste intensity and potential postoral inhibitory actions must be considered in comparing non-caloric and caloric sweeteners. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. High-throughput search for caloric materials: the CaloriCool approach

    Science.gov (United States)

    Zarkevich, N. A.; Johnson, D. D.; Pecharsky, V. K.

    2018-01-01

    The high-throughput search paradigm adopted by the newly established caloric materials consortium—CaloriCool®—with the goal to substantially accelerate discovery and design of novel caloric materials is briefly discussed. We begin with describing material selection criteria based on known properties, which are then followed by heuristic fast estimates, ab initio calculations, all of which has been implemented in a set of automated computational tools and measurements. We also demonstrate how theoretical and computational methods serve as a guide for experimental efforts by considering a representative example from the field of magnetocaloric materials.

  17. Effect of consuming different caloric sweeteners on bone health and possible mechanisms.

    Science.gov (United States)

    Tsanzi, Embedzayi; Fitch, Cindy W; Tou, Janet C

    2008-06-01

    Western diets are high in caloric sweeteners and since the 1980s there has been a shift from the use of sucrose as the predominant sweetener to high-fructose corn syrup. This may have important implications for bone, as sugar consumption has been shown to negatively impact mineral balance. This article reviews the existing scientific evidence regarding the effect of caloric sweeteners and the type of sweetener on bone health and the potential mechanisms of action. A better understanding of the role of sugar consumption on mineral balance and bone can contribute to the determination of dietary recommendations to reduce bone loss and the future risk of osteoporosis.

  18. Isotermas e calor isostérico de sementes de Buchenavia capitata (Vahl) Eichler

    OpenAIRE

    Costa,Lílian Moreira; Resende,Osvaldo; Oliveira,Daniel Emanuel Cabral de; Sousa,Kelly Aparecida de

    2015-01-01

    RESUMODiante da importância do conhecimento da higroscopicidade e do calor isostérico para as operações de secagem e armazenamento, objetivou-se neste trabalho determinar as isotermas de dessorção de sementes de Buchenavia capitata (Vahl) Eichler, bem como ajustar diferentes modelos matemáticos aos dados experimentais, selecionando aquele que melhor representa o fenômeno e, assim, utilizá-lo para determinar o calor isostérico de dessorção. Para obtenção do teor de água de equilíbrio higroscóp...

  19. Effects of Experimental Sleep Restriction on Weight Gain, Caloric Intake, and Meal Timing in Healthy Adults.

    Science.gov (United States)

    Spaeth, Andrea M; Dinges, David F; Goel, Namni

    2013-07-01

    Examine sleep restriction's effects on weight gain, daily caloric intake, and meal timing. Repeated-measures experiments assessing body weight at admittance and discharge in all subjects (N = 225) and caloric intake and meal timing across days following 2 baseline nights, 5 sleep restriction nights and 2 recovery nights or across days following control condition nights in a subset of subjects (n = 37). Controlled laboratory environment. Two hundred twenty-five healthy adults aged 22-50 y (n = 198 sleep-restricted subjects; n = 31 with caloric intake data; n = 27 control subjects; n = 6 with caloric intake data). Approximately 8-to-1 randomization to an experimental condition (including five consecutive nights of 4 h time in bed [TIB]/night, 04:00-08:00) or to a control condition (all nights 10 h TIB/night, 22:00-08:00). Sleep-restricted subjects gained more weight (0.97 ± 1.4 kg) than control subjects (0.11 ± 1.9 kg; d = 0.51, P = 0.007). Among sleep-restricted subjects, African Americans gained more weight than Caucasians (d = 0.37, P = 0.003) and males gained more weight than females (d = 0.38, P = 0.004). Sleep-restricted subjects consumed extra calories (130.0 ± 43.0% of daily caloric requirement) during days with a delayed bedtime (04:00) compared with control subjects who did not consume extra calories (100.6 ± 11.4%; d = 0.94, P = 0.003) during corresponding days. In sleep-restricted subjects, increased daily caloric intake was due to more meals and the consumption of 552.9 ± 265.8 additional calories between 22:00-03:59. The percentage of calories derived from fat was greater during late-night hours (22:00-03:59, 33.0 ± 0.08%) compared to daytime (08:00-14:59, 28.2 ± 0.05%) and evening hours (15:00-21:59, 29.4 ± 0.06%; Ps sleep restriction promoted weight gain. Chronically sleep-restricted adults with late bedtimes may be more susceptible to weight gain due to greater daily caloric intake and the consumption of calories during late-night hours

  20. Normal physical activity obliterates the deleterious effects of high-caloric intake

    DEFF Research Database (Denmark)

    Krogh-Madsen, Rikke; Pedersen, Maria; Solomon, Thomas

    2013-01-01

    A high-caloric intake combined with a sedentary lifestyle is an important player in the development of type 2 diabetes mellitus (T2DM). The present study was undertaken to examine if the level of physical activity has impact on the metabolic effects of a high-caloric (+2,000 kcal/day) intake...... function with regard to capacity of attention. In conclusion, we find evidence to support that habitual physical activity may prevent pathophysiological symptoms associated with diet-induced obesity....

  1. Adapter, c’est (parfois) trahir : fiction et stéréotypes de genre dans les séries inspirées de Diario de una abuela de verano de Rosa Regàs et El mundo amarillo d’Albert Espinosa

    OpenAIRE

    Houdiard, Jennifer

    2017-01-01

    Les séries Abuela de verano (TVE, 2005) et Polseres vermelles (TV3, 2011-2013) sont deux fictions télévisées inspirées d’ouvrages non fictionnels. La première est l’adaptation de Diario de una abuela de verano, un essai-témoignage dans lequel la romancière Rosa Regàs relate son expérience de grand-mère. Dans El mundo amarillo, œuvre qui a inspiré la série Polseres vermelles, le réalisateur et comédien Albert Espinosa évoque le bouleversement qu’a provoqué le cancer dans sa vie d’adolescent, l...

  2. Effects of a Canary pine forest wildfire (Tenerife, Canary Islands, summer 2007 on selected soil properties and their relationship with short- to medium-term soil water repellency Efectos de un incendio forestal (Tenerife, Islas Canarias, verano de 2007 bajo bosques de pinar sobre algunas propiedades del suelo y su relación con la repelencia al agua a corto y medio plazo Efeitos dum incéndio (Tenerife, Ilhas Canárias, verão 2007 em florestas de pinheiros sobre algunas propriedades do solo, e sua relação com a repelência à água de curto e médio prazo

    Directory of Open Access Journals (Sweden)

    Alexis Hernández

    2013-03-01

    Full Text Available Forest fires modify the soil environment, often triggering severe soil degradation. In this paper, we studied the impact of a large northern Tenerife Canariy pine forest wildfire on a set of relevant soil properties, focusing on their evolution in time and relationship with soil water repellency. To do this, soils were sampled at four sites (burned and non-burned and several soil physical and chemical parameters were measured. The results show significant variations for soil pH, electric conductivity (CE1:5, and NH4+-N between burned and non-burned samples, whereas non-significant increases were found in burned soils for oxidizable carbon (Cox, total nitrogen (Ntot , Ca2+, Mg2+, Na+ and K+, and soil hydrophobicity. The differences caused by the fire were no longer evident one year later. Furthermore, in one sampling site (Vitric Leptosols under low pine forest with a mixed heath/beech tree understory a wide variation in the content of Cox and Ntot and high water repellency was observed relative to the other sites. These differences can be attributed to the composition of the understory vegetation. Significant correlations between soil hydrophobicity with CE1:5, aggregate stability and the contents of Cox, Ntot, NH4+-N, Ca2+, Mg2+, Na+ and K+ were found.Los incendios forestales alteran las propiedades de los suelos, llegando en ocasiones a desencadenar severos procesos de degradación. En este trabajo se evalúa el impacto sobre algunas propiedades fisicoquímicas en suelos afectados por un incendio bajo bosque de pinar canario en el norte de Tenerife, así como su evolución temporal y la posible relación con la repelencia al agua del suelo. Para ello, se han muestreado cuatro ubicaciones (quemadas y no quemadas en las que se han medido parámetros físicos y químicos relevantes del suelo. Los resultados muestran variaciones significativas en los valores de pH, conductividad eléctrica (C.E.1:5, y NH4+-N. También se han detectado aumentos, en

  3. Solución numérica de procesos de transferencia de calor en aleaciones con condiciones de contorno no lineales

    Directory of Open Access Journals (Sweden)

    Alhama, F.

    2005-12-01

    Full Text Available Thermal properties of a great number of alloys, especially specific heat, show a sharply temperature dependence both during the phase change and the allotropic transformations. This fact, in conjunction with the existence of convection or radiation boundary conditions, or both simultaneously, increase the complexity of the transient heat transfer problem because of the inherent no linearity. The numerical model proposed for the solution of this problem is able to assume the above hypothesis as well as the temperature dependencies of the thermal conductivity. Applications to alloys are presented.

    Las propiedades térmicas de numerosas aleaciones, especialmente la capacidad calorífica, acusan una marcada dependencia con la temperatura tanto en los cambios de fase como en las transformaciones alotrópicas. Este hecho, junto con la aplicación de condiciones de contorno de convección, radiación o ambas, simultáneamente, aumentan la complejidad del problema de transferencia de calor en los procesos transitorios debido a la no linealidad inherente. El modelo numérico propuesto para la solución de este problema es capaz de asumir las hipótesis anteriores así como las posibles dependencias de la conductividad térmica con la temperatura. Se presentan aplicaciones a procesos térmicos en aleaciones.

  4. Modelación de la transferencia de calor y masa en el absorbedor de una máquina de refrigeración por absorción. Resultados para un banco de tubos. // Heat and mass transference modeling in the absorbent of an absorbator cooling machine.( Results for a bank

    Directory of Open Access Journals (Sweden)

    C. A. Cisneros Ramírez

    2002-05-01

    Full Text Available En este artículo se presenta el comportamiento de la temperatura, la concentración y el coeficiente de traspaso de calor,tanto local como promedio, durante el proceso de absorción sobre un banco de tubos. Además se presenta la ecuaciónobtenida a partir del modelo presentado en artículos anteriores, que caracteriza el comportamiento del producto delcoeficiente global de traspaso de calor (U por el área de traspaso de calor (A para el banco de tubos.Palabras claves: Modelación, absorbedores, refrigeración por absorción, transferencia de calor y masa.______________________________________________________________________Abstract.This article deals with the performance of temperature, concentration and heat and mass transfer coefficient ( both, globaland local during the absorption process in a tube bank. Also, the equation for the value of the UA product in the absorberis given.Key words: Model, absorber, absorption refrigeration, heat and mass transference.

  5. Effect of Replacing Sugar with Non-Caloric Sweeteners in Beverages on the Reward Value after Repeated Exposure

    NARCIS (Netherlands)

    Griffioen-Roose, S.; Smeets, P.A.M.; Weijzen, P.L.G.; Rijn, van I.; Bosch, van den I.; Graaf, de C.

    2013-01-01

    Background: The reward value of food is partly dependent on learned associations. It is not yet known whether replacing sugar with non-caloric sweeteners in food is affecting long-term acceptance. Objective: To determine the effect of replacing sugar with non-caloric sweeteners in a nutrient-empty

  6. DESHIDRATACION Y SOBREHIDRATACION VOLUNTARIAS DURANTE EL EJERCICIO EN EL CALOR: POSIBLES FACTORES RELACIONADOS

    Directory of Open Access Journals (Sweden)

    Andrea Solera Herrera

    2006-12-01

    Full Text Available Los efectos negativos de la deshidratación sobre la salud y el rendimiento han sido bien documentados. Recientemente, también se han documentado problemas por sobrehidratación. La presente investigación se hizo para estudiar los posibles factores que influyen sobre la ingesta voluntaria de líquido durante el ejercicio y determinar si existe relación entre el grado de deshidratación voluntaria y la creencia de que la ingesta de líquido provoca cólico. Para ello, se contó con 94 estudiantes universitarios jóvenes, varones, quienes se ejercitaron a un 60% de su FCmáx durante una hora, alternando cada 10 min. entre bicicleta estacionaria, subir y bajar un escalón, y una máquina simuladora de esquí. Esto se realizó en un laboratorio de ambiente controlado a 30úC, 70% humedad relativa. Durante el ejercicio se midió la ingesta voluntaria de una bebida deportiva, así como también las percepciones de calor ambiental, llenura estomacal, malestar gastrointestinal y palatabilidad de la bebida. Los sujetos fueron pesados desnudos y secos antes y después del ejercicio. Al final se les aplicó un cuestionario sobre la importancia de la hidratación, y sus creencias sobre el cólico. El equilibrio hídrico promedio fue de 0.14 ± 0.98% del peso corporal, con un rango entre -2.38% y 2.84%. La tasa de sudoración promedio fue de 1208.3 ± 381.7ml·h-1; y la ingesta de 1132 ± 610ml·h-1. Dos análisis de regresión múltiple determinaron que: (a los predictores más fuertes de la ingesta voluntaria de líquido fueron la importancia asignada a la hidratación durante el ejercicio (R2 = 0.13; p < 0.0005 y la percepción de llenura estomacal al minuto 25 (R2 = 0.08; p = 0.005; (b los predictores más fuertes del equilibrio hídrico fueron la ingesta voluntaria por kg de peso (R2 = 0.73; p < 0.0005, y la tasa de sudoración (R2 = 0.08; p = 0.006. No obstante, el equilibrio hídrico no estuvo asociado con ninguna de las percepciones, ni con las

  7. Transferencia de calor y su efecto en el proceso de prensado de tableros contrachapados

    Directory of Open Access Journals (Sweden)

    D. Zavala Zavala

    2004-01-01

    Full Text Available El proceso de prensado determina la calidad de los contrachapados (triplay a través de la interrelación de las propiedades tecnológicas de la madera, de las características de los adhesivos y de la interacción de la temperatura y presión que se generan en la prensa. Este trabajo se realizó con la finalidad de analizar el efecto de la transferencia de calor en la polimerización de adhesivos preparados con urea y fenol formaldehído, para determinar la secuela optima de prensado de triplay de 6, 9, 12, 15, 18 y 34 mm de espesor; y para evaluar la compactación de los tableros por efecto de la temperatura y presión durante el prensado. Se utilizó chapa de Pinus herrerai Martínez, P. michoacana Martínez y P. pseudostrobus Lindl., a un contenido de humedad de 6 a 8 %, una prensa calentada con vapor, adhesivo de urea formaldehído para tableros para interiores de 6, 9, 12, 15 y 18 mm y fenol formaldehído para triplay para exteriores de 34 mm de espesor. Se utilizaron ciclos de prensado aplicando temperaturas de 115, 130 y 140 °C y presiones de 10.62 kg·cm-2 (151 psi y 8.51 kg·cm-2 (121 psi en triplay para interiores, y para los tableros tipo exterior de 140, 150 y 160 °C de temperatura y 12.23, 13.29 y 14.34 kg·cm-2 (174, 189 y 204 psi de presión. La temperatura de las líneas de pegamento más externas aumenta rápidamente al cerrarse la prensa y manifiesta una diferencia en relación a las más internas, que tiende a reducirse conforme transcurre el tiempo de prensado, igualándose aproximadamente al 73 % del tiempo para cada tipo de tablero. A través de la evaluación de adhesión de los pegamentos de los tableros para interiores con la norma PS1-95, se determinó que todos pasan las especificaciones requeridas para ese uso En los tableros de 34 mm de espesor, con un incremento de la temperatura de 140 a 160 °C, una presión de 12.23 a 14.34 kg·cm-2 (174 a 204 psi y un contenido de sólidos del fenol formaldehído de 29.9 a 32

  8. Efecto de una doble concentración de bióxido de carbono en la atmósfera sobre la disponibilidad de agua en la cuenca del río Guayalejo-Tamesí en el estado de Tamaulipas, México.

    Directory of Open Access Journals (Sweden)

    Pedro Estrada Bellmann

    2003-11-01

    Full Text Available La utilización de combustible fósil para uso industrial y doméstico, así como la quema de biomasa, producen gases de efecto invernadero que absorben y emiten la radiación infrarroja en todas direcciones y atrapan el calor en la atmósfera, originando el cambio climático global. Además de modificar la temperatura, este fenómeno altera la precipitación y humedad atmosférica, el nivel del mar, los patrones de circulación atmosférica y oceánica, la extensión de la cubierta de hielo y nieve y la presencia de eventos extremos. Para hacer frente a este fenómeno y proponer medidas de adaptación y mitigación, en México se llevó a cabo el Estudio de País, cuyo objetivo principal fue la construcción de escenarios de cambio climático regional. Sin embargo, las resoluciones espacial y temporal empleadas en el mismo, impiden su aplicación directa en modelos de balance hidrológico a nivel subcuenca, por lo cual se plantea la realización del presente estudio. Este tiene como objetivo estimar la disponibilidad de agua actual y la proyectada para una doble concentración de bióxido de carbono en la atmósfera, sobre una base estacional, en ocho regiones de la cuenca del Río Guayalejo. Para ello, se desarrollaron ecuaciones de regresión múltiple, relacionando la temperatura y precipitación de cada zona con variables de gran escala. Posteriormente, éstas se aplicaron en el Modelo del Sistema para la Comunidad Climática en su versión 2.0.1, del Centro Nacional para la Investigación Atmosférica, con el fin de obtener las proyecciones de la temperatura y precipitación de cada zona. Los resultados presentan una disminución de la precipitación en la cuenca de 9.49% y un incremento máximo en la temperatura de 1.76°C durante el verano. Sin embargo, se proyecta un incremento de un 15% en la precipitación de invierno y de un 12% anual para la subcuenca del Río Comandante, con disminuciones considerables en el resto de las estaciones

  9. Influenza pandemic (H1N1 2009 activity during summer 2009: Effectiveness of the 2008-9 trivalent vaccine against pandemic influenza in Spain Actividad de la gripe pandémica (H1N1 2009 durante el verano de 2009: Efectividad de la vacuna trivalente 2008-9 frente a la gripe pandémica en España

    Directory of Open Access Journals (Sweden)

    Amparo Larrauri

    2011-02-01

    Full Text Available Introduction: The Spanish influenza surveillance system (SISS maintained its activity during the summer of 2009 to monitor the influenza pandemic. Objectives: To describe pandemic influenza activity from May to September 2009 and to estimate the effectiveness of the 2008-9 seasonal influenza vaccine against laboratory-confirmed pandemic (H1N1 2009 influenza. Methods: Data from the SISS were used to identify the trend of pandemic (H1N1 2009 influenza outside the influenza season. For the effectiveness study, we compared the vaccination status of notified cases [influenza-like illnesses (ILI laboratory confirmed as pandemic influenza] with that of the test-negative controls. Results: The first laboratory-confirmed case of the pandemic virus was notified in the system in week 20/2009. The ILI rate increased gradually in the study period, exceeding basic activity in week 38. The proportion of pandemic (H1N1 2009 influenza viruses detected by the system represented 14% in week 20/2009 and rapidly increased to 90% in week 34. The adjusted vaccine effectiveness of the 2008-9 seasonal vaccine against laboratory-confirmed pandemic influenza was 12% (-30; 41. Conclusions: The SISS became an essential tool for pandemic monitoring in Spain. The improved SISS will provide more accurate information on influenza activity in future seasonal or pandemic waves. Using surveillance data, we could not demonstrate the effectiveness of the seasonal 2008-9 vaccine against laboratory-confirmed pandemic influenza.Introducción: El Sistema de Vigilancia de Gripe en España (SVGE continuó y reforzó su actividad durante el verano de 2009 con el objetivo de vigilar la evolución de la pandemia en España. Objetivos: Describir la actividad de la gripe pandémica en España de mayo a septiembre de 2009 y estimar la efectividad de la vacuna antigripal estacional 2008-2009 frente a casos confirmados de gripe pandémica (H1N1 2009. Métodos: Se utilizaron datos del SVGE para

  10. Thermoregulatory, Cardiovascular, and Metabolic Responses to Mild Caloric Restriction in the Brown Norway Rat

    Science.gov (United States)

    Caloric restriction (CR) has been demonstrated to prolong the life span of a variety of species. CR-induced reduction in core temperature (Tc) is considered a key mechanism responsible for prolonging life span in rodents; however, little is known on the regulation of CR-induced h...

  11. Biochemical composition and caloric potential of zooplankton from Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Sreepada, R.A.; Rivonker, C.U.; Parulekar, A.H.

    .62, 4.95, 1.54, 0.43, 4.4 and 4.16 respectively on wet weight basis. A good correlation of caloric potential with protein and lipid indicated to a certain extent that protein and lipid act as metabolic reserves of the zooplankton in the area...

  12. Effects of Caloric Restriction on Cardiac Oxidative Stress and Mitochondrial Bioenergetics: Potential Role of Cardiac Sirtuins

    Directory of Open Access Journals (Sweden)

    Ken Shinmura

    2013-01-01

    Full Text Available The biology of aging has not been fully clarified, but the free radical theory of aging is one of the strongest aging theories proposed to date. The free radical theory has been expanded to the oxidative stress theory, in which mitochondria play a central role in the development of the aging process because of their critical roles in bioenergetics, oxidant production, and regulation of cell death. A decline in cardiac mitochondrial function associated with the accumulation of oxidative damage might be responsible, at least in part, for the decline in cardiac performance with age. In contrast, lifelong caloric restriction can attenuate functional decline with age, delay the onset of morbidity, and extend lifespan in various species. The effect of caloric restriction appears to be related to a reduction in cellular damage induced by reactive oxygen species. There is increasing evidence that sirtuins play an essential role in the reduction of mitochondrial oxidative stress during caloric restriction. We speculate that cardiac sirtuins attenuate the accumulation of oxidative damage associated with age by modifying specific mitochondrial proteins posttranscriptionally. Therefore, the distinct role of each sirtuin in the heart subjected to caloric restriction should be clarified to translate sirtuin biology into clinical practice.

  13. Caloric variability of Corbicula fluminea (Mollusca, Bivalvia in Rosana Reservoir, Brazil

    Directory of Open Access Journals (Sweden)

    Yara Moretto Bagatini

    2007-01-01

    Full Text Available The purpose of the present study was to investigate temporal and longitudinal variation of caloric density of Corbicula fluminea in Rosana Reservoir. Significant differences concerning the caloric density of C. fluminea were observed throughout the year at the three reservoir sites. The caloric density variation during the year was probably related to reproductive activity, which demanded higher allocation of energy in certain period. The food source used by this species might be an important factor in the caloric value temporal and spatial variation of C. fluminea in Rosana Reservoir.O objetivo deste estudo foi investigar a variação temporal e longitudinal da densidade calórica de C. fluminea no reservatório de Rosana. Diferenças significativas na densidade calórica de C. fluminea foram observadas ao longo do ano e nas três estações do reservatório. A variação na densidade calórica de C. fluminea, durante o ano, provavelmente foi relacionada à atividade reprodutiva, que exige uma maior alocação de energia em determinado período. O recurso alimentar utilizado por esta espécie pode ser um importante fator na variação temporal e espacial do valor calórico de C. fluminea no reservatório de Rosana.

  14. Benefits of caloric restriction in the myenteric neuronal plasticity in aging rats

    Directory of Open Access Journals (Sweden)

    JOICE N.B. PEREIRA

    2014-09-01

    Full Text Available Aging is a biologic process characterized by progressive damage of structures and functions of organic systems. In gastrointestinal tract, it can involve enteric nervous system, which plays an important role in digestion and absorption of nutrients, causing hastening of intestinal transit thus reducing its absorptive function. Caloric restriction has been used in several studies with the intention of delaying deleterious effects of aging. This study aimed to evaluate the effects of caloric restriction on myenteric neurons of ileum by aging in rats. 30 Wistar rats were grouped as follows: GI (animals aged 6 months fed with normal diet, GII (animals aged 18 months fed with normal diet and GIII (animals aged 18 months subject to 31% of caloric restriction. The rats of the GI group were euthanized at 6 months of age and after experimental period of 12 months animals of the group GII and GIII were euthanized, the ileum of all groups were collected, measured and processed by NADPH-dp and Acetylcholinesterase. Quantitative analysis of neurons revealed that aging promotes the increasing of myenteric neurons NADPH-dp and reduces Acetylcholinesterase neuronal population. However, in the cellular profile area, were not observed significant differences between the groups. The caloric restriction has been efficient and can be used preventively because it minimizes quantitative changes associated with aging on ileum myenteric plexuses.

  15. Benefits of caloric restriction in the myenteric neuronal plasticity in aging rats.

    Science.gov (United States)

    Pereira, Joice N B; Mari, Renata B; Stabille, Sandra R; de Faria, Haroldo G; Mota, Thais F M; Ferreira, Walter M

    2014-09-01

    Aging is a biologic process characterized by progressive damage of structures and functions of organic systems. In gastrointestinal tract, it can involve enteric nervous system, which plays an important role in digestion and absorption of nutrients, causing hastening of intestinal transit thus reducing its absorptive function. Caloric restriction has been used in several studies with the intention of delaying deleterious effects of aging. This study aimed to evaluate the effects of caloric restriction on myenteric neurons of ileum by aging in rats. 30 Wistar rats were grouped as follows: GI (animals aged 6 months fed with normal diet), GII (animals aged 18 months fed with normal diet) and GIII (animals aged 18 months subject to 31% of caloric restriction). The rats of the GI group were euthanized at 6 months of age and after experimental period of 12 months animals of the group GII and GIII were euthanized, the ileum of all groups were collected, measured and processed by NADPH-dp and Acetylcholinesterase. Quantitative analysis of neurons revealed that aging promotes the increasing of myenteric neurons NADPH-dp and reduces Acetylcholinesterase neuronal population. However, in the cellular profile area, were not observed significant differences between the groups. The caloric restriction has been efficient and can be used preventively because it minimizes quantitative changes associated with aging on ileum myenteric plexuses.

  16. Influencia del calor y del aclarado sobre la germinación de Cistus laurifolius y Cistus ladanifer

    OpenAIRE

    Valbuena, L.; Alonso, I.; Tárrega, R.; Luis, E.

    1992-01-01

    The aim of this study is to determine if the increase of the temperature of the soil while a wildfire improves the germination of Cistus laurifolius and Cistus ladanifer. Laboratory experiments were carried out by heating the seeds to different temperatures and at different periods of time. On the other hand, the regeneration of both species in the field was studied in experimental plots that were subjected to prescribed burning, as well as to cutting of the aerial biomass. Cistus ladanifer r...

  17. Validation of a smooth configuration surface for compact heat exchangers using a numerical method//Validación de la superficie de un intercambiador de calor compacto en configuración lisa utilizando un método numérico

    Directory of Open Access Journals (Sweden)

    José‐L. Leiro‐Garrido

    2014-08-01

    Full Text Available This work determines the thermo hydraulics behavior of smooth configuration surface for a compact heat exchanger by means of numerical simulation. The objective is to use the results as baseline for research in the enhancement of heat transfer and drag reduction, directed to reduce the energy consumption and diminish the environmental impact. The fin tube heat exchanger models described.The constraints used in the implementation of the equation solver are announced. The average heat transfer coefficient and pressure drop obtained from numerical simulation are compare to experimental results presented in literature for models with the same dimensions and configuration. A good agreement between numerical and experimental results is reached. Local mechanisms responsible for the heat transfer and pressure drop are detailed. The study is conducted inside thelaminar regime for frontal velocities ranging between 0.5 and 6 m/s.Key words: compact heat exchanger, heat transfer coefficient, numerical simulation, pressure drop.______________________________________________________________________________ResumenEste trabajo determina el comportamiento termo hidráulico de una superficie perteneciente a un intercambiador de calor compacto en configuración lisa utilizando un método de simulación numérica. El objetivo es caracterizar la superficie para poder utilizarla como una referencia en las comparaciones con superficies de intercambio de calor intensificadas. Los datos obtenidos seutilizaran en la determinación de los valores relativos de intensificación de la transferencia de calor y el arrastre intentando reducir el consumo energético y su impacto ambiental. Se describe el modelo de intercambiador de calor con tubos aletados. Los resultados numéricos obtenidos presentan unbuen ajuste con los valores experimentales. Los resultados del coeficiente de transferencia de calor global y la caída de presión son explicados a partir de las

  18. La enseñanza de la educación física y el deporte en las colonias de vacaciones del municipio de Avellaneda

    OpenAIRE

    Ganz, Nancy; Bamonte, Luis; Benito, Francisco J.; Ronconi, Piero

    2013-01-01

    La presentación que a continuación se detalla, es una investigación que se propuso indagar aspectos relacionados con la enseñanza de la Educación Física y los deportes en las colonias de verano del Municipio de Avellaneda, las cuales, implementadas desde el gobierno local con fines inclusivos, reciben a sectores sociales en condiciones de vulnerabilidad. La relevancia de este trabajo se relaciona con dos ejes bien detallados, uno, con los aspectos vinculados a la educación no formal de la ...

  19. España y la política internacional del fin de la guerra civil al comienzo de la mundial

    OpenAIRE

    José Alfonso Durango

    1992-01-01

    No es ningún secreto que la guerra civil y la posición del nuevo Estado durante la segunda guerra mundial han acaparado la atención de la historiografía frente a los breves meses de paz durante la primavera y el verano de 1939, contemplados como un ínterin cuando no considerados de importancia secundaria. Sin embargo, si la política exterior debe contemplarse como un proceso estos meses adquieren una relevante importancia como gozne entre la guerra civil y la posición desde la que el régimen ...

  20. Software para la enseñanza de la dinámica y control de intercambiadores de calor de tubos y coraza

    Directory of Open Access Journals (Sweden)

    Fiderman Machuca

    2008-01-01

    Full Text Available Este trabajo presenta la estructura de un software desarrollado para la enseñanza y aprendizaje de la dinámica y control de intercambiadores de calor de tubos y coraza. El programa presenta, de manera numérica y gráfica, el comportamiento dinámico en lazo abierto y cerrado del proceso para diferentes parámetros de diseño y condiciones de operación variables. El software permite modificar condiciones tanto de operación como de diseño, por ejemplo, temperatura y caudales de entrada a los tubos y coraza, número y longitud de tubos, número de pasos, diámetro externo e interno de los tubos, diámetro interno de coraza y factor de ensuciamiento.

  1. The comparative effect of fasting with and without caloric restriction in Rat on oxidative stress parameters

    Directory of Open Access Journals (Sweden)

    Nurina Tyagita

    2016-09-01

    Full Text Available Introduction: Fasting, like Islamic Ramadan Fasting, has been associated with health benefits. Islamic Ramadan fasting, a form of caloric restriction (CR or alternate day fasting that. Studies suggest a comparable effect of ADF and caloric restriction. Despite the fact that fasting can be considered as a form of dietary restriction, fasters tend to have difficulty to reduce their food intake during non-fasting period by overeating leading to the excessive calorie intake. To compare the effect of fasting with and without caloric restriction in Sprague Dawley rats. Methods: The rats were assigned to one of three groups: ADF with 70 % calorie intake (30% CR, ADF with 100 % calorie intake (0% CR, and ADF with 140 % calorie intake (excessive calorie intake and AL (fed ad libitum. All groups were subjected to 6 hour fasting per day (9 a.m. until 3 p.m. or 15 days. The plasma sample was taken for MDA level assessment. Urinary 8-oxodG levels were determined by using ELISA. Results: ADF with 30% calorie restriction (F70 group had the lowest MDA level. Measurement of 8-oxodG level showed that group F70 had the highest production of 8-oxodG. There was an inverse relationship between MDA level and 8-oxodG level meaning the lower MDA level, the lower 8-oxodG levels were produced. Conclusion: ADF fasting with 30% caloric restriction reduce the MDA level but increase 8-oxodG levels. This study suggest the beneficial effect of fasting requires decrease in overall caloric intake.

  2. [Comparison of caloric responses between vestibular migraine and Ménière disease patients].

    Science.gov (United States)

    Yang, Yuechang; Zhuang, Jianhua; Zhou, Lili; Tong, Bei; Zhou, Xiaowen; Gao, Bo

    2016-01-01

    To compare the features of caloric tests in vestibular migraine (VM) and Menière's disease (MD) patients, and provide objective evidence for differentiating the 2 groups of patients. This case-control study included 11 MD patients with left ear involved and mild to moderate impaired hearing, and 18 matched cases with VM. All participants received caloric tests. Maximum slow phase velocities (SPVmax) were used to describe horizontal and vertical nystagmus respectively and were compared between the 2 groups. Horizontal and vertical canal parasis(CP) were calculated according to respective SPVmax. Unilateral (UW-VR) or bilateral (BW-VR) weakness of vestibular response, and positive unilateral (UVR) or bilateral (BVR) vertical response or negative bilateral vertical response (NBVR) were judged by the boundary point of SPVmax of 5°/s respectively. Total left (LV) or right (RV) Vertical reactions were calculated accoeding to vertical SPVmax,and inter ears difference of vertical responses (IED-VR) calculated from LV minus RV. There were no significant differences in age and gender between the 2 groups. Horizontal SPVmax of all of caloric tests of VM group,except the left cold (LC), were statistically larger than that of MD group (P VR and BW-VR in VM group (5.56%, 0) were significantly lower than that in MD group (27.27%, 18.18%) (P VR in VM group (left intenser: 16.67%, right intenser: 83.33%) was statistically different from that in MD group (left intenser: 36.36%, right intenser: 9.09%, both no difference: 54.55%) (P Vestibular responses of caloric test are more sensitive, and vertical reactions are more easily induced in VM patients than in MD. Caloric test can be used to differentiate the 2 groups of diseases.

  3. Focos de Calor na Mata Atlântica do Estado do Rio de Janeiro

    Directory of Open Access Journals (Sweden)

    Sara dos Santos Clemente

    Full Text Available Resumo O estudo avaliou a ocorrência de focos de calor nos remanescentes da Mata Atlântica no estado do Rio de Janeiro, sob o aspecto climático. As informações obtidas da base de dados BDQueimadas, do período de junho de 1998 a dezembro de 2015, sofreram estatística descritiva, exploratória e paramétrica. As maiores ocorrências de focos de calor foram registradas nos meses de agosto, setembro e outubro e, os anos com os maiores registros foram nos ciclos 2010/2011 (16,06% e 2014/2015 (41, 24%, ambos somaram 57,30% da série temporal, referente a La Niña e El Niño nas categorias forte e fraco. O teste paramétrico mostrou uma repetição dos meses de abril e junho nos anos avaliados na série temporal de focos de calor. As regiões de Governo Centro-Sul Fluminense e Médio Paraíba registraram os maiores registros de focos de calor, segundo a avaliação espacial. Nossos resultados demonstram que o acesso a uma base gratuita de dados permite a prevenção de danos causados pelas queimadas e incêndios. Com a evolução dos sensores de temperatura e de algoritmos de tratamento de dados, será possível diferenciar os focos de calor que representam incêndios e queimadas daqueles que indicam, por exemplo, atividade de indústrias.

  4. Method to allow the estimation of heat transfer coefficients in solar stills; Metodo para determinar coeficientes locales de transferencia de calor en destiladores solares

    Energy Technology Data Exchange (ETDEWEB)

    Rubio Cerda, Eduardo; Porta Gandara, Miguel A [CIBNOR, Mexico D.F (Mexico); Fernandez Zayas, Jose Luis [UNAM Mexico, D.F. (Mexico)

    2000-07-01

    This work reports an experimental method that allows to estimate the heat transfer coefficients in the neighborhood of walls or flat plates subject to convective transport phenomena. This method can be applied to a great variety of thermal systems since it is based on the knowledge of the border condition for the temperature at the surface of the plate, and the temperature profile that characterize the dimensionless coefficient of heat transfer in the fluid, according to its definition given by the Nusselt number. The approach of this work are the foundations of the method and the system that has been developed to apply it, that incorporates automatic acquisition equipment for continuos monitoring of the information and elements to control the parameters of interest. In addition, the experimental cavities on which the method will be evaluated are discussed, considering two different scales, as well as experiments in cavities filled with air, and with a mixture of air and steam water, as is the case for solar distillation. [Spanish] En este trabajo se presenta un metodo que permite determinar de manera experimental coeficientes de transferencia de calor por conveccion. Este metodo puede ser aplicado a una gran variedad de sistemas termicos ya que se fundamenta en el conocimiento de la condicion de frontera para la temperatura en la superficie de la placa, y del perfil de temperaturas que caracteriza el coeficiente adimensional de transferencia de calor en el fluido, de acuerdo a la definicion de este, dada por el numero de Nusselt. El trabajo que aqui se reporta esta enfocado a la fundamentacion del metodo y al equipamiento que se ha desarrollado para instrumentarlo, que incorpora equipos automaticos de adquisicion continua de informacion y elementos de control para los parametros de interes. Se presentan ademas, las cavidades experimentales sobre las que sera evaluado el metodo, que considera dos escalas diferentes, asi como experimentos en cavidades llenas de aire

  5. Proyecto de Docencia y Pedagogía acerca de plantas medicinales presentes en Colombia que se utilizan de manera rutinaria en la Medicina Tradicional China para drenar calor

    OpenAIRE

    Bueno Bedoya, María Amelia

    2014-01-01

    La Medicina Tradicional China (MTCh) tiene varios arsenales terapéuticos, entre ellos está la herbolaria. En el país se encuentran de manera natural algunas de las plantas que utiliza la herbolaria china, entre ellas aquellas que se utilizan para drenar calor. Los médicos que ejercen la MTCh en el país tienen poca información acerca de esta área del conocimiento. Sin embargo es de gran importancia ampliarla y hacerla práctica con el fin de tratar de manera más integral y eficie...

  6. Restauración en el Inmunoblotting de proteínas de Neisseria meningitidis dañadas por calor y agentes reductores

    Directory of Open Access Journals (Sweden)

    Rolando Ochoa

    2015-12-01

    Full Text Available En este trabajo se utilizaron cinco detergentes para restaurar las proteínas de membrana externas (PME del meningococo dañadas por el efecto del calor y de agentes reductores utilizados en el Inmunoblotting. La acción de los detergentes fue evaluada en la solución de lavado, en el diluente de la muestra y del conjugado. Las bandas de proteínas, reconocidas por la IgG del suero, fueron identificadas usando un conjugado anti IgG humana peroxidasa. Los antígenos reconocidos por el control positivo se corresponden con las proteínas P1, P3, P4 y P5 atendiendo a su peso molecular. Además, fueron reconocidas bandas de 80, 70, 24 kDa y otra con peso mayor a 150 kDa. En general el reconocimiento de todas las PME, excepto esta última de alto peso molecular (APM, se vieron favorecidas con la utilización del Tween 20, con el que se logró un incremento del número y la intensidad de las bandas así como la disminución de los fondos con respecto al resto de detergentes evaluados (Empigen BB, Triton X-100, Nonidet NP-40 y CHAPS. El reconocimiento de la proteína de APM (>150 kDa se vio afectado por la presencia de detergente como el Tween 20 y Empigen BB. Los lavados con Tween 20 constituyeron los pasos más importantes en la renaturalización de los sitios de unión de la IgG a las PME

  7. Misiones-patrones e indígenas-siringueros: el caucho entre los chacobos del Beni (siglo xx

    Directory of Open Access Journals (Sweden)

    Lorena I. Córdoba

    2013-04-01

    Full Text Available El artículo describe la continuidad paradójica entre la crítica de los misioneros católicos a la captación de mano de obra indígena durante el llamado «boom cauchero» en la Amazonía boliviana, a fi nes del siglo XIX y comienzos del XX, y la relación más compleja que establecieron posteriormente los misioneros protestantes del Instituto Lingüístico de Verano con los chacobos (pano, desde 1955 hasta 1980, incentivando activamente a los indígenas a trabajar en la industria cauchera e integrarse en la economía regional.

