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Sample records for coronal estudio retrospectivo

  1. Estudio retrospectivo de 145 dientes supernumerarios

    OpenAIRE

    Fernández Montenegro, P.; Valmaseda Castellón, E.; Berini Aytés, Leonardo; Gay Escoda, Cosme

    2006-01-01

    Objetivo: El presente estudio retrospectivo pretende describir la distribución de los dientes supernumerarios en una población de pacientes que acuden a una Unidad ambulatoria de Cirugía Bucal. Introducción: Los dientes supernumerarios y la hiperodoncia múltiple se asocian normalmente con diferentes síndromes como el de Gardner o con fisuras faciales; sin embargo, pueden aparecer en pacientes sin ningún tipo de patología. Su prevalencia oscila entre el 0,5 y el 3,8% en la dentición permane...

  2. Estudio retrospectivo de la ocurrencia de accidente cerebrovascular en pacientes diabéticos.

    OpenAIRE

    NEIRA SANCHEZ, Elsa Rosa; SECLEN SANTISTEBAN, Segundo

    2013-01-01

    Objetivo: Determinar la frecuencia de diabetes mellitus en la población hospitalizada por ACV, describir las características clínicas del ACV en pacientes diabéticos y no diabéticos y determinar la presencia de otros factores de riesgo para ACV en pacientes diabéticos. Material y Métodos: Es un estudio retrospectivo que incluye pacientes hospitalizados con diagnóstico al alta de ACV, a los que se aplicaron criterios de selección para definir ACV y Diabetes Mellitus. Resultados: La prevalencia...

  3. Ameloblastoma en población del noreste de Brasil: un estudio retrospectivo de 60 casos

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    Thiago de Santana Santos

    2010-06-01

    Full Text Available El ameloblastoma es un tumor de epitelio odontogénico, caracterizado por la invasión local y aumento de la tasa de recidiva. Por esto se realizó este estudio descriptivo para determinar el comportamiento de los ameloblastomas en nuestro medio. Método: estudio retrospectivo de 17 años basado en los datos existentes de los archivos del Departamento Oral de Patología. Se analizaron los archivos de pacientes de enero de 1992 a mayo de 2009, con un diagnóstico definitivo de ameloblastoma. Fué recogida la información respecto al sexo, raza, presencia de síntomas, ubicación anatómica y extensión. Resultados: dentro de los 60 pacientes con ameloblastoma se observó, mayor incidencia en la tercera década de vida (28,3 %. Las mujeres fueron más comprometidas que los hombres, con una proporción 1,22:1. La mayoría de lesiones fueron observadas en la raza blanca (51,7 %. El sitio más habitual por la ocurrencia de tumor fue la mandíbula (85 %. Los pacientes fueron sintomáticos en el 75 %. La mayoría de pacientes presentaron lesiones de 3,5 a 6,0 centímetros de extensión (55 %. Conclusiones: el ameloblastoma es mayormente observado en mujeres, en la tercera década de la vida y en la mandíbula. Las diferencias con otros estudios entre el sexo, la edad, raza, extensión, localización anatómica y los síntomas pueden ser atribuidos a las diferencias geográficas.

  4. Expansores tisulares en reconstrucción de defectos craneofaciales: estudio multicéntrico retrospectivo

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    J.P. Sorolla

    2014-12-01

    Full Text Available El objetivo del presente estudio es describir y analizar el uso de expansores tisulares para reconstrucción de los defectos craneofaciales en 3 centros de alta complejidad del país (Chile. Corresponde a un estudio descriptivo retrospectivo de pacientes tratados en el Departamento de Cirugía Plástica del Hospital Militar de Santiago, Clínica Alemana e Instituto de Neurocirugía Asenjo entre los años 2004 y 2012 por defectos en el área craneofacial. Recopilamos en un total de 37 pacientes los datos médicos, demográficos, de la operación, tiempo, volumen, número de expansores utilizados, registros fotográficos, complicaciones, volumen de sobrexpansión, y un cuestionario de satisfacción de los pacientes en relación al uso del expansor tisular. Se obtuvo cobertura adecuada del defecto en la totalidad de los casos. En 16 pacientes (43,2 % mediante el uso de 2 expansores tisulares; en 15 (40,5 % con 1 expansor; en 4 (10,8 % con 3 expansores y en 2 pacientes (5,4 % con 4 expansores. El tiempo total de tratamiento en promedio correspondió a 70 días, con un porcentaje de complicaciones menores en un 35,1 % de los casos, y mayores en un 2,7 % . En relación al cuestionario aplicado, obtuvimos un 94,6 % de respuestas positivas respecto al resultado final de la cirugía; sólo un 54,1 % de los pacientes recomendaría este método de expansión tisular a un tercero. En conclusión, nuestro estudio determina que se logró un buen resultado final, con bajo porcentaje de complicaciones mayores y alto porcentaje de satisfacción en el resultado de la cirugía por parte de los pacientes. La aplicación del cuestionario, resulta útil para la obtención de información más objetiva respecto a la opinión sobre este procedimiento por parte de los pacientes.

  5. Mallas profilácticas en laparotomía urgente. Resultados a largo plazo en un estudio retrospectivo.

    OpenAIRE

    2013-01-01

    El objetivo de nuestro estudio fue determinar la eficacia y seguridad del uso de mallas sintéticas profilácticas en laparotomías urgentes para la prevención de hernia incisional y evisceración. Planteamos un estudio retrospectivo de datos informatizados de 266 pacientes sometidos a laparotomía media urgente durante dos años. Se analizaon las complicaciones postoperatorias y la incidencia de hernia incisional según el tipo de cierre de pared. Podemos concluir que el uso de malla profiláctica s...

  6. Estudio retrospectivo de la ocurrencia de accidente cerebrovascular en pacientes diabéticos

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    Elsa Rosa Neira Sanchez

    2000-04-01

    Full Text Available Objetivo: Determinar la frecuencia de diabetes mellitus en la población hospitalizada por ACV, describir las características clínicas del ACV en pacientes diabéticos y no diabéticos y determinar la presencia de otros factores de riesgo para ACV en pacientes diabéticos. Material y Métodos: Es un estudio retrospectivo que incluye pacientes hospitalizados con diagnóstico al alta de ACV, a los que se aplicaron criterios de selección para definir ACV y Diabetes Mellitus. Resultados: La prevalencia del ACV tipo isquémico fue mayor en los pacientes diabéticos que en los no diabéticos (83% vs. 57%, p<0.005. De los pacientes diabéticos, 11 de ellos fueron diagnosticados en el momento de la hospitalización, de los 30 pacientes con diagnóstico previo de esta patología el 33% tenían de 10 a 15 años de diagnóstico de diabetes y 24% tenían más de 15 años de enfermedad. La mayoría de pacientes diabéticos eran portadores de nefropatía diabética (73%y retinopatía diabética (46%. La hipertensión arterial fue 1.2 veces más frecuente en los pacientes diabéticos que en los no diabéticos. También se encontraron más alteraciones en el perfil lipídico de los pacientes diabéticos. Conclusiones: El 15% de la población con ACV tuvo diagnóstico de Diabetes Mellitus. El ACV tipo isquémico fue mas frecuente en los pacientes diabéticos. En los pacientes diabéticos el ACV ocurre mas frecuentemente en aquellos con mas de diez años de enfermedad en los que la diabetes contribuye a aumentar el daño vascular, pero además presentan otras patologías que contribuyen a este daño, como hipertensión arterial, enfermedad cardiovascular y dislipidemias. ( Rev Med Hered 2000; 11:54-61 .

  7. Las malformaciones congénitas en Costa Rica. II (Estudio retrospectivo hospitalario de caso-control)

    OpenAIRE

    Barrantes-Mesén, Ramiro

    1985-01-01

    Artículo científico -- Universidad de Costa Rica. Instituto de Investigaciones en Salud, 1985 Se realizó un estudio retrospectivo de caso-control de malformaciones congénitas en Costa Rica, utilizando expedientes clínicos de los Hospitales Nacional de Niños Carlos Sáenz Herrera y la Maternidad Carit, entre 1970 y 1977. Se estudió la frecuencia de anomalías congénitas y 33 variables concomitantes relacionadas con los padres y el recién nacido en 2072 niños malformados y 2163 testigos. Las m...

  8. Fracturas en prótesis híbrida implantosoportada. Estudio retrospectivo

    OpenAIRE

    Ventura de la Torre, Javier

    2014-01-01

    Texto completo descargado desde Teseo INTRODUCCIÓN Es un hecho conocido que el descubrimiento de la osteointegración se produjo de forma fortuita durante unas investigaciones que comenzaron a realizarse en 1952 con estudios microscópicos in situ de la médula ósea del peroné de conejo . A comienzo de los años 60, para seguir la evolución de la médula y el hueso se implantaron cámaras de titanio, en lugar de las de tantalio que normalmente se utilizaban, porque parecía tener unas mejor...

  9. Causas de proteinuria post-renal en el perro: Estudio retrospectivo de 162 casos

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    Zaragoza-Bayle, C.

    2009-05-01

    Full Text Available ResumenLa proteinuria se define como la cantidad anormalmente elevada deproteínas presente en la orina. Dichas proteínas pueden tener un origen pre-renal, renal o post-renal. Una proteinuria de origen post-renal, a su vez, puede tener causas urinarias o extraurinarias y, generalmente, está asociada a inflamación del tracto urinario inferior. En este estudio se revisaron 162 análisis de orina con sus correspondientes historias clínicas de pacientes procedentes del Hospital Clínico Veterinario de la Universidad de Extremadura (UEx para conocer las causas relacionadas con la proteinuria post-renal debido a su importancia a la hora de instaurar un tratamiento adecuado. Los resultados demostraron que las cistitis bacterianas y la urolitiasis fueron las causas más comunes de proteinuriapos-renal. La sintomatología clínica encontrada generalmente fue laasociada a inflamación del tracto urinario inferior como hematuria conpolaquiuria y/o disuria.

  10. Estudio retrospectivo de anomalias dentales y alteraciones oseas de maxilares en ninos de cinco a catorce anos de las clinicas de la Facultad de Odontologia de la Universidad de Antioquia

    National Research Council Canada - National Science Library

    Espinal Botero, Gabriel; Aguilar Mendez, German; Manco Guzman, Hugo Alexander; Castrillon Pino, Liliana; Marin Botero, Martha Lucia; Rendon Giraldo, Juan Esteban

    2009-01-01

    Introduccion: el proposito de esta investigacion es efectuar un estudio retrospectivo epidemiologico sobre el tipo y frecuencia de alteraciones a nivel oseo y dental, en pacientes de cinco a catorce anos...

  11. Electrocardiografía dinámica (holter: Estudio retrospectivo Dynamic electrocardiography (holter: A retrospective study

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    B. Ditollo

    2006-12-01

    Full Text Available Los autores presentan los resultados retrospectivos de la comparación de los diagnósticos obtenidos por medio del electrocardiograma convencional y la electrocardiografía dinámica de 143 pacientes caninos afectados por distintos padecimientos cardiovasculares. Seis de dichos casos fueron utilizados sólo para verificar el resultado de la terapéutica. De la comparación de 137 casos, se observó que la coincidencia entre los resultados del electrocardiograma convencional y el diagnostico obtenido con la electrocardiografía dinámica fue de sólo el 26,54% (32 casos contra 105. Si los resultados se analizan en función de los diagnósticos originales se observó que de los 61 electrocardiogramas convencionales considerados normales sólo 12 (19,4% estudios dinámicos coincidieron con el diagnóstico previo, mientras que los restantes 49 (79,03% demostraron la presencia de alguna forma de arritmia cardíaca y que de los 75 electrocardiogramas convencionales que mostraron la presencia de arritmias, veinte (26,67% arrojaron un diagnóstico coincidente mientras que los restantes estudios dinámicos (55 - 73,33% presentaron diagnósticos distintos, sea por la frecuencia o el tipo de arritmia encontrada. Sobre la base de los datos presentados aquí, se puede concluir que la electrocardiografía dinámica o ambulatoria, conocida coloquialmente como «Holter cardíaco» es una técnica altamente confiable y estrictamente necesaria para obtener diagnósticos adecuados y pronósticos más ajustados a la realidad de cada paciente en vista de las disparidades encontradas respecto de los diagnóstico obtenidos por medio del electrocardiograma convencional y la técnica dinámica.The authors present the results of a retrospective comparison between the conventional electrocardiogram and the dynamic electrocardiogram (Holter diagnoses of 143 dogs affected by different cardiovascular diseases. In six cases the comparison was utilized to verify the result of

  12. Prevalencia de infección por Staphylococcus aureus resistente a meticilina en heridas crónicas en atención primaria de Lleida: estudio retrospectivo

    OpenAIRE

    Carme Marquilles Bonet; Sandra Alexandre Lozano; Jordi Real Gatius

    2015-01-01

    Objetivo: averiguar la prevalencia de infecciones por Staphylococcus aureus (S. aureus) y S. aureus resistente a meticilina (MRSA) en los cultivos de heridas crónicas en atención primaria de la región sanitaria de Lleida y valorar la prescripción de antibioterapia oral según resultado del antibiograma. Diseño: estudio transversal retrospectivo. Muestra: cultivos realizados en heridas crónicas de enero de 2010 a diciembre 2012. Resultados: se estimó una prevalencia de cultivos positivos a Stap...

  13. Los implantes MG-OSSEOUS: Estudio multicéntrico retrospectivo MG-OSSEOUS implants: A multicentric retrospective study

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    E. Serrano Caturla

    2006-12-01

    Full Text Available Objetivo. Aportar unos datos estadísticamente fiables sobre la supervivencia e incidencias asociadas a los implantes y prótesis del modelo MG-OSSEOUS (Mozo-Grau, S.L., Valladolid, España y demostrar que su eficacia es comparable a todas las marcas comerciales. Material y método. Estudio multicéntrico retrospectivo coordinado por la empresa Scientific Management in O&SS (Barcelona, España. Se colocaron 1001 implantes en 247 pacientes y se diseñaron 328 prótesis, entre los años 2004 y 2005, con un seguimiento de 2 años. Todos los implantes cargados. Se analizan y pormenorizan todos los implantes, por diámetros, longitudes, posiciones, fases quirúrgicas, cargas, tipos y modelos de prótesis y técnicas complementarias aplicadas, tanto sincrónica como anacrónicamente. Resultados. Tras la homogeneización de las muestras, se objetiva una supervivencia del 97,8% a los 2 años, detallando los fracasos según las características de cada caso clínico. No se reporta ningún fracaso de la prótesis. Discusión. Protocolizamos una serie de criterios e indicaciones a la hora de colocar los implantes MG-OSSEOUS según los casos clínicos. Comparamos nuestros resultados con la bibliografía, tanto pretérita como actual, coincidiendo con la manera de actuar a lo largo de la historia de la implantología. Finalmente, extrapolamos los resultados que consideramos comparables a los publicados por el grupo Branemark. Conclusión. La calidad del implante MG-OSSEOUS combinada con protocolos implantológicos científicamente contrastados, muestra un 2,2% de fracaso a los 2 años de seguimiento, con un porcentaje de éxito del 100% tanto en la recolocación del implante como en la fase protésica.Objective. We present some statistically contrasted results regarding the survival and incidences of MG-OSSEOUS implants and prosthetic components (Mozo-Grau, S.L., Valladolid, Spain, and we prove that they have the same efficacy when compared with other

  14. La demanda hotelera en España: estudio retrospectivo de la década 1990-2000

    OpenAIRE

    Fernando Garrigós Simón; Yeamduan Narangajavana

    2002-01-01

    El presente estudio pretende realizar un análisis de los principales factores determinantes de la demanda turística a nivel mundial y su evolución, con especial incidencia en la relación entre las motivaciones de los turistas y su concreción en demanda efectiva. Además, el trabajo realiza un análisis descriptivo de cómo algunos de estos factores han influido en el comportamiento de la demanda hotelera española en la última década. Tras el estudio hemos corroborado la importanci...

  15. La polémica sobre las lumbalgias y su relación con el trabajo: estudio retrospectivo en trabajadores con invalidez

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    Mariano Noriega-Elío

    Full Text Available La lumbalgia es un padecimiento de alta prevalencia en la población trabajadora mexicana y tiene repercusiones económico-sociales de enorme alcance. Las cifras oficiales muestran que por lo menos entre el 10,0 y 15,0% de los dictámenes de invalidez se deben a ella. Este dictamen se otorga sólo cuando se ha demostrado que la enfermedad no tuvo relación con el trabajo. Sin embargo, esta investigación muestra que existe tal relación. El estudio fue retrospectivo y se consideraron a todos los trabajadores con dictamen de invalidez por lumbalgia (210 casos, en un hospital del IMSS de la Ciudad de México, durante un periodo de 7 años. Los resultados muestran la asociación e interacciones entre la lumbalgia invalidante y variables laborales como: puesto de trabajo, antigüedad, esfuerzo físico y levantamiento de cargas. Se discute sobre las dificultades y la precisión diagnósticas de la lumbalgia, así como sobre la causalidad del síndrome. Se sugieren algunas vías clínicas, epidemiológicas y legales para su estudio y prevención.

  16. La polémica sobre las lumbalgias y su relación con el trabajo: estudio retrospectivo en trabajadores con invalidez

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    Noriega-Elío Mariano

    2005-01-01

    Full Text Available La lumbalgia es un padecimiento de alta prevalencia en la población trabajadora mexicana y tiene repercusiones económico-sociales de enorme alcance. Las cifras oficiales muestran que por lo menos entre el 10,0 y 15,0% de los dictámenes de invalidez se deben a ella. Este dictamen se otorga sólo cuando se ha demostrado que la enfermedad no tuvo relación con el trabajo. Sin embargo, esta investigación muestra que existe tal relación. El estudio fue retrospectivo y se consideraron a todos los trabajadores con dictamen de invalidez por lumbalgia (210 casos, en un hospital del IMSS de la Ciudad de México, durante un periodo de 7 años. Los resultados muestran la asociación e interacciones entre la lumbalgia invalidante y variables laborales como: puesto de trabajo, antigüedad, esfuerzo físico y levantamiento de cargas. Se discute sobre las dificultades y la precisión diagnósticas de la lumbalgia, así como sobre la causalidad del síndrome. Se sugieren algunas vías clínicas, epidemiológicas y legales para su estudio y prevención.

  17. Incidencia de sexo, edad y raza en perros con proteinuria post-renal: estudio retrospectivo de 162 casos.

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    Barrera-Chacón, R

    2009-05-01

    Full Text Available ResumenExisten varias patologías que están relacionadas con proteinuria post-renal en el perro. En ocasiones, el desarrollo de algunas de estas patologías puede estar influenciado por ciertos factores como edad, sexo y raza del paciente; estos parámetros fueron considerados en este estudio. Con el objetivo de conocer la influencia de dichos factores en la aparición de proteinuria pos-renal se revisaron 162 análisis de orina de pacientes procedentes del Hospital Clínico Veterinario de la UEx.

  18. Cobertura radicular obtenida tras el tratamiento de recesiones gingivales: estudio retrospectivo de dos técnicas quirúrgicas

    OpenAIRE

    2016-01-01

    124 p. Los diferentes estudios epidemiológicos realizados sobre la enfermedad periodontal en seres humanos han demostrado la gran prevalencia de las recesiones gingivales, lo que hace que sean motivo de demanda de tratamiento. A lo largo de la historia se han descrito numerosas técnicas de cirugía mucogingival cuyo objetivo es la cobertura radicular, pero la evidencia científica demuestra que las técnicas de tratamiento para conseguir una mayor predictibilidad en cuanto a cobertura y mejor...

  19. La demanda hotelera en España: estudio retrospectivo de la década 1990-2000

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    Fernando Garrigós Simón

    2002-01-01

    Full Text Available El presente estudio pretende realizar un análisis de los principales factores determinantes de la demanda turística a nivel mundial y su evolución, con especial incidencia en la relación entre las motivaciones de los turistas y su concreción en demanda efectiva. Además, el trabajo realiza un análisis descriptivo de cómo algunos de estos factores han influido en el comportamiento de la demanda hotelera española en la última década. Tras el estudio hemos corroborado la importancia de la elasticidad de la demanda hotelera española a factores como la renta o las situaciones políticas internacionales. A su vez hemos observado la evolución de la demanda hacia una mayor preferencia por la calidad, así como el proceso de transformación de esta hacia nuevos segmentos. Finalmente, el análisis de la estacionalidad ha remarcado los efectos de la especialización de nuestra demanda en el segmento de sol y playa y en los mercados de España, Gran Bretaña y Alemania.