  8. El calor de la teoría

    Directory of Open Access Journals (Sweden)

    Fernando J. García Selgas

    2015-11-01

    Full Text Available Este trabajo es una reflexión crítica sobre la apuesta metateórica que Alfonso Pérez Agote hace por lo que él denomina “teoría caliente” (TC. Empiezo analizando qué entiende por TC, cómo argumenta su preferencia por ella frente a la “teoría fría” y cómo la aplica de manera efectiva. Tras recordar que esta tesis resulta un salto en el vacío respecto a planteamientos previos mejor asentados, paso a cuestionar algunos de sus supuestos e implicaciones. Todo ello, más el hecho de que la practica sociológica del propio Alfonso parece incumplir su propuesta, viene a mostrar que la tesis de la TC resulta ser una excusa innecesaria y perjudicial para quien, queriendo ceñirse a la investigación empírica, no puede evitar tomar partido en los debates teóricos y ve la realidad social como una realidad predefinida.

  9. Programa de cómputo para el cálculo del accidente de pérdida del refrigerante de un reactor nuclear del tipo piscina

    OpenAIRE

    Villanueva, Luis

    1982-01-01

    Se ha elaborado un programa de cómputo que calcula el accidente de perdida del refrigerante en la mitad superior de los elementos combustibles, producido por la rotura del tubo tangencial de irradiación de un reactor nuclear del tipo piscina. El programa esta diseñado para canales rectangulares de refrigeración, formados por placas combustibles. Los modos de transferencia de calor considerados son: 1) Convención forzada turbulenta, 2) Convención forzada en régimen de transición, 3) Convención...

  10. Research on heat pumps in Mexico operating with geothermal energy and waste heat; Investigacion sobre bombas de calor en Mexico operando con energia geotermica y calor de desecho

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Gutierrez, A; Barragan-Reyes, R.M; Arellano-Gomez, V [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: aggarcia@iie.org.mx

    2008-01-15

    The Instituto de Investigaciones Electricas and the Comision Federal de Electricidad have done research and development (R&D) on heat pumps (HP) in past years. Tested systems include mechanical compression, absorption and heat-transformers. The main R&D aspects on HP are briefly described, and also a more detailed description about three of the main studies is presented: (a) a mechanical compression HP of the water-water type operated with low-pressure geothermal steam at the Los Azufres; Mich., geothermal field, and designed for purification of brine; (b) an absorption HP for cooling and refrigeration operating with ammonia-water and low-enthalpy geothermal energy, which was tested in the Los Azufres and Cerro Prieto, BC, geothermal fields; and (c) a heat-transformer by absorption-Absorption Heat Pump Type II-tested to assess the performance of several ternary solutions as work fluids. Plans exist to install and test a geothermal heat pump at Cerro Prieto or Mexicali, BC. [Spanish] El Instituto de Investigaciones Electricas y la Comision Federal de Electricidad han realizado trabajo de investigacion y desarrollo (I&D) sobre bombas de calor (BC) en el pasado. Los sistemas probados incluyen compresion mecanica, absorcion y transformadores termicos. Este trabajo describe brevemente los principales aspectos de I&D sobre bombas de calor en forma general, y se da una descripcion mas detallada de tres de los principales estudios: (a) una BC por compresion mecanica tipo agua-agua disenada para purificacion de salmueras operando con vapor geotermico de baja presion en el campo geotermico de Los Azufres, Mich.; (b) una BC por absorcion para enfriamiento y refrigeracion operando con amoniaco-agua y energia geotermica de baja entalpia, la cual fue probada en los campos geotermicos de Los Azufres y Cerro Prieto, BC; y (c) un transformador termico por absorcion -llamado Bomba de Calor por Absorcion Tipo II--, el cual fue probado para evaluar el comportamiento de diversas

  11. El «Programa Poincaré» o funciones del matemático

    Directory of Open Access Journals (Sweden)

    de Lorenzo Martínez, Javier

    2004-08-01

    Full Text Available Ante todo, agradecer a la Real Academia de Ciencias Exactas, Físicas y Naturales estar hoy, aquí, ante ustedes. No ya a la Real Academia sino a las personas que lo han hecho factible: a José Manuel Aroca y, muy en especial, a Manuel López Pellicer. Nos encontramos conmemorando un aniversario. Algo que puede convertirse en rutina, en autojustificación para reuniones; lo que, en cierta manera, está ocurriendo en otros campos. Aunque entre en esa rutina, me permito una sugerencia: Justamente este verano se cumplirá el centenario del nacimiento del Axioma de elección.…

  12. Incremento de la productividad por recuperación de calor en gases de chimenea de un horno de cubilote

    OpenAIRE

    Mejía Arango, Héctor Daniel; Silva, Claudia; Aristizábal Sierra, Ricardo Emilio

    2003-01-01

    Sobre la base de la primera ley de la termodinámica se realiza el balance de calor para dos cubilotes típicos y para el cubilote de la Universidad de Antioquia, en este último, antes y después de ser instalado y puesto a punto el sistema de recuperación de calor, que opera con dos regeneradores de lecho empacado. Con los resultados obtenidos en el prototipo eco-eficiente se demuestran las ventajas de trabajar un cubilote con sistemas que recuperen calor de los gases de chimenea, resaltando en...

  13. Beneficial Effects of Caloric Restriction on Chronic Kidney Disease in Rodent Models: A Meta-Analysis and Systematic Review.

    Science.gov (United States)

    Xu, Xiao-Meng; Cai, Guang-Yan; Bu, Ru; Wang, Wen-Juan; Bai, Xue-Yuan; Sun, Xue-Feng; Chen, Xiang-Mei

    2015-01-01

    Numerous studies have demonstrated the life-extending effect of caloric restriction. It is generally accepted that caloric restriction has health benefits, such as prolonging lifespan and delaying the onset and progression of CKD in various species, especially in rodent models. Although many studies have tested the efficacy of caloric restriction, no complete quantitative analysis of the potential beneficial effects of reducing caloric intake on the development and progression of CKD has been published. All studies regarding the relationship between caloric restriction and chronic kidney diseases were searched in electronic databases, including PubMed/MEDLINE, EMBASE, Science Citation Index (SCI), OVID evidence-based medicine, Chinese Bio-medical Literature and Chinese science and technology periodicals (CNKI, VIP, and Wan Fang). The pooled odds ratios (OR) and 95% confidence intervals (95% CI) were calculated by using fixed- or random-effects models. The data from 27 of all the studies mentioned above was used in the Meta analysis. Through the meta-analysis, we found that the parameter of blood urea nitrogen, serum creatinine and urinary protein levels of the AL group was significant higher than that of the CR group, which are 4.11 mg/dl, 0.08mg/dl and 33.20mg/kg/24h, respectively. The incidence of the nephropathy in the caloric restriction (CR) group was significantly lower than that in the ad libitum-fed (AL) group. We further introduced the subgroup analysis and found that the effect of caloric restriction on the occurrence of kidney disease was only significant with prolonged intervention; the beneficial effects of CR on the 60%-caloric-restriction group were greater than on the less-than-60%-caloric-restriction group, and caloric restriction did not show obvious protective effects in genetically modified strains. Moreover, survival rate of the caloric restriction group is much higher than that of the ad libitum-fed (AL) group. Our findings demonstrate for the

  14. Beneficial Effects of Caloric Restriction on Chronic Kidney Disease in Rodent Models: A Meta-Analysis and Systematic Review.

    Directory of Open Access Journals (Sweden)

    Xiao-Meng Xu

    Full Text Available Numerous studies have demonstrated the life-extending effect of caloric restriction. It is generally accepted that caloric restriction has health benefits, such as prolonging lifespan and delaying the onset and progression of CKD in various species, especially in rodent models. Although many studies have tested the efficacy of caloric restriction, no complete quantitative analysis of the potential beneficial effects of reducing caloric intake on the development and progression of CKD has been published.All studies regarding the relationship between caloric restriction and chronic kidney diseases were searched in electronic databases, including PubMed/MEDLINE, EMBASE, Science Citation Index (SCI, OVID evidence-based medicine, Chinese Bio-medical Literature and Chinese science and technology periodicals (CNKI, VIP, and Wan Fang. The pooled odds ratios (OR and 95% confidence intervals (95% CI were calculated by using fixed- or random-effects models.The data from 27 of all the studies mentioned above was used in the Meta analysis. Through the meta-analysis, we found that the parameter of blood urea nitrogen, serum creatinine and urinary protein levels of the AL group was significant higher than that of the CR group, which are 4.11 mg/dl, 0.08mg/dl and 33.20mg/kg/24h, respectively. The incidence of the nephropathy in the caloric restriction (CR group was significantly lower than that in the ad libitum-fed (AL group. We further introduced the subgroup analysis and found that the effect of caloric restriction on the occurrence of kidney disease was only significant with prolonged intervention; the beneficial effects of CR on the 60%-caloric-restriction group were greater than on the less-than-60%-caloric-restriction group, and caloric restriction did not show obvious protective effects in genetically modified strains. Moreover, survival rate of the caloric restriction group is much higher than that of the ad libitum-fed (AL group.Our findings

  15. Video head-impulse test (vHIT) in dizzy children with normal caloric responses.

    Science.gov (United States)

    Khater, Ahmed Mohammed; Afifi, Pretty O

    2016-08-01

    The caloric test and the video head-impulse test are diagnostic tools to examine dizzy patients through assessing the function of the semicircular canals. There are major differences between the two tests as regards stimulus characteristics, methodology, and function examined. The aim of this study is to evaluate the results of vHIT in children and adolescents with normal caloric test. This work was performed on 63 patients, but 14 were excluded because of technical problems in the caloric test. So, this is a prospective work in 49 patients (27 females and 22 males) with different types of vestibular disease seen because of vertigo in which both procedures were performed the same day. The caloric test was performed with air at two different temperatures in which both ears were irrigated alternately. Then, the video head-impulse test was carried out. Main outcome measures were the gain of vestibulo-ocular reflex, gain asymmetry, and refixation saccades in the vHIT. in all studied cases, caloric test was normal. The mean age of patients was 16 years. By vHIT, in 8 patients (16%) no abnormality was detected, while abnormal findings were found in 41 patients. Single canal affection was seen in 29 patients whereas 12 patients had combined canal affection. The right side was affected in 27 and left side in 22 patients. In single canal affection, isolated horizontal canals were affected in 4, anterior canals in 5 and posterior canals in 20 patients. While in combined canal affection, the affection is seen in the same ear. Moreover the most common pattern seen is affection of left anterior and left posterior canals. The caloric and vHIT is very important tests in diagnosis of dizzy patients. The information from both methods is redundant in some cases but complementary in most. vHIT is a "child friendly," relatively easy-to-use, and simple tool to evaluate each of the 6 semicircular canals. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  16. Biología reproductiva del pulpo Octupus mimus (Mollusca: Cephalopoda de la región de Matarani, Arequipa, Perú

    Directory of Open Access Journals (Sweden)

    Victor Ishiyama

    2014-06-01

    Full Text Available De mayo de 1995 a abril de 1996, se realizaron al azar muestreos mensuales de 25 ejemplares de Octopus mimus de los desembarques del puerto de Matarani, Arequipa (16° 59'40"S y 72° 06'13"W. Son animales gonocóricos, presentan dimorfismo sexual, y los machos tienen el brazo ectocotilizado o copulador. La proporción de sexos fue de 2,1:1,0 a favor de los machos; se determinaron ocho estadios de desarrollo de los ovocitos, durante la ovogénesis. De acuerdo a su comportamiento reproductivo, se estableció la siguiente escala de madurez gonadal: a indiferenciado, b inmaduro, c inicio de maduración, d en desarrollo, e maduros, fl cópula, g postcópula, autofecundación y evacuación, h postevacuación. Las hembras maduras se encontraron preferentemente, en la primavera y verano; los machos maduros a fines de la primavera y en el verano; la cópula se realizó preferentemente durante el verano; la autofecundación y evacuación de los huevos, se evidenciaron en agosto (50%, octubre 50%, noviembre (71,4%, diciembre (33% y enero (33%. La primera madurez en los machos se encontró a los 9,5 cm y en las hembras a los 12,5 cm de la longitud dorsal del cuerpo. Se observó algunas hembras con ovocitos maduros en lisis y con inicio de ovogénesis avanzada de un nuevo ciclo, que evidencia que no todas las hembras mueren después de cuidar los huevos hasta el final de la eclosión.

  17. Is the caloric curve a robust signal of the phase transition in hot nuclei?

    Science.gov (United States)

    Vient, E.

    2017-11-01

    The richness of the data set, collected by the INDRA Collaboration during the last twenty years, enabled us to build a set of caloric curves for nuclei of various sizes, by using, for the first time, a single experimental set-up and a single experimental protocol. We will therefore present the different caloric curves ( E^{\\ast}-T obtained by a new calorimetry, for Quasi-Projectiles produced by symmetric or quasi symmetric reactions at different incident energies (Au + Au, Xe + Sn, Ni + Ni). For all these systems, a clear change of the de-excitation process of hot nuclei is observed but this one is neither a plateau nor a back-bending, but a sudden change of slope.

  18. Transferência de calor no escoamento turbulento em desenvolvimento entre placas planas paralelas

    OpenAIRE

    Marcio Bueno dos Santos

    1991-01-01

    O presente trabalho tem por finalidade a análise experimental do problema de convecção forçada entre placas paralelas no escoamento com transição laminar-turbulento, com condições assimétricas do perfil de temperatura. A determinação dos valores locais dos coeficientes de transferência de calor é obtida aplicando-se a técnica se Sublimação de Naftaleno. De acordo com a analogia entre transferência de calor e transferência de massa as condições experimentais correspondem a situação de transfer...

  19. Caloric Intake From Fast Food Among Children and Adolescents in the United States, 2011-2012.

    Science.gov (United States)

    Vikraman, Sundeep; Fryar, Cheryl D; Ogden, Cynthia L

    2015-09-01

    Consumption of fast food has been linked to weight gain in adults (1). Fast food has also been associated with higher caloric intake and poorer diet quality in children and adolescents (2). From 1994 through 2006, caloric intake from fast food increased from 10% to 13% among children aged 2-18 years (3). This report presents the most recent data on the percentage of calories consumed from fast food among U.S. children by sex, age group, race and Hispanic origin, poverty status, and weight status. All material appearing in this report is in the public domain and may be reproduced or copied without permission; citation as to source, however, is appreciated.

  20. Los molinos verticales en la industria del cemento

    Directory of Open Access Journals (Sweden)

    Hidalgo de Cisneros Alonso, Juan M.

    1977-09-01

    Full Text Available Con ocasión de los V Coloquios de Directores y Técnicos de fábricas de cemento tuvimos la oportunidad de exponer a Vds. lo que entonces era una pequeña visión de futuro dentro del marco de la utilización de los molinos verticales o de rodillos para la molienda de crudo de cemento, destinado a la alimentación de hornos de gran producción, y utilizando el calor contenido en los gases de salida para realizar, durante la molienda, y en el interior del molino, el proceso de secado del crudo.

  1. Esclavistes versus monopolistes? Els litigis entorn del trànsit d'esclaus al virregnat rioplatense (1780-1810)

    OpenAIRE

    Martín Schlez, Mariano

    2016-01-01

    A partir del cas del comerciant espanyol Diego d'Agüero, l'article analitza els debats que el tràfic d'esclaus va desencadenar a l'interior dels comerciants majoristes rioplatenses durant l'última etapa de l'Imperi Espanyol (1780-1810). A través de la seva correspondència i de les actes del Consolat de Buenos Aires, vam mostrar l'existència de dues fraccions de mercaders que van aprofundir el seu enfrontament a la calor de la crisi mercantil de fins del segle XVIII i principis del XIX. ...

  2. Caloric restriction in lean and obese strains of laboratory rat: effects on body composition, metabolism, growth and overall health

    Data.gov (United States)

    U.S. Environmental Protection Agency — Data related to obese and lean strains of rat commonly used in the laboratory that are calorically restricted and its effects on physiologic parameters (Body...

  3. Effects of Moderate Aerobic Exercise Combined With Caloric Restriction on Circulating Estrogens and IGF-I in Premenopausal Women

    National Research Council Canada - National Science Library

    Williams, Nancy I

    2004-01-01

    ... the primary prevention of breast cancer in women. This study has examined the effects of exercise training combined with caloric restriction, resulting in weight loss, on two hormonal biomarkers for breast cancer i.e...

  4. Caloric Vestibular Stimulation Reduces Pain and Somatoparaphrenia in a Severe Chronic Central Post-Stroke Pain Patient: A Case Study

    National Research Council Canada - National Science Library

    Spitoni, Grazia Fernanda; Pireddu, Giorgio; Galati, Gaspare; Sulpizio, Valentina; Paolucci, Stefano; Pizzamiglio, Luigi

    2016-01-01

    .... To date, there is limited evidence for the effective treatments of this disease. Here we used caloric vestibular stimulation to reduce pain and somatoparaphrenia in a 57-year-old woman suffering from central post-stroke pain...

  5. Análise da transferência de calor em paredes compostas por diferentes materiais

    Directory of Open Access Journals (Sweden)

    Luciano Pivoto Specht

    Full Text Available O projeto de edificações energeticamente eficientes necessita de conhecimentos sobre a transferência de calor proveniente do ambiente externo, a fim de criar soluções que associem diferentes materiais e espessuras às condições desejadas de conforto térmico. O objetivo deste trabalho é avaliar diversos tipos e disposições de materiais em paredes de tijolos maciços, sob a ótica da térmica de edifícios. Para a realização dos experimentos, modelos em escala real foram confeccionados, instrumentados e acoplados a uma câmara térmica, desenvolvida especialmente para esse fim. O problema de transferência de calor foi modelado pela equação da energia, resolvida em Diferenças Finitas Centrais, utilizando-se o Método Implícito. As difusividades térmicas dos materiais foram calculadas resolvendo o Problema Inverso de transferência de calor. Também foi calculado o fluxo de calor e o custo total de cada alternativa, finalizando-se com a obtenção da relação termoeconômica para cada parede. Através da análise termoeconômica pode-se constatar que, apesar de o investimento inicial ser relativamente maior nas paredes mais espessas e/ou com isolamento térmico, estas apresentam um comportamento térmico muito superior às tradicionais. Notadamente, a parede com EPS na face exterior apresentou o melhor desempenho.

  6. Caloric Value of Some Forest Fuels of the Southern United States

    Science.gov (United States)

    Walter A. Hough

    1969-01-01

    The caloric value of a variety of southern forest fuels was determined in an oxygen bomb calorimeter. High heat values ranged between about 3,600 and 5,200 cal./g. for fuels as sampled and between 4,500 and 5,600 cal./g. for fuels on an ash-free basis. Additional tests of forest fuels from the Southern, Eastern, and North Central United States showed a...

  7. Caloric beverages were major sources of energy among children and adults in Mexico, 1999-2012.

    Science.gov (United States)

    Stern, Dalia; Piernas, Carmen; Barquera, Simon; Rivera, Juan A; Popkin, Barry M

    2014-06-01

    Mexico, with 1 of the highest obesity prevalences in the world, instituted a 10% excise tax for any sugar-sweetened beverage (SSB) starting on 1 January 2014. Understanding the recent patterns and trends in beverage intake and sales in Mexico provides both background and baseline data for the importance of SSBs and other beverages in the Mexican diet. We analyzed a single 24-h dietary recall from 2 nationally representative surveys: the Mexican Nutrition Survey 1999 (n = 6049) and the National Health and Nutrition Survey 2012 (n = 10,343). To describe trends and patterns in beverages, we calculated the volume and energy intake per capita and per consumer and the proportion of consumers of each beverage group in each survey. A commercial sales dataset was used to describe beverage sales trends from 1999 to 2012. From 1999 to 2012, total daily energy from beverages increased among children aged 5-11 y (+45.3 kcal), females aged 12-19 y (+57.3 kcal), and adult females aged 20-49 y (+96.4 kcal) (P total daily energy intake per capita in children aged 1-19 y and adults aged ≥20 y, respectively. In 2012, flavored milk beverages, caloric soda, and high-fat milk were the top 3 major contributors to total daily energy intake per capita in all children aged 1-19 y. Caloric soda, caloric coffee/tea, and agua fresca were the top 3 major energy contributors in adults aged ≥20 y. From 1999 to 2012, sales of soda, fruit-flavored drinks, and flavored waters increased. In conclusion, consumption of several beverages with added sugars increased among children and adult females in Mexico. Because caloric soda is currently 1 of the top beverages consumed, a 10% tax on SSBs might help to significantly reduce added sugars intake in Mexico. © 2014 American Society for Nutrition.

  8. Caloric compensation in preschool children: Relationships with body mass and differences by food category.

    Science.gov (United States)

    Carnell, S; Benson, L; Gibson, E L; Mais, L A; Warkentin, S

    2017-09-01

    Maintaining a healthy weight may involve compensating for previously consumed calories at subsequent meals. To test whether heavier children demonstrated poorer caloric compensation across a range of conditions, and to explore whether compensation failure was the result of inadequate adjustment of overall intake or specific over-consumption of highly palatable, high energy-density 'junk' foods, we administered two compensation tests to a sample of 4-5 y olds. For Test A, preloads varied only in carbohydrate content and were organoleptically indistinguishable (200 ml orange-flavored beverage [0 kcal vs. 200 kcal]). For Test B, the preloads varied substantially in both macronutrient composition and learned gustatory cues to caloric content (200 ml water [0 kcal] vs. 200 ml strawberry milkshake [200 kcal]). Each preload was followed 30 min later by a multi-item ad-libitum meal containing junk foods (chocolate cookies, cheese-flavored crackers) and core foods (fruits and vegetables, bread rolls, protein foods). Testing took place at the children's own school under normal lunch-time conditions. Children were weighed and measured. Caloric compensation occurred in both tests, in terms of total, junk and core food intake (RMANOVA, all p junk food intake (RMANOVA preload-by-weight group interaction p effect for core foods. Our results suggest that caloric compensation is consistently poorer in heavier children, and that overweight/obese children's preferences for junk foods may overwhelm intake regulation mechanisms within meals containing those foods. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Influence of Caloric Vestibular Stimulation on Body Experience in Healthy Humans

    OpenAIRE

    Andreas eSchönherr; Christian-Albrecht eMay

    2016-01-01

    The vestibular system has more connections with and influence on higher cortical centers than previously thought. These interactions with higher cortical centers and the phenomena that they elicit require a structural intact cerebral cortex. To date, little is known about the role and influence of the vestibular system on one’s body experience. In this study we show that caloric vestibular stimulation (CVS) in healthy participants has an effect on the perceptive component of one’s body experi...

  10. Shifts in the Distribution of Mass Densities Is a Signature of Caloric Restriction in Caenorhabditis elegans

    OpenAIRE

    Alfonso Reina; Anand Bala Subramaniam; Anna Laromaine; Aravinthan D T Samuel; Whitesides, George M.

    2013-01-01

    Although the starvation response of the model multicellular organism Caenorhabditis elegans is a subject of much research, there is no convenient phenotypic readout of caloric restriction that can be applicable to large numbers of worms. This paper describes the distribution of mass densities of populations of C. elegans, from larval stages up to day one of adulthood, using isopycnic centrifugation, and finds that density is a convenient, if complex, phenotypic readout in C. elegans. The dens...

  11. Comparison of caloric and head-impulse tests during the attacks of Meniere's disease.

    Science.gov (United States)

    Lee, Sun-Uk; Kim, Hyo-Jung; Koo, Ja-Won; Kim, Ji-Soo

    2017-03-01

    To aid in diagnosis of Meniere's disease (MD) during the attacks using caloric and head-impulse tests (HITs). Retrospective case series review. We analyzed the results of bithermal caloric and HITs during the attacks in 16 patients with MD. Quantitative analyses of HITs were conducted using a magnetic search coil technique. In unilateral MD (14 patients, 42 semicircular canals), the head impulse gain of the vestibulo-ocular reflex (VOR) was either normal (28 of 42, 67%), decreased (8 of 42, 19%), or increased (6 of 42, 14%) for each semicircular canal in the affected ear. Likewise, the head impulse VOR gain was either normal (29 of 42, 69%), increased (11 of 42, 26%), or decreased (2 of 42, 5%) in the intact ear. The VOR gain for the horizontal canal was significantly lower on the affected side (P = 0.013). However, the VOR gains for the anterior and posterior canals did not differ between the sides (P = 0.270, P = 0.282). In bilateral MD (two patients, 12 semicircular canals), the VOR gain was either decreased (6 of 12, 50%) or normal (6 of 12, 50%) in either ear. In contrast, the caloric responses were usually decreased in the affected ear (7 of 11, 64%, including one with bilateral MD). During the attacks of MD, HITs showed varied results between the ears and among the canals, although the caloric responses were usually decreased in the involved ear. These dissociations suggest a frequency-dependent impairment of canal function or mechanical property of the endolymphatic hydrops during the attacks of MD. 4. Laryngoscope, 127:702-708, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  12. Adipose-immune interactions during obesity and caloric restriction: reciprocal mechanisms regulating immunity and health span

    OpenAIRE

    Dixit, Vishwa Deep

    2008-01-01

    Increasing evidence suggests a tight coupling of metabolic and immune systems. This cross-talk mediated by neuroendocrine peptides as well as numerous cytokines and chemokines is believed to be responsible for integrating energy balance to immune function. These neuroendocrine-immune interactions are heightened during the state of chronic positive energy balance, as seen during obesity, and negative energy balance caused by caloric restriction (CR). Emerging evidence suggests that obesity may...

  13. Estudio de la transferencia de calor en la etapa de cocido en la elaboración de aceitunas verdes al estilo sevillano

    Directory of Open Access Journals (Sweden)

    Tarrado-Castellarnau, M.

    2013-09-01

    Full Text Available This article describes for the first time at the industrial level the temperature rise that occurs inside the processing tank during the lye treatment. Relationships between variables that define the lye treatment have been determined from the study of the thermal characteristics of this process. The initial temperature influences other variables of this treatment, such as its duration or the slope of the linear increase of temperature produced. The study estates that this generation of heat can be principally caused by the alkaline hydrolysis reactions that occur in the interior of the fruit and, to a lesser extent, by the dilution of sodium hydroxide solution with water present in the pulp of the olives.En este artículo se describe por primera vez a nivel industrial el aumento de temperatura que se produce en el interior de los tanques de elaboración durante la etapa de cocido. A partir del estudio de las características térmicas de la etapa de cocido se han podido determinar relaciones entre las variables que definen el proceso. Se ha demostrado que la temperatura al inicio del tratamiento de cocido influye en otras de las características del proceso como la duración de éste o la pendiente del aumento lineal de temperatura durante la etapa. El estudio establece que esta generación de calor puede provenir principalmente de las reacciones de hidrólisis alcalina que ocurren en el interior del fruto y, en menor proporción, de la dilución de la solución de hidróxido de sodio con el agua presente en la pulpa de las aceitunas.

  14. Conceptos actualizados sobre la molienda del cemento

    Directory of Open Access Journals (Sweden)

    Osório de Rocha e Melo, José

    1961-12-01

    Full Text Available Not availableLa molienda del clínker consume, en una fábrica de cemento, cerca del 40% de energía total; el rendimiento energético de la molienda es también pésimo, ya que resulta ser apenas del orden del 1%. Los otros 99% se pierden bajo forma de calor en calentar la máquina, las placas de blindaje, cuerpos moledores, el cemento, el aire ambiente y bajo la forma de sonido. Se ha procurado mejorar estos bajos rendimientos que se reflejan en la economía general de la fabricación, y en este sentido se presentan algunos caminos que han sido explorados con este objeto.

  15. Effects of caloric deprivation and satiety on sensitivity of the gustatory system

    Directory of Open Access Journals (Sweden)

    Zverev Yuriy P

    2004-02-01

    Full Text Available Abstract Background Sensitivity of the gustatory system could be modulated by a number of short-term and long-term factors such as body mass, gender, age, local and systemic diseases and pathological processes, excessive alcohol drinking, drug dependence, smoking, composition of oral fluid, state of oral hygiene, consumption of some foods among many others. A few studies have demonstrated the effects of hunger and caloric satiety on sensitivity of the gustatory system in obese humans and animals. The aim of the present study was to assess the effects of short-term caloric deprivation and satiety on recognition taste thresholds of healthy, non-smoking, non-drinking, non-obese young male subjects. The two-alternative forced-choice technique was used to measure taste threshold. Results Recognition thresholds for sucrose and salt were significantly lower during fasting state than after a meal (t = 2.23, P Conclusions Short-term caloric deprivation in our study model was associated with increased taste sensitivity to sweet and salty substances compared to satiated state while taste sensitivity to bitter substances was not affected by the conditions of measurements. Selective modulation of sensitivity of the gustatory system might reflect the different biological importance of salty, sweet and bitter qualities of taste.

  16. Importance of silvopastoral systems on caloric stress reduction in tropical livestock productions

    Directory of Open Access Journals (Sweden)

    Alexander Navas Panadero

    2010-06-01

    Full Text Available Livestock systems in Colombia have been developed taking concepts and technologies from the green revolution, where gramineous monocrop is privileged over arboreal cover in grazing lands. This model has not taken into account the climatic conditions of the different tropical ecosystems, in which variables as temperature, relative humidity and evaporation can limit the animal´s productive and reproductive efficiency, besides being a risk factor for illness occurrence in the herd. Bos Taurus and Bos Indicus breeds show termoneutral ranges where its genetic potential can be express. However, out of this comfort area animals can enter in caloric stress which in consequence reduces its performance and sometimes can end up causing death. Silvopastoral systems comprise several functions; it contributes to lessen caloric stress since temperature under the tree canopy can reach between 2 and 9°C lower in comparison to open pastures. Differences in temperature reduction have been found among silvopastoral systems and species, being the tree group arrangements and the species with high density canopy, those with superior effect. Interactions among components should be analyzed in order to design systems that incorporate enough arboreal cover to achieve caloric stress reductions, but without affecting forage production in pastures. Silvopastoral systems contribute to improve animal welfare.

  17. CALOR2012 XVth International Conference on Calorimetry in High Energy Physics

    Energy Technology Data Exchange (ETDEWEB)

    Akchurin, Nural .

    2015-05-04

    The International Conferences on Calorimetry in High Energy Physics, or the CALOR series, have always been where the calorimeter experts come together to review the state of calorimetry and bring forth new ideas every two years. The fteenth conference, CALOR2012, in Santa Fe was no exception. Although they were built roughly a decade ago, we are now witnessing the exceptional power of the LHC calorimeters and the crucial role they have been playing in the discovery of the 125 GeV Higgs-like boson. As we ruminate on the coming generation of experiments at the next (linear) collider and on the upgrades at the LHC, we are heartened by the substantial advances we made in calorimetry in the last decade. These advances will certainly help uncover new physics in the years to come, not only at colliders but also in astroparticle experiments that take advantage of natural elements such as air, water, and ice. The proceedings were published by the IOP in Journal of Physics, Vol 404 2011. The conference web site is calor2012.ttu.edu.

  18. Normal physical activity obliterates the deleterious effects of a high-caloric intake.

    Science.gov (United States)

    Krogh-Madsen, Rikke; Pedersen, Maria; Solomon, Thomas P J; Knudsen, Sine Haugaard; Hansen, Louise Seier; Karstoft, Kristian; Lehrskov-Schmidt, Louise; Pedersen, Karin Kaereby; Thomsen, Carsten; Holst, Jens Juul; Pedersen, Bente K

    2014-02-01

    A high-caloric intake combined with a sedentary lifestyle is an important player in the development of type 2 diabetes mellitus (T2DM). The present study was undertaken to examine if the level of physical activity has impact on the metabolic effects of a high-caloric (+2,000 kcal/day) intake. Therefore, healthy individuals on a high-caloric intake were randomized to either 10,000 or 1,500 steps/day for 14 days. Step number, total energy expenditure, dietary records, neuropsychological tests, maximal oxygen uptake (Vo2max), whole body dual-energy X-ray absorptiometry (DXA) and abdominal magnetic resonance imaging (MRI) scans, continuous glucose monitoring (CGM), and oral glucose tolerance tests (OGTT) with stable isotopes were performed before and after the intervention. Both study groups gained the same amount of body weight. However, the inactive group accumulated significantly more visceral fat compared with the active group. Following the 2-wk period, the inactive group also experienced a poorer glycemic control, increased endogenous glucose production, decreased hepatic insulin extraction, increased baseline plasma levels of total cholesterol and LDL, and a decreased cognitive function with regard to capacity of attention. In conclusion, we find evidence to support that habitual physical activity may prevent pathophysiological symptoms associated with diet-induced obesity.

  19. Peripheral ghrelin enhances sweet taste food consumption and preference, regardless of its caloric content.

    Science.gov (United States)

    Disse, Emmanuel; Bussier, Anne-Lise; Veyrat-Durebex, Christelle; Deblon, Nicolas; Pfluger, Paul T; Tschöp, Matthias H; Laville, Martine; Rohner-Jeanrenaud, Françoise

    2010-09-01

    Ghrelin is one of the most potent orexigens known to date. While the prevailing view is that ghrelin participates in the homeostatic control of feeding, the question arose as to whether consummatory responses evoked by this compound could be related to search for reward. We therefore attempted to delineate the involvement of ghrelin in the modulation of non-caloric but highly rewarding consumption. We tested the effect of intraperitoneally injected ghrelin on the acceptance and preference for a 0.3% saccharin solution using single bottle tests and free-choice preference test procedures in C57BL6/J mice, as well as in mice lacking the ghrelin receptor (GHSR1a -/-) and their wild-type (WT) littermates. In the single bottle tests, peripheral ghrelin consistently increased the consumption of saccharin, independently of availability of caloric food. In the free-choice preference test procedures, ghrelin increased the preference for saccharin in WT mice, while it did had not effect in GHSR1a -/-animals, indicating that the ghrelin receptor pathway is necessary to mediate this parameter. Peripheral ghrelin enhances intake and preference for a sweet food, regardless of whether the food has caloric content. This effect, mediated through the ghrelin receptor pathway, may serve as additional enhancers of energy intake. Copyright 2010 Elsevier Inc. All rights reserved.

  20. Weight cycling and cancer: weighing the evidence of intermittent caloric restriction and cancer risk.

    Science.gov (United States)

    Thompson, Henry J; McTiernan, Anne

    2011-11-01

    Overweight and obese individuals frequently restrict caloric intake to lose weight. The resultant weight loss, however, typically is followed by an equal or greater weight gain, a phenomenon called weight cycling. Most attention to weight cycling has focused on identifying its detrimental effects, but preclinical experiments indicating that intermittent caloric restriction or fasting can reduce cancer risk have raised interest in potential benefits of weight cycling. Although hypothesized adverse effects of weight cycling on energy metabolism remain largely unsubstantiated, there is also a lack of epidemiologic evidence that intentional weight loss followed by regain of weight affects chronic-disease risk. In the limited studies of weight cycling and cancer, no independent effect on postmenopausal breast cancer but a modest enhancement of risk for renal cell carcinoma, endometrial cancer, and non-Hodgkin's lymphoma have been reported. An effect of either intermittent caloric restriction or fasting in protecting against cancer is not supported by the majority of rodent carcinogenesis experiments. Collectively, the data argue against weight cycling and indicate that the objective of energy balance-based approaches to reduce cancer risk should be to strive to prevent adult weight gain and maintain body weight within the normal range defined by body mass index.

  1. POTENCIAL ENERGÉTICO DE RESIDUOS AGROINDUSTRIALES DEL DEPARTAMENTO DEL CAUCA, A PARTIR DEL PODER CALORÍFICO INFERIOR

    Directory of Open Access Journals (Sweden)

    DEYANIRA MUÑOZM

    2013-12-01

    Full Text Available Se determinaron los valores energéticos de los residuos agroindustriales del departamento del Cauca, mediante análisis del poder calorífico, datos técnicos reportados en las tablas estadísticas del Anuario Estadístico del Sector Agropecuario y Pesquero 2011 y con las expresiones simples presentadas en la metodología de Antolín G.G para el cálculo de variables energéticas.Los valores obtenidos del poder caloríficoen base seca fueron: 116187,97kJ/kgpara bagacillo de caña, 15419,95kJ/kg para polvillo de fique y 15262,18kJ/kg para afrecho de yuca.El valor promediodelas mezcla fue de 15623,35kJ/kg.Se concluye que 15623,35 kJ/kg representa la energía promedio que puede liberarse en un proceso de combustión deestos residuos y es comparable con la energía liberada por otras fuentes de biomasa. El potencial energético del bagacillo de caña con el valor de 163.45TJ/año, contribuye con el 35.73% de la energía, por lo cual ofrece mayores ventajas energéticas en comparación alvalor del afrecho de yuca,que tiene un potencial de 0.91 TJ/año. La mezcla con la mejor característica energética esta compuesta por 33.3% bagacillo de caña, 33.3% polvillo de fique y 33.3% afrecho de yuca y tiene un potencial energético de 48.39 TJ/año.

  2. Revisando las reglas del juego: conversación con Pablo Iglesias Turrion, Jesús Espasadín López e Iñigo Errejón Galván

    Directory of Open Access Journals (Sweden)

    Walter D. Mignolo

    2008-01-01

    Full Text Available Esta es una respuesta a un debate planteado en los seminarios de verano, organizados por la Universidad Complutense, en el Escorial, en Julio del 2006. He condensado la respuesta en dos tópicos, que me parecen dos ejes sobre los que giró el debate: la cuestión de la exterioridad y la cuestión de la objetividad, sin y con paréntesis. La mía es una respuesta que presupone al mismo tiempo que avanza el pensamiento y la opción descolonial, que fue precisamente el planteamiento que originó el debate.

  3. Caloric Beverages Were Major Sources of Energy among Children and Adults in Mexico, 1999–2012123

    Science.gov (United States)

    Stern, Dalia; Piernas, Carmen; Barquera, Simon; Rivera, Juan A.; Popkin, Barry M.

    2014-01-01

    Mexico, with 1 of the highest obesity prevalences in the world, instituted a 10% excise tax for any sugar-sweetened beverage (SSB) starting on 1 January 2014. Understanding the recent patterns and trends in beverage intake and sales in Mexico provides both background and baseline data for the importance of SSBs and other beverages in the Mexican diet. We analyzed a single 24-h dietary recall from 2 nationally representative surveys: the Mexican Nutrition Survey 1999 (n = 6049) and the National Health and Nutrition Survey 2012 (n = 10,343). To describe trends and patterns in beverages, we calculated the volume and energy intake per capita and per consumer and the proportion of consumers of each beverage group in each survey. A commercial sales dataset was used to describe beverage sales trends from 1999 to 2012. From 1999 to 2012, total daily energy from beverages increased among children aged 5–11 y (+45.3 kcal), females aged 12–19 y (+57.3 kcal), and adult females aged 20–49 y (+96.4 kcal) (P agua fresca (fruit water made in stalls or at home, usually with added sugars), and fruit drinks among children aged 5–11 y and females aged 12–19 y and caloric coffee/tea, soda, and agua fresca among adult females aged 20–49 y. In 2012, beverages represented 17.5% (325 kcal) and 19.0% (382 kcal) of the total daily energy intake per capita in children aged 1–19 y and adults aged ≥20 y, respectively. In 2012, flavored milk beverages, caloric soda, and high-fat milk were the top 3 major contributors to total daily energy intake per capita in all children aged 1–19 y. Caloric soda, caloric coffee/tea, and agua fresca were the top 3 major energy contributors in adults aged ≥20 y. From 1999 to 2012, sales of soda, fruit-flavored drinks, and flavored waters increased. In conclusion, consumption of several beverages with added sugars increased among children and adult females in Mexico. Because caloric soda is currently 1 of the top beverages consumed, a 10% tax

  4. Cosecha temprana, apertura forzada y vida en el vaso de flores de cuatro variedades de clavel (Dianthus cariophyllus L., en invierno y en verano Early harvest, forced flower opening and vase life of four varieties of carnation (Dianthus cariophyllus L. in winter and summer

    Directory of Open Access Journals (Sweden)

    A. de. L. Avila

    2007-12-01

    Full Text Available Se evaluó la cosecha temprana y la apertura forzada de pimpollos con sacarosa, en invierno y en verano, en flores de 4 variedades de clavel (Moresco, Mabel, Nov y Golden Odino. Las flores fueron cosechadas en cinco estados de desarrollo, desde botón cerrado hasta flor abierta (estados 0 al 4, hidratadas en frío (2 ºC con una solución de tiosulfato de plata (0,1 M durante 24 horas y luego transfe ridas a una solución de ácido cítrico (500 mg l-1 y citrato de hydroxyquinoleina (60 mg l-1; la solución de apertura contenía, además, 100 g l-1 de sacarosa. Cuando se completó la apertura de la flor se evaluó tamaño, intensidad de color y vida en el vaso. El tamaño de la flor fue similar en invierno y verano en las varie dades Moresco, Golden Odino y Nov, sin embargo, en todas las variedades la vida en el vaso fue menor en verano. El agregado de sacarosa mejoró la aper tura, el tamaño de las flores e intensificó los colores en todas las variedades y estados de corte. La mayor calidad se logró combinando el agregado de saca rosa y la cosecha en estado 0 -1 en verano y 2 -3 en invierno.Early harvest and forced flower opening with sucrose addition in the preservative solution effects were evaluated during winter and summer, in Moresco, Mabel, Nov and Golden Odino carnation varieties. The flowers were harvested at five dif ferent stages of development: from tight flower buds to open flowers (state 0 to 4. Immediately, these were hydrated during 24 h using a silver thiosulfate solution (0,1 M at 2 ºC. Then, the flowers were treated with a preservative solution containing citric acid (500 mg l-1 and hydroxyquinoline citrate (60 mg l-1, with and without sucrose (100 g l-1. Petal color, vase life and flower size were evaluated when the full open flower stage was obtained. The flower size was similar during winter and summer in Moresco, Nov and Golden Odino, but the vase life was significantly reduced in the summer. The sucrose addition

  5. ESTUDIO DE LA VARIABILIDAD ESPACIAL DE LA TEMPERATURA DE SUPERFICIE EN EL NORTE DE LA PROVINCIA DEL NEUQUÉN CON IMÁGENES SATELITALES

    Directory of Open Access Journals (Sweden)

    Marisa Gloria Cogliati

    2015-12-01

    Full Text Available La zona noroeste de la provincia del Neuquén constituye una zona importante debido a su utilización con fines ganaderos, pero los sistemas áridos o semi áridos como el estudiado en el presente trabajo son vulnerables a procesos de uso del suelo y desertización. En este trabajo se presenta el análisis de la temperatura de superficie obtenida a partir de información del canal térmico del satélite Landsat 7 ETM+ para esa región durante un periodo fresco (otoño-invierno y cálido (primavera-verano. El estudio es parte de un proyecto de análisis geoecológico utilizando imágenes Landsat. La zona no cuenta con estudios de la variabilidad espacial de la temperatura del aire y del suelo debido a la necesidad de contar con redes de información micro o meso meteorológicas que incorporen una mayor densidad espacial de observaciones siguiendo el gradiente altitudinal y la complejidad del terreno debido a que el área es de difícil acceso y ho hay datos de superficie disponibles. Esto hace necesario utilizar métodos alternativos para el estudio de la distribución espacial de variables topo meteorológicas. La información satelital provee información en distintas escalas temporales y espaciales a un menor costo. En el presente trabajo, se obtuvo la radiancia emitida en la superficie utilizando la radiancia medida por el satélite a partir de la ecuación de transferencia radiativa y el modelo MODTRAN con información de reanálisis disponibles en línea. Se analizaron seis escenas libres de nubosidad. La temperatura de superficie presentó un comportamiento correlacionado con la topografía principalmente en el período frío, con una menor relación en verano. La isoterma de 273 K (0 oC alcanzó alturas de 1900 m, restringiéndose a alturas mayores a 3700 m en verano. Las áreas con temperatura menor a 273 K fueron las que presentaron mayores diferencias entre el período cálido y el período frío analizados

  6. Comportamiento productivo del pasto ovillo (Dactylis glomerata L. en respuesta al pastoreo.

    Directory of Open Access Journals (Sweden)

    Filogonio Jesús Hernández-Guzmán

    2015-01-01

    Full Text Available El objetivo del estudio fue determinar los patrones de variación en los componentes de la productividad forrajera del pasto ovillo (Dactylis glomerata L. bajo pastoreo. En Montecillo, Texcoco, Estado de México, México, de junio 2005 a junio 2006, se estudió la combinación de tres frecuencias (21, 28 y 35 días y dos intensidades (5-7 y 9-11 cm en el forraje residual de pastoreo, en un diseño de bloques al azar con tres repeticiones. Se evaluó el rendimiento anual y la distribución estacional de forraje, tasa de crecimiento, composición botánica y morfológica y densidad de tallos. La frecuencia de pastoreo de 35 días superó a las de 21 y 28 (P<0,05 en el rendimiento anual, durante primavera y verano. Independientemente de la frecuencia e intensidad de pastoreo, el rendimiento estacional se distribuyó de la siguiente forma: 49,5, 31,6, 14,1 y 4,8% para primavera, verano, invierno y otoño, respectivamente. La mayor tasa de crecimiento se registró en primavera al pastorear cada 35 días y la menor en otoño al pastorear cada 28 días (P<0,01. Durante invierno se dio mayor presencia de otras especies, siendo el pastoreo cada veintiún días a una intensidad ligera el que originó un aporte al rendimiento de otras especies del 60%. No se presentaron efectos de intensidad ni de frecuencia de pastoreo en la densidad de tallos. El mayor rendimiento y tasa de crecimiento se obtuvieron al pastorear cada 35 días.

  7. España y la política internacional del fin de la guerra civil al comienzo de la mundial

    Directory of Open Access Journals (Sweden)

    José Alfonso Durango

    1992-01-01

    Full Text Available No es ningún secreto que la guerra civil y la posición del nuevo Estado durante la segunda guerra mundial han acaparado la atención de la historiografía frente a los breves meses de paz durante la primavera y el verano de 1939, contemplados como un ínterin cuando no considerados de importancia secundaria. Sin embargo, si la política exterior debe contemplarse como un proceso estos meses adquieren una relevante importancia como gozne entre la guerra civil y la posición desde la que el régimen se enfrentaría con la revisión del orden internacional emprendido por las potencias del Eje en la segunda guerra mundial.

  8. Aptitud del agua caliente para su uso en agricultura de regadío

    OpenAIRE

    Villar Mir, Josep M.; Carrasco Martín, Israel

    2002-01-01

    En este trabajo se considera el suelo como el sumidero más importante para el calor residual industrial. El agua es el refrigerante más utilizado en las plantas productoras de energía para disipar el exceso de energía calorífica industrial. Esta agua, una vez ha realizado su función y con la temperatura más elevada, puede ser reutilizada en agricultura a través del riego. Se ha realizado una revisión bibliográfica de las experiencias realizadas en todo el mundo sobre los efectos que puede ...

  9. First records of pelagic polychaetes in southern Chile (Boca del Guafo - Elefantes Channel Primeros registros de poliquetos pelágicos en el sur de Chile (Boca del Guafo - Canal Elefantes

    Directory of Open Access Journals (Sweden)

    Marcela Bilbao

    2008-01-01

    Full Text Available Pelagic polychaetes collected at 29 oceanographic stations in the southern channels of Chile between Boca del Guafo and Elefantes Channel (spring 1998, summer 1999 were analyzed. Seven species of pelagic polychaetes were identified: Tomopterisplanktonis Apstein, T. septentrionalis Steenstrup, Pelagobia longicirrata Greeff, Lopadorhynchus krohnii (Claparede, Maupasia caeca Viguier, Typhloscolex muelleri Busch, and Phalacrophorus pictus Greeff. Seven species were collected in spring and five in summer. All the identified species are cosmopolitan and were recorded for the first time in this sector of southern Chile's interior waters. Maupasia caeca, Lopadorhynchus krohnii, and Typhloscolex muelleri are recorded for the first time in the southeastern Pacific Ocean and the southern distribution limit of Phalacrophorus pictus was extended to the coast of Chile.Se analizaron los poliquetos pelágicos colectados en 29 estaciones oceanógraficas en canales australes chilenos localizados entre la boca del Guafo y el estero Elefantes, en primavera de 1998 y verano de 1999. Se identificaron siete especies de poliquetos pelágicos: Tomopteris planktonis Apstein, T. septentrionalis Steenstrup, Pelagobia longicirrata Greeff, Lopadorhynchus krohnii (Claparede, Maupasia caeca Viguier, Typhloscolex muelleri Busch y Phalacrophorus pictus Greeff. Siete especies se colectaron en primavera y cinco en verano. Todas las especies identificadas son cosmopolitas y se registran por primera vez en este sector de aguas interiores del sur de Chile. Maupasia caeca, Lopadorhynchus krohnii y Typhloscolex muelleri se registran por primera vez en aguas del Pacífico suroriental y Phalacrophorus pictus extiende su límite de distribución sur hasta la costa de Chile.

  10. EFECTO DEL SISTEMA DE RIEGO Y CLIMA EN LA EFICIENCIA DEL USO DE AGUA DE NOGAL PECANERO

    Directory of Open Access Journals (Sweden)

    Alejandro Zermeño González

    2014-01-01

    Full Text Available El nogal pecanero (Carya illinoensis K. es una especie frutícola de gran importancia para México, su cultivo se realiza en regiones de clima semidesértico donde el agua es el factor limitante de la producción, por lo que es necesario obtener la máxima eficiencia del uso de este recurso, que es función del sistema de riego y de las condiciones climáticas de la región. Sobre esta base, el objetivo de este estudio fue evaluar la eficiencia del uso del agua de dos huertas de nogal pecanero bajo dos sistemas de riego y diferentes condiciones climáticas. El estudio se realizó en el verano de 2008, en dos huertas de nogal pecanero del noreste de México: una de ellas ubicada en el sureste del estado de Coahuila (Mieleras, municipio de Matamoros con riego por goteo subsuperficial, y la otra en el norte del mismo estado (Zaragoza regada con aspersión. La eficiencia del uso del agua de las huertas del nogal pecanero se definió como la relación entre moles de CO2 asimilados por mol de agua evapotranspirada por el dosel de los árboles. Los resultados del estudio mostraron que aunque la asimilación de CO2 promedio diurna en la huerta de Mieleras (441.68 mmol m-2 fue estadísticamente igual a la observada en la huerta de Zaragoza (489.04 mmol m 2; la eficiencia promedio diaria del uso del agua (mmol CO2 mol-1 H2O fue mayor (P ≤ 0.05 en la huerta de Zaragoza (1.82 que la que se obtuvo en la huerta de Mieleras (1.42. Esto se debió a que las condiciones climáticas en Matamoros fueron de un mayor déficit de presión de vapor y una mayor tasa de evapotranspiración, que tuvieron un efecto mayor en la eficiencia del uso del agua que el sistema de riego utilizado en cada huerta.

  11. Obesity, abdominal obesity, physical activity, and caloric intake in US adults: 1988 to 2010.

    Science.gov (United States)

    Ladabaum, Uri; Mannalithara, Ajitha; Myer, Parvathi A; Singh, Gurkirpal

    2014-08-01

    Obesity and abdominal obesity are associated independently with morbidity and mortality. Physical activity attenuates these risks. We examined trends in obesity, abdominal obesity, physical activity, and caloric intake in US adults from 1988 to 2010. Univariate and multivariate analyses were performed using National Health and Nutrition Examination Survey data. Average body mass index (BMI) increased by 0.37% (95% confidence interval [CI], 0.30-0.44) per year in both women and men. Average waist circumference increased by 0.37% (95% CI, 0.30-0.43) and 0.27% (95% CI, 0.22-0.32) per year in women and men, respectively. The prevalence of obesity and abdominal obesity increased substantially, as did the prevalence of abdominal obesity among overweight adults. Younger women experienced the greatest increases. The proportion of adults who reported no leisure-time physical activity increased from 19.1% (95% CI, 17.3-21.0) to 51.7% (95% CI, 48.9-54.5) in women, and from 11.4% (95% CI, 10.0-12.8) to 43.5% (95% CI, 40.7-46.3) in men. Average daily caloric intake did not change significantly. BMI and waist circumference trends were associated with physical activity level but not caloric intake. The associated changes in adjusted BMIs were 8.3% (95% CI, 6.9-9.6) higher among women and 1.7% (95% CI, 0.68-2.8) higher among men with no leisure-time physical activity compared with those with an ideal level of leisure-time physical activity. Our analyses highlight important dimensions of the public health problem of obesity, including trends in younger women and in abdominal obesity, and lend support to the emphasis placed on physical activity by the Institute of Medicine. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Nutrients, not caloric restriction, extend lifespan in Queensland fruit flies (Bactrocera tryoni).

    Science.gov (United States)

    Fanson, Benjamin G; Weldon, Christopher W; Pérez-Staples, Diana; Simpson, Stephen J; Taylor, Phillip W

    2009-09-01

    Caloric restriction (CR) has been widely accepted as a mechanism explaining increased lifespan (LS) in organisms subjected to dietary restriction (DR), but recent studies investigating the role of nutrients have challenged the role of CR in extending longevity. Fuelling this debate is the difficulty in experimentally disentangling CR and nutrient effects due to compensatory feeding (CF) behaviour. We quantified CF by measuring the volume of solution imbibed and determined how calories and nutrients influenced LS and fecundity in unmated females of the Queensland fruit fly, Bactocera tryoni (Diptera: Tephritidae). We restricted flies to one of 28 diets varying in carbohydrate:protein (C:P) ratios and concentrations. On imbalanced diets, flies overcame dietary dilutions, consuming similar caloric intakes for most dilutions. The response surface for LS revealed that increasing C:P ratio while keeping calories constant extended LS, with the maximum LS along C:P ratio of 21:1. In general, LS was reduced as caloric intake decreased. Lifetime egg production was maximized at a C:P ratio of 3:1. When given a choice of separate sucrose and yeast solutions, each at one of five concentrations (yielding 25 choice treatments), flies regulated their nutrient intake to match C:P ratio of 3:1. Our results (i) demonstrate that CF can overcome dietary dilutions; (ii) reveal difficulties with methods presenting fixed amounts of liquid diet; (iii) illustrate the need to measure intake to account for CF in DR studies and (iv) highlight nutrients rather than CR as a dominant influence on LS.

  13. Effect of solid-meal caloric content on gastric emptying kinetics of solids and liquids.

    Science.gov (United States)

    Urbain, J L; Siegel, J A; Mortelmans, L; van Cutsem, E; van den Maegdenbergh, V; de Roo, M

    1989-08-01

    In this study, we have evaluated the effect of the caloric content of a physiological test meal on the gastric emptying kinetics of solids and liquids. 22 healthy male volunteers were studied in two groups matched for age. After an overnight fast, each volunteer underwent the same test procedure; in the first group (G I), 10 volunteers received a meal consisting of bread, 111In-DTPA water and 1 scrambled egg labeled with 99mTc-labelled sulphur colloid; in the second group (G II) 12 volunteers were given the same meal but with 2 labeled eggs in order to increase the caloric content of the solid phase meal. Simultaneous anterior and posterior images were recorded using a dual-headed gamma camera. Solid and liquid geometric mean data were analyzed to determine the lag phase, the emptying rate and the half-emptying time for both solids and liquids. Solid and liquid gastric half-emptying times were significantly prolonged in G II compared to G I volunteers. For the solid phased, the delay was accounted for by a longer lag phase and a decrease in the equilibrium emptying rate. The emptying rate of the liquid phase was significantly decreased in G II compared to G I. Within each group, no statistically significant difference was observed between solid and liquid emptying rates. We conclude that the caloric content of the solid portion of a meal not only alters the emptying of the solid phase but also affects the emptying of the liquid component of the meal.

  14. [Caloric value and ash content of dominant plants in plantation communities in Heshan of Guangdong, China].

    Science.gov (United States)

    Zeng, Xiao-ping; Cai, Xi-an; Zhao, Ping; Rao, Xing-quan

    2009-03-01

    Different parts of twenty dominant plant species in five plantation communities on the subtropical hilly lands in Heshan of Gunagdong as well as the litters from three of the five plantation communities were sampled, and their gross caloric value (GCV) and ash content were measured by using a PARR-1281 oxygen bomb calorimeter and a muffle furnace. Based on the measurements, the ash-free caloric value (AFCV) of the samples was calculated, and the characteristics of caloric value and ash content of the samples, according to plant part, individual, and plant growth form, were analyzed. The results showed that the GCV and AFCV of leaf, branch, stem wood, stem bark, and root were in the range of 10.7-22.17 kJ x g(-1) and 13.89-23.04 kJ x g(-1), respectively. The GCV and AFCV of leaf were significantly higher than those of other parts (P shrub layer (19.46 kJ x g(-1) > herb layer (18.77 kJ x g(-1)), with indigenous coniferous tree (19.86 kJ x g(-1)) > indigenous broad-leaved tree (19.55 kJ x g(-1)) > exotic eucalyptus (19.18 kJ x g(-1)), while the mean ash content was just the opposite. In Acacia mangium, coniferous, and Schima plantation communities, the GCV and AFCV of litters were higher than those of various plant parts (P mangium and coniferous plantations had higher mean GCV and AFCV than the litters and fresh leaves of tree layer, while the fresh leaves of tree layer in Schima plantation showed higher mean GCV and AFCV.

  15. Lost in processing? Perceived healthfulness, taste and caloric content of whole and processed organic food.

    Science.gov (United States)

    Prada, Marília; Garrido, Margarida V; Rodrigues, David

    2017-07-01

    The "organic" claim explicitly informs consumers about the food production method. Yet, based on this claim, people often infer unrelated food attributes. The current research examined whether the perceived advantage of organic over conventional food generalizes across different organic food types. Compared to whole organic foods, processed organic foods are less available, familiar and prototypical of the organic food category. In two studies (combined N = 258) we investigated how both organic foods types were perceived in healthfulness, taste and caloric content when compared to their conventional alternatives. Participants evaluated images of both whole (e.g., lettuce) and processed organic food exemplars (e.g., pizza), and reported general evaluations of these food types. The association of these evaluations with individual difference variables - self-reported knowledge and consumption of organic food, and environmental concerns - was also examined. Results showed that organically produced whole foods were perceived as more healthful, tastier and less caloric than those produced conventionally, thus replicating the well-established halo effect of the organic claim in food evaluation. The organic advantage was more pronounced among individuals who reported being more knowledgeable about organic food, consumed it more frequently, and were more environmentally concerned. The advantage of the organic claim for processed foods was less clear. Overall, processed organic (vs. conventional) foods were perceived as tastier, more healthful (Study 1) or equally healthful (Study 2), but also as more caloric. We argue that the features of processed food may modulate the impact of the organic claim, and outline possible research directions to test this assumption. Uncovering the specific conditions in which food claims bias consumer's perceptions and behavior may have important implications for marketing, health and public-policy related fields. Copyright © 2017 Elsevier

  16. Conclusiones generales mesa solución política del conflicto armado

    Directory of Open Access Journals (Sweden)

    Congreso Comité Académico

    2012-07-01

    Full Text Available Al calor de 6 ponencias fueron abordados múltiples temas sobre el conflicto armado y la paz. El tema de la memoria fue ambientado por la presentación del contexto histórico del conflicto armado. Recuento experiencial del sufrimiento armado y de la lucha eterna por la reivindicación de los derechos, por la paz, por el reconocimiento del dolor causado y de la legitimación que el pueblo colombiano ha dado a un gobierno extremista que demagógicamente desde la derecha ha causado más crímenes ‘legales’ que los peores terroristas

  17. Modeling Isosteric Heat of Soya Bean for Desorption Energy Estimation Using Neural Network Approach Modelación de Calor Isostérico de Soya para Estimación de Energía de Desorción usando Red neural

    Directory of Open Access Journals (Sweden)

    Reza Amiri Chayjan

    2010-12-01

    Full Text Available Sorption isotherm of soya bean (Glycine max (L. Merr. was obtained by the dynamic experimental method. Artificial Neural Networks (ANNs were used for modeling soya bean equilibrium moisture content (EMC. Thermodynamic equations and trained ANN for prediction of two thermodynamic properties of net isosteric heat and entropy of soya bean were utilized. The ANN models were better compared with mathematical models. In this study, the isosteric heat and entropy of sorption of soya bean were separately predicted by two power models as a EMC function. Predictive power of the models was high (R² ≈ 0.99. At the moisture content above 11% (dry basis, db, isosteric heat and entropy of sorption of soya bean were smoothly decreased, while they were highest at moisture content about 8% (db. Isosteric heat and entropy would be useful in the storage simulation of dried soya bean. The ANN model predicts soya bean EMC more accurately than mathematical models. Hence, better equations could be developed for the prediction of heat of sorption and entropy based on data from the ANN model.La isoterma de desorción de soya (Glycine max (L. Merr. se obtuvo por el método experimental dinámico. Se usaron redes neuronales artificiales (ANN para modelación del contenido de humedad de equilibrio (EMC de soya. Se utilizaron ecuaciones termodinámicas y ANN dirigidas para predicción de dos propiedades termodinámicas, calor isostérico neto y entropía de soya. Los modelos ANN fueron mejores comparados con modelos matemáticos. En este estudio, el calor isostérico y entropía de absorción de soya fueron predichas separadamente por dos modelos de poder como una función de EMC. El poder predictivo de los modelos fue alto (R² ≈ 0.99. A un contenido de humedad superior a 11% (db, el calor isostérico y entropía de absorción de soya fueron ligeramente reducidos, y fueron las más altas a un contenido de 8% (db. El calor isostérico y entropía podrían ser útiles en

  18. Roles of Caloric Restriction, Ketogenic Diet and Intermittent Fasting during Initiation, Progression and Metastasis of Cancer in Animal Models: A Systematic Review and Meta-Analysis: e115147

    National Research Council Canada - National Science Library

    Mengmeng Lv; Xingya Zhu; Hao Wang; Feng Wang; Wenxian Guan

    2014-01-01

      Background The role of dietary restriction regimens such as caloric restriction, ketogenic diet and intermittent fasting in development of cancers has been detected via abundant preclinical experiments...

  19. The late-luteal leptin level, caloric intake and eating behaviors among women with premenstrual dysphoric disorder.

    Science.gov (United States)

    Ko, Chih-Hung; Yen, Cheng-Fang; Long, Cheng-Yu; Kuo, Yu-Ting; Chen, Cheng-Sheng; Yen, Ju-Yu

    2015-06-01

    A marked increased in food intake in the late-luteal phase is a characteristic symptom of premenstrual dysphoric disorder (PMDD). The aim of the study was to evaluate the leptin level, caloric intake, and eating behaviors of women with PMDD across the menstrual cycle among normal-weight and overweight subjects, respectively. A total of 62 women with PMDD and 69 controls were recruited following psychiatric interviewing and underwent prospective investigation. The leptin level, caloric intake, and three factors related to eating behavior were assessed in both the late-luteal and follicular phases. The women with PMDD had greater increases in caloric intake, sweet caloric intake, and uncontrolled eating in the late-luteal phase than the controls. Among the normal-weight women, the leptin level was negatively correlated with caloric intake. The normal-weight women with PMDD had a lower leptin level, a lower leptin/body fat percentage (BFP), a higher caloric intake, and higher uncontrolled eating and emotional eating in the late-luteal phase than the normal-weight controls. Their leptin level was correlated negatively with sweet caloric intake. On the other hand, the overweight women with PMDD had a higher leptin level than the normal-weight women with PMDD and no decline was observed in their leptin level in the late-luteal phase. There were no differences in the leptin level between the overweight women with PMDD and the overweight controls. They also had a higher sweet caloric intake and higher uncontrolled eating and emotional eating than the overweight controls. A decline in the leptin level is associated with late-luteal overeating among normal-weight women with PMDD. Hyperleptinemia and a high sweet caloric intake of overweight women with PMDD should be monitored and addressed in order to attenuate the risk of leptin resistance. The detailed roles of leptin and other psycho-neuro-endocrinology factors in the mechanism of overeating among women with PMDD should

  20. Evaluation of a direct contact heat exchanger; Evaluacion de un intercambiador de calor de contacto directo

    Energy Technology Data Exchange (ETDEWEB)

    Siqueiros, J.; Bonilla, O. [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1997-12-31

    In this paper the application areas of the direct contact heat exchangers is discussed, as well as its main characteristics. A description is made of the experimental equipment designed and built at pilot scale including the instrumentation employed. The methodology employed as well as the analysis and the discussion of the results are also presented. [Espanol] Se mencionan las areas de aplicacion de los intercambiadores de calor de contacto directo, asi como sus caracteristicas principales. Se describe el equipo experimental a nivel piloto disenado y construido incluyendo la instrumentacion utilizada. Se presenta la metodologia empleada asi como el analisis y discusion de los resultados.

  1. Diseño de una máquina de rotomoldeo sin aporte de calor

    OpenAIRE

    Montes Cale, Pablo

    2016-01-01

    El presente proyecto consiste en el diseño de una máquina de rotomoldeo sin aporte de calor con la que se puedan generar piezas huecas de plástico de resina autocurable detallando los tipos de estas resinas utilizadas en este sistema al principio. La máquina está construida mediante un sistema modular para facilitar la reparación o el cambio de piezas ante posible rotura. El movimiento de la máquina está gobernado mediante un variador de frecuencia acoplado a un motorreducto...

  2. The minimal caloric test asymmetric response in vertigo-free migraine patients

    Directory of Open Access Journals (Sweden)

    Eliana Teixeira Maranhão

    2016-02-01

    Full Text Available ABSTRACT Vertigo symptoms and subclinical vestibular dysfunctions may occur in migraine. The Minimal Caloric Test (MCT, an easy-to-perform, convenient and yet informative procedure was used to test the vestibular function in 30 vertigo-free migraine patients outside attacks and 30 paired controls. Although not statistically significant, a right-to-left nystagmus duration asymmetry greater than 25% was present in both groups. This difference was greater in the patients group, suggesting the presence of subclinical vestibular imbalance in migraine.

  3. Targeting energy metabolism in brain cancer with calorically restricted ketogenic diets.

    Science.gov (United States)

    Seyfried, Thomas N; Kiebish, Michael; Mukherjee, Purna; Marsh, Jeremy

    2008-11-01

    Information is presented on the calorically restricted ketogenic diet (CRKD) as an alternative therapy for brain cancer. In contrast to normal neurons and glia, which evolved to metabolize ketone bodies as an alternative fuel to glucose under energy-restricted conditions, brain tumor cells are largely glycolytic due to mitochondrial defects and have a reduced ability to metabolize ketone bodies. The CRKD is effective in managing brain tumor growth in animal models and in patients, and appears to act through antiangiogenic, anti-inflammatory, and proapoptotic mechanisms.

  4. Mechanism-Based Modeling of Gastric Emptying Rate and Gallbladder Emptying in Response to Caloric Intake

    DEFF Research Database (Denmark)

    Guiastrennec, B; Sonne, David Peick; Hansen, M

    2016-01-01

    concentrations, and GBE was developed on data from 33 patients with type 2 diabetes and 33 matched nondiabetic individuals who were administered various test drinks. A feedback action of the caloric content entering the proximal small intestine was identified for the rate of GE. The cholecystokinin...... concentrations were not predictive of GBE, and an alternative model linking the nutrients amount in the upper intestine to GBE was preferred. Relative to fats, the potency on GBE was 68% for proteins and 2.3% for carbohydrates. The model predictions were robust across a broad range of nutritional content and may...

  5. Relationship of Mediterranean diet and caloric intake to phenoconversion in Huntington disease.

    Science.gov (United States)

    Marder, Karen; Gu, Yian; Eberly, Shirley; Tanner, Caroline M; Scarmeas, Nikolaos; Oakes, David; Shoulson, Ira

    2013-11-01

    Adherence to Mediterranean-type diet (MeDi) may delay onset of Alzheimer and Parkinson diseases. Whether adherence to MeDi affects time to phenoconversion in Huntington disease (HD), a highly penetrant, single-gene disorder, is unknown. To determine if MeDi modifies the time to clinical onset of HD (phenoconversion) in premanifest carriers participating in Prospective Huntington at Risk Observational Study (PHAROS), and to examine the effects of body mass index and caloric intake on time to phenoconversion. A prospective cohort study of 41 Huntington study group sites in the United States and Canada involving 1001 participants enrolled in PHAROS between July 1999 and January 2004 who were followed up every 9 months until 2010. A total of 211 participants aged 26 to 57 years had an expanded CAG repeat length (≥ 37). A semiquantitative food frequency questionnaire was administered 33 months after baseline. We calculated daily gram intake for dairy, meat, fruit, vegetables, legumes, cereals, fish, monounsaturated and saturated fatty acids, and alcohol and constructed MeDi scores (0-9); higher scores indicate higher adherence. Demographics, medical history, body mass index, and Unified Huntington's Disease Rating Scale (UHDRS) score were collected. Cox proportional hazards regression models to determine the association of MeDi and phenoconversion. RESULTS Age, sex, caloric intake, education status, and UHDRS motor scores did not differ among MeDi tertiles (0-3, 4-5, and 6-9). The highest body mass index was associated with the lowest adherence to MeDi. Thirty-one participants phenoconverted. In a model adjusted for age, CAG repeat length, and caloric intake, MeDi was not associated with phenoconversion (P for trend = 0.14 for tertile of MeDi, and P = .22 for continuous MeDi). When individual components of MeDi were analyzed, higher dairy consumption (hazard ratio, 2.36; 95% CI, 1.0-5.57; P = .05) and higher caloric intake (P = .04) were associated with risk of

  6. Caloric stimulation

    Science.gov (United States)

    ... hearing and balance. The test also checks for damage to the brain stem. ... eye movements do not occur even after ice cold water is given, there may be damage to the: Nerve of the inner ear Balance ...

  7. Modelación de la transferencia de calor y masa en el absorbedor de una máquina de refrigeración por absorción. // Heat and mass transference modeling in the absorvetor of an absorption cooling device.

    Directory of Open Access Journals (Sweden)

    C. Cisneros Ramírez

    2003-01-01

    Full Text Available En este artículo se dan las expresiones que caracterizan el comportamiento de la temperatura y del producto coeficienteglobal de traspaso de calor (U por el área de traspaso de calor (A , de un absorbedor de una máquina de refrigeración porabsorción que trabaja con la solución amoniaco – agua.Palabras claves: Modelación, absorbedores, refrigeración por absorción.______________________________________________________________________________Abstract.In this article the expressions that characterize the temperature performance and the global heat exchange (U by the heatexchange area (A of the absorvetor of an absorption refrigerating equipment with aqua–ammonia solution are given.Key words: Model, absorber, absorption refrigeration.

  8. Uso de transdutores de fluxo de calor no estudo da transferência de calor em alimentos embalados The use of heat flux transducers to study heat transfer in canned foods

    OpenAIRE

    Carciofi, B.; S. Güths; J. B. Laurindo

    2002-01-01

    A densidade de fluxo de calor que atravessa uma superfície é classicamente determinada mediante a medição das temperaturas apropriadas e da aplicação da Lei de Fourier. Uma alternativa a esse procedimento é a utilização de transdutores de fluxo de calor, os quais geram um sinal elétrico proporcional ao fluxo térmico que os atravessa. Neste trabalho, processos de aquecimento e de resfriamento de alimentos foram estudados em laboratório, utilizando-se um recipiente de vidro cilíndrico para simu...

  9. Computing simulated endolymphatic flow thermodynamics during the caloric test using normal and hydropic duct models.

    Science.gov (United States)

    Rey-Martinez, Jorge; McGarvie, Leigh; Pérez-Fernández, Nicolás

    2017-03-01

    The obtained simulations support the underlying hypothesis that the hydrostatic caloric drive is dissipated by local convective flow in a hydropic duct. To develop a computerized model to simulate and predict the internal fluid thermodynamic behavior within both normal and hydropic horizontal ducts. This study used a computational fluid dynamics software to simulate the effects of cooling and warming of two geometrical models representing normal and hydropic ducts of one semicircular horizontal canal during 120 s. Temperature maps, vorticity, and velocity fields were successfully obtained to characterize the endolymphatic flow during the caloric test in the developed models. In the normal semicircular canal, a well-defined endolymphatic linear flow was obtained, this flow has an opposite direction depending only on the cooling or warming condition of the simulation. For the hydropic model a non-effective endolymphatic flow was predicted; in this model the velocity and vorticity fields show a non-linear flow, with some vortices formed inside the hydropic duct.

  10. Remission of anosognosia for right hemiplegia and neglect after caloric vestibular stimulation.

    Science.gov (United States)

    Ronchi, Roberta; Rode, Gilles; Cotton, François; Farnè, Alessandro; Rossetti, Yves; Jacquin-Courtois, Sophie

    2013-01-01

    Neglect and related phenomena, as anosognosia for hemiplegia and somatoparaphrenia, are often associated to right-hemisphere lesions. These deficits can be alleviated by caloric vestibular stimulation, but little is known about the efficacy of this physiological intervention on neglect following left-hemisphere lesions. Here we report the case of an ambidextrous left brain-damaged patient with severe right personal and extrapersonal neglect, anosognosia for right hemiplegia and somatoparaphrenia. These symptoms co-occurred with more typical manifestations of left-brain damage, such as aphasia and apraxia. Neurological examination revealed right hemiplegia, hemianesthesia and hemianopia. Visuo-spatial tests for personal and extrapersonal neglect, as well as an anosognosia questionnaire, were submitted before and after caloric vestibular stimulation. Results showed a dramatic improvement of anosognosia for hemiplegia and neglect; no change was observed for the remaining deficits. The results confirm the notion of the selectivity of vestibular stimulation for neglect and related disorders and extend this notion by showing that similar effects can be obtained after lesion of the left hemisphere, suggesting that similar mechanisms are responsible for left- and right-sided neglect. Such a peculiar association of language and visuo-spatial disorders jointly present after a left-sided lesion opens the question of the link between handedness and lateralization of cognitive functions.

  11. Modeling body mass variation: incorporating social influence into calculations of caloric intake and energy expenditure.

    Science.gov (United States)

    Hernández-Hernández, Ana María; Huerta-Quintanilla, Rodrigo

    2014-01-01

    Variations in individual body mass and composition have long been a key focus in the health sciences, particularly now that overweight and obesity are considered as public health problems. We study a mathematical model that describes body mass variations which are determined by the energy balance between caloric intake and total energy expenditure. To calculate the change in caloric intake and energy expenditure over time, we proposed a relationship for each of these quantities, and we used measured values that are reported in the literature for the initial conditions. To account for small variations in the daily energy balance of an individual, we include social interactions as the multiplication of two terms: social proximity and social influence. We observe that social interactions have a considerable effect when the body mass of an individual is quite constant and social interactions take random values. However, when an individual's mass value changes (either increases or decreases), social interactions do not have a notable effect. In our simulation, we tested two different models that describe the body mass composition, and it resulted that one fits better the data.

  12. Caloric vestibular stimulation as a treatment for conversion disorder: A case report and medical hypothesis

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    Michael eNoll-Hussong

    2014-06-01

    Full Text Available Conversion disorder is a medical condition in which a person has paralysis, blindness, or other neurological symptoms that cannot be clearly explained physiologically. To date, there is neither specific nor conclusive treatment. In this paper, we draw together a number of disparate pieces of knowledge to propose a novel intervention to provide transient alleviation for this condition. As caloric vestibular stimulation (CVS has been demonstrated to modulate transiently a variety of cognitive functions associated with brain activations, especially in the temporal-parietal cortex, anterior cingulate cortex, and insular cortex, there is evidence to assume an effect in specific mental disorders. Therefore, we go on to hypothesize that lateralized cold vestibular caloric stimulation will be effective in treating conversion disorder and we present provisional evidence from one patient that supports this conclusion. If our hypothesis is correct, this will be the first time in psychiatry and neurology that a clinically well-known mental disorder, long considered difficult to understand and to treat, is relieved by a simple or common, non-invasive medical procedure.

  13. In-shell pistachio nuts reduce caloric intake compared to shelled nuts.

    Science.gov (United States)

    Honselman, Carla S; Painter, James E; Kennedy-Hagan, Karla J; Halvorson, Amber; Rhodes, Kathy; Brooks, Tamatha L; Skwir, Kaitlin

    2011-10-01

    It was hypothesized that consuming in-shell pistachios, compared to shelled pistachios, causes individuals to consume less. A convenience sample of students at a mid-western university (n=140) was recruited, asking them to evaluate a variety of brands of pistachios. A survey at the end of class determined fullness and satisfaction. Subjects entering the classroom were given a 16-ounce cup and asked to self-select a portion of pistachios. Portion weight was recorded and subjects consumed pistachios at their leisure during class. At class end, pistachios remaining in the cup were weighed and total consumption by weight was determined. The caloric content of each portion was then calculated. In condition one, subjects offered in-shell pistachios consumed an average of 125 calories. In condition two, subjects offered shelled pistachios consumed an average of 211 calories; a difference of 86 calories. Subjects in condition one consumed 41% fewer calories compared to subjects in condition two (p≤.01). Fullness and satisfaction ratings were not significantly different (p≥.01). Caloric intake was influenced by the initial form of the food. The difference in calories consumed may be due to the additional time needed to shell the nuts or the extra volume perceived when consuming in-shell nuts. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Is caloric restriction associated with development of eating-disorder symptoms? Results from the CALERIE trial.

    Science.gov (United States)

    Williamson, Donald A; Martin, Corby K; Anton, Stephen D; York-Crowe, Emily; Han, Hongmei; Redman, Leanne; Ravussin, Eric

    2008-01-01

    This study tested a secondary hypothesis of the CALERIE trial (Heilbronn et al., 2006) that a 12-month period of intentional dietary restriction would be associated with an increase in eating disorder symptoms. To test this hypothesis, 48 overweight adults were randomly assigned to four treatment arms in a 12-month study: (1) 25% calorie restriction, (2) 12.5% calorie restriction and 12.5% increased energy expenditure by structured exercise, (3) low-calorie diet, and (4) healthy diet (no-calorie restriction). Primary outcome measures for the study were changes in: eating disorder symptoms, mood, dietary restraint, body weight, and energy balance. All three dietary restriction arms were associated with increased dietary restraint and negative energy balance, but not with increased ED symptoms or other harmful psychological effects. Participants in the three calorie restriction arms lost significant amounts of body weight. The psychological and behavioral effects were maintained during a 6-month follow-up period. These results did not support the hypothesis that caloric restriction causes increased eating disorder symptoms in overweight adults. In general, caloric restriction had either benign or beneficial psychological and behavioral effects. (Copyright) 2008 APA.

  15. AMP activated protein kinase is indispensable for myocardial adaptation to caloric restriction in mice.

    Directory of Open Access Journals (Sweden)

    Kai Chen

    Full Text Available Caloric restriction (CR is a robust dietary intervention known to enhance cardiovascular health. AMP activated protein kinase (AMPK has been suggested to mediate the cardioprotective effects of CR. However, this hypothesis remains to be tested by using definitive loss-of-function animal models. In the present study, we subjected AMPKα2 knockout (KO mice and their wild type (WT littermates to a CR regimen that reduces caloric intake by 20%-40% for 4 weeks. CR decreased body weight, heart weight and serum levels of insulin in both WT and KO mice to the same degree, indicating the effectiveness of the CR protocol. CR activated cardiac AMPK signaling in WT mice, but not in AMPKα2 KO mice. Correspondingly, AMPKα2 KO mice had markedly reduced cardiac function during CR as determined by echocardiography and hemodynamic measurements. The compromised cardiac function was associated with increased markers of oxidative stress, endoplasmic reticulum stress and myocyte apoptosis. Mechanistically, CR down-regulated the expression of ATP5g2, a subunit of mitochondrial ATP synthase, and reduced ATP content in AMPKα2 KO hearts, but not in WT hearts. In addition, CR accelerated cardiac autophagic flux in WT mice, but failed to do so in AMPKα2 KO mice. These results demonstrated that without AMPK, CR triggers adverse effects that can lead to cardiac dysfunction, suggesting that AMPK signaling pathway is indispensible for energy homeostasis and myocardial adaptation to CR, a dietary intervention that normally produces beneficial cardiac effects.