  20. Proyecto Wernicke-Semi: Estudio multicéntrico y retrospectivo sobre la encefalopatía de Wernicke

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    Antonio Javier Chamorro Fernández

    2012-09-01

    Full Text Available La encefalopatía de Wernicke (EW es una patología neuropsiquiátrica aguda o subaguda debida al déficit de tiamina y que clásicamente se caracteriza por la presencia de confusión mental, oftalmoplejía y ataxia de lamarcha. Existen numerosas áreas de incertidumbre desde los puntos devista epidemiológico, clínico, diagnóstico y terapéutico, motivos por los quese ha diseñado un estudio multicéntrico dentro del grupo de trabajo de Alcohol y Alcoholismo de la Sociedad Española de Medicina Interna (SEMIque trate de dilucidar estos aspectos.

  1. Prevalencia de infección por Staphylococcus aureus resistente a meticilina en heridas crónicas en atención primaria de Lleida: estudio retrospectivo

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    Carme Marquilles Bonet

    2015-12-01

    Full Text Available Objetivo: averiguar la prevalencia de infecciones por Staphylococcus aureus (S. aureus y S. aureus resistente a meticilina (MRSA en los cultivos de heridas crónicas en atención primaria de la región sanitaria de Lleida y valorar la prescripción de antibioterapia oral según resultado del antibiograma. Diseño: estudio transversal retrospectivo. Muestra: cultivos realizados en heridas crónicas de enero de 2010 a diciembre 2012. Resultados: se estimó una prevalencia de cultivos positivos a Staphylococcus aureus resistente a meticilina de 3,77% (intervalo de confianza IC al 95%: 2,1-5,5 y de S. aureus no resistente a meticilina de 8,79% (IC 95%: 1,1-6,1 calculado sobre el número total de cultivos registrados en este periodo. Conclusiones: la prescripción de antibióticos respecto al antibiograma es más precisa al tener como respuesta un MRSA que un cultivo de S. aureus.

  2. TABAQUISMO Y RIESGO CORONARIO EN LA POBLACIÓN DE UN CENTRO DE SALUD. ESTUDIO DE COHORTES RETROSPECTIVO

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    Lourdes Cañón-Barroso

    2017-01-01

    Full Text Available El tabaquismo es un importante factor de riesgo para múltiples enfermedades crónicas, tales como enfermedades cardiovasculares y cáncer, y también de muerte prematura. El objetivo fue valorar la relación entre tabaquismo y riesgo coronario total en una cohorte de pacientes de 35 a 74 años de edad. Métodos. Estudio observacional de una cohorte retrospectiva de 1.011 pacientes (edad media 55,7 años, 56,0% mujeres sin antecedentes de enfermedades cardiovasculares, seguidos durante 10 años en un centro de salud de Badajoz (Extremadura, España. Se realizó un análisis multivariante mediante regresión logística binaria, incluyéndose como variable dependiente la incidencia de eventos coronarios durante el periodo de seguimiento. Resultados. El 29,1% de la población era fumadora, con menor edad (52,1 vs 57,2 años, p<0,001, menores cifras de colesterol-HDL (45,7 vs 54,0 mg/dl, p<0,001, menor prevalencia de hipertensión arterial (46,9% vs 61,5%, p<0,01 y obesidad (25,5% vs 31,8%, p=0,055 que los pacientes no fumadores. Sin embargo, durante el seguimiento presentaron mayores tasas de mortalidad (11,2% vs 6,7%, p<0,05 e incidencia de eventos coronarios totales (14,3% vs 9,2%, p<0,05. En el análisis multivariante solamente la edad y el tabaquismo se comportaron como variables predictoras de eventos coronarios totales, correspondiendo al tabaquismo las mayores odds ratio (OR: 2,33; IC95%:1,31-4,16; p<0,01. Conclusiones. En personas de 35 a 74 años seguidos durante 10 años el consumo de tabaco duplica el riesgo de eventos coronarios.

  3. Estudio retrospectivo sobre la incidencia de las infecciones cérvico faciales en Hospital Pablo Arturo Suárez en el período comprendido entre enero del 2008 y diciembre del 2010

    OpenAIRE

    Santiago Javier Garcés Mora; Diego Patricio Maldonado Coloma

    2015-01-01

    Las infecciones odontogénicas dentro del campo de la cirugía maxilofacial son muy frecuentes y con gran poder de diseminación a espacios faciales de la cabeza y del cuello (Raspall 2006). Por esta razón, el propósito de este estudio, es identificar el grupo poblacional de mayor afectación y determinar el espacio anatómico afectado más frecuente por estas entidades infecciosas.En este estudio retrospectivo se recolecta información de los pacientes atendidos en el período comprendido entre ener...

  4. Estudio retrospectivo sobre las posibles complicaciones maternofetales de la exposición a cabergolina Retrospective Study of any potencial Adverse Effects of Cabergoline on Pregnancy and Embryofetal Development

    OpenAIRE

    G. Stalldecker; M.S. Mallea Gil; M. Guitelman; A Alfieri; M.C. Ballarino; L. Boero; M.A. Carabelli; D. Cornaló; A. Chervin; K. Danilowicz; P. Fainstein Day; N. García Basavilbaso; M. Glerean; V. Goyan; Katz, D

    2010-01-01

    Objetivos: Estimar la frecuencia de complicaciones maternofetales en mujeres que se embarazaron durante el tratamiento con cabergolina (CAB). Estimar la frecuencia de patología detectada posnacimiento en los niños producto de dichos embarazos. Material y métodos: Estudio retrospectivo y multicéntrico de 86 embarazos en 78 mujeres con hiperprolactinemia idiopática (7) o tumoral (44 micro y 27 macro), en tratamiento con CAB en el momento de la concepción. Edad: 20 a 45 años; PRL inicial: 30 a 1...

  5. Superior mesenteric venous thrombosis: a retrospective study of thirteen cases Trombosis de vena mesentérica superior: estudio retrospectivo de trece casos

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    S. Muñoz

    2004-06-01

    universitario de Madrid. Diseño experimental: estudio retrospectivo descriptivo. Se revisaron las historias clínicas de los pacientes ingresados en nuestro hospital entre enero de 1998 y diciembre de 2002 con este diagnóstico. Los datos fueron procesados mediante el programa informático SPSS vs. 11. Pacientes: los trece pacientes diagnosticados de TVMS en ese periodo fueron incluidos. Resultados: los factores de riesgo asociados fueron patología tumoral (5, patología aguda intraabdominal (2, poliglobulia (1, mutación del gen de la protrombina (1 y anticuerpos anticardiolipina (1. En 3 pacientes no se encontró factor predisponente. La presentación clínica de todos los pacientes fue dolor abdominal, siendo las náuseas y vómitos el segundo síntoma en frecuencia (7. El diagnóstico se obtuvo por TC abdominal (9, arteriografía (2, ecografía (1 y por histología tras resección intestinal (1. Se realizó anticoagulación aislada en 4 pacientes y anticoagulación más cirugía en 5 casos. En 4 no se realizó tratamiento específico por tratarse de pacientes paliativos debido a la patología de base. Cinco pacientes fallecieron, cuatro de ellos presentaban neoplasia como factor asociado. La mortalidad fue de 38,5%. Conclusiones: la TVMS es una entidad muy poco frecuente, asociada en muchos casos patología neoplásica, lo que influye en su elevada mortalidad. Por la inespecificidad de los síntomas las pruebas de imagen son esenciales para el diagnóstico y para detectar factores asociados. En nuestra serie el TC fue la prueba más rentable.

  6. Ostectomía en Cuña de la Tibia como Tratamiento de la Rotura del Ligamento Cruzado Anterior. Estudio Retrospectivo

    OpenAIRE

    Díaz-Bertrana Sánchez, M. Carmen; A. Tapia; Saez, D.; Burballa, A.; Martinez, A; Durall Rivas, Ignasi

    2010-01-01

    Analizar los resultados retrospectivos de 52 ostectomías en cuña de la tibia como tratamiento de la rotura del ligamento cruzado anterior. Específicos: • Caracterizar la población con rotura de ligamento cruzado anterior. • Describir los tipos de rotura y lesiones asociadas. • Calcular el ángulo de inclinación de la meseta tibial pre y post quirúrgico. • Analizar la evolución y resultados de la técnica de la ostectomía tibial en cuña.

  7. Acute hepatitis C in Spain: a retrospective study of 131 cases Hepatitis aguda C en España: estudio retrospectivo de 131 casos

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    Ramón Pérez-Álvarez

    2012-01-01

    Full Text Available Background and aims: the management of acute hepatitis C (AHC is controversial. We have conducted a retrospective study to determine the epidemiological and biochemical aspects, the genotypes, the spontaneous clearance of HCV (SVC, and the treatment responses in patients with AHC. Methods: we have retrospectively collected data from 131 patients with AHC from 18 Spanish hospitals. Results: the mean age was 43 ± 16 years (17-83, 69% were symptomatic. The causes of infection were nosocomial in 40% and intravenous drug users in 20%. Eighty two percent had genotype 1. The delay from symptoms-onset to HCV-RNA confirmation was 50 ± 68 days (range, 11-350 days and to treatment (in 59% 14 ±13 weeks (range, 2-58 days. In the treated group, 80% achieved sustained virological response (SVR versus 57% SVC in untreated patients (p = 0.004. Up to 96% of those treated within the first 12 weeks had SVR versus 86% of those treated later (p = 0.04. Patients with HCV-RNA(- at week 4 resolved with or without treatment more frequently than those HCV-RNA(+ (98 versus 69%, p = 0.005. The treatment was not beneficial if HCV-RNA was undetectable at week 12. No differences in SVR were found in genotype 1 patients treated for 24 or 48 weeks. Patients with low baseline viral load achieved higher SVC and SVR. The SVC in patients with bilirubin > 5 mg/dl was 78 versus 40% in those with lower values (p = 0.004. Conclusions: the most common transmission route was nosocomial. SVR was higher in patients treated than SVC in non-treated. Early treatment (before week 12 achieved the highest response rate. SVC and SVR were more common in patients with a low baseline viral load. Undetectable HCV-RNA at week 4 was associated with high SVR and SVC rates. Jaundice was related with SVC.Introducción y objetivos: el manejo de la hepatitis aguda C (HAC es objeto de controversia. Hemos realizado un estudio prospectivo para conocer los aspectos epidemiológicos, bioquímicos, los

  8. Serviço de Emergência Psiquiátrica em hospital geral: estudo retrospectivo Servicio de emergencia psiquiátrica en hospital general: estudio retrospectivo Emergency psychiatric service in general hospitals: a retrospective study

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    Fernando Sérgio Pereira de Sousa

    2010-09-01

    Full Text Available O Serviço de Emergência Psiquiátrica em Hospital Geral (SEPHG é uma proposta articulada com o movimento da reforma psiquiátrica. Objetivou-se caracterizar os clientes com sofrimento psíquico assistidos no SEPHG Dr. Estevam, em Sobral-CE. Este é um estudo do tipo documental, com abordagem quantitativa, envolvendo 191 clientes atendidos no SEPHG no período de janeiro a dezembro de 2007. Os dados foram coletados a partir de um livro de registro, cujas informações nele contidas foram retiradas dos prontuários dos clientes. Observou-se predomínio de pacientes do sexo masculino (70,15%, com idade entre 30-49 anos (48,71% e solteiros (74,86%. A maioria era proveniente da cidade de Sobral (69,64 %. Em 42,40% dos casos, o diagnóstico foi transtorno do uso de álcool. Grande parte da clientela (66,50% deu entrada no serviço por demanda espontânea. Após avaliação do SEPHG, 43,45% desses clientes foram encaminhados ao CAPS-ad. Pelos resultados, depreende-se o quão imprescindíveis são os serviços de saúde mental.El Servicio de Emergencia Psiquiátrica en Hospital General (SEPHG es una propuesta vinculada al movimiento de la reforma psiquiátrica. Se objetivó caracterizar a los pacientes con trastornos psiquiátricos atendidos en el SEPHG Dr. Estevam, en Sobral-Ceará-Brasil. Estudio de tipo documental con abordaje cualitativa, involucrando 191 pacientes atendidos en el SEPHG entre enero y diciembre de 2007. Los datos fueron recogidos a partir de un libro de registro, cuyas informaciones fueron extraídas de las historias clínicas de los pacientes. Se observó prevalencia de pacientes de sexo masculino (70,15%, con edad entre 30-49 años (48,71% y solteros (74,86%. La mayoría provenía de la ciudad de Sobral (69,64%. En el 42,40% de los casos, el diagnóstico fue trastorno provocado por abuso de alcohol. Una gran cantidad de pacientes (66,50% se presentó en el servicio en forma espontánea. Con posterioridad a la evaluación del

  9. Incidência de cirurgia cardíaca em octogenários: estudo retrospectivo Incidencia de cirugía cardíaca en octogenarios: estudio retrospectivo Incidence of cardiac surgery in octogenarian patients: retrospective study

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    Luciano Brandão Machado

    2003-09-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: O aumento da expectativa de vida faz com que pacientes cada vez mais idosos tenham indicação de tratamento cirúrgico de cardiopatias. Este estudo tem como objetivo avaliar a incidência de pacientes com mais de 80 anos submetidos à cirurgia cardíaca no Instituto do Coração do Hospital das Clínicas da FMUSP, nos últimos 16 anos. MÉTODO: Foram analisados, no período de 1986 a 2001, o número de cirurgias de revascularização do miocárdio (RM e cirurgia valvar (CV e, em cada grupo, o número de cirurgias em pacientes com mais de 80 anos. Os dados foram analisados descritivamente. RESULTADOS: Os dados revelam aumento progressivo do número de octogenários submetidos à cirurgia cardíaca. As cirurgias de revascularização do miocárdio tiveram aumento de 0,13% em 1986 para 3,5% em 2001. As cirurgias valvares aumentaram de 0% em 1986 para 1,44% em 2001, registrando o maior valor de 3,02% em 1999. CONCLUSÕES: Os conhecimentos da fisiopatologia, da senilidade e os avanços no manuseio do trauma cirúrgico estão permitindo estender os recursos da cirurgia cardíaca no grupo de paciente mais idoso. A escolhas da técnica anestésica deve ser criteriosa, bem como a hidratação, a assistência ventilatória e a analgesia pós-operatória, permitindo redução da morbimortalidade neste grupo de maior risco cirúrgico.JUSTIFICATIVA Y OBJETIVOS: El aumento de la expectativa de vida hace con que pacientes cada vez mas edosos tengan indicación de tratamiento quirúrgico de cardiopatias. Este estudio tiene como objetivo evaluar la incidencia de pacientes con más de 80 años sometidos a cirugía cardíaca en el Instituto del Corazón del Hospital de Clínicas de la FMUSP, en los últimos 16 años. MÉTODO: Fueron analizados, en el período de 1986 a 2001, el número de cirugías de revascularización del miocardio (RM y cirugía valvar (CV y, en cada grupo, el número de cirugías en pacientes con más de 80 a

  10. Endocrown: Estudio clínico retrospectivo de una serie de pacientes, en un período de 8 a 19 años

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    Ernesto Borgia Botto

    Full Text Available Resumen Objetivo: El objetivo de este trabajo es presentar el resultado clínico retrospectivo de 11 Endocrowns, realizados por el primer autor en su consultorio privado, en un período de 8 a 19 años. Materiales and Métodos: Se establecieron criterios de inclusión y exclusión para la muestra y las restauraciones. En ciento treinta pacientes seleccionados al azar, 11 Endocrowns habían sido realizados en 11 pacientes. Tres materiales restauradores y tres cementos de resina fueron utilizados. Se analizaron diferentes variables. El Indice Kappa de Cohen, referido al análisis de calidad de las restauraciones, tuvo una variación de 0.78 a 1. Para analizar las diferencias estadísticas significativas se utilizaron métodos estadísticos descriptivos. Resultados: Al momento del examen, 10 (90.9% Endocrowns estaban en función Uno (9.1% había fracasado. Conclusiones: Endocrown, es un procedimiento restaurador técnicamente sensible, conservador, estético, fácil, rápido, con muy aceptable funcionalidad y longevidad, para rehabilitar dientes posteriores endodónticamente tratados, principalmente molares

  11. Estudio retrospectivo de la fasciola hepática en vovinos lecheros empleando metodologías serológicas

    OpenAIRE

    Crosby G., R. A.; V. J. Vera; Villamil Jiménez, L. C.; Ramírez, G. C.; Parra, J. L.

    2014-01-01

    Se realizó un estudio sero-epidemilógico prospectivo de la facioliasis bovina en explitaciones lecheras del altiplano frío utilizando la técnica de Hemaglutinación pasiva, determiando el comportamiento de la enfermedad en los diferentes grupos etáreos de seis unidades ganaderas, idenfiticando áreas y grupos con mayor reactividad y estableciendo las relaciones entre dicha reactividad y algunas varialbes medioambientales.

  12. Carga inmediata de implantes monofásicos postextracción utilizando los expansores roscados atraumáticos: estudio retrospectivo 2001-2011

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    Riham Mostafa Eldibany

    2015-10-01

    Conclusiones: Tras haber analizado toda la secuencia referida a la carga inmediata, podemos concluir que los implantes monofásicos insertados con la aplicación de esta técnica son un procedimiento predecible: su éxito en el maxilar inferior en nuestro estudio de 10 años fue del 98%. Sin embargo, es necesario determinar los casos candidatos para dicho procedimiento, así como las características del implante que favorecen la implantación inmediata.

  13. Intoxicación alimentaria por Clostridium perfringens en el Centro Penitenciario de Atención Institucional de San José: estudio de cohorte retrospectivo

    OpenAIRE

    Roy Wong-Mc Clure; Armando Silva-Solórzano; Xiomara Badilla-Vargas

    2004-01-01

    Las enfermedades transmitidas por los alimentos se presentan anualmente en Costa Rica y por lo general se estudian hasta identificar el agente etiológico, pero no hasta determinar su fuente de contaminación. No se ha documentado la importancia de fortalecer la inocuidad de alimentos, lo cual produce eventos que comprometen la salud pública cada año, por lo que fue importante estudiar el presente brote. En este estudio se analiza el brote diarreico de un centro penitenciario de San José, en 20...