  16. El abastecimiento de agua en las ciudades del Mediterráneo

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    Pulido Bosch, Antonio

    1999-10-01

    Full Text Available Not available.En las ciudades costeras, como en las no costeras, una buena parte del agua captada se pierde en las redes de distribución; además, el usuario no es siempre consciente de la necesidad de ahorrar al máximo este recurso. Hay que tener en cuenta igualmente que el agua residual, una vez depurada, puede constituir un buen recurso que permite satisfacer parte de la demanda y a la vez reducir los problemas planteados por la eliminación de las aguas usadas directamente en el mar. Las soluciones a los problemas de la escasez de agua deben pasar por el ahorro de agua, la reducción de las pérdidas en las redes de distribución, la reutilización y, a veces, la importación de agua de lugares excedentarios, sin olvidar la desalación de las aguas saladas o salobres. El desarrollo sostenible exige una planificación partiendo de la demanda máxima admisible, compatible con el respeto a los equilibrios ambientales; esto puede exigir la limitación del crecimiento de las ciudades, lo que no es siempre aceptado. Por último, se comentan dos ejemplos, uno representativo de una ciudad donde no existe gran competencia por el agua entre la demanda agrícola y la demanda urbana (Almería; y el otro relativo a una ciudad donde el turismo de verano aumenta casi diez veces la población, con una agricultura para la que la demanda de agua alcanza en verano también su máximo (Almuñécar, Granada.

  17. Caracterización y evaluación de la calidad del agua de los ríos Quiscab y San Francisco, Guatemala

    Directory of Open Access Journals (Sweden)

    Normal E. Gil

    2017-03-01

    Full Text Available Los ríos Quiscab y San Francisco son los principales afluentes del lago de Atitlán. Para determinar el aporte de contaminación de estos ríos, se realizaron ocho muestreos durante dos años (septiembre 2011 a septiembre 2013, evaluando la parte alta, media y baja de las dos sub cuencas y desembocaduras en el lago de Atitlán. Se midieron los parámetros fisicoquímicos, calculando el Índice de Calidad del Agua (ICA de El Salvador. Se evaluó la presencia y cantidad de macroinvertebrados acuáticos y se calculó el Indice Biológico por Familias de El Salvador (IBF-SV-2010. Se evaluó la presencia de fitoplancton en forma cualitativa y cuantitativa en la desembocadura de los ríos en el lago. Los dos ríos presentaron valores de ICA y de IBF-SV regular y regular pobre respectivamente. La contaminación del agua no reveló diferencias significativas entre las épocas de los años estudiados (invierno y verano, es decir seca y lluviosa. Se obtuvieron dos mapas en los que se observó que en las partes altas de ambas cuencas se mostraban valores aceptables de calidad del agua. Esta calidad se va deteriorando desde la parte media hasta la parte baja de los ríos, volviendo a mejorar en la desembocadura del lago de Atitlán. En los monitoreos cuantitativos de fitoplancton de la desembocadura de los ríos se observó una alta presencia de organismos representantes de Cianophytas, no existiendo diferencias en cuanto a cantidad y género en comparación con el invierno y verano.

  18. The calorically restricted ketogenic diet, an effective alternative therapy for malignant brain cancer

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    Zhou Weihua

    2007-02-01

    Full Text Available Abstract Background Malignant brain cancer persists as a major disease of morbidity and mortality in adults and is the second leading cause of cancer death in children. Many current therapies for malignant brain tumors fail to provide long-term management because they ineffectively target tumor cells while negatively impacting the health and vitality of normal brain cells. In contrast to brain tumor cells, which lack metabolic flexibility and are largely dependent on glucose for growth and survival, normal brain cells can metabolize both glucose and ketone bodies for energy. This study evaluated the efficacy of KetoCal®, a new nutritionally balanced high fat/low carbohydrate ketogenic diet for children with epilepsy, on the growth and vascularity of a malignant mouse astrocytoma (CT-2A and a human malignant glioma (U87-MG. Methods Adult mice were implanted orthotopically with the malignant brain tumors and KetoCal® was administered to the mice in either unrestricted amounts or in restricted amounts to reduce total caloric intake according to the manufacturers recommendation for children with refractory epilepsy. The effects KetoCal® on tumor growth, vascularity, and mouse survival were compared with that of an unrestricted high carbohydrate standard diet. Results KetoCal® administered in restricted amounts significantly decreased the intracerebral growth of the CT-2A and U87-MG tumors by about 65% and 35%, respectively, and significantly enhanced health and survival relative to that of the control groups receiving the standard low fat/high carbohydrate diet. The restricted KetoCal® diet reduced plasma glucose levels while elevating plasma ketone body (β-hydroxybutyrate levels. Tumor microvessel density was less in the calorically restricted KetoCal® groups than in the calorically unrestricted control groups. Moreover, gene expression for the mitochondrial enzymes, β-hydroxybutyrate dehydrogenase and succinyl-CoA: 3-ketoacid Co

  19. The calorically restricted ketogenic diet, an effective alternative therapy for malignant brain cancer.

    Science.gov (United States)

    Zhou, Weihua; Mukherjee, Purna; Kiebish, Michael A; Markis, William T; Mantis, John G; Seyfried, Thomas N

    2007-02-21

    Malignant brain cancer persists as a major disease of morbidity and mortality in adults and is the second leading cause of cancer death in children. Many current therapies for malignant brain tumors fail to provide long-term management because they ineffectively target tumor cells while negatively impacting the health and vitality of normal brain cells. In contrast to brain tumor cells, which lack metabolic flexibility and are largely dependent on glucose for growth and survival, normal brain cells can metabolize both glucose and ketone bodies for energy. This study evaluated the efficacy of KetoCal, a new nutritionally balanced high fat/low carbohydrate ketogenic diet for children with epilepsy, on the growth and vascularity of a malignant mouse astrocytoma (CT-2A) and a human malignant glioma (U87-MG). Adult mice were implanted orthotopically with the malignant brain tumors and KetoCal was administered to the mice in either unrestricted amounts or in restricted amounts to reduce total caloric intake according to the manufacturers recommendation for children with refractory epilepsy. The effects KetoCal on tumor growth, vascularity, and mouse survival were compared with that of an unrestricted high carbohydrate standard diet. KetoCal administered in restricted amounts significantly decreased the intracerebral growth of the CT-2A and U87-MG tumors by about 65% and 35%, respectively, and significantly enhanced health and survival relative to that of the control groups receiving the standard low fat/high carbohydrate diet. The restricted KetoCal diet reduced plasma glucose levels while elevating plasma ketone body (beta-hydroxybutyrate) levels. Tumor microvessel density was less in the calorically restricted KetoCal groups than in the calorically unrestricted control groups. Moreover, gene expression for the mitochondrial enzymes, beta-hydroxybutyrate dehydrogenase and succinyl-CoA: 3-ketoacid CoA transferase, was lower in the tumors than in the contralateral normal

  20. General and persistent effects of high-intensity sweeteners on body weight gain and caloric compensation in rats

    Science.gov (United States)

    Swithers, Susan E.; Baker, Chelsea R.; Davidson, T.L.

    2009-01-01

    In four experiments, we assessed the generality of previous findings (Swithers & Davidson, 2008) that increased caloric intake, body weight gain, and reduced caloric compensation are exhibited by rats that consume a diet containing a nonnutritive, high intensity sweetener. In this earlier work, rats consumed a diet in which saccharin was mixed in low-fat yogurt, and animals were provided with a fixed amount of the yogurt. The present experiments showed that the effects of saccharin on energy intake and body weight gain are also obtained when rats were given Acesulfame Potassium (AceK), a nonnutritive high intensity sweetener that is chemically distinct from saccharin. Increased energy intake and body weight gain and impaired caloric compensation were also obtained with a saccharin-sweetened base diet (refried beans) that was calorically similar, but nutritionally distinct from low-fat yogurt. The present studies also extended earlier findings by showing that body weight differences persist after saccharin-sweetened diets are discontinued and following a shift to a diet sweetened with glucose. In addition, rats first exposed to a diet sweetened with glucose still gain additional weight when subsequently exposed to a saccharin sweetened diet. The effect of saccharin on caloric compensation was more complex in that it appeared to depend on the type of diet (yogurt or beans) in which saccharin was consumed prior to testing. The results of these experiments add support to the hypothesis that exposure to weak or non-predictive relationships between sweet tastes and caloric consequences may lead to positive energy balance. PMID:19634935

  1. Transferencia de calor en el secado solar a la intemperie de menas lateríticas ferroniquelíferas

    Directory of Open Access Journals (Sweden)

    Yoalbys Retirado-Mediaceja

    2011-03-01

    Full Text Available En Moa, las menas lateríticas son sometidas a secado solar a la intemperie para reducirles el contenido de humedad antes de incorporarlas al proceso de secado térmico convencional. Este artículo evalúa los procesos de transferencia de calor fundamentales que tienen lugar durante el secado natural con el propósito de determinar el modo predominante de transferencia de calor. En dos pilas de menas lateríticas expuestas a secado solar natural se midieron las variables climatológicas y termodinámicas que influyen en la transferencia de calor por convección y radiación durante el secado y se calcularon, además, los criterios adimensionales para determinar el tipo predominante de convección. Se comprobó que durante el secado solar a la intemperie predomina la convección y que en las condiciones de experimentación analizadas la radiación tuvo una incidencia secundaria. Los resultados evidenciaron que el calor se transfiere por convección libre, forzada y mixta, predominando la forzada, para la cual los coeficientes de transferencia de calor mínimos y máximos mostraron pequeñas variaciones entre ambas pilas. Los flujos de calor por convección promedios fueron 978,74 y 1 156,58 W/m2 , mientras que los flujos por radiación ascendieron a 324,71 y 355,36 W/m2 para las pilas #1 y #2, respectivamente.

  2. Overeat today, skip the scale tomorrow: An examination of caloric intake predicting nonadherence to daily self-weighing.

    Science.gov (United States)

    Tanenbaum, Molly L; Ross, Kathryn M; Wing, Rena R

    2016-11-01

    Daily self-weighing is an effective weight loss strategy. Little is known about "micro" factors influencing nonadherence to self-weighing (e.g., daily overeating). It was hypothesized that increased caloric intake on a given day would increase odds of not self-weighing the following day. Daily self-reports of weight and caloric intake were collected from 74 adults with overweight and obesity (mean BMI = 31.2 ± 4.5 kg/m2 , age = 50.6 ± 10 years, 69% female, 87% Caucasian) throughout a 12-week Internet-based weight management intervention. Multilevel logistic regression investigated odds of nonadherence to self-weighing on a given day based on the previous day's caloric intake. Self-monitoring adherence was high (weights: 87%; calories: 85%); adherence was associated with greater 12-week weight loss (weighing: r = -0.24, P = 0.04; calories: r = -0.26, P = 0.04). Increased caloric intake on a given day, relative to the individual's average intake, was associated with increased odds of nonadherence to self-weighing the next day (F(1,5106)  = 12.66, P = 0.0004, β = 0.001). For example, following a day of eating 300 calories more than usual, odds of not self-weighing increased by 1.33. Odds of nonadherence to self-weighing increased following a day with higher-than-usual caloric intake. Weight management interventions collecting daily self-monitoring data could provide support to participants who report increased caloric intake to prevent self-weighing nonadherence. © 2016 The Obesity Society.

  3. Observaciones ecológicas en la Isla de Salamanca (Depto. del Magdalena, Colombia Observaciones ecológicas en la Isla de Salamanca (Depto. del Magdalena, Colombia

    Directory of Open Access Journals (Sweden)

    Schnetter Marie-Luise

    1969-06-01

    énaga Grande de Santa Marta en el sur. La temperatura promedia anual es de 28° C. El verano dura cinco meses, la cantidad anual de lluvias sube probablemente a los 70 mm. En toda la región los suelos son arenosos. Vastas zonas de la Isla, sobre todo en el oeste, están cubiertas con manglares. En el este, donde se realizaron las investigaciones, las partes más elevadas están cubiertas con monte espinoso, mientras que en terrenos bajos (poco encima del nivel del mar hay tierras salinas desnudas o con vegetación de plantas halófilas, como Batis maritima y Sesuvium portulacastrum. Generalmente la salinidad del suelo es causada por aguas salinas subterráneas. Durante el verano la superficie de la tierra en las zonas desnudas esta cubierta con una costra de sal, mientras que en el verano los contenidos de sal en los estratos superiores son muy bajos. Las concentraciones de sal en áreas cubiertas con plantas halófilas pueden elevarse sobre las de las zonas desnudas, causada probablemente por la absorción de agua por las plantas. Donde el nivel de las aguas subterráneas esta cerca de la superficie de la tierra, hay un contenido alto de agua en todo el año, Al elevarse el nivel de la tierra sobre el nivel del mar, el disminuye. Al fin del verano el suministro de agua en las áreas cubiertas con plantas puede ser peor que en las zonas desnudas, pero en el invierno la cubierta vegetal reduce el desagüe superficial de las aguas de las lluvias.  Donde las aguas subterráneas no llegan hasta la superficie de la tierra, se puede desarrollar el monte espinoso, porque la concentración de sal baja notablemente en los estratos superiores. En el sitio investigado no se encontraron raíces cerca del nivel de las aguas subterráneas.  La mayoría de las especies creciendo en el monte espinoso pierde sus hojas durante el verano. Las especies con hojas fuertes, como Prosopis juliflora y Pithecollobium. spec, tienen un contenido de agua de 70%, aproximadamente. Las hojas suculentas de

  4. Predictive properties of the video head impulse test: measures of caloric symmetry and self-report dizziness handicap.

    Science.gov (United States)

    McCaslin, Devin L; Jacobson, Gary P; Bennett, Marc L; Gruenwald, Jill M; Green, Andrea P

    2014-01-01

    The purpose of this investigation was to determine whether a predictable relationship existed between self-reported dizziness handicap and video Head Impulse Test (vHIT) results in a large sample of patients reporting to a dizziness clinic. Secondary objectives included describing the characteristics of the vHIT ipsilesional and contralesional vestibulo-ocular reflex slow-phase velocity in patients with varying levels of canal paresis. Finally, the authors calculated the sensitivity and specificity of the vHIT for detecting horizontal semicircular canal impairment using the caloric test as the "gold standard." Participants were 115 adults presenting to a tertiary medical care center with symptoms of dizziness. Participants were administered a measure of self-report dizziness handicap (i.e., Dizziness Handicap Inventory) and underwent caloric testing and vHIT at the same appointment. Results showed that (1) there were no significant group differences (i.e., vHIT normal versus vHIT abnormal) in the Dizziness Handicap Inventory total score, (2) both ipsilesional and contralateral velocity gain decreased with increases in caloric paresis, and (3) a caloric asymmetry of 39.5% was determined to be the cutoff that maximized discrimination of vHIT outcome. The level of self-reported dizziness handicap is not predicted by the outcome of the vHIT, which is consistent with the majority of published reports describing the poor relationship between quantitative tests of vestibular function and dizziness handicap. Further, the study findings have demonstrated that vHIT and caloric data are not redundant, and each test provides unique information regarding the functional integrity of the horizontal semicircular canal at different points on the frequency spectrum. The vHIT does offer some advantages over caloric testing, but at the expense of sensitivity. The vHIT can be completed in less time, is not noxious to the patient, and requires very little laboratory space. However, the

  5. Inferior vestibular neuritis: 3 cases with clinical features of acute vestibular neuritis, normal calorics but indications of saccular failure

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    Økstad Siri

    2006-12-01

    Full Text Available Abstract Background Vestibular neuritis (VN is commonly diagnosed by demonstration of unilateral vestibular failure, as unilateral loss of caloric response. As this test reflects the function of the superior part of the vestibular nerve only, cases of pure inferior nerve neuritis will be lost. Case presentations We describe three patients with symptoms suggestive of VN, but normal calorics. All 3 had unilateral loss of vestibular evoked myogenic potential. A slight, asymptomatic position dependent nystagmus, with the pathological ear down, was observed. Conclusion We believe that these patients suffer from pure inferior nerve vestibular neuritis.

  6. Addressing the policy cacophony does not require more evidence: an argument for reframing obesity as caloric overconsumption.

    Science.gov (United States)

    Shelley, Jacob J

    2012-11-30

    Numerous policies have been proposed to address the public health problem of obesity, resulting in a policy cacophony. The noise of so many policy options renders it difficult for policymakers to determine which policies warrant implementation. This has resulted in calls for more and better evidence to support obesity policy. However, it is not clear that evidence is the solution. This paper argues that to address the policy cacophony it is necessary to rethink the problem of obesity, and more specifically, how the problem of obesity is framed. This paper argues that the frame "obesity" be replaced by the frame "caloric overconsumption", concluding that the frame caloric overconsumption can overcome the obesity policy cacophony. Frames are important because they influence public policy. Understood as packages that define issues, frames influence how best to approach a problem. Consequently, debates over public policy are considered battles over framing, with small shifts in how an issue is framed resulting in significant changes to the policy environment. This paper presents a rationale for reframing the problem of obesity as caloric overconsumption. The frame "obesity" contributes to the policy cacophony by including policies aimed at both energy output and energy input. However, research increasingly demonstrates that energy input is the primary cause of obesity, and that increases in energy input are largely attributable to the food environment. By focusing on policies that aim to prevent increases in energy input, the frame caloric overconsumption will reduce the noise of the obesity policy cacophony. While the proposed frame will face some challenges, particularly industry opposition, policies aimed at preventing caloric overconsumption have a clearer focus, and can be more politically palatable if caloric overconsumption is seen as an involuntary risk resulting from the food environment. The paper concludes that policymakers will be able to make better sense

  7. Addressing the policy cacophony does not require more evidence: an argument for reframing obesity as caloric overconsumption

    Directory of Open Access Journals (Sweden)

    Shelley Jacob J

    2012-11-01

    Full Text Available Abstract Background Numerous policies have been proposed to address the public health problem of obesity, resulting in a policy cacophony. The noise of so many policy options renders it difficult for policymakers to determine which policies warrant implementation. This has resulted in calls for more and better evidence to support obesity policy. However, it is not clear that evidence is the solution. This paper argues that to address the policy cacophony it is necessary to rethink the problem of obesity, and more specifically, how the problem of obesity is framed. This paper argues that the frame “obesity” be replaced by the frame “caloric overconsumption”, concluding that the frame caloric overconsumption can overcome the obesity policy cacophony. Discussion Frames are important because they influence public policy. Understood as packages that define issues, frames influence how best to approach a problem. Consequently, debates over public policy are considered battles over framing, with small shifts in how an issue is framed resulting in significant changes to the policy environment. This paper presents a rationale for reframing the problem of obesity as caloric overconsumption. The frame “obesity” contributes to the policy cacophony by including policies aimed at both energy output and energy input. However, research increasingly demonstrates that energy input is the primary cause of obesity, and that increases in energy input are largely attributable to the food environment. By focusing on policies that aim to prevent increases in energy input, the frame caloric overconsumption will reduce the noise of the obesity policy cacophony. While the proposed frame will face some challenges, particularly industry opposition, policies aimed at preventing caloric overconsumption have a clearer focus, and can be more politically palatable if caloric overconsumption is seen as an involuntary risk resulting from the food environment. Summary

  8. Transferencia de calor en el secado solar a la intemperie de menas lateríticas ferroniquelíferas

    OpenAIRE

    Yoalbys Retirado-Mediaceja; Marbelis Lamorú-Urgelles; Ever Góngora-Leyva; Enrique Torres-Tamayo; Benigno Leyva-de la Cruz; Daynelis García-Batista

    2011-01-01

    En Moa, las menas lateríticas son sometidas a secado solar a la intemperie para reducirles el contenido de humedad antes de incorporarlas al proceso de secado térmico convencional. Este artículo evalúa los procesos de transferencia de calor fundamentales que tienen lugar durante el secado natural con el propósito de determinar el modo predominante de transferencia de calor. En dos pilas de menas lateríticas expuestas a secado solar natural se midieron las variables climatológicas y termodinám...

  9. Abstenerse del terror: la paradoja de la no violencia en el Sáhara Occidental

    Directory of Open Access Journals (Sweden)

    Matthew Porges

    2016-04-01

    Full Text Available En el Sáhara Occidental, antigua colonia española ocupada por Marruecos desde 1975, no ha habido prácticamente ninguna resistencia violenta por parte del pueblo indígena saharaui desde el final de la guerra de 1975-1991 entre Marruecos y el Frente Polisario. La ausencia de violencia sorprende por varios factores: amplio apoyo de la población a la independencia, disparidades sociales y económicas entre marroquíes y saharauis, así como una brutal represión de Marruecos de la cultura, la resistencia y las manifestaciones del sentimiento independentista saharaui. Este artículo analiza la lógica de la violencia –y de su ausencia–, así como la resistencia, y extrae lecciones del Sáhara Occidental. Además de avanzar en el desarrollo teórico, se realiza un aporte metodológico al estudio de la resistencia y una mejor comprensión del conflicto del Sáhara Occidental mediante un trabajo de campo que incluyó unas 60 entrevistas con activistas saharauis realizadas durante el verano de 2014.

  10. Perfil del excursionista de cruceros que visita la isla de Cozumel

    Directory of Open Access Journals (Sweden)

    Julia Sderis Anaya Ortiz

    2015-01-01

    Full Text Available El turismo de cruceros se ha convertido en un sector de suma importancia para la isla de Cozumel, sin embargo se desconoce el perfil del excursionista que visita el destino, toda vez que la información que se obtiene a partir de las instancias federales como la Secretaría de Turismo (SECTUR o bien la emitida por los informes de los organismos del ramo como la Florida- Caribbean Cruise Association (FCCA o la Cruise Lines International Association, no revelan el tipo de consumidor que llega a los destinos del Caribe. A través de la realización de 350 cuestionarios con 19 ítems aplicados en el Muelle de Puerta Maya durante el verano de 2013, permitieron conocer algunas particularidades del excursionista, entre las que destacan el mínimo gasto que realizan en el destino, el cual 50% menor al reportado por la Secretaría de Turismo del estado de Quintana Roo, así como el hecho de ser un visitante repetitivo.

  11. Ritmos biológicos y uso del tiempo en una comunidad mapuche aislada

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    Negro, A.

    2003-01-01

    Full Text Available Este proyecto persigue establecer la influencia de factores ambientales y culturales sobre los patrones temporales de poblaciones humanas. Estudiamos la comunidad mapuche de Milaín Currical (Neuquén en distintas estaciones, registrando el ciclo diario sueño-vigilia y otros parámetros relacionados con cambios cíclicos en el comportamiento y la fisiología de los habitantes. El objetivo es lograr una explicación englobadora del uso del tiempo en poblaciones bajo distintas condiciones ambientales. Asimismo, se registró la variación estacional en los procesos migratorios y en variables epidemiológicas. Las variables ambientales (fotoperíodo, temperatura, lluvias exhibieron ciclos anuales de gran amplitud. La comunidad presenta variaciones estacionales con claras diferencias entre verano e invierno, incluyendo cambios de horario de sus actividades y del ciclo sueño-vigilia, que correlacionan con variaciones ambientales. Las consultas médicas tuvieron un pico hacia el final del invierno. La comunidad realiza una migración anual entre las tierras de veranada y de invernada, que puede ser correlacionada con las variables ambientales, en particular el fotoperíodo. El estudio de comunidades sujetas a cambios temporales profundos en el ambiente (sin sincronizadores artificiales ofrece un excelente modelo para la investigación del sistema cronobiológico humano.

  12. Influencia del porcentaje de mezcla del aceite de higuerilla en la obtención de combustible alternativo para motores diesel

    Directory of Open Access Journals (Sweden)

    Arnoldo Emilio Delgado

    2011-01-01

    Full Text Available En el presente artículo se describe el uso del aceite de higuerilla como combustible alternativo en motores diesel. Para este fi n, se obtiene biodiesel a partir de aceite de higuerilla mediante el proceso de transesterifi cación. Se prueban tres mezclas de biodiesel (B5%, B10% y B20% en un motor diesel, para el cual se midieron los siguientes parámetros: la potencia, el consumo de combustible, la temperatura del motor, y los gases de combustión;las mezclas fueron caracterizadas mediante la densidad, viscosidad, índice de refracción y calor de combustión. Se determinó que el uso del aceite de higuerilla en la mezcla genera un aumento en la viscosidad y el consumo de combustible, además también infl uye en la reducción del poder calorífico, potencia del motor, los gases de combustión como el CO y CO2, los óxidos de azufre, los hidrocarburos, la opacidad en los humos del escape del motor y ocasiona un equilibrio en el rendimiento observado en el motor diesel, manifi esto en las temperaturas del motor.

  13. One-Year Behavioral Treatment of Obesity: Comparison of Moderate and Severe Caloric Restriction and the Effects of Weight Maintenance Therapy.

    Science.gov (United States)

    Wadden, Thomas A.; And Others

    1994-01-01

    Compared weight losses of 49 obese women assigned to 52-week behavioral program combined with moderate or severe caloric restriction. Those in severe caloric restriction group lost significantly more weight during first 26 weeks but regained some weight. Reports of binge eating declined in both groups, and no relationship was observed between…

  14. Caloric Intake from Fast Food among Children and Adolescents in the United States, 2011-2012. NCHS Data Brief. Number 213

    Science.gov (United States)

    Vikraman, Sundeep; Fryar, Cheryl D.; Ogden, Cynthia L.

    2015-01-01

    Consumption of fast food has been linked to weight gain in adults. Fast food has also been associated with higher caloric intake and poorer diet quality in children and adolescents. From 1994 through 2006, caloric intake from fast food increased from 10% to 13% among children aged 2-18 years. This report presents the most recent data on the…

  15. LOS DÃAS LARGOS ARTIFICIALES CONSTANTES INCREMENTAN LA PRODUCCIÓN LÃCTEA EN LAS CABRAS ALPINAS DEL NORTE DE MÉXICO

    OpenAIRE

    Evaristo Carrillo; Carlos Leyva; Rafael Rodríguez-Martinez; José Elizundia; Pedro Antonio Robles-Trillo; Gerardo Arellano-Rodríguez; Francisco Gerardo Véliz; Juan Ramón Luna-Orozco

    2010-01-01

    Para determinar si la aplicación de días largos artificiales durante el invierno y primavera aumenta la producción láctea de las cabras Alpinas del norte de México, un grupo testigo (GT; n=14), fue expuesto a las variaciones naturales del fotoperiodo de la región durante todo el estudio (10 h y 19 m en el solsticio de invierno y 13 h con 41 m durante el solsticio de verano), mientras otro grupo experimental (GE; n=15), se sujetó a un tratamiento de días largos constantes (16 h de luz/...

  16. Validación de los datos de radiación solar UV del Ozone Monitoring Instrument (OMI a partir de medidas con base en tierra en la costa mediterránea

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    F. Marchetti

    2016-12-01

    Full Text Available La Dosis Eritemática Diaria (EDD y el Índice UV (UVI al mediodía obtenidos con el Ozone Monitoring Instrument (OMI, a bordo del satélite Aura de la NASA, han sido validados para el periodo 2005-2013 utilizando medidas con base en tierra en 5 estaciones diferentes de la costa mediterránea: Murcia, Valencia, Palma de Mallorca, Barcelona y Roma (donde sólo se tienen medidas del UVI al mediodía. Las medidas con base en tierra fueron realizadas con radiómetros YES UVB-1 en Murcia, Valencia, Palma de Mallorca y Barcelona, y con un espectrofotómetro Brewer MKIV en Roma. La evolución de la EDD muestra un claro comportamiento estacional en todas las localidades, tanto para los datos de suelo como para los satelitales, con valores máximos en verano (junio y julio y valores mínimos en invierno (diciembre y enero. Los resultados de la validación muestran una buena correlación entre los datos satelitales y las medidas con base en tierra, aunque las del OMI sobreestiman las de los instrumentos de suelo. Las diferencias entre ambos conjuntos de medidas es máxima para los meses de primavera y verano y mínima en los meses de otoño e invierno. Un elevado porcentaje de casos (>80% presenta diferencias mínimas (0 ó 1 unidades entre el UVI obtenido con el OMI y el obtenido con los instrumentos de suelo para todas las estaciones de medida. En todas ellas se alcanzan valores del UVI altos (6-7 o muy altos (8-10 en un elevado porcentaje de los días del periodo analizado, pero apenas se alcanzan valores del UVI extremos (≥11.

  17. Evaluación del confort térmico de los conductores de la empresa “Transportes Interinsulares de Tenerife” por el método de Fanger.

    OpenAIRE

    Govea-Goya, Laura

    2012-01-01

    El presente proyecto tiene la finalidad de exponer y evaluar el confort térmico mediante el cálculo del índice de satisfacción de los conductores de la empresa “Transportes Interurbanos de Tenerife (TITSA)”. El estrés térmico por calor es la carga de calor que los trabajadores reciben y acumulan en su cuerpo y que resulta de la interacción entre las condiciones ambientales del lugar donde trabajan, la actividad física que realizan y la ropa que llevan. Constituye normalmente una fuente de ...

  18. A two year randomized controlled trial of human caloric restriction: feasibility and effects on predictors of health span and longevity

    Science.gov (United States)

    Background: Caloric restriction (CR), energy intake reduced below ad libitum (AL) intake, increases life span in many species. The implications for humans can be clarified by randomized controlled trials of CR. Methods: To determine CRs feasibility, safety, and effects on predictors of longevity, di...

  19. Caloric content of leaves of five tree species from the riparian vegetation in a forest fragment from South Brazil

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    Leandro Fabrício Fiori

    2015-09-01

    Full Text Available Abstract Aim: The measurement of the caloric content evidences the amount of energy that remains in the leaf and that can be released to the aquatic trophic chain. We assessed the energy content of leaves from five riparian tree species of a forest fragment in south Brazil and analyzed whether leaf caloric content varied between leaf species and between seasons (dry and wet. The studied sites are located in Northwest of Paraná State, inside a Semi-Deciduous Forest fragment beside two headwater streams. Methods Sampling sites were located along the riparian vegetation of these two water bodies, and due to its proximity and absence of statistical differences of caloric values, analyzed as one compartment. Results Caloric content varied significantly among species and among all pairs of species, with exception of Nectandra cuspidata Ness and Calophyllum brasiliensis Cambess. Two species presented significant differences between seasons, Sloanea guianensis (Aubl. Ben and Calophyllum brasiliensis Cambess. Conclusions The absence of significant seasonal differences of energy content for some species may be due to the characteristics of the tropical forest, in which temperature did not varied dramatically between seasons. However, the energy differed between species and seasons for some species, emphasizing the necessity of a preliminary inspection of energy content, before tracing energy fluxes instead of using a single value to all species from riparian vegetation.

  20. Short-term caloric restriction normalizes hypothalamic neuronal responsiveness to glucose ingestion in patients with type 2 diabetes

    NARCIS (Netherlands)

    Teeuwisse, W.M.; Widya, R.L.; Paulides, M.; Lamb, H.J.; Smit, J.W.A.; Roos, A. de; Buchem, M.A. van; Pijl, H.; Grond, J. van der

    2012-01-01

    The hypothalamus is critically involved in the regulation of feeding. Previous studies have shown that glucose ingestion inhibits hypothalamic neuronal activity. However, this was not observed in patients with type 2 diabetes. Restoring energy balance by reducing caloric intake and losing weight are

  1. Weight loss in obese men by caloric restriction and high-dose diazoxide-mediated insulin suppression.

    NARCIS (Netherlands)

    Boekel, G.A.J van; Loves, S.; Sorge, A van; Ruinemans-Koerts, J.; Rijnders, T.; Boer, H. de

    2008-01-01

    OBJECTIVE: To examine the concept whether high-dose diazoxide (DZX)-mediated insulin suppression, in combination with moderate caloric restriction and increased physical activity, can establish a weight loss of at least 15% in obese hyperinsulinaemic men. DESIGN: Open, uncontrolled, 6-month pilot

  2. Caloric Restriction in Lean and Obese Strains of Laboratory Rat: Effects on Body Composition, Metabolism, Growth, and Overall Health

    Science.gov (United States)

    NEW FINDINGS: What is the central question of this study? How do lean and obese rats respond physiologically to caloric restriction? What is the main finding and its importance? Obese rats show marked benefits compared with lean animals. Reduced body fat is associated with improv...

  3. Comparison of Vestibular Evoked Myogenic Potential and Caloric Tests Findings in Noise Induced Hearing Loss-Affected and Healthy Individuals

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    Farinoosh Fakharnia

    2010-06-01

    Full Text Available Background and Aim: Balance disturbance is one of the non-auditory effects of noisy industrial environments that is usually neglected. The aim of the current study was to investigate the effect of occupational noise on vestibular system among workers with noise-induced hearing loss (NIHL, based on both vestibular evoked myogenic potentials (VEMP and caloric tests.Methods: Thirty male workers with noise-induced hearing loss and thirty male matched controls were examined by VEMP and caloric tests. Study parameters included unilateral weakness, p13 and n23 latencies, and p13-n23 amplitude. Caloric test was performed only for 20 patients.Results: No significant difference was observed in unilateral weakness between the two groups. On the other hand, the difference in mean latencies of p13 in the right ear (p=0.003 and left ear (p=0.01 was significant between the two groups. However, the difference in n23 latency was significant only in the right ear (p=0.03. There was no significant difference between groups in p13-n23 amplitude.Conclusion: It seems that pars inferior of vestibule is the susceptible part in individuals with NIHL. In general, abnormal findings in both VEMP and caloric tests were more common compared to functional symptoms such as vertigo, which may be due to central compensation and the symmetry of the disorder.

  4. The effect of non-caloric sweeteners on cognition, choice, and post-consumption satisfaction.

    Science.gov (United States)

    Hill, Sarah E; Prokosch, Marjorie L; Morin, Amanda; Rodeheffer, Christopher D

    2014-12-01

    Consumers often turn to non-caloric sweeteners (NCS) as a means of promoting a healthy body weight. However, several studies have now linked their long-term use to increased weight gain, raising the question of whether these products produce unintended psychological, physiological, or behavioral changes that have implications for weight management goals. In the following, we present the results of three experiments bearing on this issue, testing whether NCS-consumption influences how individuals think about and respond to food. Participants in each of our three experiments were randomly assigned to consume a sugar-sweetened beverage, an unsweetened beverage, or a beverage sweetened with NCS. We then measured their cognition (Experiment 1), product choice (Experiment 2), and subjective responses to a sugar-sweetened food (Experiment 3). Results revealed that consuming NCS-sweetened beverages influences psychological processes in ways that - over time - may increase calorie intake. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Tunable magneto-caloric effect in Gd1-xTbx heterostructures thin film

    Science.gov (United States)

    Lambert, C. H.; El Hadri, M. S.; Hamedoun, M.; Benyoussef, A.; Mounkachi, O.; Mangin, S.

    2017-12-01

    The magnetic and magneto-caloric properties of (Gd1-xTbx) alloy thin films and [Gd/Tb] multilayers have been investigated. All the samples had a total thickness of 100 nm and were deposited by DC sputtering. By changing the composition of the system, the ordering temperature (Tc) and the magnetic entropy changes of the compounds could be tuned. The results show that the Tc of the alloy thin films is close to 270 K for x = 0.2. Moreover, creating [Gd/Tb] multilayers with the same thickness and concentration of the studied Gd80Tb20 alloy film enables to strongly increase the relative cooling power, and reach values twice as big as from the corresponding alloys. These results suggest that nanostructuring of [Gd/Tb] multilayers may be a promising route to tailor the magnetocaloric response of materials.

  6. Assessment of potentially harmful elements pollution in the Calore River basin (Southern Italy).

    Science.gov (United States)

    Zuzolo, Daniela; Cicchella, Domenico; Catani, Vittorio; Giaccio, Lucia; Guagliardi, Ilaria; Esposito, Libera; De Vivo, Benedetto

    2017-06-01

    The geographical distribution of concentration values for harmful elements was determined in the Campania region, Italy. The study area consists of the drainage basin of the River Calore, a tributary of the river Volturno, the largest Southern Italian river. The results provide reliable analytical data allowing a quantitative assessment of the trace element pollution threat to the ecosystem and human health. Altogether 562 stream sediment samples were collected at a sampling density of 1 site per 5 km2. All samples were air-dried, sieved to urban settlements and industrial areas. The enrichment factor of these elements is 3-4 times higher than the background values. The southwestern area of the basin is characterized by a moderate/high degree of contamination, just where the two busiest roads of the area run and the highest concentration of industries occurs.

  7. Effects of Caloric Restriction on Cardiovascular Aging in Non-human Primates and Humans

    Science.gov (United States)

    Cruzen, Christina; Colman, Ricki J.

    2009-01-01

    Synopsis Approximately one in three Americans has some form of cardiovascular disease (CVD), accounting for one of every 2.8 deaths in the United States in 2004. Two of the major risk factors for CVD are advancing age and obesity. An intervention able to positively impact both aging and obesity, such as caloric restriction (CR), may prove extremely useful in the fight against CVD. CR is the only environmental or lifestyle intervention that has repeatedly been shown to increase maximum life span and to retard aging in laboratory rodents. In this article, we review evidence that CR in nonhuman primates and humans has a positive effect on risk factors for CVD. PMID:19944270

  8. Aging and Caloric Restriction Research: A Biological Perspective With Translational Potential

    Directory of Open Access Journals (Sweden)

    Priya Balasubramanian

    2017-07-01

    Full Text Available Aging as a research pursuit is fairly new compared with traditional lines of medical research. A growing field of investigators is focused on understanding how changes in tissue biology, physiology, and systemic homeostasis, conspire to create increased vulnerability to disease as a function of age. Aging research as a discipline is necessarily broad; in part because aging itself is multi-faceted and in part because different model systems are employed to define the underlying biology. In this review we outline aspects of aging research that are likely to uncover the pivotal events leading to age-related disease vulnerability. We focus on studies of human aging and discuss the value of research on caloric restriction, an intervention with proven efficacy in delaying aging. We propose that studies such as these will deliver target factors and processes that create vulnerability in human aging, an advance that would potentially be transformative in clinical care.

  9. Caloric Restriction as a Strategy to Improve Vascular Dysfunction in Metabolic Disorders

    Directory of Open Access Journals (Sweden)

    Concha F. García-Prieto

    2016-06-01

    Full Text Available Caloric restriction (CR has proved to be the most effective and reproducible dietary intervention to increase healthy lifespan and aging. A reduction in cardiovascular disease (CVD risk in obese subjects can be already achieved by a moderate and sustainable weight loss. Since pharmacological approaches for body weight reduction have, at present, a poor long-term efficacy, CR is of great interest in the prevention and/or reduction of CVD associated with obesity. Other dietary strategies changing specific macronutrients, such as altering carbohydrates, protein content or diet glycemic index have been also shown to decrease the progression of CVD in obese patients. In this review, we will focus on the positive effects and possible mechanisms of action of these strategies on vascular dysfunction.

  10. Repletion of TNFα or leptin in calorically restricted mice suppresses post-restriction hyperphagia

    Directory of Open Access Journals (Sweden)

    Catherine Hambly

    2012-01-01

    The causes of post-restriction hyperphagia (PRH represent a target for drug-based therapies to prevent obesity. However, the factors causing PRH are poorly understood. We show that, in mice, the extent of PRH was independent of the time under restriction, but depended on its severity, suggesting that PRH was driven by signals from altered body composition. Signals related to fat mass were important drivers. Circulating levels of leptin and TNFα were significantly depleted following caloric restriction (CR. We experimentally repleted their levels to match those of controls, and found that in both treatment groups the level of PRH was significantly blunted. These data establish a role for TNFα and leptin in the non-pathological regulation of energy homeostasis. Signals from adipose tissue, including but not limited to leptin and TNFα, regulate PRH and might be targets for therapies that support people engaged in CR to reduce obesity.

  11. Caloric restriction suppresses apoptotic cell death in the mammalian cochlea and leads to prevention of presbycusis.

    Science.gov (United States)

    Someya, Shinichi; Yamasoba, Tatsuya; Weindruch, Richard; Prolla, Tomas A; Tanokura, Masaru

    2007-10-01

    Presbycusis is characterized by an age-related progressive decline of auditory function, and arises mainly from the degeneration of hair cells or spiral ganglion (SG) cells in the cochlea. Here we show that caloric restriction suppresses apoptotic cell death in the mouse cochlea and prevents late onset of presbycusis. Calorie restricted (CR) mice, which maintained body weight at the same level as that of young control (YC) mice, retained normal hearing and showed no cochlear degeneration. CR mice also showed a significant reduction in the number of TUNEL-positive cells and cleaved caspase-3-positive cells relative to middle-age control (MC) mice. Microarray analysis revealed that CR down-regulated the expression of 24 apoptotic genes, including Bak and Bim. Taken together, our findings suggest that loss of critical cells through apoptosis is an important mechanism of presbycusis in mammals, and that CR can retard this process by suppressing apoptosis in the inner ear tissue.

  12. Adiabatic measurements of magneto-caloric effects in pulsed high magnetic fields up to 55 T

    Science.gov (United States)

    Kihara, T.; Kohama, Y.; Hashimoto, Y.; Katsumoto, S.; Tokunaga, M.

    2013-07-01

    Magneto-caloric effects (MCEs) measurement system in adiabatic condition is proposed to investigate the thermodynamic properties in pulsed magnetic fields up to 55 T. With taking the advantage of the fast field-sweep rate in pulsed field, adiabatic measurements of MCEs were carried out at various temperatures. To obtain the prompt response of the thermometer in the pulsed field, a thin film thermometer is grown directly on the sample surfaces. The validity of the present setup was demonstrated in the wide temperature range through the measurements on Gd at about room temperature and on Gd3Ga5O12 at low temperatures. The both results show reasonable agreement with the data reported earlier. By comparing the MCE data with the specific heat data, we could estimate the entropy as functions of magnetic field and temperature. The results demonstrate the possibility that our approach can trace the change in transition temperature caused by the external field.

  13. Repletion of TNFα or leptin in calorically restricted mice suppresses post-restriction hyperphagia

    Science.gov (United States)

    Hambly, Catherine; Duncan, Jacqueline S.; Archer, Zoë A.; Moar, Kim M.; Mercer, Julian G.; Speakman, John R.

    2012-01-01

    SUMMARY The causes of post-restriction hyperphagia (PRH) represent a target for drug-based therapies to prevent obesity. However, the factors causing PRH are poorly understood. We show that, in mice, the extent of PRH was independent of the time under restriction, but depended on its severity, suggesting that PRH was driven by signals from altered body composition. Signals related to fat mass were important drivers. Circulating levels of leptin and TNFα were significantly depleted following caloric restriction (CR). We experimentally repleted their levels to match those of controls, and found that in both treatment groups the level of PRH was significantly blunted. These data establish a role for TNFα and leptin in the non-pathological regulation of energy homeostasis. Signals from adipose tissue, including but not limited to leptin and TNFα, regulate PRH and might be targets for therapies that support people engaged in CR to reduce obesity. PMID:21954068

  14. Neuroimaging Biomarkers of Caloric Restriction on Brain Metabolic and Vascular Functions.

    Science.gov (United States)

    Lin, Ai-Ling; Parikh, Ishita; Hoffman, Jared D; Ma, David

    2017-03-01

    Non-invasive neuroimaging methods have been developed as powerful tools for identifying in vivo brain functions for studies in humans and animals. Here we review the imaging biomarkers that are being used to determine the changes within brain metabolic and vascular functions induced by caloric restriction (CR), and their potential usefulness for future studies with dietary interventions in humans. CR causes an early shift in brain metabolism of glucose to ketone bodies, and enhances ATP production, neuronal activity and cerebral blood flow (CBF). With age, CR preserves mitochondrial activity, neurotransmission, CBF, and spatial memory. CR also reduces anxiety in aging mice. Neuroimaging studies in humans show that CR restores abnormal brain activity in the amygdala of women with obesity and enhances brain connectivity in old adults. Neuroimaging methods have excellent translational values and can be widely applied in future studies to identify dietary effects on brain functions in humans.

  15. Acute caloric restriction counteracts hepatic bile acid and cholesterol deficiency in morbid obesity.

    Science.gov (United States)

    Straniero, S; Rosqvist, F; Edholm, D; Ahlström, H; Kullberg, J; Sundbom, M; Risérus, U; Rudling, M

    2017-05-01

    Bile acid (BA) synthesis is regulated by BA signalling in the liver and by fibroblast growth factor 19 (FGF19), synthesized and released from the intestine. In morbid obesity, faecal excretion and hepatic synthesis of BAs and cholesterol are strongly induced and caloric restriction reduces their faecal excretion considerably. We hypothesized that the high intestinal food mass in morbidly obese subjects promotes faecal excretion of BAs and cholesterol, thereby creating a shortage of both BAs and cholesterol in the liver. Ten morbidly obese women (BMI 42 ± 2.6 kg m-2 ) were monitored on days 0, 3, 7, 14 and 28 after beginning a low-calorie diet (800-1100 kcal day-1 ). Serum was collected and liver size and fat content determined. Synthesis of BAs and cholesterol was evaluated from serum markers, and the serum levels of lipoproteins, BAs, proprotein convertase subtilisin/kexin type 9 (PCSK9), insulin, glucose and FGF19 were monitored. Fifty-four nonobese women (BMI cholesterol and serum levels of BAs and PCSK9 were elevated in the obese group compared to controls. Already after 3 days on a low-calorie diet, BA and cholesterol synthesis and serum BA and PCSK9 levels normalized, whereas LDL cholesterol increased. FGF19 and triglyceride levels were unchanged, and liver volume was reduced by 10%. The results suggest that hepatic BAs and cholesterol are deficient in morbid obesity. Caloric restriction rapidly counteracts these deficiencies, normalizing BA and cholesterol synthesis and circulating PCSK9 levels, indicating that overproduction of cholesterol in enlarged peripheral tissues cannot explain this phenotype. We propose that excessive food intake promotes faecal loss of BAs and cholesterol contributing to their hepatic deficiencies. © 2017 The Authors. Journal of Internal Medicine published by John Wiley & Sons Ltd on behalf of Association for Publication of The Journal of Internal Medicine.

  16. Cognitive performances are selectively enhanced during chronic caloric restriction or resveratrol supplementation in a primate.

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    Alexandre Dal-Pan

    Full Text Available Effects of an 18-month treatment with a moderate, chronic caloric restriction (CR or an oral supplementation with resveratrol (RSV, a potential CR mimetic, on cognitive and motor performances were studied in non-human primates, grey mouse lemurs (Microcebus murinus.Thirty-three adult male mouse lemurs were assigned to three different groups: a control (CTL group fed ad libitum, a CR group fed 70% of the CTL caloric intake, and an RSV group (RSV supplementation of 200 mg.kg(-1.day(-1 fed ad libitum. Three different cognitive tests, two motor tests, one emotional test and an analysis of cortisol level were performed in each group.Compared to CTL animals, CR or RSV animals did not show any change in motor performances evaluated by rotarod and jump tests, but an increase in spontaneous locomotor activity was observed in both groups. Working memory was improved by both treatments in the spontaneous alternation task. Despite a trend for CR group, only RSV supplementation increased spatial memory performances in the circular platform task. Finally, none of these treatments induced additional stress to the animals as reflected by similar results in the open field test and cortisol analyses compared to CTL animals.The present data provided the earliest evidence for a beneficial effect of CR or RSV supplementation on specific cognitive functions in a primate. Taken together, these results suggest that RSV could be a good candidate to mimic long-term CR effects and support the growing evidences that nutritional interventions can have beneficial effects on brain functions even in adults.

  17. Cognitive Performances Are Selectively Enhanced during Chronic Caloric Restriction or Resveratrol Supplementation in a Primate

    Science.gov (United States)

    Marchal, Julia; Picq, Jean-Luc; Aujard, Fabienne

    2011-01-01

    Effects of an 18-month treatment with a moderate, chronic caloric restriction (CR) or an oral supplementation with resveratrol (RSV), a potential CR mimetic, on cognitive and motor performances were studied in non-human primates, grey mouse lemurs (Microcebus murinus). Thirty-three adult male mouse lemurs were assigned to three different groups: a control (CTL) group fed ad libitum, a CR group fed 70% of the CTL caloric intake, and an RSV group (RSV supplementation of 200 mg.kg−1.day−1) fed ad libitum. Three different cognitive tests, two motor tests, one emotional test and an analysis of cortisol level were performed in each group. Compared to CTL animals, CR or RSV animals did not show any change in motor performances evaluated by rotarod and jump tests, but an increase in spontaneous locomotor activity was observed in both groups. Working memory was improved by both treatments in the spontaneous alternation task. Despite a trend for CR group, only RSV supplementation increased spatial memory performances in the circular platform task. Finally, none of these treatments induced additional stress to the animals as reflected by similar results in the open field test and cortisol analyses compared to CTL animals. The present data provided the earliest evidence for a beneficial effect of CR or RSV supplementation on specific cognitive functions in a primate. Taken together, these results suggest that RSV could be a good candidate to mimic long-term CR effects and support the growing evidences that nutritional interventions can have beneficial effects on brain functions even in adults. PMID:21304942

  18. Effects of caloric restriction on nitrogen and carbon stable isotope ratios in adult rat bone.

    Science.gov (United States)

    Robertson, Kimberly L; Rowland, Neil E; Krigbaum, John

    2014-10-15

    Stable isotope analysis is a valuable technique for dietary estimation in ecological and archaeological research, yet many variables can potentially affect tissue stable isotope signatures. Controlled feeding studies across a range of species have consistently demonstrated impacts of caloric restriction on tissue stable isotope ratios, but most have focused on juvenile, fasting, and/or starving individuals, and most have utilized soft tissues despite the importance of bone for paleodietary analyses. The goal of this study was to determine whether temporally defined, moderate food restriction could affect stable carbon and/or nitrogen isotope ratios in adult mammalian bone - a tissue that arguably reflects long-term dietary signals. Adult rats fed a standard laboratory diet were restricted to 45% of ad libitum intakes for 3 or 6 months. Relevant anatomical and physiological parameters were measured to confirm that the restriction protocol resulted in significant nutritional stress and to provide independent data to facilitate interpretation of stable isotope ratios. Femoral bone δ(13)Ccollagen, δ(15)Ncollagen, and δ(13)Capatite values were determined by isotope ratio mass spectrometry. Calorie-restricted animals exhibited a small, yet significant enrichment in (15)Ncollagen compared with control animals, reflecting protein-calorie stress. While the δ(13)Ccollagen values did not differ, the δ(13)Capatite values revealed less enrichment in (13)C than in controls, reflecting catabolism of body fat. Independent anatomical and physiological data from these same individuals support these interpretations. Results indicate that moderate caloric restriction does not appreciably undermine broad interpretations of dietary signals in adult mammalian bone. Significant variability among individuals or groups, however, is best explained by marked differences in energy intake over variable timescales. An inverse relationship between the δ(13)Capatite and δ(15)Ncollagen

  19. Caloric intake during the perioperative period and growth failure in infants with congenital heart disease.

    Science.gov (United States)

    Nicholson, George T; Clabby, Martha L; Kanter, Kirk R; Mahle, William T

    2013-02-01

    Infants with congenital heart disease have impaired weight gain during the first several months of life. Efforts have focused on improving weight gain and nutritional status during the first months of life. Close examination of the data suggests that the immediate postoperative period is problematic. Etiology of this early growth failure should be identified to develop effective interventions. This is a retrospective study of neonates who underwent modified systemic-to-pulmonary artery shunt, including Norwood palliation, at Children's Healthcare of Atlanta between January 2009 and July 2011. We analyzed growth from time of surgical intervention to hospital discharge. Measures of calculated weight-for-age Z-score (WAZ score) were performed using the World Health Organization's Anthro Software (version 3.2.2, January 2011; WHO, Geneva, Switzerland). Seventy-three patients were identified. Eight patients did not meet inclusion criteria. Complete data were collected on the remaining 65 patients. Median caloric intake patients received was 50.4 [interquartile range (IQR) 41.6 to 63.6] calories/kg/day while exclusively on parental nutrition. At hospital discharge, the median WAZ score was -2.0 (IQR -2.7 to -1.2) representing an overall median WAZ score decrease of -1.3 (IQR -1.7 to -0.7) from time of shunt palliation to hospital discharge. Despite studies showing poor weight gain in infants with congenital heart disease after neonatal palliation, this study reports the impact of hospital-based nutritional practices on weight gain in infants during the immediate postoperative period. Our data demonstrate that actual caloric intake during the cardiac intensive care unit stay is substantially below what is recommended.

  20. Effects of caloric restriction and overnight fasting on cycling endurance performance.

    Science.gov (United States)

    Ferguson, Lisa M; Rossi, Kelly A; Ward, Emily; Jadwin, Emily; Miller, Todd A; Miller, Wayne C

    2009-03-01

    In addition to aerobic endurance and anaerobic capacity, high power-to-weight ratio (PWR) is important for cycling performance. Cyclists often try to lose weight before race season to improve body composition and optimize PWR. Research has demonstrated body fat-reducing benefits of exercise after fasting overnight. We hypothesized that fasted-state exercise in calorie-restricted trained cyclists would not result in performance decrements and that their PWR would improve significantly. We also hypothesized that substrate use during fasted-state submaximal endurance cycling would shift to greater reliance on fat. Ten trained, competitive cyclists completed a protocol consisting of baseline testing, 3 weeks of caloric restriction (CR), and post-CR testing. The testing sessions measured pre- and post-CR values for resting metabolic rate (RMR), body composition, VO2, PWR and power-to-lean weight ratio (PLWR), and power output, as well as 2-hour submaximal cycling performance, rating of perceived exertion (RPE), and respiratory exchange ratio (RER). There were no significant differences between baseline and post-CR for submaximal trial RER, power output, VO2, RMR, VO2max, or workload at VO2max. However, RPE was significantly lower, and PWR was significantly higher post-CR, whereas RER did not change. The cyclists' PWR and body composition improved significantly, and their overall weight, fat weight, and body fat percentage decreased. Lean mass was maintained. The cyclists' RPE decreased significantly during 2 hours of submaximal cycling post-CR, and there was no decrement in submaximal or maximal cycling performance after 3 weeks of CR combined with overnight fasting. Caloric restriction (up to 40% for 3 weeks) and exercising after fasting overnight can improve a cyclist's PWR without compromising endurance cycling performance.

  1. Low-versus high-glycemic index diets in women: effects on caloric requirement, substrate utilization and insulin sensitivity.

    Science.gov (United States)

    Clapp, James F; Lopez, Beth

    2007-09-01

    Lowering dietary glycemic index appears to have positive health effects in obese and/or insulin resistant individuals. However, detailed studies in lean young men show no effect. This study was designed to test the null hypothesis that a diet rich in low-glycemic carbohydrate has no effect on lipid profile, caloric requirements, fat oxidation, or insulin sensitivity in adult women when compared to one rich in high-glycemic carbohydrate. The metabolic feeding protocol used was conducted in both a free-living and in-patient setting using a randomized crossover design. Seven women were studied on each of 2 diets in which 60% of the calories were from either high- or low-glycemic carbohydrate sources. Each diet lasted 20 days with measurements of caloric requirement, resting metabolic rate, glucose and insulin responses to diet and activity, insulin sensitivity, and lipid profile over the last 7 days. Caloric requirement was determined by bomb calorimetry. Other techniques included indirect calorimetry, hydrodensitometry, stable isotope tracers, and the euglycemic clamp. On the low-glycemic index diet the women's caloric requirements were 11% +/- 1% higher, fat oxidation at fasted rest supplied an average of 45% +/- 4% versus 28% +/- 5% of oxidative requirements, average glucose and insulin levels were approximately 40% lower, low density lipoproteins (LDL) and leptin concentrations were lower, and various indices of insulin sensitivity were > 20% higher. In this group of adult women, a diet that lowered glycemic index well below that typically found in western diets increased both daily caloric requirement and fat oxidation, decreased insulin and glucose concentrations and increased insulin sensitivity.

  2. Actuaciones para el control y erradicación del teosinte (Zea mays spp.) en Aragón

    OpenAIRE

    Pardo Sanclemente, Gabriel; Fuertes, S.; Betrán, E.; Cirujeda Ranzenberger, Alicia

    2015-01-01

    En el verano de 2014 se tuvo constancia de la presencia de teosinte (Zea mays spp.) como mala hierba en campos de maíz de Aragón y en menos medida en Cataluña. Se conoce por teosinte a un grupo de especies y subespecies del género Zea, la mayoría de ellas de la misma especie que el maíz y originarias de Méjico. El maíz actual procede de antiguos teosintes mejorados, tras miles de años de selección. Debido al potencial infestante y competidor de esta especie, la Dirección General de Alimentaci...

  3. Panorama epidemiológico del loxoscelismo en el Perú.

    Directory of Open Access Journals (Sweden)

    Hernán Sanabria

    1997-07-01

    Full Text Available Se describen los principales aspectos epidemiológicos del loxoscelismo en el Perú. Las arañas caseras L. laeta y L. rufipes son las responsables del loxoscelismo an el país. Este envenenamiento se observa con mayor frecuencia en las ciudades de la costa del Pacífico. El mayor número de accidentes ocurre en los meses de verano, fundamentalmente en el interior del domicilio, en horas de la noche y primeras horas de la mañana; algunas veces la mordedura pasa desapercibida. Se revisaron casuísticas reportadas de hospitalizaciones ocurridas en el período 1943-1997 encontrándose 476 casos reportados. 74% correspondieron al síndrome cutáneo necrótico y 26% al síndrome sistémico ó cutáneo viscero-hemolítico. La mortalidad se asoció al síndrome sistémico con insuficiencia renal, siendo la letalidad mayor en pacientes menores de 13 años. Se proponen medidas de control y prevención de este emponzoñamiento y se postula qua investigaciones epidemiológicas pudieran identificar otros tipos de arañas como agentes de araneismo necrótico en el Perú diferentes a las Loxosceles.

  4. Predicción numérica de la microestructura de la zona afectada por el calor (ZAC durante el proceso de soldeo SMAW en el acero al Cr-Mo-V

    Directory of Open Access Journals (Sweden)

    Mazur, Z.

    2001-10-01

    Full Text Available Cracking associated with welds operating in high temperatures and high pressure, is a problem of consideration. The performance of welded joints, both during fabrication and operation depends strictly upon the microstructure of the heat-affected zone (HAZ, which, in a steel of a given composition, is a function of welding conditions and joint geometry. The methodology of prediction of the dimensions of the zones containing different sizes in the HAZ grain of a single-bead weld of 1.25Cr-1Mo-0.25V steel using SMAW deposition process is described. The standard heat-flow equations have been used to determine weld thermal cycles in conjunction with basic metallurgy including phases-transformation, grain growth kinetics and empirical equations to describe the effects of welding variables on weld bead dimensions.

    La fisuración de las uniones por soldeo que operan a temperaturas y presiones elevadas es un problema considerable. La eficacia de estas uniones, tanto durante el proceso de soldeo como durante su operación, depende de manera estricta de la microestructura de la zona afectada por el calor (ZAC del metal base, la cual para una composición química dada del material es una función de los parámetros de soldeo y la geometría de la unión. Se presenta una metodología de predicción de las dimensiones de las zonas que ocupan distintos tamaños de grano de la ZAC, en un cordón de soldadura aplicado al acero de baja aleación 1,25Cr-1Mo-0,25V por el proceso SMAW. Las bases para el desarrollo del algoritmo fueron las ecuaciones clásicas de transferencia del calor para determinar los ciclos térmicos de soldeo, metalurgia básica, incluyendo diagramas de fases y cinética de crecimiento de granos, y relaciones empíricas para describir la correlación de los variables de soldeo y las dimensiones del cordón de soldadura.

  5. Macrofauna del curso inferior y estuario del río Biobío (Chile: cambios asociados a variabilidad estacional del caudal hídrico Macrofauna of the lower reach and estuary of Biobío river (Chile: changes associated to seasonal changes of the river flow

    Directory of Open Access Journals (Sweden)

    CARLOS BERTRÁN

    2001-06-01

    Full Text Available Uno de los sistemas lóticos chilenos de mayor importancia de acuerdo a su caudal es el río Biobío (ca. 37º S. Su estuario es reducido, especialmente en las épocas de máximo caudal. Con el objetivo de poner a prueba la hipótesis de que en verano la disminución del caudal del río Biobío, determina una mayor depositación del material particulado fino y que el aumento del caudal en invierno resulta en el lavado y transporte del material depositado hacia el mar, y consecuentemente en una disminución de la macrofauna bentónica, se recolectaron muestras para análisis sedimentológicos y faunísticos en el curso inferior y estuario del río Biobío, durante agosto de 1993 y marzo de 1994. Los análisis sedimentológicos indican que el tamaño medio del sedimento correspondió a arenas gruesas. La depositación del material fino suspendido, que ocurre durante el verano se manifiesta en el mayor porcentaje de finos y materia orgánica durante este período. La macrofauna bentónica estuvo compuesta por 16 taxa en el muestreo de invierno y 42 taxa en el de verano. Durante el invierno, la mayoría de ellas estuvo representada por muy pocos individuos. Durante el verano aumentó la riqueza específica y abundancias totales de la macrofauna. Los taxa más abundantes fueron un Archiannelida indeterminado y el poliqueto Perinereis gualpensis. El aumento del caudal en la época invernal, determina el transporte del material depositado hacia el mar y consecuentemente el arrastre de organismos bentónicos. Aún cuando los valores de abundancia y biomasa de macrofauna durante el verano fueron de un orden de magnitud mayor que en la fase invernal, fueron menores que los citados para otros estuarios del centro-sur de Chile (ca. 39º S. Eso contribuye a confirmar el carácter atípico del estuario del río Biobío, el que debido a sus cambios estacionales de caudal genera cambios significativos en la estructura comunitaria de la macrofauna bent

  6. Interpretação e utilidade da prova calórica Interpretation and use of caloric testing

    Directory of Open Access Journals (Sweden)

    Denise Utsch Gonçalves

    2008-06-01

    Full Text Available A prova calórica é o teste da avaliação otoneurológica que verifica a integridade do reflexo vestíbulo-ocular e possibilita avaliar cada labirinto separadamente. Os principais aspectos relacionados à realização, interpretação e utilidade da prova calórica foram revistos. MÉTODOS: Realizou-se revisão sistemática sobre as publicações ocorridas nos últimos cem anos sobre o assunto. Incluíram-se artigos originais transversais e longitudinais, de revisão e meta-análise. Excluíram-se revisões de papeleta, relatos de caso e editoriais. Os descritores utilizados foram: prova calórica, nistagmo, sistema vestibular, preponderância direcional, predomínio labiríntico, teste calórico monotermal, teste calórico com água gelada, fenômeno de Bell. Pesquisou-se as bases de dados COCHRAINE, MEDLINE, LILACS, CAPES. RESULTADOS: De 818 resumos de artigos, selecionou-se inicialmente 93 que preenchiam os critérios de inclusão. A leitura dos artigos resultou na seleção final de 55. Na análise dos artigos, enfatizou-se na discussão fundamentos da prova calórica, tipos de estimulação utilizados, prova calórica monotermal e com água gelada, questões relacionadas à interpretação dos resultados, variáveis e artefatos. COMENTÁRIOS FINAIS: os valores de referência utilizados na prova calórica podem variar de serviço para serviço, com ponto de corte definido a partir de estudos locais. Semiotécnica cuidadosa é fundamental para elevar a sensibilidade do exame.Caloric testing is an otoneurologic evaluation of the status of the vestibular-ocular reflex; it allows an evaluation of each labyrinth separately. The main aspects on the use and interpretation of caloric testing are reviewed. METHOD: A systematic review of papers published in the past one hundred years on caloric testing was undertaken. The inclusion criteria were: cross-sectional, longitudinal, original articles, reviews and meta-analyses. Reviews of patient charts

  7. Looking at the label and beyond: the effects of calorie labels, health consciousness, and demographics on caloric intake in restaurants

    Science.gov (United States)

    2013-01-01

    Background Recent legislation has required calorie labels on restaurant menus as a means of improving Americans’ health. Despite the growing research in this area, no consensus has been reached on the effectiveness of menu labels. This suggests the possibility of heterogeneity in responses to caloric labels across people with different attitudes and demographics. The purpose of this study was to explore the potential relationships between caloric intake and diners’ socio-economic characteristics and attitudes in a restaurant field experiment that systematically varied the caloric information printed on the menus. Methods We conducted a field experiment in a full service restaurant where patrons were randomly assigned to one of three menu treatments which varied the amount of caloric information printed on the menus (none, numeric, or symbolic calorie label). At the conclusion of their meals, diners were asked to complete a brief survey regarding their socio-economic characteristics, attitudes, and meal selections. Using regression analysis, we estimated the number of entrée and extra calories ordered by diners as a function of demographic and attitudinal variables. Additionally, irrespective of the menu treatment to which a subject was assigned, our study identified which types of people are likely to be low-, medium-, and high-calorie diners. Results Results showed that calorie labels have the greatest impact on those who are least health conscious. Additionally, using a symbolic calorie label can further reduce the caloric intake of even the most health conscious patrons. Finally, calorie labels were more likely to influence the selection of the main entrée as opposed to supplemental items such as drinks and desserts. Conclusions If numeric calorie labels are implemented (as currently proposed), they are most likely to influence consumers who are less health conscious – probably one of the key targets of this legislation. Unfortunately, numeric labels did

  8. High Caloric Diet for ALS Patients: High Fat, High Carbohydrate or High Protein

    Directory of Open Access Journals (Sweden)

    Sarvin Sanaie

    2015-01-01

    . They showed that patients in the highcarbohydrate/high-calorie groups gained 0.39 kg more weight per month, compared with 0.11kg per month in the control group, and there was an average weight loss of 0.46 kg per month in the high-fat/high-calorie group. However, there are some concerns that highcarbohydrate low-fat diets might increase the risk of ALS and these findings should be interpreted with caution (4. Furthermore, according to Wills et al. high fat-high caloric diets could not be ideal regimens for these patients due to the associated gastrointestinal complications (3. Dorst and associates, in their study, showed that high caloric food supplement with high fat is suitable to establish body weight compared to high carbohydrate formula. Hence, it seems that high protein-high caloric diets could be more appropriate options for both improving negative nitrogen balance and decreasing muscle atrophy in patients with ALS based on the pathophysiology of proteinenergy malnutrition and hypermetabolism which is thought to be due to mitochondria problem. The multifactorial pathophysiology of ALS has resulted in hypotheses that there may be subgroups of patients, eventually defined by a specific underlying etiology or clinical presentation, which selectively respond to a particular regimen. Consequently, further RCTs with larger sample size are required to clarify the best regimen for weight gain and improved survival in ALS patients and it seems that personalized nutritional support or combined regimens might be the best way and could improve the quality of life considering the complex pathophysiology of malnutrition.

  9. Permeabilidad del arbolado urbano a la radiación solar: Estudio de dos especies representativas en entornos urbanos de baja densidad del Área Metropolitana de Mendoza, Argentina

    Directory of Open Access Journals (Sweden)

    Mariela Edith Arboit

    2015-03-01

    Full Text Available El objetivo del trabajo es generar conocimientos que permitan determinar la influencia del arbolado urbano, público o privado, sobre el potencial solar de los entornos urbano- edilicios de baja densidad del Área Metropolitana de Mendoza (AMM. El estudio de la permeabilidad del arbolado urbano ha sido desarrollado para situaciones típicas del área de Capital, Mendoza, representada por especies como: Plátano 21,80%, Morera 32,7%, Fresno europeo 20,95% y Paraíso 2,72% (Cantón, 1994-2000. Sin embargo para determinar la permeabilidad arbórea de entornos urbanos de baja densidad del AMM, en una primera etapa fue necesario realizar una recolección muestral que permitió identificar la presencia de ejemplares no evaluados como Acer 9,95% y Paraíso sombrilla 8,37%. En una segunda etapa, se elaboró un plan de mediciones para un ciclo anual, sobre un conjunto de 8 ejemplares por especie seleccionada. Los resultados obtenidos indican una reducción de la energía solar disponible, del 52,88% al 75,93% en la estación de invierno y del 85,96% al 98,38 % en verano para Acer y Paraíso Sombrilla respectivamente. El estudio ha permitido avanzar en la determinación del potencial solar en ambientes urbanos considerando la permeabilidad de dos especies arbóreas representativas del AMM.

  10. Analysis of conjugated heat transfer, in transient state of the first stage of a gas turbine; Analisis de transferencia de calor conjugada, en estado transitorio, de la primera etapa de una turbina de gas

    Energy Technology Data Exchange (ETDEWEB)

    Campos Amezcua, Alfonso; Mazur C, Zdzislaw [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Gallegos Munoz, Armando [Facultad de Ingenieria Mecanica, Electrica y Electronica (FIMEE), Universidad de Guanajuato, Guanajuato (Mexico)

    2007-11-15

    This article presents an analysis of conjugated heat transfer in the first stage of movable blades during the starting of a gas turbine, covering a period of 1,012 seconds. The developed computer model is in 3D and uses as initial and border conditions typical starting curves for stack gases, the cooling air and the angular velocity of the blades. As a result of the numerical predictions, the temperature distributions in stack gases, the trowel of the blade and the cooling air are included, doing emphasis in the results obtained in the solid (body of the blade), since these are used for thermo-mechanical stress analysis and later estimation of the blade residual life. [Spanish] Este articulo presenta un analisis de transferencia de calor conjugada en la primera etapa de alabes moviles, durante el arranque de una turbina de gas, cubriendo un periodo de 1.012 segundos. El modelo computacional desarrollado es en tres dimensiones y utiliza como condiciones iniciales y de frontera curvas de arranque tipicas para los gases de combustion, el aire de enfriamiento y la velocidad angular de los alabes. Como resultado de las predicciones numericas, se incluyen las distribuciones de temperatura en los gases de combustion, la paleta del alabe y el aire de enfriamiento, haciendo enfasis en los resultados obtenidos en el solido (cuerpo del alabe), ya que estos se utilizan para analisis de esfuerzos termomecanicos y posterior estimacion de vida residual del alabe.

  11. Hepatic mitochondrial energetics during catch-up fat after caloric restriction.

    Science.gov (United States)

    Crescenzo, Raffaella; Bianco, Francesca; Falcone, Italia; Prisco, Marina; Dulloo, Abdul G; Liverini, Giovanna; Iossa, Susanna

    2010-08-01

    The objective of the study was to investigate whether changes in liver mitochondrial energetics could underlie the enhanced energetic efficiency that drives accelerated body fat recovery (catch-up fat) during refeeding after caloric restriction. Rats were subjected to caloric restriction (50% of ad libitum intake) for 15 days and then refed for 1 or 2 weeks on an amount of chow equal to that of controls matched for weight at the onset of refeeding. Whole-body metabolism was characterized by energy balance and body composition determinations as well as by indirect calorimetric measurements of 24-hour energy expenditure, substrate oxidation, and whole-body de novo lipogenesis estimated from nonprotein respiratory quotient. Hepatic mitochondrial energetics were determined from measurements of liver mitochondrial mass, respiratory capacities, and proton leak (both basal and fatty acid stimulated), whereas hepatic oxidative status was assessed from measurements of hepatic mitochondrial lipid peroxidation, aconitase, and superoxide dismutase activity. Furthermore, hepatic lipogenic capacity was determined from assays of fatty acid synthase activity. Compared with controls, isocalorically refed rats showed an elevated energetic efficiency and body fat gain over both week 1 and week 2 of refeeding, as well as a lower 24-hour energy expenditure and higher rates of whole-body de novo lipogenesis at the end of both week 1 and week 2 of refeeding. Analysis of the liver revealed that after 1 week (but not after 2 weeks) of refeeding, the mitochondrial mass (but not mitochondrial density) was lower in refed rats than in controls, associated with higher state 3 mitochondrial respiratory capacity, increased superoxide dismutase activity, as well as higher fatty acid synthase activity. These results suggest that, although at the whole-body level elevations in energy efficiency and de novo lipogenesis are coordinated toward catch-up fat, the overall hepatic mitochondrial energetic

  12. Accumulation of long-chain glycosphingolipids during aging is prevented by caloric restriction.

    Directory of Open Access Journals (Sweden)

    María José Hernández-Corbacho

    Full Text Available BACKGROUND: Chronic kidney disease and end-stage renal disease are major causes of morbidity and mortality that are seen far more commonly in the aged population. Interestingly, kidney function declines during aging even in the absence of underlying renal disease. Declining renal function has been associated with age-related cellular damage and dysfunction with reports of increased levels of apoptosis, necrosis, and inflammation in the aged kidney. Bioactive sphingolipids have been shown to regulate these same cellular processes, and have also been suggested to play a role in aging and cellular senescence. METHODOLOGY/PRINCIPAL FINDINGS: We hypothesized that alterations in kidney sphingolipids play a role in the declining kidney function that occurs during aging. To begin to address this, the sphingolipid profile was measured in young (3 mo, middle aged (9 mo and old (17 mo C57BL/6 male mice. Interestingly, while modest changes in ceramides and sphingoid bases were evident in kidneys from older mice, the most dramatic elevations were seen in long-chain hexosylceramides (HexCer and lactosylceramides (LacCer, with C14- and C16-lactosylceramides elevated as much as 8 and 12-fold, respectively. Increases in long-chain LacCers during aging are not exclusive to the kidney, as they also occur in the liver and brain. Importantly, caloric restriction, previously shown to prevent the declining kidney function seen in aging, inhibits accumulation of long-chain HexCer/LacCers and prevents the age-associated elevation of enzymes involved in their synthesis. Additionally, long-chain LacCers are also significantly elevated in human fibroblasts isolated from elderly individuals. CONCLUSION/SIGNIFICANCE: This study demonstrates accumulation of the glycosphingolipids HexCer and LacCer in several different organs in rodents and humans during aging. In addition, data demonstrate that HexCer and LacCer metabolism is regulated by caloric restriction. Taken together

  13. EFEITO DAS ONDAS DE CALOR NA AGRICULTURA – SAFRA 2013/2014

    Directory of Open Access Journals (Sweden)

    Melhores Trabalhos .

    2015-02-01

    Full Text Available Ao aquecimento global, considerado decorrência do fenômeno popularmente conhecido como efeito estufa, têm sido atribuidas muitas das anomalias climáticas que ultimamente vêm afetando  municípios, regiões, países e até continentes inteiros. Uma dessas anomalias do clima refere-se às recentes ondas de calor ocorridas no verão de 2013/2014, agora findando, registradas nas estações meteorológicas e no desconforto de pessoas, plantas e animais que habitam a região sul da América do Sul, onde estão situados o Estado do Rio Grande do Sul e, nele,  o Município de Cruz Alta. Diante do exposto, este trabalho, na forma de artigo, tem por objetivo descrever e analisar a ocorrência de alguns desastres naturais, resultantes de fenômenos meteorológicos eventuais ou recorrentemente verificados e registrados no Estado e no Município, todos quase sempre capazes de afetar seu desenvolvimento socioeconômico. Os danos anuais causados por diferentes desastres meteorológicos sobre a agricultura são calculados, em termos globais ou mundiais, na ordem de mais 41 bilhões de dólares. Ao se efetuar uma análise sobre causas e efeitos dos fenômenos meteorológicos que incidem sobre a agricultura, tendo por base parte das informações bibliográficas, documentais e midiáticas consultadas para a elaboração deste artigo, tem-se que levar em consideração que esses fenômenos manifestam-se diferenciadamente quanto à quantização de danos e percentualidade de perdas que podem ocasionar aos cultivos agrícolas. Enquanto que os prejuízos causados por granizos, geadas e secas, por exemplo, podem ser avaliados por sintomas manifestos nas plantas (quebra e ruptura de partes de hastes e colmos, necrose foliar; congelamento de tecidos e de folhas, cobertura de gelo sobre plantas e solo; e murcha de folhas, redução de crescimento, etc. e pela visualização da intensidade de ocorrência (tamanho e número de pedras de granizo, cobertura de gelo e

  14. Eficacia del uso de la Hipertermia en el estiramiento muscular en el ámbito deportivo. Caso clínico.

    OpenAIRE

    Martínez Montejo, Diego

    2014-01-01

    Las lesiones musculares en el ámbito deportivo son una de las causas más habituales de inactividad entre sus participantes. Entre ellas destacan por su frecuencia las de la musculatura posterior del muslo. La aplicación de calor mediante distintas técnicas es útil para mejorar la elasticidad y la movilidad músculo-articular. La aplicación de calor mediante hipertermia utilizando Indiba se ha venido utilizando para el tratamiento de lesiones músculo-esqueléticas. En este estudio se valor...

  15. EFECTO DE LA COMPOSICIÓN DEL GAS DE REFINERÍA SOBRE LAS CARACTERÍSTICAS DEL PROCESO DE COMBUSTIÓN

    Directory of Open Access Journals (Sweden)

    O. M. Cala

    2013-12-01

    Full Text Available En este artículo de investigación científica se analiza el efecto del cambio de la composición del gas combustible (Gas de Refinería (GR por Gas Natural (GN sobre las características del proceso combustión en hornos de la industria de refinación del petróleo; se evaluó el poder calorífico, el índice de Wobbe (IW y exceso de oxígeno, para mezclas combustibles de composición variable. Mediante simulación computacional del proceso de combustión se calculó la temperatura adiabática de llama, eficiencia y la composición de los productos de combustión. Se evaluaron mezclas de gases combustibles con poderes caloríficos entre 800-2500 Btu/pie3 y se compararon con la combustión de gas natural. Se registró variabilidad en la temperatura adiabática y la eficiencia en función de la composición del gas y el exceso de oxígeno, lo que genera inestabilidad en el horno y mayor impacto ambiental.