  14. Intoxicación alimentaria por Clostridium perfringens en el Centro Penitenciario de Atención Institucional de San José: estudio de cohorte retrospectivo

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    Roy Wong-Mc Clure

    2004-06-01

    Full Text Available Las enfermedades transmitidas por los alimentos se presentan anualmente en Costa Rica y por lo general se estudian hasta identificar el agente etiológico, pero no hasta determinar su fuente de contaminación. No se ha documentado la importancia de fortalecer la inocuidad de alimentos, lo cual produce eventos que comprometen la salud pública cada año, por lo que fue importante estudiar el presente brote. En este estudio se analiza el brote diarreico de un centro penitenciario de San José, en 2003, procurando determinar el probable alimento contaminado. Materiales y métodos: El presente estudio corresponde a una cohorte retrospectiva que identifica exposición a los alimentos preparados dentro del Centro, en las 72 horas previas al pico epidémico. La descripción de la cohorte y el cálculo del (RR se realizó posteriormente para determinar la posible\tasociación causal. Las muestras de heces fueron procesadas en el laboratorio de referencia del INCIENSA. Resultados: La totalidad de los individuos pertenecían al sexo masculino, todos privados de libertad, con un promedio de edad de 31.1años (IC95%=28.9-33.4. La sintomatología más frecuente fue la diarrea (92.3% Y dolor abdominal tipo cólico (84.6%. El resultado de laboratorio aisló como agente etiológico el Clostridium perfringens enterotoxigénico (CPE. Al analizar los alimentos suministrados, pico epidémico y período de incubación, se tiene que el salchichón (RR=1.1;IC95%0.5-2.7 y la preparación con carne molida (RR=2.1,IC95%:0.6-7.4 mostraron ser los únicos alimentos capaces de transmitir el CPE. Discusión: El brote del Centro evidencia que la sintomatología descrita corresponde con lo documentado para la intoxicación por CPE y que, tomando en cuenta las condiciones necesarias para la transmisión, solo el salchichón y la preparación con carne molida cuentan con esta plausibilidad biológica. Al considerar el periodo de incubación, los valores de riesgo relativo

  15. Avaliação retrospectiva de artrodese cervical com enxerto autólogo versus hidroxiapatita Estudio retrospectivo de la artrodesis cervical con autoinjerto versus hidroxiapatita Retrospective study of cervical arthrodesis with autograft versus hydroxyapatite graft

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    Yoshinobu Nagasse

    2010-12-01

    Full Text Available OBJETIVO: os autores realizaram um estudo e compararam o resultado radiográfico no uso de hidroxiapatita e enxerto de crista ilíaca (autólogo no tratamento cirúrgico de hérnia discal cervical em um nível, sendo realizada artrodese cervical anterior com placa. MÉTODOS: foi realizado estudo retrospectivo com pacientes submetidos à artrodese cervical comparando-se dois grupos de dez pacientes: um em que foi utilizado enxerto de hidroxiapatita e outro em que foi utilizado enxerto de crista ilíaca (autólogo. Radiografias pós-operatórias foram mensuradas e comparadas, à busca de perdas de alinhamento angular. RESULTADOS: os dois tipos de enxerto demonstraram manter alinhamento em taxas similares, sendo observada consolidação óssea em todos os pacientes. O estudo não mostrou fragmentação do enxerto de hidroxiapatita ou soltura do material de síntese. CONCLUSÃO: nesta pequena série de casos não foi observada diferença significativa entre os resultados da artrodese cervical anterior com enxerto de hidroxiapatita em relação ao enxerto autólogo de ilíaco.OBJETIVOS: los autores realizaram un estudio y compararon el resultado radiográfico en el uso del hidroxiapatita y injerto de cresta ilíaca (autólogo, en el tratamiento quirúrgico de hernia discal cervical en un nivel, siendo realizada artrodesis cervical anterior con placa. MÉTODOS: fue realizado un estudio retrospectivo con pacientes, que habían sido sometidos a la artrodesis cervical con injerto de hidroxiapatita o injerto de cresta iliaca b.z autologa. Las radiografías postoperatorias habían sido mensuradas y comparadas, buscando para las pérdidas de alineación angular. RESULTADOS: los dos tipos de injerto habían demostrado manutención de alineación similares, donde la consolidación fue observada en todos los pacientes. El estudio no demostró la fragmentación del injerto de hidroxiapatita o de soltar el material de síntesis. CONCLUSIÓN: en esta peque

  16. Retrospective study of bovine neonatal mortality: cases reported from INTA Balcarce, Argentina Estudio retrospectivo de mortalidad neonatal bovina: Casos hallados en INTA-Balcarce, Argentina

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    E. L Morrell

    2008-09-01

    Full Text Available A retrospective study was performed on 169 beef and dairy calves aged from 1 to 7 days old submitted to the Diagnostic Laboratories at INTA Balcarce, Argentina. Bacterial culture was performed for aerobic and microaerophilic organisms. Samples from spleen and lymph nodes, and peripheral blood mononuclear cells were also cultured for viral isolation on cell culture. Bovine rotavirus was detected by direct-ELISA. Multiple tissue samples were fixed in 10% formalin, routinely processed and stained with hematoxylin and eosin for microscopic examination. Etiological diagnosis was made in 70 of the 169 calves. Infectious agents were identified in 49 cases, the most common being Escherichia coli. When the histopathological examination was performed in cases with undetermined diagnosis, it was noted that 44 specimens had histological lesions, which suggested the presence of an infectious agent. In order to characterize the causes of bovine neonatal mortality, the protocols and methodology should be improved in further works.Se realizó un estudio restrospectivo en 169 terneros muertos 1 a 7 días después del nacimiento pertenecientes a rodeos para carne y leche, remitidos a los Laboratorios de Diagnóstico del INTA Balcarce, Argentina. Para detectar organismos aeróbicos y microaerófilos se realizó el cultivo bacteriano. Para el aislamiento viral sobre cultivo celular, se recolectaron muestras de bazo, ganglios linfáticos y sangre periférica. El rotavirus bovino fue identificado por ELISA directo. Se efectuó el examen microscópico de diferentes tejidos, los cuales fueron fijados en formol al 10%, procesados y teñidos con hematoxilina y eosina. Se obtuvo un diagnóstico etiológico en 70 de los 169 terneros. Se identificaron agentes infecciosos en 49 casos, siendo el más común Escherichia coli. En los casos con diagnóstico indeterminado, el examen histopatológico realizado determinó que 44 especímenes poseían lesiones compatibles con la

  17. Intoxicación alimentaria por Clostridium perfringens en el Centro Penitenciario de Atención Institucional de San José: estudio de cohorte retrospectivo

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    Roy Wong-Mc Clure

    2004-06-01

    Full Text Available Las enfermedades transmitidas por los alimentos se presentan anualmente en Costa Rica y por lo general se estudian hasta identificar el agente etiológico, pero no hasta determinar su fuente de contaminación. No se ha documentado la importancia de fortalecer la inocuidad de alimentos, lo cual produce eventos que comprometen la salud pública cada año, por lo que fue importante estudiar el presente brote. En este estudio se analiza el brote diarreico de un centro penitenciario de San José, en 2003, procurando determinar el probable alimento contaminado. Materiales y métodos: El presente estudio corresponde a una cohorte retrospectiva que identifica exposición a los alimentos preparados dentro del Centro, en las 72 horas previas al pico epidémico. La descripción de la cohorte y el cálculo del (RR se realizó posteriormente para determinar la posible\tasociación causal. Las muestras de heces fueron procesadas en el laboratorio de referencia del INCIENSA. Resultados: La totalidad de los individuos pertenecían al sexo masculino, todos privados de libertad, con un promedio de edad de 31.1años (IC95%=28.9-33.4. La sintomatología más frecuente fue la diarrea (92.3% Y dolor abdominal tipo cólico (84.6%. El resultado de laboratorio aisló como agente etiológico el Clostridium perfringens enterotoxigénico (CPE. Al analizar los alimentos suministrados, pico epidémico y período de incubación, se tiene que el salchichón (RR=1.1;IC95%0.5-2.7 y la preparación con carne molida (RR=2.1,IC95%:0.6-7.4 mostraron ser los únicos alimentos capaces de transmitir el CPE. Discusión: El brote del Centro evidencia que la sintomatología descrita corresponde con lo documentado para la intoxicación por CPE y que, tomando en cuenta las condiciones necesarias para la transmisión, solo el salchichón y la preparación con carne molida cuentan con esta plausibilidad biológica. Al considerar el periodo de incubación, los valores de riesgo relativo

  18. Estudo retrospectivo das complicações pós-operatórias em cirurgia primária de lábio e palato Estudio retrospectivo de las complicaciones post-operatorias en la cirurgía primaria de labio y paladar Retrospective study of postoperative complications in primary lip and palate surgery

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    Janir Biazon

    2008-09-01

    Full Text Available Estudo retrospectivo das complicações de cirurgias primárias de lábio e palato, do Hospital de Reabilitação de Anomalias Craniofaciais da Universidade de São Paulo, teve como objetivos identificar as complicações mais freqüentes, e verificar a associação entre as complicações identificadas e as variáveis demográficas. Foram verificados 555 prontuários de pacientes submetidos à cirurgia de lábio e/ou palato em um período de seis meses, destes foram excluídos pacientes sindrônicos, aqueles que tiveram complicações intra-operatórias e com os prontuários incompletos, resultando numa amostra de 484 prontuários. Obteve-se o predomínio do sexo masculino (60,5, a etnia branca (91,9%, eutrófica com média de idade de 37 meses, a fissura mais incidente foi a transforame (64,5% e a cirurgia predominante foi a queiloplastia (56,6%. A dor foi a complicação mais freqüente seguida da desaturação de oxigênio e taquicardia. Não houve associação estatisticamente significante entre as complicações identificadas e o sexo, estado nutricional e procedimento cirúrgico.El presente estudio retrospectivo sobre complicaciones de cirugías primarias de labio y paladar, del Hospital de Rehabilitación de Anomalías Craneofaciales de la Universidad de Sao Paulo, tuvo como objetivos identificar las complicaciones más frecuentes y verificar la relación entre las complicaciones identificadas y las variables demográficas. Fueron verificadas 555 historias clínicas de pacientes sometidos a cirugía de labio y/o paladar en un período de seis meses, de los cuales se excluyeron los pacientes sindrómicos, aquellos que tuvieron complicaciones intraoperatorias y las historias clínicas incompletas, dando como resultado una muestra de 484 historias clínicas. Se obtuvo un predominio del sexo masculino (60.5, de raza blanca (91.9%, eutrófica con un promedio de edad de 37 meses, la fisura de mayor incidencia fue la transforame (64.5% y la

  19. Abdominoplastia multifuncional: estudio retrospectivo de 5 años de experiencia con 108 pacientes Multifunctional abdominoplasty: a five year retrospective study with 108 patients

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    C.P.D. Roxo

    2008-09-01

    Full Text Available Considerada por muchos cirujanos como la forma más segura, que permite la retirada de mayor cantidad de tejido y con menor índice de complicaciones, la abdominoplastia en ancla resurge amparada por nuevos conceptos y nueva sistematización, proporcionando mejores resultados a los pacientes a los que se les propone. A través de una marcación bimanual, inspirada en la mamoplastia tipo Pintaguy, resecamos el panículo abdominal en monobloque y modificamos la forma de la disección, iniciando de craneal hacia caudal y de lateral hacia medial, lo que hace más simple, rápida y segura la resección del colgajo dermograso. Enfatizamos sobre el hecho de que el punto más importante de esta técnica está en no disecar los colgajos remanentes para crear vectores de tracción y proporcionar mayor seguridad en el aporte vascular, con lo que disminuimos drásticamente en nuestros casos el índice de complicaciones tipo seroma, hematoma y necrosis tisular; tampoco fue necesario practicar transfusiones sanguíneas en la casuística que presentamos. Durante un periodo de 5 años, hemos intervenido a 108 pacientes, 59 mujeres y 49 hombres, con grandes perdidas pondérales (35 a 145 Kg y edades que oscilaron entre los 18 y 68 años, sometidos a abdominoplastia multifuncional con resección de piezas que variaron entre los 2.2 Kg y 21.5 Kg de peso. El periodo medio de hospitalización fue de 2 a 7 días, con retorno a sus actividades habituales a los 10 a 15 días. Por medio de este estudio demostramos que la abdominoplastia multifuncional es una técnica fácilmente reproducible, que puede aplicarse a cualquier grupo etario y proporciona al cirujano una mayor seguridad, tanto trans como postoperatoria, mejorando todo el contorno corporal.Considered by many surgeons the most secure way that allows the resection of a great amount of tissue with less complication, abdominoplasty in anchor resurge supported in new concepts and a new systematization, what brings

  20. Estudio retrospectivo de causas de trauma maxilofacial en Pasto, Colombia de 2001 a 2006 A retrospective study of maxillofacial trauma causes in Pasto, Colombia from 2001 to 2006

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    Ana Cristina Mafla

    2009-08-01

    Full Text Available Introducción: Las lesiones maxilofaciales son una condición frecuente en diferentes países, sin embargo, están asociadas a diversas causas. Metodología: Un estudio descriptivo fue realizado de Enero de 2001 a Diciembre de 2006 en tres hospitales y una institución de Pasto, Nariño, Colombia. 701 pacientes consecutivos del "Hospital San Pedro", "Hospital Universitario Departamental de Nariño", "Hospital Infantil Los Ángeles", y el Instituto de Medicina Legal y Ciencias Forenses Seccional Nariño - Putumayo fueron evaluados. Variables como año, género, distribución anatómica de la fractura, se incluyeron. Análisis descriptivos fueron usados para determinar porcentajes e intervalos de confianza. Resultados: Las causas más comunes fueron violencia, con 350 (49,9%, accidentes en motos con 104 (14,8%, en autos con 93 (13,3 %, y caídas con 66 (9,4%. Existió un incremento substancial de violencia en los años 2003 a 2004. Los niños de 0 a 6 años presentaron más caídas, mientras los jóvenes de 15 a 24 años se asociaron con violencia, al igual que accidentes en motos y automóviles. La violencia fue relacionada con fracturas de huesos propios de la nariz, caídas con lesiones naso-orbito-etmoidales, y accidentes en motos y automóviles con politraumatismo y fracturas panfaciales. Conclusiones: Debido a que la violencia, accidentes en motos y automóviles son las principales causas de lesiones maxilofaciales en la juventud, las políticas públicas deben ser dirigidas a ésta Salud UIS 2009; 41: 142-148Introduction: Maxillofacial injuries are a frequent condition in different countries; however, they are associated to different causes. Methodology: A descriptive study was performed from January 2001 to December 2006 at three hospitals and one institution from Pasto, Nariño, Colombia. 701 consecutive patients at "Hospital Los Angeles", "Hospital San Pedro", "Hospital Universitario Departamental de Nariño" and "Instituto de Medicina

  1. Perfil de exposición ocupacional a polvo de cemento y sílice cristalina en procesos de cementación y Fracturamiento hidráulico en el sector Oil & Gas en Colombia: un estudio retrospectivo (2009 – 2013).

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    Roa, Laura Tatiana

    2015-01-01

    La exposición a polvo de cemento y sílice ha sido estudiada por años en países como Estados Unidos y Canadá, cuando el polvo de cemento se inhala durante diferentes actividades, se puede ocasionar afectación del tracto respiratorio de las personas expuestas. El estudio “Perfil de exposición ocupacional a polvo de cemento y sílice cristalina en procesos de cementación y Fracturamiento hidráulico en el sector Oil & Gas en Colombia: un estudio retrospectivo (2009 – 2013).” Permitió identificar ...

  2. Profundidad tumoral y variables histopatológicas en el carcinoma epidermoide lingual: Estudio retrospectivo sobre 60 pacientes Tumoral thickness and histopathological parameters in the squamous cell carcinoma of tongue: A retrospective evaluation over 60 patients

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    JD Sánchez López

    2005-10-01

    Full Text Available I.- Introducción: La profundidad tumoral representa uno de los principales factores pronósticos del carcinoma epidermoide lingual. II.-Objetivos: Verificar si el espesor máximo tumoral se correlaciona con parámetros histopatológicos agresivos. III.-Material y Métodos: -Diseño: Estudio retrospectivo de base hospitalaria (Enero-1990 a Julio-1997 constituido por 60 pacientes afectos de carcinoma escamoso lingual. -Variables: Filiación del paciente, parámetros histopatológicos y profundidad tumoral. -Procedimientos de laboratorio. -Métodos estadísticos: Estadística descriptiva e inferencial (Método Bonferroni, C- Dunnet, Chi-cuadrado y test de Anova. IV.-Resultados: Asociación estadísticamente significativa entre Indice mitótico y profundidad tumoral (14,84;pI.-Introduction: The tumoral thickness represents one of the most ominous prognostic factors of the squamous cell carcinoma of tongue. II.-Objectives: To verify if the tumoral thickness is relationated with others aggressive histopathologic parameters. III.-Material and Methods: -Design: A hospital population retrospective study (January-1990 to July-1997 of 60 patients affected of carcinoma of tongue. -Variables: Data patients, histopathological parameters and tumoral thickness. -Laboratory procedures. -Stadistic methods: Descriptive and Inferential stadistical: Bonferroni method, C-Dunnet, Chi-square, Anova test… IV.-Results: There is a statistic association between mitotic Index and tumoral thickness (14,84; p<0,001. V.-Conclusions: Depth of invasion and mitotic Index are actually associated prognostic factors in the carcinoma epidermoid of tongue.

  3. Estudio retrospectivo sobre la incidencia de las infecciones cérvico faciales en Hospital Pablo Arturo Suárez en el período comprendido entre enero del 2008 y diciembre del 2010

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    Santiago Javier Garcés Mora

    2015-12-01

    Full Text Available Las infecciones odontogénicas dentro del campo de la cirugía maxilofacial son muy frecuentes y con gran poder de diseminación a espacios faciales de la cabeza y del cuello (Raspall 2006. Por esta razón, el propósito de este estudio, es identificar el grupo poblacional de mayor afectación y determinar el espacio anatómico afectado más frecuente por estas entidades infecciosas.En este estudio retrospectivo se recolecta información de los pacientes atendidos en el período comprendido entre enero del 2008 y diciembre del 2010. Se evalúa: año, género, grupos etarios, patologías preexistentes y las infecciones odontogénicas con sus espacios anatómicos comprometidos, determinando frecuencias simples y conjuntas en función a los objetivos planteados.El crecimiento anual es del 25% en número de casos. De 650 casos, las mujeres presentan mayor prevalencia con el 59,4%. El grupo etario más afectado es el de 21 a 30 años. La diabetes es el antecedente patológico de base más común con 18 casos. Las infecciones localizadas representan el 73,5% de la muestra, mientras que el 26,5% evolucionaron a estadios infecciosos más complejos como las celulitis odontogénicas con el 15,8%. Los focos sépticos (raíces dentales abandonadas representan el 45,2% de las infecciones localizadas. Las celulitis afectan con más frecuencia el espacio geniano con el 48,5% mientras que los abscesos se desarrollan con más facilidad en el espacio submandibular con el 42,3%. La complicación infecciosa más común es la osteomielitis con 18 casos (2,8%. Las infecciones localizadas aumentan con la edad, mientras que los estadios celulíticos disminuyen con la edad, presentando mayor prevalencia en la niñez. Las mujeres en edad fértil (21 a 30 años es el grupo más vulnerable.

  4. Estudio retrospectivo de los primeros 100 casos de ecocardiografía transesofágica en el hospital Max Peralta, durante el período 2003-2005.