  16. Diffusion and dispersion heat of hydrotermal discharge from power plant; Difusion y dispersion de calor de la descarga hidrotermal de una central termoelectrica

    Energy Technology Data Exchange (ETDEWEB)

    Rendon Villalobos, J. Rodolfo

    1996-12-31

    numerica del comportamiento hidrodinamico de la descarga al mar del agua de enfriamiento de la central termoelectrica Tuxpan (CTT) bajo dos distintas condiciones ambientales meteorologicas y oceanograficas, a saber: Caso I, viento variable de direccion SW con intensidad promedio igual a 3 m s-1 y Caso II, viento variable del NW con intensidad promedio igual a 11.10 m s-1. Las simulaciones numericas se realizaron mediante un modelo tridimensional de circulacion costera y difusion y dispersion de calor. El analisis estadistico del banco de datos de intensidad y direccion del viento medido del 1 de enero de 1981 al 31 de diciembre de 1983, indica que el numero de valores de mayor ocurrencia se presento dentro del intervalo de 180 grados a 315 grados. Por lo mismo, el efecto del viento proveniente del sector sur genera un patron de circulacion superficial de flujo norte que alejan de la obra de toma el agua caliente descargada. En contraste, el viento que proviene del sector norte genera corrientes superficiales de flujo sur que impulsa el efluente hidrotermico hacia la obra de toma. Las comparaciones entre los resultados de las simulaciones numericas y los datos de campo indican que, para una variedad de condiciones ambientales meteorologicas y oceanograficas representativas del Sitio Tuxpan (ST), el modelo simula correctamente los patrones de difusion y dispersion superficial de los efluentes medidos los dias 19, 20 y 21 de agosto de 1992 (Caso I) y 26 de noviembre de 1992 (Caso II). La precision promedio con la cual el modelo predice las areas de impacto de los efluentes descargados en el ST es de {+-} 11%. Para todos los casos analizados, el tamano real del area de impacto termico que podria alterar substancialmente el ecosistema marino no fue mayor a 0.1 Km{sup 2}. Los posibles efectos ecologicos que podrian resultar como consecuencia de los gradientes termicos inducidos por la descarga superficial de agua caliente solo podrian ser considerados de significancia local. Los

  17. Seasonal fluctuations in prevalence of dog intestinal parasites in public squares of Mar del Plata city, Argentina and its risk for humans Estacionalidad en la prevalencia de parásitos intestinales caninos en plazas públicas de Mar del Plata, Argentina, y su riesgo para la salud humana

    Directory of Open Access Journals (Sweden)

    V. Andresiuk

    2007-12-01

    obtenidos en la biblioteca del Servicio Meteorológico Nacional. La prevalencia total de parásitos fue considerablemente más alta en invierno que en verano. Ancylostoma spp. fue la especie prevalente en el período otoño-verano. La incidencia de Toxocara canis fue más alta en invierno que en el resto de las estaciones, y la de Trichuris vulpis fue alta en invierno, primavera y verano. Este trabajo muestra alta prevalencia de parásitos totales a lo largo de todo el año en las plazas públicas de Mar del Plata. Para Ancylostoma spp. verano y otoño podrían ser las estaciones con riesgo sanitario más alto para la gente. Por otra parte, T. canis podría presentar mayor riesgo para la gente en invierno y T. vulpis sería transmitido durante todo el año. La variación estacional en la prevalencia de los distintos parásitos caninos, con al menos una especie con riesgo sanitario, hace que la exposición para la gente que visita las plazas sea continua e involucre no sólo a la gente que vive en Mar del Plata sino también turistas de otras regiones de Argentina y el mundo.

  18. Evaluación de la calidad del agua en los ríos Tigre y Rincón de la península de Osa en dos períodos de tiempo distintos

    Directory of Open Access Journals (Sweden)

    Guillermo Calvo-Brenes

    2015-09-01

    El nivel de contaminación de los puntos muestreados, según el Índice Holandés, oscila entre niveles de No Contaminación hasta Contaminación Leve. El análisis estadístico no mostró diferencias significativas entre la época de invierno y la de verano, o entre los períodos de tiempo evaluados del 2008-2009 y el 2010-2011, dada la variabilidad de los datos entre épocas por punto de muestreo en un período dado. La única excepción es el punto del río Tigre en su zona baja (Ti-3 que sí presenta un incremento estadístico en los niveles de contaminación, entre un período y otro, durante la época de invierno.

  19. Study of electro-caloric effect in Ca and Sn co-doped BaTiO3 ceramics

    Science.gov (United States)

    Upadhyay, Sanjay Kumar; Fatima, Iram; Raghavendra Reddy, V.

    2017-04-01

    The present work deals with the study of structural, ferroelectric, dielectric and electro-caloric effects in lead free ferroelectric polycrystalline Ba1-x Ca x Ti0.95Sn0.05O3 (x  =  2, 5 and 10%) i.e. Ca, Sn co-doped BaTiO3 (BTO). Phase purity of the samples is confirmed from x-ray data by using Rietveld refinement. 119Sn Mössbauer reveals homogenous phase as well as iso-valent substitution of Sn at Ti site. Enhancements in ferroelectric and dielectric properties have been observed. Indirect method which is based on Maxwell equation has been used to determine the electro-caloric (EC) effect in the studied ferroelectric ceramics and maximum EC coefficient is observed for Ba0.95Ca0.05Ti0.95Sn0.05O3.

  20. Caloric Intake on the Sabbath: A Pilot Study of Contributing Factors to Obesity in the Orthodox Jewish Community.

    Science.gov (United States)

    Rosenberg, Deborah A; Swencionis, Charles; Segal-Isaacson, C J

    2016-10-01

    The American Orthodox Jewish community has specific cultural factors that may contribute to overweight and obesity. This study aimed to look at caloric intake on the Sabbath and its contribution to overweight and obesity. Twelve married or previously married women who identify themselves as Orthodox Jews were recruited to do 24-h food recalls over the phone. The participants were divided into three weight groups (normal, overweight, and obese) based on their BMI. The overweight and obese participants' data were combined into one group for the purposes of statistical testing. Paired t tests looking at the data for all participants showed significantly great caloric intake during an average Sabbath day than an average weekday [t(4) = 7.58, p Jewish community.

  1. Absorption heat pump integrated in an effluent purification system; Bomba de calor por absorcion integrada a un sistema de purificacion de efluentes

    Energy Technology Data Exchange (ETDEWEB)

    Santoyo, Socrates; Siqueiros, Javier; Heard, Christopher; Santoyo, Edgar [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1996-12-31

    The results derived of the integration of an absorption heat pump to an industrial effluents purification system, are presented. The advantages of these heat pumps with respect to heat pumps by mechanical compression of vapor, as well as the advantages in using absorption heat pumps in simple distillation systems, are mentioned. Finally, a description is made of the equipment designed and built, as well as the results obtained in a preliminary test. [Espanol] Se presentan los resultados derivados de la integracion de una bomba de calor por absorcion a un sistema de purificacion de efluentes industriales. Se mencionan las ventajas de este tipo de bombas de calor con respecto a las de calor por compresion mecanica de vapor, asi como las ventajas de usar bombas de calor en sistemas de destilacion simple. Finalmente, se describe el equipo disenado y construido, asi como los resultados obtenidos de una prueba preliminar.

  2. Caloric Vestibular Stimulation Reduces Pain and Somatoparaphrenia in a Severe Chronic Central Post-Stroke Pain Patient: A Case Study: e0151213

    National Research Council Canada - National Science Library

    Grazia Fernanda Spitoni; Giorgio Pireddu; Gaspare Galati; Valentina Sulpizio; Stefano Paolucci; Luigi Pizzamiglio

    2016-01-01

    .... To date, there is limited evidence for the effective treatments of this disease. Here we used caloric vestibular stimulation to reduce pain and somatoparaphrenia in a 57-year-old woman suffering from central post-stroke pain...

  3. Effect of replacing sugar with non-caloric sweeteners in beverages on the reward value after repeated exposure.

    Science.gov (United States)

    Griffioen-Roose, Sanne; Smeets, Paul A M; Weijzen, Pascalle L G; van Rijn, Inge; van den Bosch, Iris; de Graaf, Cees

    2013-01-01

    The reward value of food is partly dependent on learned associations. It is not yet known whether replacing sugar with non-caloric sweeteners in food is affecting long-term acceptance. To determine the effect of replacing sugar with non-caloric sweeteners in a nutrient-empty drink (soft drink) versus nutrient-rich drink (yoghurt drink) on reward value after repeated exposure. We used a randomized crossover design whereby forty subjects (15 men, 25 women) with a mean ± SD age of 21 ± 2 y and BMI of 21.5 ± 1.7 kg/m(2) consumed a fixed portion of a non-caloric sweetened (NS) and sugar sweetened (SS) versions of either a soft drink or a yoghurt drink (counterbalanced) for breakfast which were distinguishable by means of colored labels. Each version of a drink was offered 10 times in semi-random order. Before and after conditioning the reward value of the drinks was assessed using behavioral tasks on wanting, liking, and expected satiety. In a subgroup (n=18) fMRI was performed to assess brain reward responses to the drinks. Outcomes of both the behavioral tasks and fMRI showed that conditioning did not affect the reward value of the NS and SS versions of the drinks significantly. Overall, subjects preferred the yoghurt drinks to the soft drinks and the ss drinks to the NS drinks. In addition, they expected the yoghurt drinks to be more satiating, they reduced hunger more, and delayed the first eating episode more. Conditioning did not influence these effects. Our study showed that repeated consumption of a non-caloric sweetened beverage, instead of a sugar sweetened version, appears not to result in changes in the reward value. It cannot be ruled out that learned associations between sensory attributes and food satiating capacity which developed preceding the conditioning period, during lifetime, affected the reward value of the drinks.

  4. Effect of replacing sugar with non-caloric sweeteners in beverages on the reward value after repeated exposure.

    Directory of Open Access Journals (Sweden)

    Sanne Griffioen-Roose

    Full Text Available BACKGROUND: The reward value of food is partly dependent on learned associations. It is not yet known whether replacing sugar with non-caloric sweeteners in food is affecting long-term acceptance. OBJECTIVE: To determine the effect of replacing sugar with non-caloric sweeteners in a nutrient-empty drink (soft drink versus nutrient-rich drink (yoghurt drink on reward value after repeated exposure. DESIGN: We used a randomized crossover design whereby forty subjects (15 men, 25 women with a mean ± SD age of 21 ± 2 y and BMI of 21.5 ± 1.7 kg/m(2 consumed a fixed portion of a non-caloric sweetened (NS and sugar sweetened (SS versions of either a soft drink or a yoghurt drink (counterbalanced for breakfast which were distinguishable by means of colored labels. Each version of a drink was offered 10 times in semi-random order. Before and after conditioning the reward value of the drinks was assessed using behavioral tasks on wanting, liking, and expected satiety. In a subgroup (n=18 fMRI was performed to assess brain reward responses to the drinks. RESULTS: Outcomes of both the behavioral tasks and fMRI showed that conditioning did not affect the reward value of the NS and SS versions of the drinks significantly. Overall, subjects preferred the yoghurt drinks to the soft drinks and the ss drinks to the NS drinks. In addition, they expected the yoghurt drinks to be more satiating, they reduced hunger more, and delayed the first eating episode more. Conditioning did not influence these effects. CONCLUSION: Our study showed that repeated consumption of a non-caloric sweetened beverage, instead of a sugar sweetened version, appears not to result in changes in the reward value. It cannot be ruled out that learned associations between sensory attributes and food satiating capacity which developed preceding the conditioning period, during lifetime, affected the reward value of the drinks.

  5. Caloric restriction and intermittent fasting: Two potential diets for successful brain aging

    Science.gov (United States)

    Martin, Bronwen; Mattson, Mark P.; Maudsley, Stuart

    2008-01-01

    The vulnerability of the nervous system to advancing age is all too often manifest in neurodegenerative disorders such as Alzheimer's and Parkinson's diseases. In this review article we describe evidence suggesting that two dietary interventions, caloric restriction (CR) and intermittent fasting (IF), can prolong the health-span of the nervous system by impinging upon fundamental metabolic and cellular signaling pathways that regulate life-span. CR and IF affect energy and oxygen radical metabolism, and cellular stress response systems, in ways that protect neurons against genetic and environmental factors to which they would otherwise succumb during aging. There are multiple interactive pathways and molecular mechanisms by which CR and IF benefit neurons including those involving insulin-like signaling, FoxO transcription factors, sirtuins and peroxisome proliferator-activated receptors. These pathways stimulate the production of protein chaperones, neurotrophic factors and antioxidant enzymes, all of which help cells cope with stress and resist disease. A better understanding of the impact of CR and IF on the aging nervous system will likely lead to novel approaches for preventing and treating neurodegenerative disorders. PMID:16899414

  6. Transport of heat in caloric vestibular stimulation. Conduction, convection or radiation?

    Science.gov (United States)

    Feldmann, H; Hüttenbrink, K B; Delank, K W

    1991-01-01

    Experiments in temporal bone specimens were carried out under strictly controlled conditions: temperature (37 degrees C) and humidity kept constant; standardized irrigation of the external ear canal by an automated system (in 15 s, 50 ml of water, 11 degrees C above temperature of specimen), thermistor probes of 0.2 mm diameter placed in different parts of the specimens. In the intact temporal bone such an irrigation causes a rise in temperature with a gradient from the external ear canal across the bony bridge to the lateral semicircular canal as expected with heat conduction. After removal of the bony bridge, which is the main route for heat conduction, the rise in temperature in the lateral semicircular canal is greater and faster than in the intact specimen. This effect again is drastically reduced by placing a reflecting shield between tympanic membrane and labyrinth. In the intact middle ear inserting a reflecting shield or filling the cavity with gel also reduces the heat transfer to the labyrinth, although the bony routes for heat conduction are left untouched. The experiments prove that radiation plays an important part in heat transfer in caloric stimulation.

  7. Caloric restriction in grouped rats: aggregate influence on behavioural and hormonal data.

    Science.gov (United States)

    Moneo, Mikel; Martín Zúñiga, Jesús; Morón, Ignacio

    2017-10-01

    The majority of studies in short- and middle-term caloric restriction (CR) have been primarily focused on physiological parameters, improvements in aging, modulation of oxidative stress, and long-term negative effects on cognitive functions. However, single-housing associated with CR may pose many logistical problems. Thus, it is necessary to study the effects of CR under conditions in which animals are group-housed. The aims of this study were to (i) observe the possible differences in the proportion of the weights and social behaviour under ad libitum and CR (at 70%) conditions; (ii) examine the eventual inequalities in the proportion of the weights and social behaviour (the time spent eating under the feeder as an indicator of dominance and empathy, and the number of 'pushes' as an indicator of aggressiveness) in sibling and non-sibling rats under CR conditions; and (iii) compare the concentrations of corticosterone (stress biomarker) in serum under ad libitum and CR conditions. The results indicated the effectiveness of CR in different groups independent of the relationship between the rats. No extreme changes in weight were observed in the CR rats. Behavioural observations also indicated the differences in the total time spent under the feeder and in the number of pushes (higher in both cases for the sibling rats). However, no significant differences in corticosterone levels were observed. Our results suggest the viability of group-housing rats during long periods of CR maintenance.

  8. Caloric profile of pasteurized milk in the human milk bank at a university hospital.

    Science.gov (United States)

    de Moraes, Priscila Santa; de Oliveira, Márcia Maria B; Dalmas, José Carlos

    2013-01-01

    To verify the caloric and sanitary profile of human milk stored at the Human Milk Bank at Londrina University Hospital. Cross-sectional study. Data were obtained from the Human Milk Bank registry regarding the source, the amount collected in liters, the amount of calories by liter assessed by crematocrit, and the acidity of human milk determined by titration in degrees Dornic. Between 2006 and 2009, 30,846 samples of human milk were collected from donors coming from different locations and analyzed. A total of 5,869L of milk were collected and distributed. From the total human pasteurized milk, 53,5% was classified as hypocaloric (711kcal/L). Regarding the several locations where the milk was collected, the Human Milk Bank at Londrina University Hospital was the location in which a larger number of donations were observed in the three classifications. The result of the Dornic test for acidity of the collected milk revealed that 60.8% had 4.1º to 8.0º Dornic. A large volume of the collected human milk is hypocaloric and appropriate for human consumption. There is the need to intensify collection procedures in order to meet the demand for hypercaloric milk for preterm newborn infants.

  9. Differential responses of white adipose tissue and brown adipose tissue to caloric restriction in rats.

    Science.gov (United States)

    Okita, Naoyuki; Hayashida, Yusuke; Kojima, Yumiko; Fukushima, Mayumi; Yuguchi, Keiko; Mikami, Kentaro; Yamauchi, Akiko; Watanabe, Kyoko; Noguchi, Mituru; Nakamura, Megumi; Toda, Toshifusa; Higami, Yoshikazu

    2012-05-01

    Caloric restriction (CR) slows the aging process and extends longevity, but the exact underlying mechanisms remain debatable. It has recently been suggested that the beneficial action of CR may be mediated in part by adipose tissue remodeling. Mammals have two types of adipose tissue: white adipose tissue (WAT) and brown adipose tissue (BAT). In this study, proteome analysis using two-dimensional gel electrophoresis combined with MALDI-TOF MS, and subsequent analyses were performed on both WAT and BAT from 9-month-old male rats fed ad libitum or subjected to CR for 6 months. Our findings suggest that CR activates mitochondrial energy metabolism and fatty acid biosynthesis in WAT. It is likely that in CR animals WAT functions as an energy transducer from glucose to energy-dense lipid. In contrast, in BAT CR either had no effect on, or down-regulated, the mitochondrial electron transport chain, but enhanced fatty acid biosynthesis. This suggests that in CR animals BAT may change its function from an energy consuming system to an energy reservoir system. Based on our findings, we conclude that WAT and BAT cooperate to use energy effectively via a differential response of mitochondrial function to CR. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  10. Evaluation of dysphagia risk, nutritional status and caloric intake in elderly patients with Alzheimer's

    Directory of Open Access Journals (Sweden)

    Vanessa Fernanda Goes

    2014-04-01

    Full Text Available OBJECTIVE: to evaluate the risk of dysphagia and its relationship with the stage of Alzheimer's Disease, as well as the relationship between the risk of dysphagia and nutritional status and caloric intake in elderly people with Alzheimer's disease.METHODS: the sample consisted of 30 subjects of both genders with probable Alzheimer's disease. The stage of the disease, nutritional status, energy intake, and risk of dysphagia were assessed.RESULTS: it was found that increased risk of dysphagia is associated with the advance in the stages of Alzheimer's disease and that even patients in the early stages of disease have a slight risk of developing dysphagia. No association was found between nutritional status and the risk of dysphagia. High levels of inadequate intake of micronutrients were also verified in the patients.CONCLUSION: an association between dysphagia and the development of Alzheimer's disease was found. The results indicate the need to monitor the presence of dysphagia and the micronutrient intake in patients with Alzheimer's disease.

  11. Krebs cycle enzymes from livers of old mice are differentially regulated by caloric restriction.

    Science.gov (United States)

    Hagopian, Kevork; Ramsey, Jon J; Weindruch, Richard

    2004-08-01

    Krebs cycle enzyme activities and levels of five metabolites were determined from livers of old mice (30 months) maintained either on control or on long-term caloric restriction (CR) diets (28 months). In CR mice, the cycle was divided into two major blocks, the first containing citrate synthase, aconitase and NAD-dependent isocitrate dehydrogenase which showed decreased activities, while the second block, containing the remaining enzymes, displayed increased activity (except for fumarase, which was unchanged). CR also resulted in decreased levels of citrate, glutamate and alpha-ketoglutarate, increased levels of malate, and unchanged levels of aspartate. The alpha-ketoglutarate/glutamate and malate/alpha-ketoglutarate ratios were higher in CR, in parallel with previously reported increases with CR in pyruvate carboxylase activity and glucagon levels, respectively. The results indicate that long-term CR induces a differential regulation of Krebs cycle in old mice and this regulation may be the result of changes in gene expression levels, as well as a complex interplay between enzymes, hormones and other effectors. Truncation of Krebs cycle by CR may be an important adaptation to utilize available substrates for the gluconeogenesis necessary to sustain glycolytic tissues, such as brain.

  12. Caloric restriction reveals a metabolomic and lipidomic signature in liver of male mice.

    Science.gov (United States)

    Jové, Mariona; Naudí, Alba; Ramírez-Núñez, Omar; Portero-Otín, Manuel; Selman, Colin; Withers, Dominic J; Pamplona, Reinald

    2014-10-01

    Lipid composition, particularly membrane unsaturation, has been proposed as being a lifespan determinant, but it is currently unknown whether caloric restriction (CR), an accepted life-extending intervention, affects cellular lipid profiles. In this study, we employ a liquid chromatography quadrupole time-of-flight-based methodology to demonstrate that CR in the liver of male C57BL/6 mice: (i) induces marked changes in the cellular lipidome, (ii) specifically reduces levels of a phospholipid peroxidation product, 1-palmitoyl-2-glutaryl-sn-glycero-3-phosphatidylcholine, (iii) alters cellular phosphoethanolamine and triglyceride distributional profiles, (iv) affects mitochondrial electron transport chain complexes, increasing complex II and decreasing complex III and (v) is associated with specific changes in liver metabolic pathways. These data demonstrate that CR induces a specific lipidome and metabolome reprogramming event in mouse liver which is associated with lower protein oxidative damage, as assessed by mass spectrometry-based measurements. Such changes may be critical to the increased lifespan and healthspan observed in C57BL/6 mice following CR. © 2014 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  13. Artigos esterilizados em calor úmido: validação do sistema de guarda

    Directory of Open Access Journals (Sweden)

    Zilah Cândida Pereira das Neves

    2004-04-01

    Full Text Available Objetivamos identificar o tempo de validade da esterilização dos artigos processados pelo calor úmido, considerando as condições de esterilização e guarda. A validação deu-se através de testes microbiológicos realizados com instrumentais processados numa mesma carga e avaliados em tempos 0, 7, 10, 15 e 25 dias. Foram analisados 30% do instrumental de cada pacote que foi colocado em caldo Mueller Hinton e incubado a 37ºC por 72 horas. A leitura deu-se pela turvação do caldo. Das amostras avaliadas de nove cargas, em nenhuma houve crescimento microbiológico. Concluiu-se que apesar das condições de esterilização e guarda do material não se adequarem totalmente dentro dos parâmetros recomendados pela literatura, a esterilização ocorreu e manteve-se por um período de 25 dias.

  14. Caloric restriction improves efficiency and capacity of the mitochondrial electron transport chain in Saccharomyces cerevisiae

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Joon-Seok; Choi, Kyung-Mi [College of Life Sciences and Biotechnology, Korea University, Seoul 136-701 (Korea, Republic of); Lee, Cheol-Koo, E-mail: cklee2005@korea.ac.kr [College of Life Sciences and Biotechnology, Korea University, Seoul 136-701 (Korea, Republic of)

    2011-06-03

    Highlights: {yields} Calorie restriction (CR) increases electron transport chain (ETC) at both RNA and protein level. {yields} CR enhances mitochondrial membrane potential, and, regardless of ages, reduces reactive oxygen species. {yields} CR increases both efficiency and capacity of the ETC. {yields} CR induces intensive modulation at mitochondrial ETC where might be a major site leading to extension of lifespan. -- Abstract: Caloric restriction (CR) is known to extend lifespan in a variety of species; however, the mechanism remains unclear. In this study, we found that CR potentiated the mitochondrial electron transport chain (ETC) at both the transcriptional and translational levels. Indeed, mitochondrial membrane potential (MMP) was increased by CR, and, regardless of ages, overall reactive oxygen species (ROS) generation was decreased by CR. With these changes, overall growth rate of cells was maintained under various CR conditions, just like cells under a non-restricted condition. All of these data support increased efficiency and capacity of the ETC by CR, and this change might lead to extension of lifespan.

  15. Maintenance of cellular ATP level by caloric restriction correlates chronological survival of budding yeast

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Joon-Seok; Lee, Cheol-Koo, E-mail: cklee2005@korea.ac.kr

    2013-09-13

    Highlights: •CR decreases total ROS and mitochondrial superoxide during the chronological aging. •CR does not affect the levels of oxidative damage on protein and DNA. •CR contributes extension of chronological lifespan by maintenance of ATP level -- Abstract: The free radical theory of aging emphasizes cumulative oxidative damage in the genome and intracellular proteins due to reactive oxygen species (ROS), which is a major cause for aging. Caloric restriction (CR) has been known as a representative treatment that prevents aging; however, its mechanism of action remains elusive. Here, we show that CR extends the chronological lifespan (CLS) of budding yeast by maintaining cellular energy levels. CR reduced the generation of total ROS and mitochondrial superoxide; however, CR did not reduce the oxidative damage in proteins and DNA. Subsequently, calorie-restricted yeast had higher mitochondrial membrane potential (MMP), and it sustained consistent ATP levels during the process of chronological aging. Our results suggest that CR extends the survival of the chronologically aged cells by improving the efficiency of energy metabolism for the maintenance of the ATP level rather than reducing the global oxidative damage of proteins and DNA.

  16. Caloric Restriction Protects against Lactacystin-Induced Degeneration of Dopamine Neurons Independent of the Ghrelin Receptor

    Directory of Open Access Journals (Sweden)

    Jessica Coppens

    2017-03-01

    Full Text Available Parkinson’s disease (PD is a neurodegenerative disorder, characterized by a loss of dopamine (DA neurons in the substantia nigra pars compacta (SNc. Caloric restriction (CR has been shown to exert ghrelin-dependent neuroprotective effects in the 1-methyl-4-phenyl-1,2,3,6-tetrathydropyridine (MPTP-based animal model for PD. We here investigated whether CR is neuroprotective in the lactacystin (LAC mouse model for PD, in which proteasome disruption leads to the destruction of the DA neurons of the SNc, and whether this effect is mediated via the ghrelin receptor. Adult male ghrelin receptor wildtype (WT and knockout (KO mice were maintained on an ad libitum (AL diet or on a 30% CR regimen. After 3 weeks, LAC was injected unilaterally into the SNc, and the degree of DA neuron degeneration was evaluated 1 week later. In AL mice, LAC injection significanty reduced the number of DA neurons and striatal DA concentrations. CR protected against DA neuron degeneration following LAC injection. However, no differences were observed between ghrelin receptor WT and KO mice. These results indicate that CR can protect the nigral DA neurons from toxicity related to proteasome disruption; however, the ghrelin receptor is not involved in this effect.

  17. Effects of Low-Dose Non-Caloric Sweetener Consumption on Gut Microbiota in Mice

    Directory of Open Access Journals (Sweden)

    Takashi Uebanso

    2017-06-01

    Full Text Available Abstract: Non-caloric artificial sweeteners (NASs provide sweet tastes to food without adding calories or glucose. NASs can be used as alternative sweeteners for controlling blood glucose levels and weight gain. Although the consumption of NASs has increased over the past decade in Japan and other countries, whether these sweeteners affect the composition of the gut microbiome is unclear. In the present study, we examined the effects of sucralose or acesulfame-K ingestion (at most the maximum acceptable daily intake (ADI levels, 15 mg/kg body weight on the gut microbiome in mice. Consumption of sucralose, but not acesulfame-K, for 8 weeks reduced the relative amount of Clostridium cluster XIVa in feces. Meanwhile, sucralose and acesulfame-K did not increase food intake, body weight gain or liver weight, or fat in the epididymis or cecum. Only sucralose intake increased the concentration of hepatic cholesterol and cholic acid. Moreover, the relative concentration of butyrate and the ratio of secondary/primary bile acids in luminal metabolites increased with sucralose consumption in a dose-dependent manner. These results suggest that daily intake of maximum ADI levels of sucralose, but not acesulfame-K, affected the relative amount of the Clostridium cluster XIVa in fecal microbiome and cholesterol bile acid metabolism in mice.

  18. Caloric restriction preserves memory and reduces anxiety of aging mice with early enhancement of neurovascular functions.

    Science.gov (United States)

    Parikh, Ishita; Guo, Janet; Chuang, Kai-Hsiang; Zhong, Yu; Rempe, Ralf G; Hoffman, Jared D; Armstrong, Rachel; Bauer, Björn; Hartz, Anika M S; Lin, Ai-Ling

    2016-11-08

    Neurovascular integrity plays an important role in protecting cognitive and mental health in aging. Lifestyle interventions that sustain neurovascular integrity may thus be critical on preserving brain functions in aging and reducing the risk for age-related neurodegenerative disorders. Here we show that caloric restriction (CR) had an early effect on neurovascular enhancements, and played a critical role in preserving vascular, cognitive and mental health in aging. In particular, we found that CR significantly enhanced cerebral blood flow (CBF) and blood-brain barrier function in young mice at 5-6 months of age. The neurovascular enhancements were associated with reduced mammalian target of rapamycin expression, elevated endothelial nitric oxide synthase signaling, and increased ketone bodies utilization. With age, CR decelerated the rate of decline in CBF. The preserved CBF in hippocampus and frontal cortex were highly correlated with preserved memory and learning, and reduced anxiety, of the aging mice treated with CR (18-20 months of age). Our results suggest that dietary intervention started in the early stage (e.g., young adults) may benefit cognitive and mental reserve in aging. Understanding nutritional effects on neurovascular functions may have profound implications in human brain aging and age-related neurodegenerative disorders.

  19. Effects of Caloric Restriction on Age-Related Hearing Loss in Rodents and Rhesus Monkeys

    Science.gov (United States)

    Someya, Shinichi; Tanokura, Masaru; Weindruch, Richard; Prolla, Tomas A.; Yamasoba, Tatsuya

    2014-01-01

    Age-related hearing loss (AHL), also known as presbycusis, is a universal feature of mammalian aging and is the most frequently occurring sensory disorder in the elderly population. AHL is characterized by a decline of auditory function and loss of hair cells and spiral ganglion neurons in the cochlea of the inner ear. It has been postulated that AHL occurs gradually as a result of the cumulative effect with aging of exposure to noise, diet, oxidative damage, and mitochondrial DNA mutations. However, the molecular mechanisms of AHL remain unclear and no preventative or therapeutic interventions have been developed. A growing body of evidence suggests increased oxidative damage with aging to macromolecules such as DNA, proteins, and lipids may play a causal role in aging and age-related diseases. Caloric restriction (CR) extends the lifespan of most mammalian species, delays the onset of multiple age-related diseases, and attenuates both the degree of oxidative damage and the associated decline in physiological function. Here, we review studies on CR’s ability to prevent cochlear pathology and AHL in laboratory animals and discuss potential molecular mechanisms of CR’s actions. PMID:20298166

  20. Entropy Generation and Human Aging: Lifespan Entropy and Effect of Diet Composition and Caloric Restriction Diets

    Directory of Open Access Journals (Sweden)

    Carlos A. Silva

    2009-01-01

    Full Text Available The first and second laws of thermodynamic were applied to statistical databases on nutrition and human growth in order to estimate the entropy generation over the human lifespan. The calculations were performed for the cases of variation in the diet composition and calorie restriction diets; and results were compared to a base case in which lifespan entropy generation was found to be 11 404 kJ/K per kg of body mass, predicting a lifespan of 73.78 and 81.61 years for the average male and female individuals respectively. From the analysis of the results, it was found that changes of diet % of fat and carbohydrates do not have a significant impact on predicted lifespan, while the diet % of proteins has an important effect. Reduction of diet protein % to the minimum recommended in nutrition literature yields an average increase of 3.3 years on the predicted lifespan. Changes in the calorie content of the diet also have an important effect, yielding a % increase in lifespan equal or higher than the % reduction in the diet caloric content. This correlates well experimental data on small mammal and insects, in which lifespan has been increased by diet restriction.

  1. Cardiovascular risk escalation with caloric excess: a prospective demonstration of the mechanics in healthy adults.

    Science.gov (United States)

    Gupta, Alok K; Johnson, William D; Johannsen, Darcy; Ravussin, Eric

    2013-01-24

    The link between weight gain and cardiovascular risk characterized with circadian blood pressure variability [CBPV] and endothelial function [EF] is unexplored. To prospectively demonstrate weight gain in healthy adults, increases body fat [BF], enlarges waist circumference [WC], expands visceral adipose tissue [VAT], exacerbates systemic inflammation [sIF], worsens insulin resistance [IR] and enhances functional cardiovascular disease [CVD] risk. Healthy men [n=11] and women [n=3] provided initial and eight-week post-caloric excess anthropometric and fasting laboratory measures. Functional CVD risk assessments: CBPV and resting EF were also obtained with 7-day automatic ambulatory BP monitoring and increased test finger peripheral arterial tone [PAT] relative to control [reported as relative hyperemia index (RHI)], respectively. After determining individualized mean energy requirements for weight maintenance over 7-days, each participant received a personalized over feeding prescription (1.4 times; 41% carbohydrate, 44% fat, and 15% protein) for 8-weeks. mean (SEM). Participants increased body weight [BW; +7.4(0.1) kg]*, body mass index [BMI; +2.5(0.2) kg/m²]*, BF [+2.0(0.01)%]*, WC [+8.2(1.0) cm]*, and VAT [+0.2(0.03) L]* and intrahepatic lipid [IHL + 0.0004(0.002) L] :*all p risk [measured as abnormal circadian blood pressure variability and impaired resting endothelial function].

  2. Attentional biases to foods: The effects of caloric content and cognitive restraint.

    Science.gov (United States)

    Forestell, Catherine A; Lau, Pia; Gyurovski, Ivo I; Dickter, Cheryl L; Haque, Sabrina S

    2012-12-01

    The goal of the present study was to determine whether female restrained and unrestrained eaters demonstrated differential levels of attentional bias to high calorie foods when they were presented as distractors in a flanker task. This task consisted of four blocks of 68 trials in which three food pictures were briefly presented simultaneously on a computer screen. On each trial a high or low calorie target food was presented in the center of a pair of high or low calorie food flanker pictures and participants' reaction times to answer a basic question about whether they would consume the target food for breakfast were recorded. In Experiment 1, in which all participants were fed a snack prior to engaging in the flanker task, there was no evidence that restrained (n=29) or unrestrained (n=37) eaters had an attentional bias. However, in Experiment 2, when participants completed the flanker task while hungry, restrained eaters (n=27) experienced response conflict only when low calorie targets were flanked by high calorie distractors, whereas unrestrained eaters (n=46) were distracted by high calorie flankers regardless of the caloric content of the target cue. The results from this implicit task indicate that flankers interfere with hungry participants' responses to varying degrees depending on their cognitive restraint. Whether attentional bias to food cues subsequently affects food choices and eating behavior is a topic for further investigation. Published by Elsevier Ltd.

  3. Historical evolution of slope instability in the Calore River Basin, Southern Italy

    Science.gov (United States)

    Diodato, Nazzareno; Soriano, Marcella; Bellocchi, Gianni; Fiorillo, Francesco; Cevasco, Andrea; Revellino, Paola; Guadagno, Francesco Maria

    2017-04-01

    There is interest in knowing historical spatio-temporal patterns of landslide activity. However, this is challenging to reconstruct because it is difficult to obtain detailed records for past landslide activity. Here, we deal with hydro-geomorphological signatures, such as storms, downpours, floods, snowmelt and mass movement, to detect annual slope instability events (ASIEs) over historical times. In order to obtain ASIEs for each year, a monthly Instability Density Index (IDI) was used and then monthly values were summed up to obtain a yearly value. Classes of monthly IDI varying between 0 (no instability) and 4 (highest instability) were determined from historical documents. We present an application for the Calore River Basin, Southern Italy, using data from a 313-year long series (1701-2013 CE). After 1880 CE the information becomes more valuable with directly observed landslide frequency. By this cataloguing, 129 ASIEs were obtained. Their evolution shows slight instability during the 18th century. Uneven and greater slope instability occurred instead across the 19th century, when an important phase of deforestation coincided with intensification of agricultural activities. Slope instability events continued during the 20th century but their causes are mainly related to anthropisation and the effects of recent climate change. It was determined that stormy autumns until the 19th century and successive winter-times with enhanced snowmelt, may have driven the reactivation of widespread instability events. We also found that mountainous and hilly terrains have an acute sensitivity to climate change.

  4. Adipose-immune interactions during obesity and caloric restriction: reciprocal mechanisms regulating immunity and health span.

    Science.gov (United States)

    Dixit, Vishwa Deep

    2008-10-01

    Increasing evidence suggests a tight coupling of metabolic and immune systems. This cross-talk mediated by neuroendocrine peptides as well as numerous cytokines and chemokines is believed to be responsible for integrating energy balance to immune function. These neuroendocrine-immune interactions are heightened during the state of chronic positive energy balance, as seen during obesity, and negative energy balance caused by caloric restriction (CR). Emerging evidence suggests that obesity may be associated with an immunodeficient state and chronic inflammation, which contribute to an increased risk of premature death. The direct interactions between expanded leukocyte populations within the adipose tissue during obesity and an increased number of adipocytes within an aging lymphoid microenvironment may constitute an important adaptive or pathological response as a result of change in energy balance. In stark contrast to obesity, CR causes negative energy balance and robustly prolongs a healthy lifespan in all of the species studied to date. Therefore, the endogenous neuroendocrine-metabolic sensors elevated or suppressed as a result of changes in energy balance may offer an important mechanism in understanding the antiaging and potential immune-enhancing nature of CR. Ghrelin, one such sensor of negative energy balance, is reduced during obesity and increased by CR. Ghrelin also regulates immune function by reducing proinflammatory cytokines and promotes thymopoiesis during aging and thus, may be a new CR mimetic target. The identification of immune effects and molecular pathways used by such orexigenic metabolic factors could offer potentially novel approaches to enhance immunity and increase healthy lifespan.

  5. Analysis regarding steam generator furnace's incident heat, temperature and composition of combustion gases; Analisis de calor incidente, temperatura y composicion de gases de combustion en hornos de generadores de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Diego Marin, Antonio [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2006-07-01

    In order to obtain more precise evaluations of the combustion process in the furnace of a steam generator a suction pyrometer has been integrated to measure the temperature of the combustion gases; an ellipsoidal radiometer to measure the incident heat by thermal radiation in the water walls; a water cooled probe to determine the particle concentration, as well as a water cooled probe to determine the composition of the combustion gases present. This document clarifies the form of use of these instruments and their engineering specifications, simultaneously presenting an analysis that considers, unlike others, the internal conditions of the furnace to obtain a more precise evaluation of the efficiency that the combustion process presents and bases for the taking of preventive actions in specific zones of the furnace. Thus, the present work exhibits instruments and techniques of analysis to study the phenomena occurring within a steam generator. [Spanish] Con el fin de obtener evaluaciones mas precisas del proceso de combustion en el horno de un generador de vapor, se ha integrado un pirometro de succion para medir la temperatura de los gases de combustion; un radiometro elipsoidal para medir el calor incidente por radiacion termica en las paredes del agua; una sonda enfriada con agua para determinar la concentracion de particulas, asi como una sonda refrigerada con agua para determinar la composicion de los gases de combustion presentes. Este documento aclara la forma de uso de estos instrumentos y sus especificaciones tecnicas, a la vez que presenta un analisis que considera, a diferencia de otros, las condiciones internas del horno para obtener una evaluacion mas precisa sobre la eficiencia del proceso de combustion y bases para la toma de acciones preventivas en zonas especificas del horno. Asi, el presente trabajo exhibe instrumentos y tecnicas de analisis para estudiar los fenomenos que ocurren dentro de un generador de vapor.

  6. Molecular simulation of caloric properties of fluids modelled by force fields with intramolecular contributions: Application to heat capacities.

    Science.gov (United States)

    Smith, William R; Jirsák, Jan; Nezbeda, Ivo; Qi, Weikai

    2017-07-21

    The calculation of caloric properties such as heat capacity, Joule-Thomson coefficients, and the speed of sound by classical force-field-based molecular simulation methodology has received scant attention in the literature, particularly for systems composed of complex molecules whose force fields (FFs) are characterized by a combination of intramolecular and intermolecular terms. The calculation of a thermodynamic property for a system whose molecules are described by such a FF involves the calculation of the residual property prior to its addition to the corresponding ideal-gas property, the latter of which is separately calculated, either using thermochemical compilations or nowadays accurate quantum mechanical calculations. Although the simulation of a volumetric residual property proceeds by simply replacing the intermolecular FF in the rigid molecule case by the total (intramolecular plus intermolecular) FF, this is not the case for a caloric property. We describe the correct methodology required to perform such calculations and illustrate it in this paper for the case of the internal energy and the enthalpy and their corresponding molar heat capacities. We provide numerical results for c P , one of the most important caloric properties. We also consider approximations to the correct calculation procedure previously used in the literature and illustrate their consequences for the examples of the relatively simple molecule 2-propanol, CH 3 CH(OH)CH 3 , and for the more complex molecule monoethanolamine, HO(CH 2 ) 2 NH 2 , an important fluid used in carbon capture.

  7. Molecular simulation of caloric properties of fluids modelled by force fields with intramolecular contributions: Application to heat capacities

    Science.gov (United States)

    Smith, William R.; Jirsák, Jan; Nezbeda, Ivo; Qi, Weikai

    2017-07-01

    The calculation of caloric properties such as heat capacity, Joule-Thomson coefficients, and the speed of sound by classical force-field-based molecular simulation methodology has received scant attention in the literature, particularly for systems composed of complex molecules whose force fields (FFs) are characterized by a combination of intramolecular and intermolecular terms. The calculation of a thermodynamic property for a system whose molecules are described by such a FF involves the calculation of the residual property prior to its addition to the corresponding ideal-gas property, the latter of which is separately calculated, either using thermochemical compilations or nowadays accurate quantum mechanical calculations. Although the simulation of a volumetric residual property proceeds by simply replacing the intermolecular FF in the rigid molecule case by the total (intramolecular plus intermolecular) FF, this is not the case for a caloric property. We describe the correct methodology required to perform such calculations and illustrate it in this paper for the case of the internal energy and the enthalpy and their corresponding molar heat capacities. We provide numerical results for cP, one of the most important caloric properties. We also consider approximations to the correct calculation procedure previously used in the literature and illustrate their consequences for the examples of the relatively simple molecule 2-propanol, CH3CH(OH)CH3, and for the more complex molecule monoethanolamine, HO(CH2)2NH2, an important fluid used in carbon capture.

  8. Trombose induzida pelo calor endovenoso: relato de dois casos tratados com rivaroxabana e revisão da literatura

    Directory of Open Access Journals (Sweden)

    Walter Junior Boim de Araujo

    2016-01-01

    Full Text Available Resumo Define-se trombose induzida pelo calor endovenoso como a propagação do trombo a partir de uma veia superficial em direção a uma veia mais profunda. Em geral, é considerada clinicamente insignificante quando não há propagação do trombo para o sistema venoso profundo. Essa condição pode ser tratada com terapia anticoagulante, embora a observação pareça ser suficiente, principalmente para graus menores. Neste estudo, relatamos dois casos de trombose induzida pelo calor endovenoso que teriam indicação de heparina de baixo peso molecular até a resolução do quadro. Porém, optou-se pelo uso da rivaroxabana (15 mg de 12 em 12h, com resolução completa do trombo em 4 semanas (caso 1 e em 7 dias (caso 2. A rivaroxabana pode ser uma alternativa promissora no tratamento da trombose induzida pelo calor endovenoso avançada, pela simplicidade da posologia, sem comprometimento da eficácia ou da segurança. São necessários estudos prospectivos, randomizados e controlados que possibilitem melhor entendimento da condição e o desenvolvimento de recomendações mais definitivas sobre opções de prevenção e tratamento.

  9. Extension of Drosophila Lifespan by Rhodiola rosea Depends on Dietary Carbohydrate and Caloric Content in a Simplified Diet.

    Science.gov (United States)

    Schriner, Samuel E; Coskun, Volkan; Hogan, Sean P; Nguyen, Cindy T; Lopez, Terry E; Jafari, Mahtab

    2016-03-01

    The root and rhizome extract of Rhodiola rosea has been extensively used in traditional medicine to improve physical and mental performance and to protect against stress. We, and others, have reported that R. rosea can extend lifespan in flies, worms, and yeast. We also previously found that the extract can act independently of dietary restriction (DR), a treatment that can extend lifespan in a range of model organisms. In flies, DR is implemented through a reduction in dietary yeast content. Here, we report that the ability of R. rosea extract to extend lifespan in flies is dependent on the carbohydrate and caloric content when supplemented with a simplified diet composed of yeast and sucrose. R. rosea extract elevated the sugar content in flies and down-regulated hexokinase expression, suggesting that it perturbs carbohydrate metabolism in flies. In our previous studies, bananas, barley malt, and corn syrup provided dietary carbohydrates, and R. rosea extract could extend lifespan with a range of caloric levels. We conclude that the lifespan-extending effect of R. rosea extract in flies is dependent on dietary carbohydrate and caloric contents coupled with an interaction with complex dietary components present in bananas, barley, or corn.

  10. PROCEDIMIENTO DE CALIBRACIÓN EN TEMPERATURA Y FLUJO DE CALOR DE UN CALORÍMETRO DIFERENCIAL DE BARRIDO (DSC

    Directory of Open Access Journals (Sweden)

    Pablo E. Reynoso

    2016-01-01

    Full Text Available El calorímetro diferencial de barrido no es un dispositivo de medición absoluta, por lo que su utilización requiere indispensable mente una calibración. En esta contribución se presenta un procedimiento de calibración para el cual s e consideraron las temperaturas y calores de fusión aceptados en la literatura de 5 materiales puros . S e prepararon 6 muestras de dife rentes masas para cada material y s e sometió cada una de ellas a ci clos de calentamiento , desde temperatura ambiente hasta 50 ºC por encima de las temperaturas de fusión , utilizando 6 velocidades distintas por cada probeta. Luego, p ara determinar una relación de ajuste entre los datos experimentales obtenidos y los valores aceptados , se utilizó un método de regresión no lineal mediante un procedimiento matricial desarrollado en el entorno MATLAB . Los resultados obtenidos muestran una corrección con una desviación estándar de 1,2 ºC para el ajuste en temperatura y 2,1 5 J/g para el flujo de calor.

  11. [Index of Nutritional Purchasing Power Parity: comparison of caloric costs of a healthy versus an unhealthy diet].

    Science.gov (United States)

    Mendoza Velázquez, Alfonso

    2012-01-01

    Develop the Index of Nutritional Purchasing Power Parity (Nut3-CiO) as an instrument to compare the caloric costs of a healthy versus an unhealthy diet between regions or cities in a country over time. Indices of caloric prices were constructed and the "law of one price" was used to derive the Nut3-CiO index. Caloric inflation rates were obtained using basic descriptive statistics. The Nut3-CiO was applied in the major cities of Mexico during the period from January 1996 to December 2010. The statistical behavior of the Nut3-CiO revealed that, in Mexican cities, products for a typical diet are less expensive than products for a healthy diet. The findings showed a cyclical behavior to the index, a high correlation between inflation for the typical diet and inflation for the market basket, and a high persistence of prices. The Nut3-CiO index makes it possible to periodically compare the price differential of two types of diets-typical and healthy-between cities in a single country. This instrument could help health authorities identify the cities where it is easier or more difficult for consumers to access a typical or healthy diet in terms of cost. Furthermore, it makes it possible to estimate the percentage adjustment necessary in each city to attain levels of nutritional purchasing power parity.

  12. Neuroimaging to detect cortical projection of vestibular response to caloric stimulation in young and older adults using functional near-infrared spectroscopy (fNIRS).

    Science.gov (United States)

    Karim, H T; Fuhrman, S I; Furman, J M; Huppert, T J

    2013-08-01

    Functional near-infrared spectroscopy (fNIRS) is a non-invasive and portable neuroimaging technique. The method uses non-ionizing laser light in the range of red to near-infrared to detect changes in cerebral blood oxygenation. In this study, we used fNIRS to investigate cortical hemodynamic changes in the temporo-parietal and frontal regions during caloric vestibular stimulation. Caloric stimulation has previously been investigated using functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), which serves as a validation of the fNIRS imaging modality toward the measurement of vestibular related brain regions. To date, only a single study has used fNIRS during caloric irrigations, which observed blood volume changes in the temporal-parietal area in healthy younger subjects. In this current study, fNIRS was used to measure cortical vestibular activation in 10 right-handed younger subjects (5 male and 5 female, age 25+/-6 years) and 10 right-handed older subjects (6 male and 4 female, age 74+/-5 years). We investigated both warm (44 °C) and cool (30 °C) unilateral caloric vestibular stimulation. Consistent with previous reports, we found that warm (44 °C) caloric irrigation caused a bilateral activation. In addition, we found that cool (30 °C) caloric irrigation caused contralateral activation of the temporo-parietal area. This study is the first to investigate age effects of the caloric stimulation on brain activity. We found that the older subjects had stronger bilateral effects than the younger subjects. Our results confirm previous fMRI and PET studies that showed cortical activation during caloric vestibular irrigation is dependent on side of irrigation, and temperature of irrigation. Furthermore, our results demonstrate that fNIRS is a viable technique in measuring cortical effects during vestibular tasks. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Miradas del desierto. Niños saharauis retratan la sociedad occidental

    Directory of Open Access Journals (Sweden)

    Ainara Miguel Sáez de Urabain

    2010-10-01

    Full Text Available En 1966, los investigadores norteamericanos John Adair y Sol Worth prestaron siete sencillas cámaras de vídeo a siete Navajos para que grabaran sus propias películas a su manera, con una mínima instrucción técnica. La experiencia fue todo un éxito; los indios lograron reproducir en las imágenes tanto su propia concepción del mundo como su lugar en él. Este proyecto pretende reproducir aquel ensayo, entregando diez cámaras fotográficas a veinte de los niños y niñas saharauis que el pasado verano de 2009, gracias a la Asociación Burgalesa de Amigos del Pueblo Saharaui, dejaron atrás los campamentos de refugiados para pasar sus vacaciones en la provincia.Permitimos que, durante los meses de julio y agosto, los niños fotografiaran aquello que consideraran digno de fotografiar del modo en que prefirieran. Así, no sólo se retrataban a sí mismos, sino que también nos representaban a nosotros, parte de una sociedad occidental mucho más acostumbrada a mirar que a ser vista.

  14. Olympic Summer Games and Broadcast Rights. Evolution and Challenges in the New Media Environment/ Juegos Olímpicos de Verano y derechos audiovisuales. Evolución y retos en el entorno New Media

    Directory of Open Access Journals (Sweden)

    Dr. Emilio Fernández Peña

    2009-01-01

    Full Text Available Resumen: El presente trabajo realiza un recorrido histórico sobre la importancia del audiovisual en el desarrollo y difusión del movimiento Olímpico moderno y analiza el papel que los ingresos por derechos televisivos tienen en la financiación del movimiento Olímpico. Los ingresos relacionados con la comunicación (derechos audiovisuales y esponsorización representan casi el 85% de la recaudación total del movimiento Olímpico que es redistribuida en su mayoría entre las Federaciones Internacionales, los Comités Olímpicos Nacionales y Solidaridad Olímpica. El mandato de Juan Antonio Samaranch fue el de la toma de control sobre las negociaciones de los derechos audiovisuales por el CIO, implantando los contratos audiovisuales a largo plazo, lo que permitió un aumento exponencial de los ingresos y su estabilidad en el tiempo. Los primeros nueve años de Rogge como presidente han sido los del éxito financiero en la recaudación y los de la ruptura del modelo de venta conjunta en Europa a las televisiones públicas, sustiyendo en el viejo continente el modelo apoyado en el servico público por el de servicio universal. Las dinámicas de los Nuevos Medios requieren de una adaptación del viejo modelo de propiedad intelectual territorial y exclusivo y su flexibilización, que permita a los jóvenes reelaborar y compartir las imágenes Olímpicas, lo que implica cambios en la gestión de los derechos.Abstract: The project offers a historical overview of the importance of broadcasting for the development and dissemination of the Olympic Movement and its ideals. It also analyses the role of revenue from television broadcast rights in the Olympic Movement. Communication-related revenue (broadcast rights and sponsorship accounts for 85% of the Olympic Movement's total income, most of which is distributed among International Federations, National Olympic Committees and Olympic Solidarity. It was under Juan Antonio Samaranch's mandate that the

  15. Serum concentrations and gene expression of sirtuin 1 in healthy and slightly overweight subjects after caloric restriction or resveratrol supplementation: A randomized trial.

    Science.gov (United States)

    Mansur, Antonio P; Roggerio, Alessandra; Goes, Marisa F S; Avakian, Solange D; Leal, Dalila P; Maranhão, Raul C; Strunz, Célia M C

    2017-01-15

    Sirtuin 1 (Sirt1) plays an important role in vascular biology, and influences aspects of age-dependent atherosclerosis. In animals, the sirtuin system is strongly influenced by resveratrol and caloric restriction, but its expression in humans is controversial. This study investigated the effects of resveratrol and caloric restriction on Sirt1 serum concentrations and vascular biomarkers in a healthy human population. Forty-eight healthy participants (24 women) aged 55-65years were randomized to either 30days of resveratrol administration (500mg/day) or caloric restriction (1000cal/day). Blood was collected at baseline and day 30. Laboratory data analyzed were triglycerides, total cholesterol, HDL, VLDL, LDL, apolipoprotein A1, apolipoprotein B, lipoprotein (a), non-esterified fatty acids (NEFA), glucose, insulin, oxidative stress, C-reactive protein, and Sirt1. Expression of the Sirt1 gene was analyzed using real-time PCR. Caloric restriction diminished the abdominal circumference and improved the lipid profile, but not resveratrol intervention. Resveratrol and caloric restriction increased serum concentrations of Sirt1, from 1.06±0.71 to 5.75±2.98ng/mL; presveratrol treatment. Caloric restriction and resveratrol significantly increased plasma concentrations of Sirt1. The long-term impact of these interventions on atherosclerosis should be assessed. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  16. Meals of differing caloric content do not alter physical activity behavior during a subsequent simulated recess period in children.

    Science.gov (United States)

    Smith, Kelly J; Pohle-Krauza, Rachael; Uhas, Samantha; Barkley, Jacob E

    2016-01-01

    Research on adults and animals has demonstrated that chronic and acute overfeeding can alter physical activity behavior. However, there are no assessments of the acute effects of high-calorie (HC) meals on physical activity behavior in children. This is of importance as a typical school lunch is HC. If this type of meal negatively impacts subsequent physical activity behavior, the ability of post-lunch recess periods as a means to increase energy expenditure may be lessened. To assess the effect of two meals of differing caloric content, HC and low calorie (LC), on children's subsequent physical activity behavior. Nineteen healthy children (aged 6-10) completed two laboratory sessions where they were fed lunch with HC or LC content, but equivalent macronutrient distribution. Children had 15 min to consume as much of the meal as possible per session. Children consumed 659.5 ± 101.3 kcal in the HC condition and 291.8 ± 12.1 kcal in the LC condition. After the meal, children went to a gymnasium for 40 min. In the gymnasium children had free-choice access to obstacle courses, various sports equipment, and a table with sedentary activities. Children could play with any of the activities in any amount they wished for the entire activity session. Children's physical activity was monitored with accelerometers and that data was converted into caloric expenditure. Each child ate all meals and participated in the free-choice activity sessions with no other children present. Caloric expenditure during the free-choice activity sessions was not significantly different (p = 0.4) between the HC (89.2 ± 27.3 kcals) and LC (83.4 ± 34.9 kcals) conditions. However, caloric balance (kcals eaten-kcals expended) was 2.74-fold greater (p < 0.001) in the HC condition (Δ 570.3 ± 92.2 kcals) than the LC condition (Δ 208.4 ± 32.0 kcals). Children did not alter their physical activity behavior during a free-choice activity session after consuming a HC meal

  17. Hábitos alimenticios de Lagidium viscacia y Abrocoma cinerea: roedores sintópicos en ambientes altoandinos del norte de Chile Food-habits of Lagidium viscacia and Abrocoma cinerea: syntopic rodents in high Andean environments of northern Chile

    Directory of Open Access Journals (Sweden)

    ARTURO CORTÉS

    2002-09-01

    Full Text Available Lagidium viscacia y Abrocoma cinerea son dos especies de roedores herbívoros de distribución geográfica simpátrida en los ambientes altoandinos del Norte Grande de Chile, donde la disponibilidad de alimento es escasa, fluctuante y poco predecible. Dada su sintopía, y por habitar en ambientes áridos altoandinos (Segunda Región de Chile con escasez de recursos alimenticios, se espera que ambas especies de roedores seleccionen diferencialmente sus recursos, o segregarse en otros ejes de nicho (e.g., nicho espacial a fin de evitar la presumible competencia explotativa por los recursos alimenticios. En este estudio evaluamos los hábitos alimenticios de estas dos especies durante dos estaciones contrastantes (invierno, 1996 y verano, 1997. Los resultados indicaron que: (1 L. viscacia consumió 10 ítemes alimenticios en invierno y siete en verano de las 12 únicas especies de plantas presentes en su ambiente. El ítem alimenticio mayormente consumido fue Stipa bomanii, con un 20,9 % (invierno 1996 y un 30,1 % (verano 1997. Otros ítemes alimenticios importantes, pero sólo consumidos en invierno, fueron Nicotiana longibracteata (12,1 % y Parastrephia quadrangularis (9,4 %; mientras que en verano consumió: Festuca ortophylla (19,9 %. En cambio, A. cinerea consumió en invierno Baccharis tola (73,2 %, Lupinus oreophilus (11,9 %, Adesmia horrida (3,6 % y P. quadrangularis (0,4 %, mientras que en verano consumió B. tola (33,7 %, A. horrida (22,5 %, L. oreophilus (24,0 %, P. quadrangularis (2,3 % y Ephedra rupestris (2,9 %. (2 Lagidium viscacia presentó mayor amplitud de nicho trófico que A. cinerea (invierno: H' = 0,67 versus 0,25; verano: H' = 0,53 versus 0,56. (3 En invierno, L. viscacia mostró alta selección por N. longibracteata (Ei = 0,96 y Calceolaria stellarifolia (Ei = 0,80 y, en menor grado, por P. quadrangularis (Ei = 0,62 y S. bomanii (Ei = 0,26, mientras que en verano seleccionó a las gramíneas F. orthophylla (Ei = 0,52 y S

  18. Uso de un modelo de aguas someras para analizar la influencia del Atlántico Tropical Norte y del Pacífico Ecuatorial del Este sobre la circulación atmosférica en los mares Intra-Americanos

    OpenAIRE

    Eric J. Alfaro; Daniel Hernández; Arnoldo Bezanilla

    2007-01-01

    Se usó un modelo numérico de aguas someras para simular la circulación anómala en la región de los Mares Intra-Americanos (MIA) inducida por dos funciones forzantes asociadas con fuentes de calor localizadas en las regiones oceánicas del Atlántico Tropical Norte y del Pacífico Ecuatorial del Este, respectivamente. A pesar de su simplicidad, el modelo de aguas someras representó algunas de las características principales de la circulación inducida sobre los MIA por las funciones forzantes desc...

  19. Flujos de agua, flujos de capital: sistemas de abastecimiento y gobernanza del agua en Madrid y Barcelona

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    Hug March

    2010-01-01

    Full Text Available El agua es un elemento clave para el sustento del metabolismo de las ciudades. Sin embargo, los orígenes, métodos de «producción», y modelos de gestión del flujo de urbano de agua pueden variar geográficamente. En este artículo se comparan los sistemas de abastecimiento y gestión de agua potable en las dos principales regiones metropolitanas del Estado: Barcelona y Madrid. En Barcelona, el agua procede de distintas fuentes entre las cuales destaca la desalación, vigente desde el verano de 2009. En Madrid, el sistema de abastecimiento depende fuertemente de las aguas superficiales procedentes de diversos ríos que atraviesan la Comunidad. Por lo que respeta a la gestión de estos sistemas el presente trabajo hace hincapié sobre las importantes diferencias que giran entorno al distinto balance entre participación pública y privada en el ciclo del agua en ambas áreas. Finalmente el artículo reflexiona sobre los puntos de convergencia y divergencia entre ambos modelos de abastecimiento así como sus perspectivas de futuro.

  20. PREFACE: 16th International Conference on Calorimetry in High Energy Physics (CALOR 2014)

    Science.gov (United States)

    Novotny, Rainer W.

    2015-02-01

    The XVIth International Conference on Calorimetry in High Energy Physics - CALOR 2014 - was held in Giessen, Germany from 6-11 April 2014 at the Science Campus of the University. It was hosted by the Justus-Liebig-University and the HIC for FAIR Helmholtz International Center. The series of conferences on calorimetry were started in 1990 at Fermilab and are focusing primarily on operating and future calorimeter systems within the Hadron and High-Energy Physics community without neglecting the impact on other fields such as Astrophysics or Medical Imaging. Confirmed by the impressive list of over 70 oral presentations, 5 posters and over 100 attendees, the field of calorimetry appears alive and attractive. The present volume contains the written contributions of almost all presentations which can be found at http://calor2014.de. Time slots of 15 or 30 minutes including discussion were allocated. The conference was accompanied by a small exhibition of several industrial companies related to the field. The day before the opening of the scientific program, Richard Wigmans gave an excellent and vivid tutorial on basic aspects on calorimetry meant as an introduction for students and conference attendees new in the field. The opening ceremony was used to give an impression of the present and future status and the scientific program of the new FAIR facility nearby at Darmstadt presented by Klaus Peters from GSI. The conference program of the first day was dedicated to the performance and required future upgrade of the LHC experiments, dominated by ATLAS, CMS and LHCb. The program of the next day contained specific aspects on electronics and readout as well as calorimetry in outer space. Several contributions discussed in detail new concepts for hadron calorimeters within the CALICE collaboration completed by a session on sampling calorimeters. The next sections were dedicated to operating and future calorimeters at various laboratories and covering a wide range of

  1. Effect of exercise on the caloric intake of breast cancer patients undergoing treatment

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    C.L. Battaglini

    2008-08-01

    Full Text Available The purpose of this study was to examine the effects of an exercise intervention on the total caloric intake (TCI of breast cancer patients undergoing treatment. A secondary purpose was to determine whether or not a relationship existed between changes in TCI, body fat composition (%BF, and fatigue during the study, which lasted 6 months. Twenty females recently diagnosed with breast cancer, scheduled to undergo chemotherapy or radiation, were assigned randomly to an experimental (N = 10 or control group (N = 10. Outcome measures included TCI (3-day food diary, %BF (skinfolds, and fatigue (revised Piper Fatigue Scale. Each exercise session was conducted as follows: initial cardiovascular activity (6-12 min, followed by stretching (5-10 min, resistance training (15-30 min, and a cool-down (approximately 8 min. Significant changes in TCI were observed among groups (F1,18 = 8.582; P = 0.009, at treatments 2 and 3, and at the end of the study [experimental (1973 ± 419, control (1488 ± 418; experimental (1946 ± 437, control (1436 ± 429; experimental (2315 ± 455, control (1474 ± 294, respectively]. A significant negative correlation was found (Spearman rho(18 = -0.759; P < 0.001 between TCI and %BF and between TCI and fatigue levels (Spearman rho(18 = -0.541; P = 0.014 at the end of the study. In conclusion, the results of this study suggest that an exercise intervention administered to breast cancer patients undergoing medical treatment may assist in the mitigation of some treatment side effects, including decreased TCI, increased fatigue, and negative changes in body composition.

  2. Habitual sleep variability, not sleep duration, is associated with caloric intake in adolescents.

    Science.gov (United States)

    He, Fan; Bixler, Edward O; Berg, Arthur; Imamura Kawasawa, Yuka; Vgontzas, Alexandros N; Fernandez-Mendoza, Julio; Yanosky, Jeff; Liao, Duanping

    2015-07-01

    The objective of this study was to investigate the associations between objectively measured habitual sleep duration (HSD), habitual sleep variability (HSV), and energy and snack intake in adolescents. We used data from 324 adolescents who participated in the Penn State Child Cohort follow-up examination. Actigraphy was used over seven consecutive nights to estimate nightly sleep duration. The seven-night mean and standard deviation of sleep duration were used to represent HSD and HSV, respectively. The Youth/Adolescent Food Frequency Questionnaire was used to obtain the daily average total energy, protein, fat, and carbohydrate intake, and number of snacks consumed. Linear regression models were used to investigate the associations between habitual sleep patterns and caloric, protein, fat, and carbohydrate intake. Proportional odds models were used to associate habitual sleep patterns with snack consumption. After adjusting for age, sex, race, body mass index (BMI) percentile, and smoking status, an increased HSV was associated with a higher energy intake, particularly from fat and carbohydrate. For example, with a 1-h increase in HSV, there was a 170 (66)-kcal increase in the daily total energy intake. An increased HSV was also related to increased snack consumption, especially snacks consumed after dinner. For instance, a 1-h increase in HSV was associated with 65% and 94% higher odds of consuming more snacks after dinner during school/workdays and weekends/vacation days, respectively. Neither energy intake nor snack consumption was significantly related to HSD. High habitual sleep variability, not habitual sleep duration, is related to increased energy and food consumption in adolescents. Maintaining a regular sleep pattern may decrease the risk of obesity in adolescents. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Leaf Caloric Value from Tropical to Cold-Temperate Forests: Latitudinal Patterns and Linkage to Productivity.

    Science.gov (United States)

    Song, Guangyan; Hou, Jihua; Li, Ying; Zhang, Jiahui; He, Nianpeng

    2016-01-01

    Leaf caloric value (LCV) reflects the capacity of a leaf to fix and accumulate solar energy through photosynthesis. We systematically investigated the LCV of 745 plant species in 9 forests, representing a range of tropical to cold-temperate forests along the 4700-km North-South Transect of Eastern China. The goals were to explore the latitudinal patterns of LCV at the levels of species, plant functional group, and community and to establish the relationship between LCV and gross primary productivity (GPP). Our results showed that LCV for all species ranged from 12.85 to 22.15 KJ g-1 with an average of 18.46 KJ g-1. Plant functional groups had a significant influence on LCV, with trees > shrubs > herbs, conifers > broadleaved trees, and evergreens > deciduous trees. The different values of LCV represented the long-term evolution and adaptation of plant species to different environments. Unexpectedly, no apparent latitudinal trends of LCV at community level were observed, although LCV at the species level clearly decreased with increasing latitude. Use efficiency of LCV (CUE, gC KJ-1), defined as the ratio of GPP to total LCV at the community level, varied quadratic with latitude and was lower in the middle latitudes. Climate (temperature and precipitation) may explain 52.9% of the variation in spatial patterns of CUE, which was positively correlated with aridity. Our findings are the first large-scale report of the latitudinal patterns of LCV in forests at the species, plant functional group, and community levels and provide new insights into the relationship between LCV and ecosystem functions in forest communities.

  4. Leaf Caloric Value from Tropical to Cold-Temperate Forests: Latitudinal Patterns and Linkage to Productivity.

    Directory of Open Access Journals (Sweden)

    Guangyan Song

    Full Text Available Leaf caloric value (LCV reflects the capacity of a leaf to fix and accumulate solar energy through photosynthesis. We systematically investigated the LCV of 745 plant species in 9 forests, representing a range of tropical to cold-temperate forests along the 4700-km North-South Transect of Eastern China. The goals were to explore the latitudinal patterns of LCV at the levels of species, plant functional group, and community and to establish the relationship between LCV and gross primary productivity (GPP. Our results showed that LCV for all species ranged from 12.85 to 22.15 KJ g-1 with an average of 18.46 KJ g-1. Plant functional groups had a significant influence on LCV, with trees > shrubs > herbs, conifers > broadleaved trees, and evergreens > deciduous trees. The different values of LCV represented the long-term evolution and adaptation of plant species to different environments. Unexpectedly, no apparent latitudinal trends of LCV at community level were observed, although LCV at the species level clearly decreased with increasing latitude. Use efficiency of LCV (CUE, gC KJ-1, defined as the ratio of GPP to total LCV at the community level, varied quadratic with latitude and was lower in the middle latitudes. Climate (temperature and precipitation may explain 52.9% of the variation in spatial patterns of CUE, which was positively correlated with aridity. Our findings are the first large-scale report of the latitudinal patterns of LCV in forests at the species, plant functional group, and community levels and provide new insights into the relationship between LCV and ecosystem functions in forest communities.

  5. Influence of parenteral feeding on spontaneous caloric intake and food selection in rats.

    Science.gov (United States)

    Giner, M; Kawashima, Y; Campos, A C; Meguid, M M

    1992-04-01

    We compared spontaneous caloric intake (SCI) of rats exclusively receiving chow to SCI of rats given the choice of chow or Parmesan cheese, and then examined the influence of parenteral feeding on SCI and food selection. Six rats in a Chow Diet Group were offered Purina chow for 21 days, while five rats in a Choice Diet Group were offered Parmesan cheese or the same chow. Daily SCI (kcal/day) and body weight gain (BWG; g/day) were determined. Rats in the Choice Diet Group ate twice as much cheese as chow for the first 3 days of the experiment. Thereafter, SCI and BWG became comparable in both groups, with no significant differences for the rest of the study. In another group of nine rats, a central venous catheter was inserted. After 7 days, rats were offered chow and water ad libitum during the infusion of normal saline at 3 ml/hour for 3 days (Saline). Then, normal saline was replaced by a total parenteral nutrition (TPN) mixture of glucose, fat, and amino acid providing 85 kcal/day, and rats were randomized to eat either Chow Diet or Choice Diet. In both groups, SCI during TPN was significantly reduced as compared to the SCI on Saline. However, rats in the Choice Diet Group ate three times more chow than cheese during TPN. We conclude that a) food preference can increase SCI for short periods of time; b) TPN reduces SCI; c) TPN modifies food preference; and d) food preference does not increase SCI during TPN.

  6. Magneto-caloric effect in the pseudo-binary intermetallic YPrFe{sub 17} compound

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, Pablo [Departamento de Fisica, Universidad de Oviedo, Calvo Sotelo, s/n, 33007 Oviedo (Spain); Gorria, Pedro, E-mail: pgorria@uniovi.es [Departamento de Fisica, Universidad de Oviedo, Calvo Sotelo, s/n, 33007 Oviedo (Spain); Sanchez Llamazares, Jose L. [Division de Materiales Avanzados, Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la presa San Jose 2055, CP 78216, San Luis Potosi (Mexico); Perez, Maria J. [Departamento de Fisica, Universidad de Oviedo, Calvo Sotelo, s/n, 33007 Oviedo (Spain); Franco, Victorino [Departamento de Fisica de la Materia Condensada, ICMSE-CSIC, Universidad de Sevilla, P.O. Box 1065, 41080 Sevilla (Spain); Reiffers, Marian; Kovac, Jozef [Institute of Experimental Physics, Watsonova 47, SK-04001 Kosice (Slovakia); Puente-Orench, Ines [Institute Laue Langevin, 6 rue Jules Horowitz, 38042 Grenoble (France); Blanco, Jesus A. [Departamento de Fisica, Universidad de Oviedo, Calvo Sotelo, s/n, 33007 Oviedo (Spain)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer YPrFe{sub 17} exhibits a broad {Delta}S{sub M}(T) associated with the ferro-to-paramagnetic phase transition (T{sub C} Almost-Equal-To 290 K). Black-Right-Pointing-Pointer We obtain |{Delta}S{sub M}| Almost-Equal-To 2.3 J kg{sup -1} K{sup -1} and RCP Almost-Equal-To 100 J kg{sup -1}for a magnetic field change of 1.5 T. Black-Right-Pointing-Pointer A single master curve for {Delta}S{sub M} is found when compared with other isostructural R{sub 2}Fe{sub 17} binary alloys. - Abstract: We have synthesized the intermetallic YPrFe{sub 17} compound by arc-melting. X-ray and neutron powder diffraction show that the crystal structure is rhombohedral with R3{sup Macron }m space group (Th{sub 2}Zn{sub 17}-type). The investigated compound exhibits a broad isothermal magnetic entropy change {Delta}S{sub M}(T) associated with the ferro-to-paramagnetic phase transition (T{sub C} Almost-Equal-To 290 K). The |{Delta}S{sub M}| ( Almost-Equal-To 2.3 J kg{sup -1} K{sup -1}) and the relative cooling power ( Almost-Equal-To 100 J kg{sup -1}) have been calculated for applied magnetic field changes up to 1.5 T. A single master curve for {Delta}S{sub M} under different values of the magnetic field change can be obtained by a rescaling of the temperature axis. The results are compared and discussed in terms of the magneto-caloric effect in the isostructural R{sub 2}Fe{sub 17} (R = Y, Pr and Nd) binary intermetallic alloys.

  7. The ketogenic diet: initiation at goal calories versus gradual caloric advancement.

    Science.gov (United States)

    Bansal, Seema; Cramp, Laura; Blalock, Dan; Zelleke, Tesfaye; Carpenter, Jessica; Kao, Amy

    2014-01-01

    Inpatient initiation of the ketogenic diet has historically involved fasting followed by gradual advancement of calories and/or diet ratio. Complications during this initiation period are common. We sought to determine if the initiation of the diet at goal calories would reduce these complications while maintaining efficacy. Sixty patients were admitted to a tertiary care hospital for elective initiation of the ketogenic diet between October 2007 and January 2013. All patients were placed on a ketogenic diet initiation pathway. In 2010, the pathway was modified from gradual caloric advancement to initiation at goal calories. We selected 30 consecutive patients before and after the change for comparison. Each child's record was reviewed for the occurrence of hypoglycemia, number of days to reach full ketosis (defined as 4 + urine ketones), acidosis requiring commencement of sodium citrate, length of admission, and long-term efficacy. Both methods of initiation had similar rates of dehydration, vomiting, lethargy, and irritability. More patients initiated at goal received sodium citrate (P = 0.005); however, mean daily values of carbon dioxide were not significantly different. Onset of ketosis was slightly delayed (P = 0.009) in patients initiated at goal, but length of stay was not affected (P > 0.1). Hypoglycemia was uncommon and rates were similar between the groups. Efficacy at 3 months was better in patients initiated at full calories (P ketogenic diet full calories is a reasonable alternative to the current standard practice of gradual advancement of calories and/or diet ratio. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Effect of the osmolality of caloric and acaloric liquids on gastric myoelectrical activity in humans.

    Science.gov (United States)

    Syrkiewicz-Trepiak, Danuta; Jonderko, Krzysztof; Kasicka-Jonderko, Anna

    2010-05-01

    The aim was to establish the effect of the osmolality of orally consumed liquids on gastric myoelectrical activity (GMA). Twenty-five healthy volunteers (13 women, 12 men aged 29.4+/-1.4 [SE] years) underwent five examinations on separate days. After a 20-min basal electrogastrographic recording, the volunteers drank 400 ml of a) bi-distilled water, b) 0.9% NaCl, osmolality 286 mmol/kg, c) 2.9% NaCl, osmolality 827 mmol/kg, d) 5% glucose, osmolality 282 mmol/kg, energy density 209 kcal/l, or e) 15% glucose, osmolality 836 mmol/kg, 627 kcal/l. Then the registration of GMA was continued for 60 min. Gastric emptying was measured with the 13C-acetate breath test. Compared with distilled water, the isotonic glucose drink elicited a positive chronotropic influence on and stabilization of GMA. At the transition from isotonicity to hypertonicity, a pronounced destabilization of GMA was observed, with opposite directions of changes brought about by the presence or absence of a caloric load; bradygastria was manifested after the energy-free hypertonic NaCl solution whereas hypertonic glucose evoked a tachygastric pattern. A marked delay in gastric emptying was found with both hypertonic drinks. Osmolality and its interplay with chemical composition/energy density must be taken into account when choosing a test meal for an electrogastrographic examination and interpreting its results. Of the five fluids examined, isotonic glucose appeared to be the drink least disturbing to GMA.

  9. Mild caloric restriction up-regulates the expression of prohibitin: A proteome study

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Shoko; Masuda, Junko; Shimagami, Hiroshi [Department of Applied Biological Chemistry, The University of Tokyo, Tokyo (Japan); Ohta, Yutaka; Kanda, Tomomasa [Research Laboratories for Health and Gustatory Science, Asahi Breweries Limited, Ibaraki (Japan); Saito, Kenji [Department of Applied Biological Chemistry, The University of Tokyo, Tokyo (Japan); Corporate Sponsored Research Program ' Food for Life' , The University of Tokyo, Tokyo (Japan); Kato, Hisanori, E-mail: akatoq@mail.ecc.u-tokyo.ac.jp [Department of Applied Biological Chemistry, The University of Tokyo, Tokyo (Japan); Corporate Sponsored Research Program ' Food for Life' , The University of Tokyo, Tokyo (Japan)

    2011-02-18

    Research highlights: {yields} Proteomic analysis was performed to elucidate physiological alterations induced by mild CR. {yields} The results suggest good reproducibility and possibility to grasp the important response of CR. {yields} The increase in prohibitin abundance was observed in CR groups by proteomic analysis. {yields} We hypothesize that prohibitin might be involved in the longevity induced by CR. -- Abstract: Caloric restriction (CR) is well known to expand lifespan in a variety of species and to retard many age-related diseases. The effects of relatively mild CR on the proteome profile in relation to lifespan have not yet been reported, despite the more extensive studies of the stricter CR conditions. Thus, the present study was conducted to elucidate the protein profiles in rat livers after mild CR for a relatively short time. Young growing rats were fed CR diets (10% and 30% CR) for 1 month. We performed the differential proteomic analysis of the rat livers using two-dimensional electrophoresis combined with MALDI-TOF mass spectrometry. The most remarkable protein among the differentially expressed proteins was found to be prohibitin, the abundance of which was increased by 30% CR. Prohibitin is a ubiquitously expressed protein shown to suppress cell proliferation and to be related to longevity. The increase in prohibitin was observed both in 10% and 30% CR by Western blot analysis. Furthermore, induction of AMP-activated kinase (AMPK) protein, related to the actions of prohibitin in promoting longevity, was observed. The increased prohibitin level in response to subtle CR suggests that this increase may be one of the early events leading to the expansion of lifespan in response to CR.

  10. Shifts in the distribution of mass densities is a signature of caloric restriction in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Alfonso Reina

    Full Text Available Although the starvation response of the model multicellular organism Caenorhabditis elegans is a subject of much research, there is no convenient phenotypic readout of caloric restriction that can be applicable to large numbers of worms. This paper describes the distribution of mass densities of populations of C. elegans, from larval stages up to day one of adulthood, using isopycnic centrifugation, and finds that density is a convenient, if complex, phenotypic readout in C. elegans. The density of worms in synchronized populations of wildtype N2 C. elegans grown under standard solid-phase culture conditions was normally distributed, with distributions peaked sharply at a mean of 1.091 g/cm(3 for L1, L2 and L3 larvae, 1.087 g/cm(3 for L4 larvae, 1.081 g/cm(3 for newly molted adults, and 1.074 g/cm(3 at 24 hours of adulthood. The density of adult worms under starvation stress fell well outside this range, falling to a mean value of 1.054 g/cm(3 after eight hours of starvation. This decrease in density correlated with the consumption of stored glycogen in the food-deprived worms. The density of the worms increased when deprived of food for longer durations, corresponding to a shift in the response of the worms: worms sacrifice their bodies by retaining larvae, which consume the adults from within. Density-based screens with the drug Ivermectin on worms cultured on single plates resulted in a clear bimodal (double-peaked distribution of densities corresponding to drug exposed and non-exposed worms. Thus, measurements of changes in density could be used to conduct screens on the effects of drugs on several populations of worms cultured on single plates.

  11. Shifts in the Distribution of Mass Densities Is a Signature of Caloric Restriction in Caenorhabditis elegans

    Science.gov (United States)

    Laromaine, Anna; Samuel, Aravinthan D. T.; Whitesides, George M.

    2013-01-01

    Although the starvation response of the model multicellular organism Caenorhabditis elegans is a subject of much research, there is no convenient phenotypic readout of caloric restriction that can be applicable to large numbers of worms. This paper describes the distribution of mass densities of populations of C. elegans, from larval stages up to day one of adulthood, using isopycnic centrifugation, and finds that density is a convenient, if complex, phenotypic readout in C. elegans. The density of worms in synchronized populations of wildtype N2 C. elegans grown under standard solid-phase culture conditions was normally distributed, with distributions peaked sharply at a mean of 1.091 g/cm3 for L1, L2 and L3 larvae, 1.087 g/cm3 for L4 larvae, 1.081 g/cm3 for newly molted adults, and 1.074 g/cm3 at 24 hours of adulthood. The density of adult worms under starvation stress fell well outside this range, falling to a mean value of 1.054 g/cm3 after eight hours of starvation. This decrease in density correlated with the consumption of stored glycogen in the food-deprived worms. The density of the worms increased when deprived of food for longer durations, corresponding to a shift in the response of the worms: worms sacrifice their bodies by retaining larvae, which consume the adults from within. Density-based screens with the drug Ivermectin on worms cultured on single plates resulted in a clear bimodal (double-peaked) distribution of densities corresponding to drug exposed and non-exposed worms. Thus, measurements of changes in density could be used to conduct screens on the effects of drugs on several populations of worms cultured on single plates. PMID:23922767

  12. Calibration of a Fusion Experiment to Investigate the Nuclear Caloric Curve

    Science.gov (United States)

    Keeler, Ashleigh

    2017-09-01

    In order to investigate the nuclear equation of state (EoS), the relation between two thermodynamic quantities can be examined. The correlation between the temperature and excitation energy of a nucleus, also known as the caloric curve, has been previously observed in peripheral heavy-ion collisions to exhibit a dependence on the neutron-proton asymmetry. To further investigate this result, fusion reactions (78Kr + 12C and 86Kr + 12C) were measured; the beam energy was varied in the range 15-35 MeV/u in order to vary the excitation energy. The light charged particles (LCPs) evaporated from the compound nucleus were measured in the Si-CsI(TI)/PD detector array FAUST (Forward Array Using Silicon Technology). The LCPs carry information about the temperature. The calibration of FAUST will be described in this presentation. The silicon detectors have resistive surfaces in perpendicular directions to allow position measurement of the LCP's to better than 200 um. The resistive nature requires a position-dependent correction to the energy calibration to take full advantage of the energy resolution. The momentum is calculated from the energy of these particles, and their position on the detectors. A parameterized formula based on the Bethe-Bloch equation was used to straighten the particle identification (PID) lines measured with the dE-E technique. The energy calibration of the CsI detectors is based on the silicon detector energy calibration and the PID. A precision slotted mask enables the relative positions of the detectors to be determined. DOE Grant: DE-FG02-93ER40773 and REU Grant: PHY - 1659847.