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    Gabriela Castillo

    2006-01-01

    Full Text Available Introducción: La ecocardiografía transesofágica ha permitido superar las limitaciones del acceso transtoráccico lo que permite entregar con claridad y resolución, imágenes de la estructura y función cardíacas y de los grandes vasos. El objetivo de este estudio fue evaluar las indicaciones, complicaciones y diagnósticos de los primeros cien ecocardiogramas transesofágicos realizados en nuestro centro. Material y métodos: Es un estudio retrospectivo realizado en base a los expedientes clínicos desde el periodo en que se adquirió el equipo (2003 hasta completar los primeros cien ecocardiogramas tranesofágicos (setiembre 2005 en el Servicio de Cardiología del Hospital Max Peralta, Cartago, Costa Rica, con un equipo multiplanar. Resultados: Los primeros cien procedimientos se realizaron en 89 pacientes (edad promedio de 44,5 años, 49% fueron hombres. Las indicaciones más frecuentes para la realización del ecocardiograma transesofágico fueron cardiopatía congénita (36%, tumores y/o masas (13% y endocarditis (11%. Los diagnósticos definitivos fueron principalmente valvulopatías nativas, dilatación y/o hipertrofia de cámaras derechas, comunicación interauricular e hipertensión pulmonar. Sólo hubo complicaciones leves como hipotensión arterial y las relacionadas a la sedación. Conclusión: Este estudio demuestra la utilidad diagnóstica y seguridad del ecocardiograma transesofágico en nuestro centro, con resultados comparables a otras series.Introduction: Transesophageal ecocardiography has permited to overcome transthoraccic limitations approach, getting high resolution images of the heart and great vessels structure and function.This study evaluated indications, complications and diagnosis in the first 100 cases performed at our center. Material and methods: This is a retrospective study based on clinical reports from 2003 in that the mutliplanar equipment was adquired until september 2005 in the Cardiology service

  5. Factores pronósticos en neoplasias malignas primarias de glándulas salivares: Estudio retrospectivo de 20 años Prognostic factors in primary malignant salivary gland neoplasms: A 20-year retrospective study

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    A. Capote Moreno

    2005-10-01

    Full Text Available Objetivo. Analizar los posibles factores pronósticos que pueden influir en la supervivencia y el desarrollo de recurrencias en nuestra serie de pacientes con neoplasias malignas primarias de glándulas salivares. Diseño del estudio. Se realiza un estudio retrospectivo de 75 pacientes con carcinomas glandulares tratados entre 1980 y el 2003. En todos los casos el tratamiento realizado ha sido la cirugía. Se administró radioterapia postoperatoria en un 52% de los pacientes. Se emplea el modelo de Kaplan-Meier para el análisis de supervivencia y el periodo libre de enfermedad. Así mismo, se analiza la posible asociación entre los diversos factores pronósticos y estas variables mediante el test Log Rank para el estudio univariante y el modelo de Cox para el multivariante. Resultado. La supervivencia global y causa-específica de la serie a 5 y 10 años ha sido del 74,9 y 63 y del 77,7 y 65,3% respectivamente. El periodo libre de enfermedad ha sido de 51,8 y 43,2% a 5 y 10 años. De los factores analizados, la localización tumoral, el sexo, el estadio patológico, el tamaño tumoral, la parálisis facial, la infiltración perineural y la infiltración vascular han mostrado una influencia estadísticamente significativa en la supervivencia y/o recurrencias (pObjective. To analyze the possible prognostic factors for survival and disease-free survival in a group of patients with primary malignant salivary gland tumors. Design. Seventy-five patients with salivary gland carcinomas were studied retrospectively from 1980 to 2003. All cases were initially treated with surgery. Postoperative radiotherapy was applied in 52% of the patients. Survival and disease-free survival were analyzed with the Kaplan-Meier method. The association between the different prognostic factors and survival was studied with the Log Rank test for univariate analysis and the Cox proportional model for multivariate analysis. Results. The 5-year and 10-year crude survival

  6. Lesiones tendinosas del tobillo en resonancia magnética: análisis retrospectivo en 548 estudios Tendinous lesions of the ankle in MRI: retrospective review in 548 exams

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    Marcelo F. Cabrini

    2009-03-01

    Full Text Available Objetivo: Determinar la prevalencia de las diversas lesiones tendinosas del tobillo y sus características iconográficas típicas en los pacientes sometidos a Resonancia Magnética (RM. Material y métodos: Se efectuó un análisis descriptivo, retrospectivo y de corte transversal, de 548 estudios de RM de tobillo durante un período de 18 meses (entre enero de 2006 y junio de 2007, que contabiliza el total de los exámenes obtenidos en resonadores de campo cerrado en Diagnóstico por Imágenes Adrogué y en las sedes Hospital Fiorito de Avellaneda y Fundación Científica del Sur. Resultados: Del total de exámenes (n=548, el 40.3% fueron realizados a pacientes de sexo femenino (n=221 y el 59.7% a pacientes de sexo masculino (n=327, con una edad promedio de 47.6 ± 17 años. El 60.5% de los estudios (n=331 no reveló alteraciones en ningún grupo tendinoso del tobillo, mientras que el 39.5% (n=217 demostró la presencia de algún tipo de patología tendinosa. Asimismo, 64 estudios (11.7% revelaron alteraciones en el tendón tibial posterior; 47 (8.6% en el tendón de Aquiles; 34 (6.2% en el tendón peroneo lateral corto; 27 (4.9% a nivel del tendón del flexor propio del hallux; 26 (4.7% en el tendón peroneo lateral largo; 10 (1.8% en el tendón flexor común de los dedos; 6 (1.1% en el tendón tibial anterior; y 3 (0.5% en el tendón extensor común de los dedos. Conclusiones: La RM constituye una excelente herramienta en la valoración de las diversas patologías tendinosas debido a su capacidad multiplanar y a su alto contraste tisular.Purpose: To determine the prevalence of several tendinous lesions of the ankle, and the MR imaging features that characterize these lesions. Materials and methods: MR images in 548 exams of ankle were retrospectively reviewed. These studies were performed during a 18-months period of time in 3 MR scanners at Hospital Fiorito (Avellaneda, Diagnóstico por Imágenes Adrogué, and Fundación Científica del Sur

  7. Interação medicamentosa associada à reinternação hospitalar: estudo retrospectivo em um hospital geral Interacción medicamentosa asociada a la reinternación hospitalaria: estudio retrospectivo en un hospital general Hospital readmissions related to drug interactions: a retrospective study in a hospital setting

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    Cristiano Soares de Moura

    2012-12-01

    Full Text Available OBJETIVO: Analisar a relação entre interação medicamentosa potencial e reinternação hospitalar. MÉTODOS: Estudo retrospectivo com 1.487 pacientes maiores de 18 anos admitidos em um hospital geral em Vitória da Conquista, BA, de janeiro a dezembro de 2007. Os dados foram extraídos da Autorização de Internação Hospitalar do Sistema de Informação Hospitalar do Sistema Único de Saúde. O relacionamento probabilístico foi empregado para combinar múltiplas autorizações de uma mesma internação em um único registro e para identificar readmissões. Informações sobre prescrições foram agregadas manualmente aos registros do Sistema de Informação Hospitalar. Regressão logística foi utilizada para quantificar a influência de interação medicamentosa potencial e reinternação. Regressão de Cox foi empregada para testar a influência dessa variável no tempo até a primeira reinternação. RESULTADOS: Foram identificadas 99 readmissões (7% dos pacientes. Interação medicamentosa potencial foi encontrada em 35% das prescrições analisadas. Pacientes com potencial de interação medicamentosa na admissão prévia foram mais propensos à reinternação. A razão de chance ajustada indicou que esses pacientes tinham chance 2,4 vezes maior de readmissão; a taxa de risco ajustada mostrou que em pacientes com interação medicamentosa esse risco foi 79% maior (p OBJETIVO: Analizar la relación entre potencial interacción medicamentosa potencial y reinternación hospitalaria. MÉTODOS: Estudio retrospectivo con 1.487 pacientes mayores de 18 años admitidos en un hospital general en Vitória da Conquista, BA, Brasil, de enero a diciembre de 2007. Los datos fueron extraídos de la Autorización de Internación Hospitalaria del Sistema de Información Hospitalaria del Sistema Único de Salud Brasileño. La relación probabilística fue empleada para combinar múltiples autorizaciones de una misma internación en un único registro

  8. Associação entre glicemia de jejum e morbimortalidade perioperatória: estudo retrospectivo em pacientes idosos cirúrgicos Asociación entre glicemia de ayuno y morbimortalidad perioperatoria: estudio retrospectivo en pacientes ancianos quirúrgicos Association between fasting blood glucose levels and perioperative morbimortality: retrospective study in surgical elderly patients

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    Arthur Vitor Rosenti Segurado

    2007-12-01

    peri operatorias en la población de ancianos sometidos a procedimientos quirúrgicos todavía no se conocen. El objetivo de este estudio fue evaluar la Asociación entre glicemia de ayuno y morbimortalidad perioperatoria en pacientes quirúrgicos ancianos. MÉTODO: Se analizaron las hojas clínicas de pacientes de más de 60 años sometidos a diversos procedimientos quirúrgicos en un período de 6 meses, divididos de acuerdo con los valores de glicemia de ayuno en los grupos: 126 mg.dL-1. Fueron analizados en cuanto a la edad, estado físico (ASA, historial previo de diabetes melito (DM y tratamiento y riesgo cardíaco perioperatorio cirugía específica. A través de análisis univariada y de un modelo de regresión logística multivariada, se evaluó la relación entre los desenlaces (frecuencia de complicaciones postoperatorias (CPO y óbitos y las variables: glicemia de ayuno, historial previo de DM, estado físico (ASA y riesgo cardíaco. RESULTADOS: Hubo asociación estadística apenas entre los grupos glicémicos y las variables estado físico e historial previo de DM. Todas las variables estudiadas revelaron asociación estadística con relación a la mayor frecuencia de CPO y óbitos, excepto la variable presencia de historial previo de DM que no presentó relación con óbitos. En el modelo de regresión logística multivariada, hubo asociación entre las variables riesgo cardíaco y glicemia en función de la incidencia de CPO, mientras apenas las variables estado físico y riesgo cardíaco revelaron asociación estadística en función de los óbitos. CONCLUSIONES: Ese estudio retrospectivo mostró que, para la población pacientes ancianos estudiada, hubo asociación significativa entre glicemias por encima de 100 mg.dL-1 y morbimortalidad perioperatoria.BACKGROUND AND OBJECTIVES: The relationship between altered blood glucose levels and perioperative complications in elderly patients undergoing surgeries are not known. The objective of this study was to

  9. Interacciones de los fármacos antirretrovirales: de la teoría a la práctica clínica. Estudio retrospectivo de una cohorte de 2140 pacientes atendidos en la Unidad de Farmacia Ambulatoria del Hospital Clínic de Barcelona.

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    Tuset Creus, Montserrat

    2006-01-01

    Estudio retrospectivo de una cohorte de 2140 pacientes con infección por VIH. El objetivo principal ha sido determinar las principales interacciones que han tenido repercusión clínica, de los antirretrovirales entre sí o con otros fármacos y cuantificar su incidencia (nº interacciones/100 pacientes-año de seguimiento). Los objetivos secundarios han sido describir los tipos de tratamiento empleados con mayor frecuencia en combinación con los antirretrovirales y describir las asociaciones con u...

  10. Estudio retrospectivo de la variación de los parámetros seminales con la edad y su evolución en los últimos siete años en la población subfértil vizcaína

    OpenAIRE

    Gómez Abaurrea, Ainhoa

    2014-01-01

    Se trata de un estudio retrospectivo, no experimental en el que se valora la calidad seminal en relación a la edad del varón además de la evolución de los parámetros seminales a lo largo de los últimos siete años. Todo ello en una población de varones subfértiles que acudieron a la Clínica Elcano7, Vizcaya entre los años 2007 y 2013.

  11. Estudio retrospectivo sobre las posibles complicaciones maternofetales de la exposición a cabergolina Retrospective Study of any potencial Adverse Effects of Cabergoline on Pregnancy and Embryofetal Development

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    G. Stalldecker

    2010-09-01

    Full Text Available Objetivos: Estimar la frecuencia de complicaciones maternofetales en mujeres que se embarazaron durante el tratamiento con cabergolina (CAB. Estimar la frecuencia de patología detectada posnacimiento en los niños producto de dichos embarazos. Material y métodos: Estudio retrospectivo y multicéntrico de 86 embarazos en 78 mujeres con hiperprolactinemia idiopática (7 o tumoral (44 micro y 27 macro, en tratamiento con CAB en el momento de la concepción. Edad: 20 a 45 años; PRL inicial: 30 a 1429 ng/ml; duración del tratamiento previo al embarazo 1 a 120 meses; dosis: 0.125 a 4 mg/semana. El rango de exposición embriofetal a la CAB fue de 3 a 27 semanas, el 96.39% de las pacientes la recibió durante el primer trimestre y el 3.61% hasta el segundo. Resultados: No hubo complicaciones mayores durante el embarazo. Se registraron 7 abortos espontáneos (8.1% y 75 partos, de los cuales 49 fueron vaginales y 26 cesáreas. Se registraron 69 recién nacidos, 63 fueron a término y 6 pretérmino (8.8%, ninguno bajo peso para la edad gestacional. En 3 (5.2% recién nacidos se observó: 1 malformación mayor (Síndrome de Down y 2 menores (hernia umbilical e inguinal. Se obtuvo seguimiento de 42 recién nacidos; se diagnosticó epilepsia refractaria en uno y un trastorno generalizado del desarrollo en otro. No se halló una mayor frecuencia de complicaciones en los embarazos ni en los recién nacidos expuestos a CAB que en la población normal. Sería necesario mayor número de pacientes para concluir sobre la seguridad de CAB durante el embarazo.Objectives: To assess the rate of any potential adverse effects on pregnancy and embryo-fetal development in women who became pregnant under treatment with cabergoline (CAB. To follow up medical data of children who were born from mothers exposed to Cab in early weeks of gestation. Material and methods: Observational, retrospective and multicenter study on 86 pregnancies in 78 women with idiopathic or tumoral

  12. Utilización de la radiofrecuencia en el tratamiento de la patología cervical crónica: Estudio retrospectivo Radiofrecuency in the treatment of chronic cervical spine patology: Retrospective study

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    D. Abejón

    2006-01-01

    Full Text Available Objetivos: Valorar la eficacia y los efectos secundarios derivados del tratamiento de la patología cervical crónica con radiofrecuencia convencional (RF y pulsada (RFP. Material y Métodos: Se realiza un estudio retrospectivo. La muestra la componen 35 pacientes en los que se han realizado 63 tratamientos con radiofrecuencia con diagnóstico de radiculopa-tía cervical (RC, cefalea cervicogénica (CC y síndrome facetario cervical (SFC confirmado mediante pruebas de imagen, electromiografía y clínica congruente desde Enero de 2000 hasta Octubre del 2004. En todos los pacientes antes de efectuar la radiofrecuencia se realiza un bloqueo diagnóstico que ha de reducir a sintomatología de los pacientes en al menos el 50% para que se considere positivo. Se evalúa, mediante una escala numérica (EN, la intensidad del dolor en cinco momentos, el porcentaje de mejoría de los pacientes se valora según una escala propia de 4 categorías, se analiza la reducción de la medicación al inicio del tratamiento y tras aplicar la técnica, las complicaciones derivadas de la misma, si hubiera, y la necesidad de repetir el procedimiento y cuándo, si se repite. El seguimiento del estudio se realiza durante un periodo de 6 meses, y la valoración de los parámetros se realiza en 5 instantes del periodo de estudio, al inicio del mismo (basal, al mes, a los 2 meses, a los 3 y a los 6 meses. La comparación de la de la evolución de la EN a lo largo del tiempo en cada grupo etiológico (intragrupo se realizó con el análisis bilateral de la varianza no paramé-trica de Friedman. Se aplica el test de Chi cuadrado para estimar las diferencias en el porcentaje de mejoría entre los diferentes grupos diagnósticos. Se considera significación estadística cuando el valor de p es 50%. Trece pacientes redujeron la medicación según la escalera analgésica de la OMS. El número medio de procedimientos fue de 1.9 (1-9, siendo 5,6 meses (3-12 el tiempo medio en el

  13. Capacidad de sellado inmediato y a distancia de distintos materiales de obturación coronal. Estudio in vitro.

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    Pascualini, Carlos José

    2014-01-01

    Con el propósito de estudiar in vitro la capacidad de sellado que poseen distintos materiales utilizados como obturación temporal en dientes tratados endodónticamente, se efectuó mediante un método bacteriológico, un primer estudio. Para ello se seleccionaron 78 premolares recientemente extraídos con pulpa vital sana o levemente inflamada. A todos ellos se les seccionó parte de la raíz, dejando un remanente de 5mm. Luego, con alta velocidad, r...

  14. Estudio Retrospectivo del Ingreso de Animales Provenientes del Tráfico Ilegal a la Unidad de Rescate y Rehabilitación de Animales Silvestres (URRAS), entre febrero de 1996 y agosto de 2006

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    Sandra Milena Lamprea-Maldonado; P A Moreno; O. SÁNCHEZ; Ximena Gómez; Nelson Jurado

    2009-01-01

    Este estudio da a conocer las cifras de animales provenientes del  tráfico y tenencia ilegal que ingresaron a la Unidad de Rescate y Rehabilitación de Animales Silvestres  (URRAS) de la Facultad de Medicina Veterinaria y Zootecnia de la Universidad Nacional de Colombia, en el período comprendido entre Febrero de 1996 y Agosto de 2006. A partir de la información recopilada en la base de datos y actas de ingreso, se establecieron las principales taxas afectadas por el ilícito, tipos de ingreso ...

  15. Uso das precauções-padrão na assistência de enfermagem: um estudo retrospectivo El uso de las precauciones el modelo en la asistencia de enfermería: estudio retrospectivo The use of the precautions pattern in the nursing attendance: retrospective study

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    Daniele Fernandes de Aguiar

    2008-09-01

    Full Text Available Este estudo tem como objetivos analisar as publicações científicas e técnicas sobre os procedimentos de precauções-padrão em periódicos nacionais e internacionais e destacar aspectos importantes dos artigos no que se refere ao papel da enfermeira na prevenção e controle da infecção hospitalar. Constituíram como amostra da pesquisa as fontes secundárias em forma de livros e periódicos, com a finalidade de nos colocar em contato direto com os artigos levantados sobre o uso das precauções-padrão para as infecções hospitalares na assistência de enfermagem, entre 1999 e 2005. Foram encontrados 10 artigos relacionados ao uso de precauções-padrão: 70% foram obtidos em Banco de Teses, 20%, no site Scielo e 10%, na biblioteca de uma universidade pública do Rio de Janeiro, sendo 40% publicados no ano de 2003. Os resultados mostraram que, neste período, apesar de poucas publicações, houve uma contínua renovação do tema, tanto a nível nacional, quanto internacional.Este estudio tiene como objetivos analizar las publicaciones científicas y técnicas, que los procedimientos de las precauciones estándares en periódicos nacionales e internacionales, separar aspectos importantes de artículos acerca del papel de la enfermera en la prevención y controlar la infección en hospital. Ellos constituirán como proba, los orígenes secundarios en la forma de libros y periódicos de la investigación, con el propósito de ponernos en contacto directo con los artículos en el uso de las precauciones estándares para las infecciones del hospital en la atención de enfermería, entre 1999 y 2005 con el uso de las precauciones. 10 artículos se relacionaron con el uso de precauciones habían sido encontrado: 70% habían sido conseguidos en Banco de Teses, el 20% en el sitio Scielo y el 10% en la biblioteca de una universidad pública de Río de Janeiro, siendo 40% publicado en el año de 2003. Los resultados mostraban que, en este per

  16. Frecuencia y caracterización de lesiones anatomo-patológicas en la enfermedad de gumboro y enfermedades secundarias asociadas en nuestras condiciones ambientales. Estudio retrospectivo (Frequency and characterization of anatomo-pathological lesions in gumboro disease and secondary illnesses associated under our environmental conditions. A retrospective study

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    Roberto González Insua

    2005-07-01

    Full Text Available El análisis retrospectivo de las historias clínicas de 59 casos de la enfermedad de Gumboro diagnosticados durante el período 1994-1998 a través de la sintomatología clínica y el estudio morfopatológico de las lesiones, determinó las frecuencias de lesiones observadas en diferentes órganos así como enfermedades secundarias y gérmenes más frecuentes asociados a ella. El diagnóstico de laboratorio se realizó mediante los hallazgos de lesiones macroscópicas en la bolsa de Fabricio durante la necropsia y la evaluación microscópica de esas lesiones utilizando para ello la técnica de inclusión en parafina y la coloración de hematoxilina-eosina. Se incluyeron las enfermedades y patologías más frecuentes asociadas a la entidad patológica, se expresan en una tabla y dos gráficos las características más sobresalientes de la bursitis infecciosa en el periodo mencionado.

  17. Disturbios da olfacao: estudo retrospectivo

    Directory of Open Access Journals (Sweden)

    Luciano Lobato Gregorio

    2014-01-01

    Full Text Available Introdução: O olfato, fenômeno subjetivo de grande importância, é pouco compreendido e estudado no ser humano. Médicos com maior conhecimento sobre os distúrbios desse sentido tendem a considerar a doença mais importante e manejar melhor o diagnóstico e o tratamento. Objetivo: Descrever a amostra dos pacientes com queixa principal de distúrbios do olfato e mostrar a experiência do serviço no manejo e tratamento. Delineamento: Estudo retrospectivo de coorte histórica com corte transversal. Materiais e métodos: Descrição da amostra e avaliação de resposta ao tratamento de pacientes com queixa principal de hiposmia ou anosmia atendidos no ambulatório de Rinologia no período de janeiro de 2005 a outubro de 2011. Resultados: Dos 38 pacientes com distúrbio da olfação, 68,4% dos pacientes apresentaram queixa de hiposmia e 31,5% de anosmia, com duração média de 30,8 meses. Os diagnósticos etiológicos principais foram idiopática (31,5%, rinopatia alérgica (28,9% e RSC com pólipos (10,5%. As respostas ao tratamento com corticosteroide tópico e ácido alfa-lipoico foram variáveis, assim como na literatura. Conclusão: Maior importância deve ser dada aos distúrbios do olfato na prática do otorrinolaringologista, uma vez que o diagnóstico diferencial é amplo e pode trazer grande morbidade ao paciente, com impacto na sua qualidade de vida.

  18. A retrospective study of pediatric endoscopy as performed in an adult endoscopy unit Estudio retrospectivo sobre la endoscopia pediátrica desarrollada en un servicio de endoscopias de adultos

    Directory of Open Access Journals (Sweden)

    L. Julián-Gómez

    2010-02-01

    Full Text Available Gastrointestinal endoscopy is a safe, efficient technique with minimal complications, and a useful diagnostic tool for the pediatric population. Under ideal conditions endoscopies for children should be performed by experienced pediatric endoscopists. In this study we report our experience with pediatric endoscopy at the general adult endoscopy unit in our hospital. Our goal is to quantify the number of endoscopies performed in children, as well as their indications and findings, the type of sedation or anesthesia used, and the time waiting for the test to occur. Our experience demonstrates that endoscopists in a general adult gastroenterology department, working together with pediatricians, may perform a relevant number of endoscopies in children in a fast, safe, effective manner.La endoscopia gastrointestinal es una técnica segura y eficiente con mínimas complicaciones, así como una útil herramienta diagnóstica en la población pediátrica. En condiciones ideales, las endoscopias en niños deberían ser realizadas por endoscopistas pediátricos experimentados. En este estudio reportamos nuestra experiencia en la realización de endoscopias pediátricas en la Unidad de Endoscopias general de adultos de nuestro hospital. El objetivo es cuantificar la cantidad de endoscopias realizadas en niños, así como las indicaciones y hallazgos de las mismas, el tipo de sedación o anestesia empleado y el tiempo de espera para la realización de la prueba. Nuestra experiencia demuestra que los endoscopistas de un servicio de gastroenterología general de adultos, en colaboración con pediatras, pueden realizar un número importante de endoscopias a niños, de forma rápida, segura y eficaz.

  19. Cambio en la clasificación macroscópica de la apendicitis. ¿Tiene algún impacto? Estudio retrospectivo en un Hospital Universitario Pediátrico

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    Sergio David Castañeda-Espinosa

    2015-04-01

    Full Text Available Antecedentes. La definición actual de apendicitis diferencia la aguda en apéndices no perforados y perforados. Esta clasificación describe los apéndices perforados como aquellos con la presencia de un orificio visible en el apéndice o la presencia de un fecalito libre en la cavidad y ha cambiado el manejo postoperatorio actual. Objetivo. Determinar si el cambio en la definición macroscópica de la apendicitis aguda tiene alguna influencia en la duración de la estancia hospitalaria y la tasa de complicaciones dado el cambio en el manejo antibiótico postoperatorio. Materiales y métodos. Se llevó a cabo un rastreo de aquellos pacientes llevados a cirugía con diagnóstico de apendicitis aguda durante el primer semestre del año 2009 y el segundo semestre del año 2011 en la Fundación HOMI. Se excluyeron los pacientes llevados a laparoscopia diagnóstica por estudio del dolor abdominal, apendicectomias incidentales y los pacientes manejados en el protocolo de apendicectomía de Intervalo. Resultados. Se observó una disminución en el número de días de hospitalización/año y en el número de dosis de antibiótico/año y reducción en el número de complicaciones, lo cual demuestra que la clasificación y el protocolo de manejo actual no se correlacionan con un aumento en el número de complicaciones y se asocia con menores costos. Conclusión. El cambio en la clasificación macroscópica y el aportar la nueva definición sobre apendicitis perforada ha logrado disminuir la estancia hospitalaria y la cantidad de antibióticos utilizados sin una repercusión significativa en la tasa de complicaciones.

  20. Coronal dynamics

    Science.gov (United States)

    Nakariakov, V. M.

    2007-07-01

    The lectures present the foundation of solar coronal physics with the main emphasis on the MHD theory and on wave and oscillatory phenomena. We discuss major challenges of the modern coronal physics; the main plasma structures observed in the corona and the conditions for their equilibrium; phenomenology of large scale long period oscillatory coronal phenomena and their theoretical modelling as MHD waves. The possibility of the remote diagnostics of coronal plasmas with the use of MHD oscillations is demonstrated.

  1. Uso de dexmedetomidina em pacientes obesos mórbidos submetidos a gastroplastia: estabilidade cardiovascular e consumo de anestésicos venosos. Estudo retrospectivo Uso de dexmedetomidina en pacientes obesos mórbidos sometidos a gastroplastia: estabilidad cardiovascular y consumo de anestésicos venosos. Estudio retrospectivo Dexmedetomidine in morbid obese patients undergoing gastroplasty: cardiovascular stability and consumption of intravenous anesthetics. A retrospective study

    Directory of Open Access Journals (Sweden)

    Luiz Piccinini Filho

    2006-04-01

    o houve efeitos colaterais imputáveis ao uso da dexmedetomidina.JUSTIFICATIVA Y OBJETIVOS: La utilización de agentes anestésicos potentes y de corta duración es fundamental en pacientes sometidos a la intervención quirúrgica bariátrica. La dexmedetomidina, agonista alfa 2-adrenérgica, surgió como una opción de auxilio a la técnica de anestesia venosa. El objetivo de esta investigación fue la de evaluar la eficacia de la dexmedetomidina asociada a la anestesia venosa en pacientes obesos mórbidos, sometidos a la gastroplastia. MÉTODO: Análisis retrospectivo de pacientes portadores de obesidad mórbida, sometidos a la intervención quirúrgica bariátrica abierta, bajo anestesia con propofol y alfentanil con o sin dexmedetomidina. Los pacientes fueron colocados en dos grupos: Control (propofol y alfentanil y Dexmedetomidina (propofol, alfentanil y dexmedetomidina. El mantenimiento de la anestesia en los dos grupos constó de: propofol = 0,075 a 0,1 mg.kg-1.min-1 y alfentanil = 0,75 a 1 µg.kg-1.min-1; en el grupo Dexmedetomidina en la dosis inicial de 1 µg.kg-1 en 10 min y mantenimiento con 0,4 a 0,7 µg.kg-1.h-1. Las variables estudiadas fueron la edad, sexo, IMC, tiempo quirúrgico y de despertar, frecuencia cardiaca (FC, presión arterial sistólica y diastólica (PAS, PAD, saturación periférica de hemoglobina (SpO2, consumo de propofol y alfentanil y efectos colaterales. RESULTADOS: Se registró una reducción significativa en el consumo de propofol y alfentanil en el grupo Dex-medetomidina. La FC presentó variación significativa apenas en el grupo Dexmedetomidina. La PAS y la PAD presentaron una reducción estadística significativa en los dos grupos en los primeros 20 min, estabilizándose a continuación. Los pacientes de los dos grupos no presentaron efectos colaterales. CONCLUSIONES: Ese estudio demostró la eficacia del uso de la dexmedetomidina asociada a la anestesia venosa con propofol y alfentanil, trayendo una reducción del consumo de los

  2. Derivaciones al Servicio de Urgencias del hospital en una población de ancianos residentes: Estudio retrospectivo sobre sus causas y adecuación Hospital transfers from a population of elderly residents: A retrospective study about the causes and suitability

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    José Carlos Bermejo Higuera

    2010-09-01

    Full Text Available Objetivo: analizar las causas y la adecuación de las derivaciones de ancianos institucionalizados al Servicio de Urgencias del hospital. Método: estudio descriptivo retrospectivo transversal sobre la población de una residencia de la Comunidad de Madrid. Se recogieron datos de 45 pacientes derivados durante el año 2008, con un total de 62 derivaciones. Derivación adecuada o pertinente fue aquella que cumpliera uno de los siguientes criterios: 1 el paciente ingresó o estuvo en observación más de 24 horas; 2 precisó ser valorado por un especialista y/o requirió pruebas diagnósticas no disponibles en el centro; y 3 necesitó tratamiento no disponible en el centro. Análisis estadístico descriptivo. Resultados: el 98,4% de las derivaciones cumplió los criterios de adecuación; 67% Criterio 1,21% Criterio 2 y no otros, y 77,4% Criterio 3. La causa más frecuente de derivación fue la sospecha de fractura poscaída (32,3%. El porcentaje anual de fallecidos (22,38% fue menor que el observado en otras residencias madrileñas, de ellos, el 15,55% falleció en el hospital.Aim: to analyse the causes and suitability of elderly resident transfers to hospital emergencies service. Methods: a retrospective and descriptive study about the resident population in a Residence of Comunidad de Madrid. We recorded data from 45 patients transferred in 2008, out of a total of 62 transfers. A suitable or appropriate derivation was one fulfilling at least one of the following criteria: 1-the patient was admitted to hospital or stayed in observation for more than 24 hours, 2- the patient had to be seen by a specialist or required a diagnosis test that was not available in the centre, 3- the patient needed treatment that was not available in the centre. The statistical analysis was descriptive. Results: 98.4% of the transfers complied with the suitability criteria: 67% criterion 1,21% criterion 2 but not other and 77% criterion 3. The most frequent cause for

  3. Coronal Partings

    CERN Document Server

    Nikulin, Igor F

    2015-01-01

    The basic observational properties of the 'coronal partings'--the special type of the coronal magnetic structures, identified by a comparison of the coronal X-ray images and solar magnetograms--are considered. They represent channels inside the unipolar large-scale magnetic fields, formed by the rows of magnetic arcs directed to the neighboring fields of opposite polarity. The most important characteristics of the partings are revealed. It is found that--from the evolutionary and spatial point of view--the partings can transform to the coronal holes and visa versa. The classes of global, intersecting, and complex partings are identified.

  4. Estudio clínico retrospectivo del uso de un sistema de hidrocirugía en pacientes lesionados medulares con úlceras por presión crónicas Retrospective clinical study of an hydrogurgery system on spinal cord injured patients with chronic pressure ulcers

    Directory of Open Access Journals (Sweden)

    J.M. Arévalo Velasco

    2011-03-01

    Full Text Available Realizamos un estudio clínico retrospectivo con pacientes lesionados medulares crónicos en el Hospital Nacional de Parapléjicos (Toledo, España, intervenidos quirúrgicamente por una o varias úlceras por presión de carácter crónico durante el año 2008. Revisamos 84 historias clínicas de pacientes a los cuales se realizaron 141 procedimientos quirúrgicos. Sólo en 8 casos se realizó una cirugía puramente de limpieza (bisturí más hidrocirugía sin realizar consecutivamente el tratamiento de cobertura de la lesión. Los restantes 133 procedimientos de limpieza más cobertura inmediata se distribuyeron en 2 grupos según el tipo de desbridamiento realizado: grupo I (n = 71, sólo desbridamiento quirúrgico con bisturí y grupo II (n = 62 desbridamiento con bisturí más uso posterior de un sistema de hidrocirugía de flujo continuo a alta presión. Según la localización, las lesiones ulcerosas tratadas fueron: isquiáticas 69 (48,94 %, sacras 49 (34,75 %, trocantéreas 15 (10,63 % y otras (talones y maléolos 8 (5,67%. Como conclusiones, establecemos que más del 54 % de los procedimientos llevados a cabo (72 de 133 curaron en la primera intervención y no necesitaron más cirugías; un 38% (51 de 133 fueron intervenciones realizadas en pacientes con úlceras muy evolucionadas y/o de difícil solución; la tasa de recidivas al año fue del 4,4 %; no encontramos diferencias significativas en cuanto a la tasa de curación entre los grupos I y II (p We carried out a retrospective study on spinal cord injured patients from the National Hospital for Paraplegics (Toledo, Spain, who were surgically treated during 2008 to alleviate the problems elicited by one or more pressure ulcers of chronic nature. We reviewed the clinical histories of 84 patients that received 141 surgical procedures, 8 were of radical nature (scalpel plus hidrosurgery without wound covering. The remaining 133 procedures of surgical cleaning and immediate wound

  5. Tratamiento quirúrgico de la escoliosis idiopática del adolescente. Estudio comparativo de los resultados clínicos y radiológicos de la instrumentación con tornillos pediculares versus los constructos híbridos

    OpenAIRE

    Balaguer Andrés, Jaume

    2011-01-01

    El tratamiento quirúrgico de la escoliosis idiopática del adolescente está en constante evolución. El uso de la instrumentación vertebral posterior con tornillos pediculares se asocia a una mejora de los resultados cuando se comparan con otros métodos de fijación. Se trata de un estudio retrospectivo en el que se comparan los resultados clínicos (SRS-22) y radiológicos (ángulo Cobb en el plano coronal) del tratamiento quirúrigico de la EIA. Un grupo intervenido con tornillos pediculares, y el...

  6. Coronal magnetometry

    CERN Document Server

    Zhang, Jie; Bastian, Timothy

    2014-01-01

    This volume is a collection of research articles on the subject of the solar corona, and particularly, coronal magnetism. The book was motivated by the Workshop on Coronal Magnetism: Connecting Models to Data and the Corona to the Earth, which was held 21 - 23 May 2012 in Boulder, Colorado, USA. This workshop was attended by approximately 60 researchers. Articles from this meeting are contained in this topical issue, but the topical issue also contains contributions from researchers not present at the workshop. This volume is aimed at researchers and graduate students active in solar physics. Originally published in Solar Physics, Vol. 288, Issue 2, 2013 and Vol. 289, Issue 8, 2014.

  7. Comparação entre raquianestesia, bloqueio combinado raqui-peridural e raquianestesia contínua para cirurgias de quadril em pacientes idosos: estudo retrospectivo Comparación entre raquianestesia, bloqueo combinado raqui-peridural y raquianestesia continua para cirugías de cuadril en pacientes ancianos: estudio retrospectivo Comparison between spinal, combined spinal-epidural and continuous spinal anesthesias for hip surgeries in elderly patients: a retrospective study

    Directory of Open Access Journals (Sweden)

    Luiz Eduardo Imbelloni

    2002-06-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: Diversas questões envolvem os estudos, as análises e o tamanho da amostra para que sejam demonstrados os benefícios da anestesia regional. Análise de dados geralmente custa menos e requer menos tempo quando comparado com amplo estudo aleatório controlado. Esta análise retrospectiva compara a raquianestesia contínua, o bloqueio combinado raqui-peridural e a raquianestesia simples para cirurgias de quadril em pacientes idosos durante quatro anos, para determinar as possíveis vantagens e desvantagens das três técnicas. MÉTODO: Foram avaliados 300 prontuários sendo que: 100 pacientes receberam raquianestesia simples (Grupo 1, 100 receberam bloqueio combinado raqui-peridural (Grupo 2 e 100 receberam raquianestesia contínua (Grupo 3 nos últimos quatro anos. Todos os bloqueios foram realizados em decúbito lateral esquerdo. Foram avaliados: sucesso de punção, nível da analgesia, bloqueio motor de membros inferiores, qualidade da anestesia, necessidade de complementação, incidência de falhas, parestesias, cefaléia pós-punção, alterações cardiovasculares, confusão mental e delírio, transfusão sangüínea e mortalidade. RESULTADOS: Não existiu diferença significativa entre os grupos em relação a idade, peso e sexo. Os pacientes do grupo 2 foram menores do que os do grupo 1 e 3. As doses utilizadas foram de 15,30 mg de bupivacaína no grupo 1; 23,68 mg no grupo 2 e 10,10 mg no grupo 3. Não foi encontrada diferença significativa (p JUSTIFICATIVA Y OBJETIVOS: Diversas cuestiones envuelven los estudios, las análisis y el tamaño de la muestra para que sean demostrados los beneficios de la anestesia regional. Las análisis de datos generalmente cuestan menos y requieren menos tiempo, cuando comparado con un amplio estudio aleatorio controlado. Esta análisis retrospectiva compara la raquianestesia continua, el bloqueo combinado raqui-peridural y la raquianestesia simple para cirugías de cuadril en

  8. Coronal Holes

    Directory of Open Access Journals (Sweden)

    Steven R. Cranmer

    2009-09-01

    Full Text Available Coronal holes are the darkest and least active regions of the Sun, as observed both on the solar disk and above the solar limb. Coronal holes are associated with rapidly expanding open magnetic fields and the acceleration of the high-speed solar wind. This paper reviews measurements of the plasma properties in coronal holes and how these measurements are used to reveal details about the physical processes that heat the solar corona and accelerate the solar wind. It is still unknown to what extent the solar wind is fed by flux tubes that remain open (and are energized by footpoint-driven wave-like fluctuations, and to what extent much of the mass and energy is input intermittently from closed loops into the open-field regions. Evidence for both paradigms is summarized in this paper. Special emphasis is also given to spectroscopic and coronagraphic measurements that allow the highly dynamic non-equilibrium evolution of the plasma to be followed as the asymptotic conditions in interplanetary space are established in the extended corona. For example, the importance of kinetic plasma physics and turbulence in coronal holes has been affirmed by surprising measurements from the UVCS instrument on SOHO that heavy ions are heated to hundreds of times the temperatures of protons and electrons. These observations point to specific kinds of collisionless Alfvén wave damping (i.e., ion cyclotron resonance, but complete theoretical models do not yet exist. Despite our incomplete knowledge of the complex multi-scale plasma physics, however, much progress has been made toward the goal of understanding the mechanisms ultimately responsible for producing the observed properties of coronal holes.

  9. Estudo retrospectivo das infecções pós-operatórias em cirurgia de coluna: correlação com o número de limpezas cirúrgicas realizadas Estudio retrospectivo de infecciones postoperatorias en cirugía de espina dorsal: correlación con el número de desbridamientos quirúrgicos realizados Retrospective study of post-operative infections in spine surgery: correlation with the number of surgical debridement performed

    Directory of Open Access Journals (Sweden)

    Guilherme Pereira Corrêa Meyer

    2011-01-01

    ón primaria de la espina dorsal (osteomielitis o espondilodiscitis totalizando 3 casos. Variables relativas al paciente, realización de tratamientos y resultados fueron evaluadas y correlacionadas con las variables clave: número de desbridamientos quirúrgicos y cultivos aislados de agentes infecciosos. RESULTADOS: La tasa de infección, después de la cirugía, fue 9,83%. Algunas variables fueron relacionadas con el número de desbridamientos quirúrgicos realizados y no fue posible establecer alguna relación. No obstante, se descubrió que pacientes con un mayor número de tratamientos quirúrgicos realizados tuvieron una tasa mayor de dolor postoperatorio. CONCLUSIÓN: Pacientes que recibieron un mayor número de tratamientos realizados tuvieron más dolor en el período postoperatorio. No hubo correlación, estadísticamente significativa, entre el número de desbridamientos o agentes infecciosos, o con otras variables. Puede ser necesario tener un mayor número de pacientes en el estudio, a fin de identificar otras relaciones.OBJECTIVE: To evaluate the characteristics of post-operative infections and determine their resolution in relation to the number of surgical debridement and infectious agents. METHOD: We collected all records of patients who developed post-operative infection for 30 months and several variables were analyzed and correlated. In those 30 months, 40 patients developed post-operative infection of a total of 410 surgeries. We excluded cases of primary infection of the spine (osteomyelitis or spondylodiscitis totaling 3 cases. Variables related to the patient, procedure and outcome were evaluated and correlated with the key variables: number of surgical debridement and infectious agents isolated from cultures. RESULTS: The rate of infection after surgery was 9.83%. Several variables were related to the number of surgical debridement performed and it was not possible to establish any relationship. However, it was found that patients with higher number

  10. Estudo retrospectivo de latrodectismo na Bahia, Brasil

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    Rejâne Maria Lira-da-Silva

    1995-09-01

    Full Text Available O trabalho apresenta um estudo retrospectivo de setenta e sete casos de latrodectismo no Estado da Bahia, Brasil, de agosto de 1980 a julho de 1990. Os dados foram levantados nos livros de registro e arquivo de fichas do CIAVE. O agente etiológico em 28% dos acidentes aracnídeos foi a espécie L. curacaviensis e a maior incidência foi registrada no meio urbano (57%, em indivíduos do sexo masculino (70% e faixa etária de 10 a 29 anos (58%. Os principais sinais locais foram dor (56%, pápula eritematosa (21% e edema discreto (17%, e os sistêmicos foram dor em membros inferiores (29%, tremores e contraturas (29%, sudorese (28% parestesia em membros (21% e dor abdominal (17%. O tratamento foi sintomático em 67% dos casos e específico em 21%. O tempo de permanência hospitalar após o uso do soro antilatrodectus foi menor que 24 horas em 64% dos casos.