  13. Balanced Caloric Restriction Minimizes Changes Caused by Aging on the Colonic Myenteric Plexus.

    Science.gov (United States)

    Mari, Renata de Britto; Stabille, Sandra Regina; de Faria, Haroldo Garcia; Pereira, Joice Naiara Bertaglia; Guimarães, Juliana Plácido; Marinsek, Gabriela Pustiglione; de Souza, Romeu Rodrigues

    2017-07-31

    Aging can promote significant morphofunctional changes in the gastrointestinal tract (GIT). Regulation of GIT motility is mainly controlled by the myenteric neurons of the enteric nervous system. Actions that aim at decreasing the aging effects in the GIT include those related to diet, with caloric restriction (CR). The CR is achieved by controlling the amount of food or by manipulating the components of the diet. Therefore, the objective of this study was to evaluate different levels of CR on the plasticity of nicotinamide adenine dinucleotide phosphate- (NADPH-) reactive myenteric neurons in the colon of Wistar rats during the aging process using ultrastructural (transmission electron microscopy) and morphoquantitative analysis. Wistar male rats (Rattus norvegicus) were distributed into 4 groups (n = 10/group): C, 6-month-old animals; SR, 18-month-old animals fed a normal diet; CRI, 18-month-old animals fed a 12% CR diet; CRII, 18-month-old animals fed a 31% CR diet. At 6 months of age, animals were transferred to the laboratory animal facility, where they remained until 18 months of age. Animals of the CRI and CRII groups were submitted to CR for 6 months. In the ultrastructural analysis, a disorganization of the periganglionar matrix with the aging was observed, and this characteristic was not observed in the animals that received hypocaloric diet. It was observed that the restriction of 12.5% and 31% of calories in the diet minimized the increase in density and cell profile of the reactive NADPH neurons, increased with age. This type of diet may be adapted against gastrointestinal disturbances that commonly affect aging individuals.

  14. Contribución a la epigrafía del Oeste de la provincia de Salamanca : el conjunto de Medina del Campo (Valladolid

    Directory of Open Access Journals (Sweden)

    A. Jiménez de Furundarena

    1993-01-01

    Full Text Available A finales del verano de 1991 estudiamos una colección particular de 28 epígrafes romanos depositados en una casa de campo próxima a la localidad de Medina del Campo'. Los epígrafes proceden de una gran necrópolis romana situada en un cerro llamado Cabeza de San Pedro, en el término municipal de Hinojosa de Duero (Salamanca junto al salto de Saucelle, durante cuya construcción —fue inaugurado en 1956— pasaron estas lápidas a manos de particulares. El objetivo de este trabajo es, pues, hacer algunas referencias y puntualizaciones sobre todo el conjunto de epígrafes de Hinojosa de Duero, relacionándolo con la epigrafía de algunas localidades, como Astorga o Chaves, y de algunas regiones, como la comprendida entre los ríos Duero y Sabor, la zona zamorana y el occidente salmantino.

  15. Dieta del Pirincho (Guira guira en el nordeste de la provincia de Buenos Aires, Argentina (Cuculiformes: Cuculidae

    Directory of Open Access Journals (Sweden)

    Guillermo E Soave

    2008-12-01

    Full Text Available Se estudió la dieta y ecología alimentaria del ave conocida en Argentina como Pirincho (Guira guira, a través del análisis de 62 contenidos estomacales. Las muestras fueron obtenidas entre 1991 y 1997 (23 en primavera, 16 en verano, 10 en otoño y 13 en invierno, en las localidades de La Balandra y Punta Blanca, partido de Magdalena, provincia de Buenos Aires. Ambos sexos fueron analizados en conjunto debido a que no se encontraron diferencias significativas en el número y en el peso de las presas consumidas por machos y hembras (U de Mann-Whitney. La dieta estuvo compuesta en un 100 % por ítemes de origen animal, representada por 92 entidades taxonómicas. Los invertebrados constituyeron más del 96% de la muestra por número, y los vertebrados un 31% del peso total. Los insectos fueron hallados en el 98% de las muestras, representando el 85% y 59% en número y peso del total consumido, respectivamente. En los contenidos estomacales se hallaron además anélidos, moluscos, crustáceos, arácnidos, anfibios, reptiles y aves. Estacionalmente no se encontraron diferencias significativas en el número de las presas capturadas. En lo referente al peso, las muestras de invierno resultaron más pesadas que las de primavera y verano (Kruskal-Wallis. El Pirincho es un ave oportunista que consume exclusivamente presas de origen animal.Feeding ecology of the Guira Cuckoo (Guira guira in the northeastern Buenos Aires Province. We studied the diet and feeding ecology of the Guira Cuckoo (Guira guira, a bird that has a wide distribution in Argentina. We analyzed 62 stomachs, obtained between 1991 and 1997 (26 in spring, 13 in summer, 10 in autumn and 13 in winter, in the localities La Balandra and Punta Blanca, Magdalena district, Buenos Aires province. in order to establish the contribution of each prey item, we applied the relative importance index. The dietary contribution in terms of number and volume was also taken into account. This species feeds

  16. Influencia del calor y del aclarado sobre la germinación de Cistus laurifolius y Cistus ladanifer

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    Valbuena, L.

    1992-12-01

    Full Text Available The aim of this study is to determine if the increase of the temperature of the soil while a wildfire improves the germination of Cistus laurifolius and Cistus ladanifer. Laboratory experiments were carried out by heating the seeds to different temperatures and at different periods of time. On the other hand, the regeneration of both species in the field was studied in experimental plots that were subjected to prescribed burning, as well as to cutting of the aerial biomass. Cistus ladanifer regrows better than Cistus laurifolius. The answer, in terms of seedling number, is also better in the burnt plots than in the cut. The height in each case follows different patterns. The field results agree with those of the laboratory.

    [es] El objetivo de este estudio es determinar si el aumento de temperatura que se produce en el suelo durante los incendios favorece la germinación de las semillas de Cistus laurliolius y Cistus ladanifer. Se realizan ensayos de germinación en el laboratorio, calentando las semillas a diferentes temperaturas durante distintos tiempos. Paralelamente, se estudia la regeneración de ambas especies en condiciones de campo, en parcelas experimentales sometidas a quema controlada y corta de la biomasa aérea. Cistus ladanifer se regenera mejor que Cistus laurifolius, en términos de número de plántulas, y mejor en las parcelas quemadas que en las cortadas. La altura en cada caso sigue patrones diferentes. Los resultados de campo concuerdan con los de laboratorio.
    [fr] L'objectif de cette étude consiste à déterminer l'augmentation de la température dans le sol pendant les incendies favorise la germination des semences de Cistus laurifolius et Cistus ladanifer. On a réalisé des essais de germination au laboratoire, en faisant chauffer les semences à plusieurs températures pendant des temps différents. En même temps on a étudié la régénération de ces deux espèces sur le terrain, dans des parcelles expérimentales soumises à un brûlage contrôlé et court de la biomasse aérienne. Cistus ladanifer se régénère mieux que Cistus laurifolius, en ce qui concerne le nombre de plantules, et mieux dans les parcelles brûlées que dans celles coupées. La hauteur a suivi des modèles différents. Les résultats de terrain concordent avec ceux obtenus au laboratoire.

  17. Propuesta numérica para el cálculo generalizado del factor de efectividad

    Directory of Open Access Journals (Sweden)

    Hermes A. Rangel Jara

    1995-01-01

    Full Text Available El presente trabajo desarrolla y pone a prueba una propuesta numérica de tipo generalizado para calcular el factor de efectividad de una pastilla catalítica. La estrategia numérica se elabora a partir del análisis del sistema acoplado de ecuaciones diferenciales, originado de la aplicación de los principios de conservación de masa y energía a los fenómenos de transferencia de masa, calor y de la reacción química, bajo una condición estable.

  18. Propuesta numérica para el cálculo generalizado del factor de efectividad

    Directory of Open Access Journals (Sweden)

    Hermes A. Rangel Jara

    2011-06-01

    Full Text Available El presente trabajo desarrolla y pone a prueba una propuesta numérica de tipo generalizado para calcular el factor de efectividad de una pastilla catalítica. La estrategia numérica se elabora a partir del análisis del sistema acoplado de ecuaciones diferenciales, originado de la aplicación de los principios de conservación de masa y energía a los fenómenos de transferencia de masa, calor y de la reacción química, bajo una condición estable.

  19. Control system pre-feedbacked for the super heated steam temperature in heat recovering units; Sistema de control pre-retroalimentado para la temperatura de vapor sobrecalentado en recuperadores de calor

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Alvarez, Hilario; Madrigal Espinosa, Guadalupe [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1996-12-31

    The study that is presented corresponds to the analysis, design and development of a pre-feedbacked control system for the superheated steam temperature regulation in the heat recovery units of a combined cycle thermoelectric power plant. The designs of the feedback controller and the pre-feedback control system were implemented based in a linear model of the tempering zone. This linear model was obtained through the application of parametric identification techniques to the non-linear mathematical model of a combined cycle power plant. [Espanol] El estudio que se presenta corresponde al analisis, diseno y desarrollo de un sistema de control pre-retroalimentado para regular la temperatura de vapor sobrecalentado en los recuperadores de calor de una central termoelectrica de ciclo combinado. Los disenos del controlador retroalimentado y del sistema de control prealimentado se realizaron con base en un modelo lineal de la zona de atemperacion. Este modelo lineal se obtuvo aplicando tecnicas de identificacion parametrica al modelo matematico no-lineal de una central de ciclo combinado.

  20. EFECTO DE LA SEVERIDAD DEL FUEGO EN LAS CARACTERÍSTICAS DE LA ESTRUCTURA FORESTAL EN RODALES DE CONÍFERAS

    Directory of Open Access Journals (Sweden)

    Diana Y. Ávila-Flores

    2014-01-01

    Full Text Available El objetivo del presente trabajo fue realizar un análisis exploratorio de la distribución espacial del arbolado en rodales mixtos de coníferas de la Sierra Madre Oriental, afectados por un incendio en el verano de 1998, con el fin de conocer el grado en que la severidad de un incendio modifica las características estructurales de los mismos. El área seleccionada comprendió tres rodales mixtos de coníferas con tres grados de severidad de incendio (bajo, medio y alto. Los patrones de distribución espacial del arbolado se analizaron a través de la función K de Ripley. Asimismo, se analizó la interacción espacial de los árboles en relación con sus dimensiones y especies mediante una función de correlación de marca kmm(r. Se observó que conforme la severidad del incendio aumenta, la distribución espacial del arbolado tiende a la agregación y a la formación de rodales dimensionalmente heterogéneos, mientras que la composición de especies no fue afectada. El fuego influyó en estos bos- ques como un promotor de la diversidad dimensional, a pesar de que la mezcla espacial de especies tuvo una tendencia a la homogeneidad.

  1. Área de acción del Chigüiro (Hydrochoerus hydrochaeris, en el municipio de Paz de Ariporo (Casanare, Colombia, durante la época seca: algunas consideraciones para su manejo

    Directory of Open Access Journals (Sweden)

    Montenegro Olga Lucía

    2006-12-01

    Full Text Available La disminución de las poblaciones de chigüiro (Hydrochoerus hydrochaeris en la Orinoquía colombiana, han motivado investigaciones que permitan la conservación y manejo de la especie. Con este fin, se analizaron los movimientos y el área de acción de cuatro individuos en la sabana inundable del Casanare (Orinoquía colombiana,
    en época de verano. Se empleó la técnica de telemetría para su seguimiento durante los meses de enero y febrero
    en intervalos de tres horas, entre las ocho de la mañana y cinco de la tarde. Se obtuvieron 243 localizaciones
    para la determinación del área de acción la cual fue estimada en 6,19 ha (SE 0,14 en promedio para los cuatro
    animales. Las diferencias de las áreas de acción entre la época de invierno (32,74 ha y verano, evidencia la
    necesidad de los cuerpos de agua para estos animales y la vulnerabilidad de los mismos en época seca. Se discute
    la importancia de la determinación del patrón de movimientos de estos animales en diferentes épocas para la conservación o manejo de la especie. Estos elementos deben ser considerados en el diseño y tamaño de un área
    de manejo, así como en programas de aumento de la población o adecuación de hábitats, entre otros.

  2. Contribución al conocimiento del comportamiento térmico y la gestión térmica de los motores de combustión interna alternativos.

    OpenAIRE

    Romero Piedrahita, Carlos Alberto

    2009-01-01

    El trabajo desarrollado en la presente tesis está encaminado a estudiar los fenómenos de la transmisión de calor y balance térmico en los motores de combustión interna alternativos, tanto en el cilindro como en el sistema de refrigeración. El principal objetivo de la tesis ha sido la utilización y extensión de un programa computacional de predicción de temperaturas de paredes del motor y de dos programas comerciales de modelado de sistemas termohidráulicos para estudiar los flujos de calor de...

  3. Soluble Fermentable Dietary Fibre (Pectin) Decreases Caloric Intake, Adiposity and Lipidaemia in High-Fat Diet-Induced Obese Rats

    Science.gov (United States)

    Adam, Clare L.; Thomson, Lynn M.; Williams, Patricia A.; Ross, Alexander W.

    2015-01-01

    Consumption of a high fat diet promotes obesity and poor metabolic health, both of which may be improved by decreasing caloric intake. Satiety-inducing ingredients such as dietary fibre may be beneficial and this study investigates in diet-induced obese (DIO) rats the effects of high or low fat diet with or without soluble fermentable fibre (pectin). In two independently replicated experiments, young adult male DIO rats that had been reared on high fat diet (HF; 45% energy from fat) were given HF, low fat diet (LF; 10% energy from fat), HF with 10% w/w pectin (HF+P), or LF with 10% w/w pectin (LF+P) ad libitum for 4 weeks (n = 8/group/experiment). Food intake, body weight, body composition (by magnetic resonance imaging), plasma hormones, and plasma and liver lipid concentrations were measured. Caloric intake and body weight gain were greatest in HF, lower in LF and HF+P, and lowest in the LF+P group. Body fat mass increased in HF, was maintained in LF, but decreased significantly in LF+P and HF+P groups. Final plasma leptin, insulin, total cholesterol and triglycerides were lower, and plasma satiety hormone PYY concentrations were higher, in LF+P and HF+P than in LF and HF groups, respectively. Total fat and triglyceride concentrations in liver were greatest in HF, lower in LF and HF+P, and lowest in the LF+P group. Therefore, the inclusion of soluble fibre in a high fat (or low fat) diet promoted increased satiety and decreased caloric intake, weight gain, adiposity, lipidaemia, leptinaemia and insulinaemia. These data support the potential of fermentable dietary fibre for weight loss and improving metabolic health in obesity. PMID:26447990

  4. ISOTERMAS E CALOR ISOSTÉRICO DE ADSORÇÃO DA ÁGUA DO AMIDO DE QUINOA

    Directory of Open Access Journals (Sweden)

    AUGUSTO PUMACAHUA RAMOS

    2017-07-01

    Full Text Available A quinoa possui mais de 60% de amido, sendo uma alternativa de extração e comercialização. Para isto é necessário conhecer o comportamento do amido frente à temperatura e umidade relativa do ar. O objetivo desta pesquisa foi avaliar as isotermas de adsorção do amido de quinoa em cinco temperaturas (20, 30, 40, 50 e 60ºC e dez atividades de água (0,036 a 0,907. Os pontos experimentais foram ajustados aos modelos matemáticos GAB, Oswin, Henderson, Peleg e Ferro-Foltan. Foram determinadas as energias de ativação da adsorção da água pelas constantes do modelo GAB e o calor isostérico pelo modelo de Peleg. As isotermas mostraram ser do tipo II na classificação de Brunauer. Os teores de água da monocamada (Xm determinados pelo modelo de GAB variaram de 7,90% a 10,38% base seca (b.s. para temperaturas de 60 e 20°C e as energias de ativação obtidas pelas constantes Xm, C e K do modelo de GAB foram de 300; 160 e 6 kJ/kg, respectivamente. O calor isostérico de adsorção foi de 3732 kJ/kg para umidade de equilíbrio de 0,5% b.s. e diminuiu com o aumento da umidade até valor próximo ao calor latente de vaporização da água pura a 36% b.s. As propriedades determinadas são características de amidos com elevado teor de amilopectina.

  5. Soluble Fermentable Dietary Fibre (Pectin Decreases Caloric Intake, Adiposity and Lipidaemia in High-Fat Diet-Induced Obese Rats.

    Directory of Open Access Journals (Sweden)

    Clare L Adam

    Full Text Available Consumption of a high fat diet promotes obesity and poor metabolic health, both of which may be improved by decreasing caloric intake. Satiety-inducing ingredients such as dietary fibre may be beneficial and this study investigates in diet-induced obese (DIO rats the effects of high or low fat diet with or without soluble fermentable fibre (pectin. In two independently replicated experiments, young adult male DIO rats that had been reared on high fat diet (HF; 45% energy from fat were given HF, low fat diet (LF; 10% energy from fat, HF with 10% w/w pectin (HF+P, or LF with 10% w/w pectin (LF+P ad libitum for 4 weeks (n = 8/group/experiment. Food intake, body weight, body composition (by magnetic resonance imaging, plasma hormones, and plasma and liver lipid concentrations were measured. Caloric intake and body weight gain were greatest in HF, lower in LF and HF+P, and lowest in the LF+P group. Body fat mass increased in HF, was maintained in LF, but decreased significantly in LF+P and HF+P groups. Final plasma leptin, insulin, total cholesterol and triglycerides were lower, and plasma satiety hormone PYY concentrations were higher, in LF+P and HF+P than in LF and HF groups, respectively. Total fat and triglyceride concentrations in liver were greatest in HF, lower in LF and HF+P, and lowest in the LF+P group. Therefore, the inclusion of soluble fibre in a high fat (or low fat diet promoted increased satiety and decreased caloric intake, weight gain, adiposity, lipidaemia, leptinaemia and insulinaemia. These data support the potential of fermentable dietary fibre for weight loss and improving metabolic health in obesity.

  6. Effects of immobilisation and caloric restriction on antioxidant parameters and T-cell apoptosis in healthy young men

    Science.gov (United States)

    Ellinger, S.; Arendt, B. M.; Boese, A.; Juschus, M.; Schaefer, S.; Stoffel-Wagner, B.; Goerlich, R.

    Background: Astronauts are exposed to oxidative stress due to radiation and microgravity, which might impair immune functions. Effects of hypocaloric nutrition as often observed in astronauts on oxidative stress and immune functions are not clear. We investigated, if microgravity, simulated by 6 Head-down tilt (HDT) and caloric restriction (-25%, fat reduced) with adequate supply of micronutrients affect DNA-damage in peripheral leukocytes, antioxidant parameters in plasma, and T-cell apoptosis. Material & Methods: 10 healthy male non-smokers were subjected to 4 different interventions (normocaloric diet or caloric restriction (CR) in upright position (UP) or HDT) for 14 days each (cross-over). DNA-damage in peripheral leukocytes (Comet Assay), trolox equivalent antioxidant capacity (TEAC) and uric acid in plasma were measured before, after 5, 10, and 13 days of intervention, and after 2 days recovery. T-cell apoptosis (Annexin V binding test) was assessed before and after intervention. Results: Preliminary results show that only endogenous, but not ex vivo H2O2-induced DNA strand breaks were reduced by CR compared to normocaloric diet. In upright position, endogenous DNA strand breaks decreased continuously during CR, reaching significance after recovery. During HDT, caloric restriction seems to counteract a temporary increase in DNA strand breaks observed in subjects receiving normocaloric diet. TEAC was reduced during HDT compared to UP in subjects under caloric restriction. An increase in plasma uric acid related to intervention occurred only after 5 days HDT in CR vs. normocaloric diet. T-cell apoptosis was not affected by any kind of intervention. Conclusion: Neither HDT nor CR with sufficient supply of micronutrients seem to induce oxidative stress or T-cell apoptosis in healthy young men. In contrast, CR might prevent endogenous DNA-damage in peripheral leukocytes. As DNA-damage is a risk factor for carcinogenesis, protective effects of energy reduction are

  7. Distúrbios causados pelo frio e pelo calor durante corridas de longa distância

    Directory of Open Access Journals (Sweden)

    1999-06-01

    Full Text Available Muitos corredores amadores e de elite participam todos os anos de corridas de longa distância. Quando estes eventos ocorrem em temperaturas altas ou baixas, aumenta o risco de distúrbios térmicos. Contudo, a hipertermia induzida pelo exercício, a hipotermia, a desidratação e outros problemas relacionados podem ser minimizados através de esclarecimentos e um preparo antes do evento. Este documento fornece recomendações para o diretor médico e outras autoridades da organização das corridas nas seguintes áreas: planejamento, profissionais envolvidos na organização, instalações, suprimentos, equipamento e comunicação; fornecimento de esclarecimentos aos participantes; avaliação do estresse térmico; fornecimento de líquidos; e prevenção de questões legais em potencial. Este posicionamento oficial também descreve as condições predisponentes, as formas de diagnóstico e o tratamento dos quatro distúrbios ambientais mais comuns: exaustão pelo calor, colapso pelo calor, hipotermia e congelamento de extremidades. Os objetivos deste documento são: 1 Educar os organizadores e os participantes de corridas de longa distância a respeito das formas mais comuns de distúrbios térmicos incluindo as condições predisponentes, sinais de alerta, suscetibilidade e a redução de sua incidência; 2 Alertar os organizadores sobre as suas responsabilidades civis em potencial no que concerne à segurança do evento e à prevenção de lesões; 3 Recomendar que os organizadores consultem arquivos locais de meteorologia e planejem eventos em horas que provavelmente causem menos estresse térmico de modo a minimizar os efeitos deletérios sobre os participantes; 4 Estimular os organizadores a alertar os participantes sobre o estresse térmico no dia da corrida e as suas implicações no que tange aos distúrbios causados pelo frio e pelo calor; 5 Informar os organizadores sobre as ações preventivas que podem reduzir a incidência dos

  8. Transferencia de calor durante la congelación, el almacenamiento y la descongelación de alimentos

    OpenAIRE

    Salvadori, Viviana Olga

    1994-01-01

    En el presente trabajo se estudian distintos aspectos relacionados con la congelación y el almacenamiento de productos congelados, con los siguientes objetivos: - Optimizar el diseño de sistemas para la congelación o almacenamiento de alimentos a través de un mejor conocimiento de los fenómenos de transferencia de calor que tienen lugar en los mismos. Esto involucra un adecuado dimensionamiento de los equipos con el consiguiente ahorro en los costos de inversión. - Desar...

  9. Adaptación de las TIC al Laboratorio de Transferencia de Calor en el Instituto Minas Fredonia

    OpenAIRE

    Pérez Montes, Ricardo Adolfo

    2014-01-01

    Resumen: Se implementó el laboratorio de Transferencia de Calor con cinco puestos de trabajo computarizado. Cada uno está constituido por un sistema de adquisición utilizando la tarjeta Arduino y sensores de temperatura, sobre el sistema operativo Windows 8. Se probó con una Unidad de Enseñanza Potencialmente Significativa-UEPS para los grados Noveno, décimo y once en la Institución Educativa de Minas Fredonia, institución de media técnica agropecuaria. Para comparar las bondades en la enseña...

  10. Chemotherapy for Isolated Locoregional Recurrence of Breast Cancer: The CALOR Randomised Trial

    Science.gov (United States)

    Aebi, Stefan; Gelber, Shari; Anderson, Stewart J.; Láng, István; Robidoux, André; Martín, Miguel; Nortier, Johan W.R.; Paterson, Alexander H.G.; Rimawi, Mothaffar F.; Cañada, José Manuel Baena; Thürlimann, Beat; Murray, Elizabeth; Mamounas, Eleftherios P.; Geyer, Charles E.; Price, Karen N.; Coates, Alan S.; Gelber, Richard D.; Rastogi, Priya; Wolmark, Norman; Wapnir, Irene L.

    2014-01-01

    BACKGROUND Patients with isolated locoregional recurrences (ILRR) of breast cancer have a high risk of distant metastasis and death from breast cancer. We investigated adjuvant chemotherapy for such patients in a randomised clinical trial. METHODS The CALOR trial (clinicaltrials.gov NCT00074152) accrued patients 2003-2010. The 162 patients with resected ILRR were centrally randomised using permuted blocks and stratified by prior chemotherapy, ER/PgR status, and location of ILRR. Eighty-five were allocated to chemotherapy (type selected by the investigator; multidrug for at least four courses recommended) and 77 to no chemotherapy. Patients with oestrogen receptor-positive ILRR received adjuvant endocrine therapy; radiation therapy was mandated for patients with microscopically involved surgical margins, and anti-HER2 therapy was optional. The primary endpoint was disease-free survival (DFS). All analyses were by intention to treat. FINDINGS At a median follow up of 4·9 (IQR 3.6,6.0) years we observed 24 DFS events and nine deaths in the chemotherapy group compared with 34 DFS events and 21 deaths in the no chemotherapy group. Five-year DFS was 69% vs. 57%, (hazard ratio for chemotherapy versus no chemotherapy, 0·59; 95% confidence interval 0·35 to 0·99; P=0·046) and five-year overall survival was 88% vs. 76%, (hazard ratio, 0·41; 95% CI, 0·19 to 0·89; P=0·02). Adjuvant chemotherapy was significantly more effective for women with oestrogen receptor-negative disease measured in the recurrence (interaction P=0·04), but analyses of DFS based on the oestrogen receptor status of the primary tumour were not statistically significant (interaction P=0·43). Among the 85 patients who received standard chemotherapy, 12 reported SAEs. INTERPRETATION Adjuvant chemotherapy should be recommended for patients with completely resected isolated locoregional recurrences of breast cancer, especially if the recurrence is oestrogen receptor negative. FUNDING Public Service

  11. Chemotherapy for isolated locoregional recurrence of breast cancer (CALOR): a randomised trial.

    Science.gov (United States)

    Aebi, Stefan; Gelber, Shari; Anderson, Stewart J; Láng, István; Robidoux, André; Martín, Miguel; Nortier, Johan W R; Paterson, Alexander H G; Rimawi, Mothaffar F; Cañada, José Manuel Baena; Thürlimann, Beat; Murray, Elizabeth; Mamounas, Eleftherios P; Geyer, Charles E; Price, Karen N; Coates, Alan S; Gelber, Richard D; Rastogi, Priya; Wolmark, Norman; Wapnir, Irene L

    2014-02-01

    Patients with isolated locoregional recurrences (ILRR) of breast cancer have a high risk of distant metastasis and death from breast cancer. We aimed to establish whether adjuvant chemotherapy improves the outcome of such patients. The CALOR trial was a pragmatic, open-label, randomised trial that accrued patients with histologically proven and completely excised ILRR after unilateral breast cancer who had undergone a mastectomy or lumpectomy with clear surgical margins. Eligible patients were enrolled from hospitals worldwide and were centrally randomised (1:1) to chemotherapy (type selected by the investigator; multidrug for at least four courses recommended) or no chemotherapy, using permuted blocks, and stratified by previous chemotherapy, oestrogen-receptor and progesterone-receptor status, and location of ILRR. Patients with oestrogen-receptor-positive ILRR received adjuvant endocrine therapy, radiation therapy was mandated for patients with microscopically involved surgical margins, and anti-HER2 therapy was optional. The primary endpoint was disease-free survival. All analyses were by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00074152. From Aug 22, 2003, to Jan 31, 2010, 85 patients were randomly assigned to receive chemotherapy and 77 were assigned to no chemotherapy. At a median follow-up of 4·9 years (IQR 3·6-6 ·0), 24 (28%) patients had disease-free survival events in the chemotherapy group compared with 34 (44%) in the no chemotherapy group. 5-year disease-free survival was 69% (95% CI 56-79) with chemotherapy versus 57% (44-67) without chemotherapy (hazard ratio 0·59 [95% CI 0·35-0·99]; p=0·046). Adjuvant chemotherapy was significantly more effective for women with oestrogen-receptor-negative ILRR (pinteraction=0·046), but analyses of disease-free survival according to the oestrogen-receptor status of the primary tumour were not statistically significant (pinteraction=0·43). Of the 81 patients who

  12. Insights Into The Beneficial Effect Of Caloric/ Dietary Restriction For A Healthy And Prolonged Life

    Directory of Open Access Journals (Sweden)

    Rani ePallavi

    2012-08-01

    Full Text Available Over the last several years, new evidence has kept pouring in about the remarkable effect of caloric restriction (CR on the conspicuous bedfellows- aging and cancer. Through the use of various animal models, it is now well established that by reducing calorie intake one can not only increase life span but, also, lower the risk of various age related diseases such as cancer. Cancer cells are believed to be more dependent on glycolysis for their energy requirements than normal cells and, therefore, can be easily targeted by alteration in the energy-metabolic pathways, a hallmark of CR. Apart from inhibiting the growth of transplantable tumors, CR has been also shown to inhibit the development of spontaneous, radiation and chemically induced tumors. The question regarding the potentiality of the anti-tumor effect of CR in humans has been in part answered by the resistance of a cohort of women, who had suffered from anorexia in their early life, to breast cancer. However, human research on the beneficial effect of CR is still at an early stage and needs further validation. Though the complete mechanism of the anti-tumor effect of CR is far from clear, the plausible involvement of nutrient sensing pathways or IGF-1 pathways proposed for its anti-aging action cannot be overruled. In fact, cancer cell lines, mutant for proteins involved in IGF-1 pathways, failed to respond to CR. In addition, CR decreases the levels of many growth factors, anabolic hormones, inflammatory cytokines and oxidative markers that are deregulated in several cancers.In this review, we discuss the anti-tumor effect of CR, describing experiments done in vitro in tumor models and in vivo in mouse models in which the tumor was induced by means of radiation or chemical exposure, expressing oncogenes or deleting tumor suppression genes. We also discuss the proposed mechanisms of CR anti-tumor action. Lastly, we argue the necessity of gene expression studies in cancerous versus

  13. Heat transformers simulation coupled to industrial processes and experimental evaluation of a thermal transformer of two KW power; Simulacion de transformadores de calor acoplados a procesos industriales y evaluacion experimental de un transformador termico de dos kw de potencia

    Energy Technology Data Exchange (ETDEWEB)

    Cerezo Roman, Jesus

    2001-12-15

    recovering temperature and between 42% and 96% at high temperature for the use of this additives. [Spanish] La quema de combustibles primarios en los diferentes sectores industriales y de transporte, han provocado grandes problemas de salud a la humanidad y contaminacion al medio ambiente, debido principalmente a sus altas emisiones de sustancias y gases, ademas de problemas socioeconomicos en muchos paises. Debido a esto, muchos paises estan investigando nuevas tecnologias alternas para su sustitucion. Uno de los principales tecnologias propuestas son los transformadores de calor. Estos equipos son capaces de ahorrar energia calorifica principalmente en procesos industriales. Debido a esto, estas tesis realiza estudios teoricos de transformadores de calor en procesos industriales tipicos de la region como es la destilacion de derivados de petroleo y refinacion de azucar morena, para observar la energia que puede ser ahorrada por el uso de estos equipos. Por otra parte se realizo una evaluacion experimental de un transformador de calor con aditivos debido a que aumentan la absorcion en el absorbedor, mejorando el coeficiente de operacion. En la simulacion de la columna de destilacion de petroleo se utilizo el simulador de procesos quimicos Aspen Plus version 9.3-2, debido a que este tiene modelos termodinamicos muy confiables para estudiar el comportamiento de cada uno de sus componentes. Los resultados mostraron que con el transformador de calor de una etapa operando con la mezcla LiBr-H{sub 2} O se puede ahorrar hasta un 45% de la energia suministra a la caldera y hasta un 32% con el transformador de doble absorcion. Para la modelacion de la refineria del azucar morena se uso el paquete Visual Basic, version 6.2. El paquete fue utilizado debido a que es un lenguaje grafico y de facil manejo. Los resultados mostraron que se puede recuperar hasta un 15% de la energia suministrada a la caldera. En la experimentacion se utilizo la mezcla bromuro de litio-agua y bromuro de

  14. Reducción de la fertilización sintética con composta y optimización del riego sobre la pudrición del tallo (Fusarium spp del maíz

    Directory of Open Access Journals (Sweden)

    Blanca E. López Valenzuela

    2014-01-01

    Full Text Available El maíz es el cultivo agrícola de grano más importante de México por ser sembrado con mayor superficie yser la base de la alimentación en toda la nación siendo Sinaloa el principal productor.La siembra repetitiva delcultivo efectuada a través de los años,ha favorecidola proliferación de enfermedades como la pudrición detallos y la pudrición de mazorcas, atribuidas principalmente aFusariumspp, las cuales representan unpotencial de riesgo y han alertado al productor a poner mucha atención en el manejo del cultivo. Con elobjetivo de evaluar el efecto de la fertilización sintética con composta y riego sobre la pudrición de tallos ymazorcas de maíz en elValle delFuerte; experimentos de campo se condujeron en el ciclo agrícola primavera-verano 2009en el INIFAP. El experimento fue diseñado en parcelas divididas en bloques completos al azarcon tres repeticiones; al final del ciclo se encontró que no hubo diferencias significativas del factorfertilización y riego respecto al rendimiento así como lasvariables fenológicas evaluadas. La incidencia depudrición de tallos evaluada a los 53 días después de la siembra fue de 100%. Sin embargo, se encontrarondiferencias significativas en cuanto a la severidad de mazorcas podridas donde se aplicaron menos riegos.Finalmente, el estudio morfológico mostro que el principal agente asociado en pudrición de tallos fueFusarium verticilliodesy en cuanto a pudrición de mazorcas se detectó una mayor diversidad de agentesasociados tales comoApergillus spp, Penicillum pinophilum,y con mayor incidenciaFusarium verticilliodes.

  15. The effect of a pre-load experiment on subsequent food consumption. Caloric and macronutrient intake in the days following a pre-load manipulation.

    Science.gov (United States)

    Timko, C Alix; Juarascio, Adrienne; Chowansky, Amy

    2012-04-01

    The current study was designed to test potential caloric and macronutrient counter-regulation or compensation amongst 76 participants who participated in a milkshake preload experiment. Participants completed food diaries for 2 days before and 2 days after participating in the pre-load experiment. It was hypothesized that dieters and restrained eaters might respond to the pre-load by compensating or counter-regulating food consumption during the rest of the day following the experiment, and on the 2 days post-experiment. Results indicated that there were no significant differences in caloric or macronutrient consumption between the experimental and control groups on the days after the experiment. There were also no interactions between restraint and dieting status and the experimental condition. However, there was a main effect of caloric intake across dieting status, with those dieting to lose weight showing lower caloric intake than those not dieting and those dieting to maintain weight. The results of this study suggests that disinhibitory food stimuli may be less powerful than once thought or relatively short acting, as long-term counter-regulation or compensation did not occur for most people. Overall, the current study provides additional insight into potential long term caloric counter-regulation or compensation in participants who participated in a preload experiment, but additional research is needed to better understand this phenomenon. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Chronic Caloric Restriction and Exercise Improve Metabolic Conditions of Dietary-Induced Obese Mice in Autophagy Correlated Manner without Involving AMPK

    Directory of Open Access Journals (Sweden)

    Mingxia Cui

    2013-01-01

    Full Text Available Aim. To investigate the role of AMPK activation and autophagy in mediating the beneficial effects of exercise and caloric restriction in obesity. Methods. Dietary-induced obesity mice were made and divided into 5 groups; one additional group of normal mice serves as control. Mice in each group received different combinations of interventions including low fat diet, caloric restriction, and exercise. Then their metabolic conditions were assessed by measuring serum glucose and insulin, serum lipids, and liver function. AMPK phosphorylation and autophagy activity were detected by western blotting. Results. Obese mice models were successfully induced by high fat diet. Caloric restriction consistently improved the metabolic conditions of the obese mice, and the effects are more prominent than the mice that received only exercise. Also, caloric restriction, exercise, and low fat diet showed a synergistic effect in the improvement of metabolic conditions. Western blotting results showed that this improvement was not related with the activation of AMPK in liver, skeletal muscle, or heart but correlates well with the autophagy activity. Conclusion. Caloric restriction has more prominent beneficial effects than exercise in dietary-induced obese mice. These effects are correlated with the autophagy activity and may be independent of AMPK activation.

  17. Patrimonio tangible e intangible: Aportes al debate del distingo, desde las "prácticas agroculturales"

    Directory of Open Access Journals (Sweden)

    Marcelo Tapia Pérez

    2012-01-01

    Full Text Available El presente artículo propone, mediante el análisis de dos prácticas relativas a ciertos recursos naturales de la zona de San Juan de la Costa, Región de Los Lagos, Chile, una faceta cultural al concepto de sustentabilidad y un aporte a la discusión sobre el patrimonio desde lo productivo y cultural. Metodológicamente, se toman como ejemplos, la práctica del barbecho de verano y de la recolección del voqui fuco para la elaboración de productos de artesanía. Se hace hincapié en el distingo entre lo que es meramente una práctica productiva y lo que viene a ser, mediante el presente estudio, una “práctica agrocultural”. Los resultados muestran que es evidente dejar de lado la arbitrariedad de hacer la separación entre lo material e inmaterial, para lo cual se propone ser reemplazado por el concepto de “prácticas agroculturales”, siendo ello una forma de reconocer las formas de producción y de lo que acontece en un territorio

  18. MITIGACIÓN DEL ESTRÉS CALÓRICO DURANTE EL PREPARTO EN VACAS LECHERAS

    Directory of Open Access Journals (Sweden)

    G. D. TOFFOLI

    2017-06-01

    Full Text Available Se utilizaron 30 vacas en preparto que se alojaron en un corral seco con acceso a sombra artificial durante el verano. Las vacas fueron distribuidas en dos grupos: sin refrescado (TS y con refrescado (TR en el sector comedero. El peso corporal y la condición corporal fueron evaluadas al inicio y a los 25 días. La frecuencia respiratoria se realizó dos veces por semana en cuatro momentos del día. El registro de comportamiento dos veces a la semana. Los datos de analizaron con t Student y χ2. El peso y condición corporal no presentaron diferencia signifi cativa. Se observó un efecto del tratamiento en el día y horario para la frecuencia respiratoria (p<0,0001. La conducta de parado a la sombra fue al que dedicaron mayor tiempo en ambos tratamientos 27 % en TS y 29 % en TR. No hubo diferencias en la producción lechera entre TS y TR: 31,4 l/v/d y 30,6 l/v/d respectivamente.

  19. Alleviation of senescence and epithelial-mesenchymal transition in aging kidney by short-term caloric restriction and caloric restriction mimetics via m