  11. Coronal Holes

    CERN Document Server

    Cranmer, Steven R

    2009-01-01

    Coronal holes are the darkest and least active regions of the Sun, as observed both on the solar disk and above the solar limb. Coronal holes are associated with rapidly expanding open magnetic fields and the acceleration of the high-speed solar wind. This paper reviews measurements of the plasma properties in coronal holes and how these measurements are used to reveal details about the physical processes that heat the solar corona and accelerate the solar wind. It is still unknown to what extent the solar wind is fed by flux tubes that remain open (and are energized by footpoint-driven wave-like fluctuations), and to what extent much of the mass and energy is input intermittently from closed loops into the open-field regions. Evidence for both paradigms is summarized in this paper. Special emphasis is also given to spectroscopic and coronagraphic measurements that allow the highly dynamic non-equilibrium evolution of the plasma to be followed as the asymptotic conditions in interplanetary space are establish...

  12. Estudo retrospectivo de latrodectismo na Bahia, Brasil

    Directory of Open Access Journals (Sweden)

    Rejâne Maria Lira-da-Silva

    1995-09-01

    Full Text Available O trabalho apresenta um estudo retrospectivo de setenta e sete casos de latrodectismo no Estado da Bahia, Brasil, de agosto de 1980 a julho de 1990. Os dados foram levantados nos livros de registro e arquivo de fichas do CIAVE. O agente etiológico em 28% dos acidentes aracnídeos foi a espécie L. curacaviensis e a maior incidência foi registrada no meio urbano (57%, em indivíduos do sexo masculino (70% e faixa etária de 10 a 29 anos (58%. Os principais sinais locais foram dor (56%, pápula eritematosa (21% e edema discreto (17%, e os sistêmicos foram dor em membros inferiores (29%, tremores e contraturas (29%, sudorese (28% parestesia em membros (21% e dor abdominal (17%. O tratamento foi sintomático em 67% dos casos e específico em 21%. O tempo de permanência hospitalar após o uso do soro antilatrodectus foi menor que 24 horas em 64% dos casos.This work is a retrospective study of latrodectism in the State of Bahia, Brazil, from August 1980 to July 1990. The data concerning the accidents were obtained from file cards at the Antivenom Information Center of Bahia (AVICB. Latrodectus curacavienis was the ethiologic agent identified in 28% of the arachnid accidents. The major incidence was registered in urban area (57% affecting men (70% more than women, with 10 to 29year-old age group (58%. Local pain (56%, erythematous papula (29% and light oedema (17% were the principal local symptoms. Pain in the limbs (29%, tremor and rigidities (29%, sweating (28%, limbs and arms paresthesia (21% and abdominal pain (17% were systemic ones. The treatment was mainly symptomatic (67% and antivenin serum was used in 21% of the cases. After serotherapy, 64% of the patients left the hospital within less than 24 hours.

  13. Histerectomias: estudo retrospectivo de 554 casos

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    Eddie Fernando Cândido Murta

    Full Text Available OBJETIVO: A histerectomia é uma operação muito realizada, entretanto há poucos trabalhos na literatura nacional sobre suas indicações, técnica e complicações. O objetivo deste trabalho é avaliar estes procedimentos realizados na Disciplina de Ginecologia e Obstetrícia da Faculdade de Medicina do Triângulo Mineiro. MÉTODO: Estudo retrospectivo de 470 histerectomias abdominais e 84 vaginais foi conduzido analisando as indicações, tempo de cirurgia e internação, tipo de incisão e morbidez. RESULTADOS: As principais indicações foram o mioma uterino e o prolapso uterino para as histerectomias abdominais e vaginais, respectivamente. As complicações intra-operatórias aconteceram em 3,4% e as pós-operatórias em 2,4% do total de casos. Nenhuma diferença estatística foi encontrada no número de complicações em relação ao tipo de incisão (vertical ou transversal. O tempo de cirurgia e o de hospitalização foram estatisticamente maiores nas incisões verticais. A hemorragia foi a mais freqüente complicação intra-operatória e a infecção da incisão operatória foi a mais freqüente no pós-operatório. CONCLUSÕES: A histerectomia é um procedimento de baixo risco, no entanto, a realização de revisões sobre indicações e complicações, e a pesquisa de melhores técnicas cirúrgicas são necessárias para torná-la cada vez mais segura.

  14. Asociación del anticuerpo anti-C1q con las manifestaciones clínicas, hematológicas e inmunológicas en el Lupus Eritematoso Sistémico : Estudio observacional retrospectivo de 135 casos.

    OpenAIRE

    Córica, María Emilia

    2012-01-01

    : Las concentraciones de anticuerpo anti-C1q están elevadas en los pacientes afectados de LES. Según algunos estudios la presencia de este anticuerpo está asociada a la nefropatía lúpica, sin embargo en otros estudios esta relación no se comprobó. En nuestro trabajo relacionamos la positividad del anticuerpo anti-C1q con las manifestaciones clínicas, hematológicas e inmunológicas de la enfermedad. A diferencia de estudios previos sólo pudimos establecer una relación estadísticamente significa...

  15. Implantes dentales en pacientes adultos postrauma dentoalveolar. Estudio descriptivo

    OpenAIRE

    Edgardo González; Christian Pedemonte; Ilich Vargas; Francisco Verdugo-Avello

    2016-01-01

    Objetivo: Realizar un estudio descriptivo y retrospectivo para analizar el éxito de la rehabilitación dentaria con o sin aumento óseo alveolar. Materiales y métodos: Se realizó un estudio retrospectivo mediante la revisión de historias clínicas de pacientes que concurrieron al Servicio de Cirugía Máxilofacial del Hospital Clínico Mutual de Seguridad, Chile, en el período de 3 años (enero 2003 – diciembre 2005). Resultados: Un total de 135 pacientes ingresaron al estudio en los cuales se...

  16. Estudio retrospectivo de la Rabia en Animales de Importancia Económica en el Estado de Puebla, México, del año 2001 al 2008 - A Retrospective Study of Rabies in Animals of Economic Importance in the State of Puebla, Mexico, during the years 2001 to 2008

    Directory of Open Access Journals (Sweden)

    Ortega-Chávez, Verónica

    2009-09-01

    Full Text Available Resumenpérdidas económicas directas e indirectas en ganadería, y representaun grave riesgo sanitario debido a los contactos entre personas yanimales infectados principalmente. Por lo que, se realizó un estudioretrospectivo de la rabia de animales de importancia económica, deacuerdo a los registros de los focos rábicos desde el año 2001 al 2008analizando las características geográficas de la región. El Estado dePuebla a nivel sanitario está dividido en 10 Jurisdicciones Sanitarias(J.S.. Se presentaron 333 casos de rabia durante los años de 2001 a2008 en el Estado, de los cuales el 52.9% de los casos correspondió arabia paralítica, de éstos 151 casos se presentaron en bovinos. Loscasos de rabia paralítica se han presentado en 6 J.S. y 95 localidades han sido afectadas que corresponden a 40 municipios; la J.S. No. 1 presentó mayor número de localidades afectadas y un mayor número de casos (117 durante el periodo de estudio. De acuerdo a las zonas sonde se han presentado los casos de rabia, se dedujo que losprincipales factores que influyen en la distribución del murciélagohematófago en el Estado de Puebla, son la disponibilidad de alimentoy hábitat, esto último está determinado por factores antropogénicoscomo la deforestación y la presencia de zonas ganaderas.SummaryBovine paralytic rabies is a viral disease that causes severe direct and indirect economic losses in livestock, also causes a serious health risk because of contact between people and infected animals. Because of this, We did a retrospective study of rabies in animals of economic importance, according to records of rabies outbreaks from 2001 to 2008, and we analyzed the geographical features of the region. The State of Puebla, in a health level, is divided into 10 health jurisdictions (HJ. As a result, 333 cases of rabies were reported during 2001 to 2008 in the State, of which 52.9% corresponded of paralytic rabies, of which 151 cases went for bovines. The

  17. Coronal influence on dynamos

    CERN Document Server

    Warnecke, Jörn

    2013-01-01

    We report on turbulent dynamo simulations in a spherical wedge with an outer coronal layer. We apply a two-layer model where the lower layer represents the convection zone and the upper layer the solar corona. This setup is used to study the coronal influence on the dynamo action beneath the surface. Increasing the radial coronal extent gradually to three times the solar radius and changing the magnetic Reynolds number, we find that dynamo action benefits from the additional coronal extent in terms of higher magnetic energy in the saturated stage. The flux of magnetic helicity can play an important role in this context.

  18. Cáncer de Tiroides: Estudio descriptivo retrospectivo Thyroid carcinoma: A descriptive retrospective study

    Directory of Open Access Journals (Sweden)

    Carolina C. González

    2006-12-01

    Full Text Available Entre todos los tumores, el carcinoma tiroideo (CT es poco frecuente, se caracteriza por su lenta evolución y elevado porcentaje de curación. Nuestro objetivo es estudiar las características de los pacientes con CT. Analizamos retrospectivamente a 171 pacientes, edad media al diagnóstico 41.1( ± 14.6 años, que consultaron entre los años 2000-04 por CT. Se evaluaron datos de anamnesis, métodos de diagnóstico, anatomía patológica y evolución. Agrupamos a los tumores por el tamaño y según TNM (tumor-adenopatía-metástasis en estadios (E. La presencia de tiroglobulina estimulada (Tg > 2 ng/ml e imagen positiva (con 131I u otro radiotrazador fueron consideradas como positivas para CT residual. De la población total el 88% fue sexo femenino, el 62% menores de 45 años, y el 77.1% tuvo función tiroidea normal. La punción con aguja fina (PAAF fue diagnóstica en 78%. El 96% fue carcinoma papilar (CTP, 63% presentaban E I; 14% E II; 19% E III y 4% E IV. Se detectó CT residual en el 90% de los pacientes con Tg entre 2 y 10, y en el 100% con Tg > 10 ng/ml, mientras que con Tg The thyroid carcinoma (TC is not very frequent among all cancers. Its course is slow and is high potentially curable. Our aim was to analyse the characteristics in patients with TC. A retrospective analysis on 171 patients, with an average age of 41.1 (±14,6, who asked for TC to our service between the years 2000-04, was performed. From case histories it was evaluated: anamnesis, diagnostic image, histopathology and evolution. Tumours were grouped for size and TNM (tumour-nodule-metastasis in stages (S. A stimulated serum thyroglobulin level > 2 ng/ml and positive image with 131I or another nuclear marker were considered as positive for residual TC. In the totality of the analyzed patients 88% were female, 62% below 45 years old, and in 77% the thyroid function was normal. The fine needle aspiration (FNA was diagnostic in 78%. Papillary thyroid carcinoma (PTC in 96%. The 63% was SI; 14% SII; 19% SIII and 4% SIV. During follow-up, we observed that 90% of patients with Tg between 2 and 10 had evidence of residual TC, and 100% with Tg > 10 ng/ml, whereas 18% of those whose stimulated Tg < 2 presented positive image. There was not found significative correlation with pathologic antecedents or relevant image signs. In conclusion: TCP was the most frequent carcinoma in women, in patients younger than 45 years and in those who have euthyroid function. A stimulated serum thyroglobulin level was a good indicator for residual TC, but failed to select those patients who were disease free.

  19. MEJORAS DE ACCESIBILIDAD VIARIA: UN ESTUDIO RETROSPECTIVO PARA LA ESPAÑA PENINSULAR

    Directory of Open Access Journals (Sweden)

    Adelheid Holl

    2011-01-01

    Full Text Available Desde los años ochenta, se ha incrementado considerablemente la red de autovías y autopistas en España. Esta investigación presenta un análisis de las mejoras en accesibilidad que los programas de construcción de vías rápidas de gran capacidad han generado. Se calculan dos indicadores de accesibilidad a nivel municipal para toda la península española y para el periodo de 1980-2005: acceso a autovías y autopistas interregionales y potencial de mercado. La distancia media de los municipios a la autovía o autopista mas cercana se ha reducido considerablemente. En general, la accesibilidad ha mejorado en todo el país, pero no todas las zonas se han beneficiado al mismo nivel.

  20. Síndrome de Guillain-Barré en el anciano: un estudio retrospectivo

    OpenAIRE

    MELANO CARRANZA,EFRÉN; CARRILLO MARAVILLA,EDUARDO; GULÍAS HERRERO,ALFONSO; ÁVILA FUNES,JOSÉ ALBERTO

    2004-01-01

    El síndrome de Guillain-Barré (SGB) es la principal causa de parálisis flácida. Su pronóstico usualmente es bueno pero algunos tienen secuelas neurológicas graves y la mortalidad es del 1 al 3%. Objetivo: reconocer las características clínicas del SGB en el anciano y compararlos con pacientes jóvenes. Material y métodos: se revisaron los expedientes de pacientes con el diagnóstico de SGB de 1995 al 2002. Los enfermos fueron divididos en dos grupos: igual o mayores de 60 años (grupo 1) y menor...

  1. La investigación sobre eficacia escolar en el Salvador: estudio retrospectivo y prospectivo

    OpenAIRE

    Ramos Ramírez, Gustavo

    2013-01-01

    Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Formación de Profesorado y Educación, Departamento de Didáctica y Teoría de la Educación. Fecha de lectura : 29 de mayo de 2013

  2. Homicidio múltiple Interfamiliar : Un estudio retrospectivo, resentimiento, envidia y odio

    OpenAIRE

    Cabello, Javier Osvaldo

    2015-01-01

    Transcurrido tantos años del luctuoso hecho, luego de haber intervenido como perito de parte de la querella, reviendo y replanteándome las motivaciones desde una perspectiva menos ju-rídica y más analítica, alejada de lo patológico y más próxima al intento de comprender al hombre ante la necesidad de pertenencia al grupo y al esfuerzo que realiza por adaptarse al medio; sus desengaños, los sentimientos que despierta, los rencores y necesidad de revancha, los deseos no correspondidos, el odio,...

  3. Estudio retrospectivo de caracterización de la hepatozoonosis canina en Buenos Aires

    OpenAIRE

    Scodellaro, Carla Floriana

    2015-01-01

    La hepatozoonosis canina es una enfermedad parasitaria causada por protozoarios del género Hepatozoon (Apicomplexa, Eucoccida) y trasmitida por garrapatas. En Argentina, esta enfermedad fue descripta por primera vez en 1999 y recién en 2007 fue identificado Hepatozoon canis como el agente etiológico. El objetivo de este trabajo fue caracterizar la hepatozoonosis en perros del sur del Gran Buenos Aires. Para ello, se analizaron los hemogramas de 100123 muestras de sangre canina remitidas entre...

  4. Coronal Mass Ejections

    Science.gov (United States)

    Crooker, Nancy; Joselyn, Jo Ann; Feynman, Joan

    The early 1970's can be said to mark the beginning of The Enlightenment in the history of the Space Age, literally as well as by analogy to European history. Instruments blinded by Earth's atmosphere were lifted above and, for the first time, saw clearly and continuously the ethereal white light and sparkling x-rays from the solar corona. From these two bands of the light spectrum came images of coronal mass ejections and coronal holes, respectively. But whereas coronal holes were immediately identified as the source of high-speed solar wind streams, at first coronal mass ejections were greeted only by a sense of wonder. It took years of research to identify their signatures in the solar wind before the fastest ones could be identified with the well-known shock disturbances that cause the most violent space storms.

  5. Coronal Waves and Oscillations

    Directory of Open Access Journals (Sweden)

    Nakariakov Valery M.

    2005-07-01

    Full Text Available Wave and oscillatory activity of the solar corona is confidently observed with modern imaging and spectral instruments in the visible light, EUV, X-ray and radio bands, and interpreted in terms of magnetohydrodynamic (MHD wave theory. The review reflects the current trends in the observational study of coronal waves and oscillations (standing kink, sausage and longitudinal modes, propagating slow waves and fast wave trains, the search for torsional waves, theoretical modelling of interaction of MHD waves with plasma structures, and implementation of the theoretical results for the mode identification. Also the use of MHD waves for remote diagnostics of coronal plasma - MHD coronal seismology - is discussed and the applicability of this method for the estimation of coronal magnetic field, transport coefficients, fine structuring and heating function is demonstrated.

  6. Mechanisms of Coronal Heating

    Indian Academy of Sciences (India)

    S. R. Verma

    2006-06-01

    The Sun is a mysterious star. The high temperature of the chromosphere and corona present one of the most puzzling problems of solar physics. Observations show that the solar coronal heating problem is highly complex with many different facts. It is likely that different heating mechanisms are at work in solar corona. Recent observations show that Magnetic Carpet is a potential candidate for solar coronal heating.

  7. Estudo retrospectivo da peste humana no Nordeste oriental do Brasil

    Directory of Open Access Journals (Sweden)

    Dalva A. Mello

    1970-02-01

    Full Text Available Utilizando dados do Departamento Nacional de Endemias Rurais, o autor faz um estudo retrospectivo da peste humana no Nordeste Oriental do Brasil no período de 1935-1967. Os aspectos epidemiológicos abordados foram os seguintes: morbidade, mortalidade, letalidade, "point" epidêmicos, tendência secular e variações mensais. Os coeficientes de morbidade e mortalidade variaram muito. A letalidade apresentou-se bastante alta. Dez anos de "point" epidêmicos foram registrados no periodo estudado. A análise estatística dos casos distribuídos por mês mostrou que a peste humana atinge o pcnto máximo na estação sêca. Ficou demonstrada urna variação cíclica da doença, em que aumentos e decréscimos ocorrem em períodos que variam de 6 a 12 anos.

  8. Global Coronal Waves

    CERN Document Server

    Chen, P F

    2016-01-01

    After the {\\em Solar and Heliospheric Observatory} ({\\em SOHO}) was launched in 1996, the aboard Extreme Ultraviolet Imaging Telescope (EIT) observed a global coronal wave phenomenon, which was initially named "EIT wave" after the telescope. The bright fronts are immediately followed by expanding dimmings. It has been shown that the brightenings and dimmings are mainly due to plasma density increase and depletion, respectively. Such a spectacular phenomenon sparked long-lasting interest and debates. The debates were concentrated on two topics, one is about the driving source, and the other is about the nature of this wavelike phenomenon. The controversies are most probably because there may exist two types of large-scale coronal waves that were not well resolved before the {\\em Solar Dynamics Observatory} ({\\em SDO}) was launched: one is a piston-driven shock wave straddling over the erupting coronal mass ejection (CME), and the other is an apparently propagating front, which may correspond to the CME frontal...

  9. Traumatismo alveolodentário na dentição decídua: associação do grau de maturidade radicular no momento de injuria e sequelas após acompanhamento longitudinal retrospectivo.

    OpenAIRE

    2012-01-01

    Este estudo teve como objetivo investigar a influência do grau de maturidade radicular dos dentes decíduos nas sequelas dos traumatismos alveolodentários, assim como investigar o momento que tais sequelas ocorrem. Para tal, foram conduzidos dois estudos longitudinais retrospectivos, os quais coletaram dados clínicos e radiográficos de registros de pacientes com traumatismo dentário em um ou mais incisivo central superior decíduo. No primeiro, sequelas como discoloração coronária, obliteração ...

  10. Toxoplasmose em primatas neotropicais: estudo retrospectivo de sete casos

    Directory of Open Access Journals (Sweden)

    Renata A. Casagrande

    2013-01-01

    Full Text Available A toxoplasmose é considerada uma doença parasitária fatal em primatas neotropicais. O objetivo deste trabalho foi descrever, através de um estudo retrospectivo, os casos de toxoplasmose em primatas neotropicais. No período de 1999-2009 foram realizados 86 exames anatomopatológicos em primatas e a toxoplasmose foi a enfermidade mais comum (7/86, relatando-se um caso em sagui-do-tufo-preto (Callithrix penicillata e seis em bugio-ruivo (Alouatta guariba. Dois animais foram encontrados mortos e cinco morreram em poucos dias. Os sinais clínicos mais frequentes foram apatia e anorexia (5/7, distensão abdominal (4/7 e febre (3/7. Na necropsia observou-se esplenomegalia (4/7, hemorragia do trato digestório, linfonodos e bexiga (4/7, pulmões avermelhados (3/7 e hepatomegalia (2/7. No exame histopatológico evidenciou-se hepatite (7/7, esplenite (3/7, miocardite (2/7, enterite (2/7, linfadenite (1/7 e sialite (1/7 necróticas e, pneumonia intersticial (4/7. Em fígado, pulmões, baço, coração, linfonodos e glândula salivar havia taquizoítos de Toxoplasma gondii que foram também detectados pelo exame de imuno-histoquímica anti-T. gondii em fígado, baço e pulmões (5/7. A toxoplasmose pode causar alta mortalidade em colônias de primatas neotropicais e representar mais uma ameaça à conversação dessas espécies em cativeiro. Sendo assim, medidas preventivas devem ser tomadas para evitar a contaminação desses animais.

  11. Otomycosis: a retrospective study Otomicoses: um estudo retrospectivo

    Directory of Open Access Journals (Sweden)

    Zélia Braz Vieira da Silva Pontes

    2009-06-01

    Full Text Available Otomycosis is a fungal infection of the external ear canal with only a few studies about its real frequence in Brazil. AIM: to evaluate otomycosis frequence and characteristics in patients with clinical suspicion of external otitis. STUDY DESIGN: Retrospective study with transversal cohort (2000-2006. MATERIALS AND METHODS:103 patients were assigned to mycological diagnosis (direct microscopic examination and culture. RESULTS: Otomycosis was diagnosed in 19.4% of the patients. Patient age varied from 2 to 66 years (an average of 23.5 years of age, and 60% of otomycosis cases were seen in women between 2 to 20 years of age. Chronic otitis, previous antibiotic therapy and the lack of cerumen were predisposing factors; itching, otalgia, otorrhea and hypoacusis were the symptoms reported by the patients. The most frequently isolated species were C. albicans (30%, C. parapsilosis (20%, A. niger (20%, A. flavus (10%, A. fumigatus (5%, C. tropicalis (5%, Trichosporon asahii (5% and Scedosporium apiospermum (5%. CONCLUSIONS: Otomycosis is endemic in João Pessoa-PB. Clinical exam and mycological studies are important for diagnostic purposes because otomycosis symptoms are not specific.Otomicose é uma infecção fúngica do conduto auditivo externo com poucos estudos sobre sua real frequência no Brasil. OBJETIVO: Avaliar a frequência e características das otomicoses em pacientes com suspeita clínica de otite externa. DESENHO DO ESTUDO: Estudo retrospectivo com corte transversal (2000-2006. MATERIAL E MÉTODOS: 103 pacientes foram atendidos para diagnóstico micológico (exame microscópico direto e cultivo. RESULTADOS: Otomicoses foram diagnosticadas em 19,4% dos pacientes. A idade desses pacientes variou de 2 a 66 anos (média de 23,5 anos e 60% das otomicoses foram observadas em mulheres entre 2 a 20 anos de idade. Otite crônica, antibioticoterapia prévia e ausência de cerume foram os fatores predisponentes e prurido otológico, otalgia

  12. Coronal Mass Ejections

    CERN Document Server

    Kunow, H; Linker, J. A; Schwenn, R; Steiger, R

    2006-01-01

    It is well known that the Sun gravitationally controls the orbits of planets and minor bodies. Much less known, however, is the domain of plasma fields and charged particles in which the Sun governs a heliosphere out to a distance of about 15 billion kilometers. What forces activates the Sun to maintain this power? Coronal Mass Ejections (CMEs) and their descendants are the troops serving the Sun during high solar activity periods. This volume offers a comprehensive and integrated overview of our present knowledge and understanding of Coronal Mass Ejections (CMEs) and their descendants, Interplanetary CMEs (ICMEs). It results from a series of workshops held between 2000 and 2004. An international team of about sixty experimenters involved e.g. in the SOHO, ULYSSES, VOYAGER, PIONEER, HELIOS, WIND, IMP, and ACE missions, ground observers, and theoreticians worked jointly on interpreting the observations and developing new models for CME initiations, development, and interplanetary propagation. The book provides...

  13. Coronal radiation belts

    CERN Document Server

    Hudson, H S; Frewen, S F N; DeRosa, M L

    2009-01-01

    The magnetic field of the solar corona has a large-scale dipole character, which maps into the bipolar field in the solar wind. Using standard representations of the coronal field, we show that high-energy ions can be trapped stably in these large-scale closed fields. The drift shells that describe the conservation of the third adiabatic invariant may have complicated geometries. Particles trapped in these zones would resemble the Van Allen Belts and could have detectable consequences. We discuss potential sources of trapped particles.

  14. Coronal Magnetic Field Models

    Science.gov (United States)

    Wiegelmann, Thomas; Petrie, Gordon J. D.; Riley, Pete

    2017-09-01

    Coronal magnetic field models use photospheric field measurements as boundary condition to model the solar corona. We review in this paper the most common model assumptions, starting from MHD-models, magnetohydrostatics, force-free and finally potential field models. Each model in this list is somewhat less complex than the previous one and makes more restrictive assumptions by neglecting physical effects. The magnetohydrostatic approach neglects time-dependent phenomena and plasma flows, the force-free approach neglects additionally the gradient of the plasma pressure and the gravity force. This leads to the assumption of a vanishing Lorentz force and electric currents are parallel (or anti-parallel) to the magnetic field lines. Finally, the potential field approach neglects also these currents. We outline the main assumptions, benefits and limitations of these models both from a theoretical (how realistic are the models?) and a practical viewpoint (which computer resources to we need?). Finally we address the important problem of noisy and inconsistent photospheric boundary conditions and the possibility of using chromospheric and coronal observations to improve the models.

  15. Coronal Mass Ejections: Observations

    Directory of Open Access Journals (Sweden)

    David F. Webb

    2012-06-01

    Full Text Available Solar eruptive phenomena embrace a variety of eruptions, including flares, solar energetic particles, and radio bursts. Since the vast majority of these are associated with the eruption, development, and evolution of coronal mass ejections (CMEs, we focus on CME observations in this review. CMEs are a key aspect of coronal and interplanetary dynamics. They inject large quantities of mass and magnetic flux into the heliosphere, causing major transient disturbances. CMEs can drive interplanetary shocks, a key source of solar energetic particles and are known to be the major contributor to severe space weather at the Earth. Studies over the past decade using the data sets from (among others the SOHO, TRACE, Wind, ACE, STEREO, and SDO spacecraft, along with ground-based instruments, have improved our knowledge of the origins and development of CMEs at the Sun and how they contribute to space weather at Earth. SOHO, launched in 1995, has provided us with almost continuous coverage of the solar corona over more than a complete solar cycle, and the heliospheric imagers SMEI (2003 – 2011 and the HIs (operating since early 2007 have provided us with the capability to image and track CMEs continually across the inner heliosphere. We review some key coronal properties of CMEs, their source regions and their propagation through the solar wind. The LASCO coronagraphs routinely observe CMEs launched along the Sun-Earth line as halo-like brightenings. STEREO also permits observing Earth-directed CMEs from three different viewpoints of increasing azimuthal separation, thereby enabling the estimation of their three-dimensional properties. These are important not only for space weather prediction purposes, but also for understanding the development and internal structure of CMEs since we view their source regions on the solar disk and can measure their in-situ characteristics along their axes. Included in our discussion of the recent developments in CME

  16. The coronal fricative problem

    Science.gov (United States)

    Dinnsen, Daniel A.; Dow, Michael C.; Gierut, Judith A.; Morrisette, Michele L.; Green, Christopher R.

    2013-01-01

    This paper examines a range of predicted versus attested error patterns involving coronal fricatives (e.g. [s, z, θ, ð]) as targets and repairs in the early sound systems of monolingual English-acquiring children. Typological results are reported from a cross-sectional study of 234 children with phonological delays (ages 3 years; 0 months to 7;9). Our analyses revealed different instantiations of a putative developmental conspiracy within and across children. Supplemental longitudinal evidence is also presented that replicates the cross-sectional results, offering further insight into the life-cycle of the conspiracy. Several of the observed typological anomalies are argued to follow from a modified version of Optimality Theory with Candidate Chains (McCarthy, 2007). PMID:24790247

  17. Solar Coronal Plumes

    Directory of Open Access Journals (Sweden)

    Giannina Poletto

    2015-12-01

    Full Text Available Polar plumes are thin long ray-like structures that project beyond the limb of the Sun polar regions, maintaining their identity over distances of several solar radii. Plumes have been first observed in white-light (WL images of the Sun, but, with the advent of the space era, they have been identified also in X-ray and UV wavelengths (XUV and, possibly, even in in situ data. This review traces the history of plumes, from the time they have been first imaged, to the complex means by which nowadays we attempt to reconstruct their 3-D structure. Spectroscopic techniques allowed us also to infer the physical parameters of plumes and estimate their electron and kinetic temperatures and their densities. However, perhaps the most interesting problem we need to solve is the role they cover in the solar wind origin and acceleration: Does the solar wind emanate from plumes or from the ambient coronal hole wherein they are embedded? Do plumes have a role in solar wind acceleration and mass loading? Answers to these questions are still somewhat ambiguous and theoretical modeling does not provide definite answers either. Recent data, with an unprecedented high spatial and temporal resolution, provide new information on the fine structure of plumes, their temporal evolution and relationship with other transient phenomena that may shed further light on these elusive features.

  18. Solar coronal jets

    Science.gov (United States)

    Dobrzyck, D.

    The solar jets were first observed by SOHO instruments (EIT, LASCO, UVCS) during the previous solar minimum. They were small, fast ejections originating from flaring UV bright points within large polar coronal holes. The obtained data provided us with estimates of the jet plasma conditions, dynamics, evolution of the electron temperature and heating rate required to reproduce the observed ionization state. To follow the polar jets through the solar cycle a special SOHO Joint Observing Program (JOP 155) was designed. It involves a number of SOHO instruments (EIT, CDS, UVCS, LASCO) as well as TRACE. The coordinated observations have been carried out since April 2002. The data enabled to identify counterparts of the 1996-1998 solar minimum jets. Their frequency of several events per day appear comparable to the frequency from the previous solar minimum. The jets are believed to be triggered by field line reconnection between emerging magnetic dipole and pre-existing unipolar field. Existing models predict that the hot jet is formed together with another jet of a cool material. The particular goal of the coordinated SOHO and TRACE observations was to look for possible association of the hot and cool plasma ejections. Currently there is observational evidence that supports these models.

  19. Tumores del estroma gastrointestinal: Estudio retrospectivo de 43 casos Gastrointestinal stromal tumors: a retrospective study of 43 cases

    Directory of Open Access Journals (Sweden)

    S. Alberto

    2008-11-01

    Full Text Available Introducción: los tumores del estroma gastrointestinal (GIST son poco frecuentes, con una incidencia de 10 a 20 casos por millón de habitantes y año. Aparecen en todo el tubo digestivo, mesenterio o epiplón adyacente; siendo más frecuentes en el estómago (60-70%; también pueden aparecer en el intestino delgado (20-25%, colon y recto (5% y esófago (Background: gastrointestinal stromal tumors (GISTs are rare (10 to 20/million. They exist in the whole digestive system and its surroundings, and are most common in the stomach (70%, followed by the small intestine (20-25%, colon and rectum (5%, and esophagus (< 5%. Their clinical presentation varies from small, incidentally found nodules to large and aggressive tumors. Nowadays GISTs are classified according to Fletcher's classification. Objective: to review the features of our GIST population. Methods: a retrospective study of GIST patients identified by immunohistochemical criteria, from 1997 to December 2007, and classified according to Fletcher's criteria. Results: 43 patients were included (24 men, 19 women with a mean age of 62.7 years. Gastric GISTs (20 cases, 46.5%, small intestine GISTs (18 cases, 41.9%; in 5 cases metastases of occult tumors were found. Eighteen cases had no symptoms. Tumors were classified according to Fletcher's criteria as high-risk (n = 19, intermediate-risk (n = 7, low-risk (n = 12, and indeterminate-risk (n = 5. Death occurred in 10 patients, and 13 patients had metastatic disease. Conclusions: our results are in accordance with the world literature, in which a majority of cases are men with gastric tumors. The 5-year survival rate was 42%. Fletcher's criteria were easily applicable criteria and could predict tumor behavior.

  20. Cetoacidosis diabética en niños: experiencia hospitalaria. Estudio retrospectivo de 15 años

    OpenAIRE

    Gómez Rivera, Norberto; García Zárate, María Guadalupe; Fonseca Chon, Ignacio; Gómez Figueroa, Cesar Omar; Gómez Jiménez, Isaac Albéniz; Villalobos García, Luis

    2015-01-01

    Introducción: La cetoacidosis diabética (CAD) es una de las complicaciones más graves de la diabetes mellitus (DM). El objetivo de este trabajo fue destacar la importancia clínica y de laboratorio en el tratamiento de pacientes con CAD, atendidos en el Hospital Infantil del Estado de Sonora (HIES) durante un periodo de 15 años. Métodos: Se revisaron en forma retrospectiva 140 pacientes con episodios de CAD para informar el seguimiento clínico, de laboratorio y mortalidad con el Protocolo H...

  1. Exéresis de las lesiones hiperplásicas de la cavidad bucal: estudio retrospectivo de 128 casos

    National Research Council Canada - National Science Library

    Berini Aytés, Leonardo; Delgado Molina, Esther; Tamarit Borrás, Meritxell; Gay Escoda, Cosme

    2005-01-01

    Aims: Based on our accumulated experience, the present study evaluates and discusses the indications, advantages and inconveniences of oral cavity epulis resection using the carbon dioxide laser (CO2) versus the Erbium:YAG laser (Er:YAG...

  2. Evaluación a largo plazo de la enfermedad periimplantaria en pacientes desdentados parciales y total : un estudio retrospectivo

    OpenAIRE

    2013-01-01

    Antecedentes: La rehabilitación oral con implantes dentales osteointegrados se considera una alternativa segura y predecible, con cifras de supervivencia a largo plazo de entre el 85 y el 100% de los implantes colocados. Sin embargo, no está exenta de complicaciones. Una de las complicaciones biológicas que pueden tener lugar una vez colocada la prótesis es la enfermedad periimplantaria, que agrupa dos entidades: la mucositis periimplantaria (inflamación reversible de los tejidos blandos que ...

  3. Resumen del resultado de un estudio retrospectivo de broncoscopias en caninos (Summary of the result of Canine bronchoscopy retrospective study

    Directory of Open Access Journals (Sweden)

    Muñoz, Loreto

    2006-02-01

    Full Text Available La broncoscopia permite la visualización directa de las estructuras y del epitelio respiratorio, además permite la toma de muestras en forma guiada. Se analizaron 30 broncoscopias del Hospital Clínico Veterinario de la Facultad de Ciencias Veterinarias de la Universidad de Chile, entre el 2000 – 2003. Se registraron los datos del paciente, el tiempo que presentaba la patología, los cambios macroscópicos a la broncoscopía, y el análisis citológico y microbiológico con sus antibiogramas, de los lavados bronquioalveolares. Para las broncoscopias se utilizó el ureteroscopio flexible 11276B Storz y a través de él se realizaron los lavados bronquialveolares con suero fisiológico.

  4. Coronal Seismology -- Achievements and Perspectives

    Science.gov (United States)

    Ruderman, Michael

    Coronal seismology is a new and fast developing branch of the solar physics. The main idea of coronal seismology is the same as of any branches of seismology: to determine basic properties of a medium using properties of waves propagating in this medium. The waves and oscillations in the solar corona are routinely observed in the late space missions. In our brief review we concentrate only on one of the most spectacular type of oscillations observed in the solar corona - the transverse oscillations of coronal magnetic loops. These oscillations were first observed by TRACE on 14 July 1998. At present there are a few dozens of similar observations. Shortly after the first observation of the coronal loop transverse oscillations they were interpreted as kink oscillations of magnetic tubes with the ends frozen in the dense photospheric plasma. The frequency of the kink oscillation is proportional to the magnetic field magnitude and inversely proportional to the tube length times the square root of the plasma density. This fact was used to estimate the magnetic field magnitude in the coronal loops. In 2004 the first simultaneous observation of the fundamental mode and first overtone of the coronal loop transverse oscillation was reported. If we model a coronal loop as a homogeneous magnetic tube, then the ratio of the frequencies of the first overtone and the fundamental mode should be equal to 2. However, the ratio of the observed frequencies was smaller than 2. This is related to the density variation along the loop. If we assume that the corona is isothermal and prescribe the loop shape (usually it is assumed that it has the shape of half-circle), then, using the ratio of the two frequencies, we can determine the temperature of the coronal plasma. The first observation of transverse oscillations of the coronal loops showed that they were strongly damped. This phenomenon was confirmed by the subsequent observations. At present, the most reliable candidate for the

  5. Geometry of solar coronal rays

    Science.gov (United States)

    Filippov, B. P.; Martsenyuk, O. V.; Platov, Yu. V.; Den, O. E.

    2016-02-01

    Coronal helmet streamers are the most prominent large-scale elements of the solar corona observed in white light during total solar eclipses. The base of the streamer is an arcade of loops located above a global polarity inversion line. At an altitude of 1-2 solar radii above the limb, the apices of the arches sharpen, forming cusp structures, above which narrow coronal rays are observed. Lyot coronagraphs, especially those on-board spacecrafts flying beyond the Earth's atmosphere, enable us to observe the corona continuously and at large distances. At distances of several solar radii, the streamers take the form of fairly narrow spokes that diverge radially from the Sun. This radial direction displays a continuous expansion of the corona into the surrounding space, and the formation of the solar wind. However, the solar magnetic field and solar rotation complicate the situation. The rotation curves radial streams into spiral ones, similar to water streams flowing from rotating tubes. The influence of the magnetic field is more complex and multifarious. A thorough study of coronal ray geometries shows that rays are frequently not radial and not straight. Coronal streamers frequently display a curvature whose direction in the meridional plane depends on the phase of the solar cycle. It is evident that this curvature is related to the geometry of the global solar magnetic field, which depends on the cycle phase. Equatorward deviations of coronal streamers at solar minima and poleward deviations at solar maxima can be interpreted as the effects of changes in the general topology of the global solar magnetic field. There are sporadic temporal changes in the coronal rays shape caused by remote coronal mass ejections (CMEs) propagating through the corona. This is also a manifestation of the influence of the magnetic field on plasma flows. The motion of a large-scale flux rope associated with a CME away from the Sun creates changes in the structure of surrounding field

  6. Ponderomotive Acceleration in Coronal Loops

    Science.gov (United States)

    Dahlburg, R. B.; Laming, J. M.; Taylor, B. D.; Obenschain, K.

    2016-11-01

    Ponderomotive acceleration has been asserted to be a cause of the first ionization potential (FIP) effect, the well-known enhancement in abundance by a factor of 3-4 over photospheric values of elements in the solar corona with FIP less than about 10 eV. It is shown here by means of numerical simulations that ponderomotive acceleration occurs in solar coronal loops, with the appropriate magnitude and direction, as a “by-product” of coronal heating. The numerical simulations are performed with the HYPERION code, which solves the fully compressible three-dimensional magnetohydrodynamic equations including nonlinear thermal conduction and optically thin radiation. Numerical simulations of coronal loops with an axial magnetic field from 0.005 to 0.02 T and lengths from 25,000 to 75,000 km are presented. In the simulations the footpoints of the axial loop magnetic field are convected by random, large-scale motions. There is a continuous formation and dissipation of field-aligned current sheets, which act to heat the loop. As a consequence of coronal magnetic reconnection, small-scale, high-speed jets form. The familiar vortex quadrupoles form at reconnection sites. Between the magnetic footpoints and the corona the reconnection flow merges with the boundary flow. It is in this region that the ponderomotive acceleration occurs. Mirroring the character of the coronal reconnection, the ponderomotive acceleration is also found to be intermittent.

  7. Coronal Mass Ejections An Introduction

    CERN Document Server

    Howard, Timothy

    2011-01-01

    In times of growing technological sophistication and of our dependence on electronic technology, we are all affected by space weather. In its most extreme form, space weather can disrupt communications, damage and destroy spacecraft and power stations, and increase radiation exposure to astronauts and airline passengers. Major space weather events, called geomagnetic storms, are large disruptions in the Earth’s magnetic field brought about by the arrival of enormous magnetized plasma clouds from the Sun. Coronal mass ejections (CMEs) contain billions of tons of plasma and hurtle through space at speeds of several million miles per hour. Understanding coronal mass ejections and their impact on the Earth is of great interest to both the scientific and technological communities. This book provides an introduction to coronal mass ejections, including a history of their observation and scientific revelations, instruments and theory behind their detection and measurement, and the status quo of theories describing...

  8. Motion magnification in coronal seismology

    CERN Document Server

    Anfinogentov, Sergey

    2016-01-01

    We introduce a new method for the investigation of low-amplitude transverse oscillations of solar plasma non-uniformities, such as coronal loops, individual strands in coronal arcades, jets, prominence fibrils, polar plumes, and other contrast features, observed with imaging instruments. The method is based on the two-dimensional dual tree complex wavelet transform (DT$\\mathbb{C}$WT). It allows us to magnify transverse, in the plane-of-the-sky, quasi-periodic motions of contrast features in image sequences. The tests performed on the artificial data cubes imitating exponentially decaying, multi-periodic and frequency-modulated kink oscillations of coronal loops showed the effectiveness, reliability and robustness of this technique. The algorithm was found to give linear scaling of the magnified amplitudes with the original amplitudes provided they are sufficiently small. Also, the magnification is independent of the oscillation period in a broad range of the periods. The application of this technique to SDO/A...

  9. Observational Analysis of Coronal Fans

    Science.gov (United States)

    Talpeanu, D.-C.; Rachmeler, L; Mierla, Marilena

    2017-01-01

    Coronal fans (see Figure 1) are bright observational structures that extend to large distances above the solar surface and can easily be seen in EUV (174 angstrom) above the limb. They have a very long lifetime and can live up to several Carrington rotations (CR), remaining relatively stationary for many months. Note that they are not off-limb manifestation of similarly-named active region fans. The solar conditions required to create coronal fans are not well understood. The goal of this research was to find as many associations as possible of coronal fans with other solar features and to gain a better understanding of these structures. Therefore, we analyzed many fans and created an overview of their properties. We present the results of this statistical analysis and also a case study on the longest living fan.

  10. Coronal Fourier power spectra: implications for coronal seismology and coronal heating

    CERN Document Server

    Ireland, Jack; Inglis, Andrew R

    2014-01-01

    The dynamics of regions of the solar corona are investigated using Atmospheric Imaging Assembly (AIA) 171\\AA\\ and 193\\AA\\ data. The coronal emission from the quiet Sun, coronal loop footprints, coronal moss, and from above a sunspot is studied. It is shown that the mean Fourier power spectra in these regions can be described by a power law at lower frequencies that tails to flat spectrum at higher frequencies, plus a Gaussian-shaped contribution that varies depending on the region studied. This Fourier spectral shape is in contrast to the commonly-held assumption that coronal time-series are well described by the sum of a long time-scale background trend plus Gaussian-distributed noise, with some specific locations also showing an oscillatory signal. The implications of this discovery to the field of coronal seismology and the automated detections of oscillations are discussed. The power law contribution to the shape of the Fourier power spectrum is interpreted as being due to the summation of a distribution ...

  11. Coronal ``Wave'': Magnetic Footprint of a Coronal Mass Ejection?

    Science.gov (United States)

    Attrill, Gemma D. R.; Harra, Louise K.; van Driel-Gesztelyi, Lidia; Démoulin, Pascal

    2007-02-01

    We investigate the properties of two ``classical'' EUV Imaging Telescope (EIT) coronal waves. The two source regions of the associated coronal mass ejections (CMEs) possess opposite helicities, and the coronal waves display rotations in opposite senses. We observe deep core dimmings near the flare site and also widespread diffuse dimming, accompanying the expansion of the EIT wave. We also report a new property of these EIT waves, namely, that they display dual brightenings: persistent ones at the outermost edge of the core dimming regions and simultaneously diffuse brightenings constituting the leading edge of the coronal wave, surrounding the expanding diffuse dimmings. We show that such behavior is consistent with a diffuse EIT wave being the magnetic footprint of a CME. We propose a new mechanism where driven magnetic reconnections between the skirt of the expanding CME magnetic field and quiet-Sun magnetic loops generate the observed bright diffuse front. The dual brightenings and the widespread diffuse dimming are identified as innate characteristics of this process.

  12. A Solar Coronal Jet Event Triggers A Coronal Mass Ejection

    CERN Document Server

    Liu, Jiajia; Shen, Chenglong; Liu, Kai; Pan, Zonghao; Wang, S

    2015-01-01

    We present the multi-point and multi-wavelength observation and analysis on a solar coronal jet and coronal mass ejection (CME) event in this paper. Employing the GCS model, we obtained the real (three-dimensional) heliocentric distance and direction of the CME and found it propagate in a high speed over 1000 km/s . The jet erupted before and shared the same source region with the CME. The temporal and spacial relation- ship between them guide us the possibility that the jet triggered the CME and became its core. This scenario could promisingly enrich our understanding on the triggering mechanism of coronal mass ejections and their relations with coronal large-scale jets. On the other hand, the magnetic field configuration of the source region observed by the SDO/HMI instrument and the off- limb inverse Y-shaped configuration observed by SDO/AIA 171 A passband, together provide the first detailed observation on the three-dimensional reconnection process of large-scale jets as simulated in Pariat et al. 2009. ...

  13. Hipovitaminosis D en Costa Rica, reporte inicial: Estudio de casos y controles

    OpenAIRE

    2012-01-01

    Objetivo: describir, por primera vez en Costa Rica, las características clínicas de pacientes con hipovitaminosis D. Materiales y métodos: estudio retrospectivo, en donde se detectó, entre los reportes del Laboratorio de Hormonas del Hospital San Juan de Dios, a 17 pacientes con niveles de 25-hidroxivitamina D (25(OH)VD)en rangos subnormales (

  14. Exploring Coronal Structures with SOHO

    Indian Academy of Sciences (India)

    Μ. Karovska; Β. Wood; J. Chen; J. Cook; R. Howard

    2000-09-01

    We applied advanced image enhancement techniques to explore in detail the characteristics of the small-scale structures and/or the low contrast structures in several Coronal Mass Ejections (CMEs) observed by SOHO. We highlight here the results from our studies of the morphology and dynamical evolution of CME structures in the solar corona using two instruments on board SOHO: LASCO and EIT.

  15. Prueba de tolerancia oral a la glucosa modificada en puérperas como diagnóstico retrospectivo de diabetes gestacional

    Directory of Open Access Journals (Sweden)

    Joel Cárdenas

    2004-03-01

    Full Text Available Objetivo: Determinar la relación entre la prueba de tolerancia oral a la glucosa (PTOG en puérperas con macrosomia fetal y plantearla como método de diagnóstico retrospectivo para diabetes gestacional. Diseño de estudio: Estudio clínico, de corte transversal, analítico, casos y controles. Material y Métodos: Estudio de 142 puérperas, 71 con recién nacidos macrosómicos y 71 con recién nacidos con pesos en percentiles de la normalidad. Se realizó una PTOG modificada de dos horas (basal, 1h y 2 h, con 100 g de glucosa, entre las primeras 8 y 48 horas posparto (positivo si [glicemia 2h - basal] + [glicemia 1h - basal] 110 mg/dL. Se utilizó el SPSS 10,0 para crear la base de datos y realizar el análisis estadístico: análisis univariado, bivariado para evaluar la hipótesis, y finalmente un análisis multivariado. Resultados: La PTOG anormal resultó un factor de riesgo para macrosomia fetal, con un odds ratio ajustado de 5,9; IC95% 2,6-13,4. Se encontró asociación entre antecedente de macrosomia fetal, odds ratio 15,7; IC95% 1,9-123,6 y control prenatal odds ratio 5,7; IC95% 1,2-26,8. Conclusión: Existe relación entre la PTOG en puérperas y macrosomia fetal, que puede ser usada como prueba diagnóstica retrospectiva de diabetes gestacional.

  16. Procedimiento para el análisis retrospectivo y prospectivo de sistemas lecheros

    Directory of Open Access Journals (Sweden)

    J.A Herrera

    Full Text Available Con el objetivo de proponer un procedimiento integrador para el análisis retrospectivo y prospectivo de sistemas lecheros, se realizó una investigación documental basada en una revisión bibliográfica narrativa. La información provino de dos tipos de fuente: primaria y secundaria, mientras que la estrategia de búsqueda se basó en combinaciones de palabras clave. El procedimiento, que consistió en realizar 22 operaciones de manera ordenada, se basó en el enfoque de ingeniería de sistema y contempló las cuatro dimensiones generales (productiva, económica, social y ambiental que definen la sostenibilidad de los sistemas agropecuarios. Se utilizó este enfoque por considerar que el análisis de dichos sistemas se debe orientar al examen holístico de lo que en ellos ocurre, así como a proponer soluciones concretas con bases científicas. Los resultados demostraron que la secuencia de operaciones propuesta puede ser considerada como un procedimiento útil para realizar el análisis retrospectivo y prospectivo de sistemas lecheros, con un enfoque sistémico e integrador que permite interrelacionar la caracterización del sistema de producción de leche en pastoreo, el análisis de la eficiencia y el diseño de alternativas tecnológicas para la mejora de este.

  17. Comorbilidad psicopatológica en el alcoholismo: un estudio descriptivo

    OpenAIRE

    Natalia Landa; Javier Fernández-Montalvo; José J. López-Goñi; Iñaki Lorea

    2006-01-01

    En este estudio se lleva a cabo un análisis del perfil de bebida y de la comorbilidad psicopatológica en 50 pacientes alcohólicos que acuden en busca de tratamiento a un programa ambulatorio de Proyecto Hombre de Navarra. Para ello, se lleva a cabo un estudio ex post facto, de carácter retrospectivo y con un grupo cuasi control. Se utilizan los criterios diagnósticos del DSM-IV-TR para la dependencia alcohólica, el Müncher Alkoholismus Test (MALT) para valorar la gravedad del a...

  18. Intrinsic Instability of Coronal Streamers

    CERN Document Server

    Chen, Y; Song, H Q; Shi, Q Q; Feng, S W; Xia, L D; 10.1088/0004-637X/691/2/1936

    2009-01-01

    Plasma blobs are observed to be weak density enhancements as radially stretched structures emerging from the cusps of quiescent coronal streamers. In this paper, it is suggested that the formation of blobs is a consequence of an intrinsic instability of coronal streamers occurring at a very localized region around the cusp. The evolutionary process of the instability, as revealed in our calculations, can be described as follows: (1) through the localized cusp region where the field is too weak to sustain the confinement, plasmas expand and stretch the closed field lines radially outward as a result of the freezing-in effect of plasma-magnetic field coupling; the expansion brings a strong velocity gradient into the slow wind regime providing the free energy necessary for the onset of a subsequent magnetohydrodynamic instability; (2) the instability manifests itself mainly as mixed streaming sausage-kink modes, the former results in pinches of elongated magnetic loops to provoke reconnections at one or many loc...

  19. Motion Magnification in Coronal Seismology

    Science.gov (United States)

    Anfinogentov, Sergey; Nakariakov, Valery M.

    2016-11-01

    We introduce a new method for the investigation of low-amplitude transverse oscillations of solar plasma non-uniformities, such as coronal loops, individual strands in coronal arcades, jets, prominence fibrils, polar plumes, and other contrast features that have been observed with imaging instruments. The method is based on the two-dimensional dual-tree complex wavelet transform (DTℂWT). It allows us to magnify transverse, in the plane-of-the-sky, quasi-periodic motions of contrast features in image sequences. The tests performed on the artificial data cubes that imitated exponentially decaying, multi-periodic and frequency-modulated kink oscillations of coronal loops showed the effectiveness, reliability, and robustness of this technique. The algorithm was found to give linear scaling of the magnified amplitudes with the original amplitudes, provided these are sufficiently small. In addition, the magnification is independent of the oscillation period in a broad range of the periods. The application of this technique to SDO/AIA EUV data cubes of a non-flaring active region allowed for the improved detection of low-amplitude decay-less oscillations in the majority of loops.

  20. Ponderomotive Acceleration in Coronal Loops

    CERN Document Server

    Dahlburg, R B; Taylor, B D; Obenschain, K

    2016-01-01

    Ponderomotive acceleration has been asserted to be a cause of the First Ionization Potential (FIP) effect, the by now well known enhancement in abundance by a factor of 3-4 over photospheric values of elements in the solar corona with FIP less than about 10 eV. It is shown here by means of numerical simulations that ponderomotive acceleration occurs in solar coronal loops, with the appropriate magnitude and direction, as a "byproduct" of coronal heating. The numerical simulations are performed with the HYPERION code, which solves the fully compressible three-dimensional magnetohydrodynamic equations including nonlinear thermal conduction and optically thin radiation. Numerical simulations of a coronal loops with an axial magnetic field from 0.005 Teslas to 0.02 Teslas and lengths from 25000 km to 75000 km are presented. In the simulations the footpoints of the axial loop magnetic field are convected by random, large-scale motions. There is a continuous formation and dissipation of field-aligned current sheets...

  1. Caracterização dos diagnósticos de enfermagem identificados em prontuários de idosos: um estudo retrospectivo

    Directory of Open Access Journals (Sweden)

    Ariana de Souza Rodrigues dos Santos

    2008-01-01

    Full Text Available Se trata de un estudio de carácter exploratorio-descriptivo y retrospectivo, con los siguientes objetivos: identificar, a partir de los datos contenidos en los prontuarios, los diagnósticos de enfermería, y caracterizar esos diagnósticos por medio de un mapeamiento según la Taxonomía II de la North American Nursing Diagnosis Association. La recolección de los datos, realizada en los meses de octubre y noviembre de 2006, fue hecha por medio de un cuestionario con ocho preguntas cerradas, en los 196 prontuarios existentes en el Programa Interdisciplinario de Geriatría y Gerontología de la Universidad Federal Fluminense, en Niteroi, RJ - Brasil. Los datos fueron reunidos y organizados para análisis estadístico descriptivo simple. Como principales diagnósticos de enfermería se obtuvieron los siguientes: riesgo de integridad de la piel, memoria y dentición perjudicadas. Se concluyó que el inventario realizado se reveló conforme la taxonomía diagnóstica, ayudó en la construcción de un instrumento patrón y validó la necesidad de esa tecnología como un sistema estándar de lenguaje.

  2. A SOLAR CORONAL JET EVENT TRIGGERS A CORONAL MASS EJECTION

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jiajia; Wang, Yuming; Shen, Chenglong; Liu, Kai; Pan, Zonghao; Wang, S. [CAS Key Laboratory of Geospace Environment, Earh and Space Science School, University of Science and Technology of China, No. 96, JinZhai Road, Hefei, Anhui 230026 (China)

    2015-11-10

    In this paper, we present multi-point, multi-wavelength observations and analysis of a solar coronal jet and coronal mass ejection (CME) event. Employing the GCS model, we obtained the real (three-dimensional) heliocentric distance and direction of the CME and found it to propagate at a high speed of over 1000 km s{sup −1}. The jet erupted before the CME and shared the same source region. The temporal and spacial relationship between these two events lead us to the possibility that the jet triggered the CME and became its core. This scenario hold the promise of enriching our understanding of the triggering mechanism of CMEs and their relations to coronal large-scale jets. On the other hand, the magnetic field configuration of the source region observed by the Solar Dynamics Observatory (SDO)/HMI instrument along with the off-limb inverse Y-shaped configuration observed by SDO/AIA in the 171 Å passband provide the first detailed observation of the three-dimensional reconnection process of a large-scale jet as simulated in Pariat et al. The eruption process of the jet highlights the importance of filament-like material during the eruption of not only small-scale X-ray jets, but likely also of large-scale EUV jets. Based on our observations and analysis, we propose the most probable mechanism for the whole event, with a blob structure overlaying the three-dimensional structure of the jet, to describe the interaction between the jet and the CME.

  3. From Forbidden Coronal Lines to Meaningful Coronal Magnetic Fields

    CERN Document Server

    Judge, Philip G; Landi, Enrico

    2013-01-01

    We review methods to measure magnetic fields within the corona using the polarized light in magnetic-dipole (M1) lines. We are particularly interested in both the global magnetic-field evolution over a solar cycle, and the local storage of magnetic free energy within coronal plasmas. We address commonly held skepticisms concerning angular ambiguities and line-of-sight confusion. We argue that ambiguities are in principle no worse than more familiar remotely sensed photospheric vector-fields, and that the diagnosis of M1 line data would benefit from simultaneous observations of EUV lines. Based on calculations and data from eclipses, we discuss the most promising lines and different approaches that might be used. We point to the S-like [Fe {\\sc XI}] line (J=2 to J=1) at 789.2nm as a prime target line (for ATST for example) to augment the hotter 1074.7 and 1079.8 nm Si-like lines of [Fe {\\sc XIII}] currently observed by the Coronal Multi-channel Polarimeter (CoMP). Significant breakthroughs will be made possibl...

  4. Magnetic shuffling of coronal downdrafts

    Science.gov (United States)

    Petralia, A.; Reale, F.; Orlando, S.

    2017-02-01

    Context. Channelled fragmented downflows are ubiquitous in magnetized atmospheres, and have recently been addressed based on an observation after a solar eruption. Aims: We study the possible back-effect of the magnetic field on the propagation of confined flows. Methods: We compared two 3D magnetohydrodynamic simulations of dense supersonic plasma blobs that fall down along a coronal magnetic flux tube. In one, the blobs move strictly along the field lines; in the other, the initial velocity of the blobs is not perfectly aligned with the magnetic field and the field is weaker. Results: The aligned blobs remain compact while flowing along the tube, with the generated shocks. The misaligned blobs are disrupted and merge through the chaotic shuffling of the field lines. They are structured into thinner filaments. Alfvén wave fronts are generated together with shocks ahead of the dense moving front. Conclusions: Downflowing plasma fragments can be chaotically and efficiently mixed if their motion is misaligned with field lines, with broad implications for disk accretion in protostars, coronal eruptions, and rain, for example. Movies associated to Figs. 2 and 3 are available at http://www.aanda.org

  5. Pre-flare coronal dimmings

    CERN Document Server

    Zhang, Q M; Ji, H S

    2016-01-01

    In this paper, we focus on the pre-flare coronal dimmings. We report our multiwavelength observations of the GOES X1.6 solar flare and the accompanying halo CME produced by the eruption of a sigmoidal magnetic flux rope (MFR) in NOAA active region (AR) 12158 on 2014 September 10. The eruption was observed by the Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamic Observatory (SDO). The photospheric line-of-sight magnetograms were observed by the Helioseismic and Magnetic Imager (HMI) aboard SDO. The soft X-ray (SXR) fluxes were recorded by the GOES spacecraft. The halo CME was observed by the white light coronagraphs of the Large Angle Spectroscopic Coronagraph (LASCO) aboard SOHO.} {About 96 minutes before the onset of flare/CME, narrow pre-flare coronal dimmings appeared at the two ends of the twisted MFR. They extended very slowly with their intensities decreasing with time, while their apparent widths (8$-$9 Mm) nearly kept constant. During the impulsive and decay phases of flare, typical fanlike ...

  6. Professionalism in practice: the Coroner's Court.

    Science.gov (United States)

    Griffith, Richard

    2017-01-02

    A coroner recently declared a district nursing service as unfit for purpose following the death of a patient and held the care given by district nurses was unprofessional and contributed to the patient's decline and death. In this article Richard Griffith considers the coroners concerns in relation to the professional standards imposed on district nurses.

  7. Deep coronal hole associated with quiescent filament

    Science.gov (United States)

    Kesumaningrum, Rasdewita; Herdiwidjaya, Dhani

    2014-03-01

    We present a study of the morphology of quiescent filament observed by H-alpha Solar Telescope at Bosscha Observatory in association with coronal hole observed by Atmospheric Imaging Assembly (AIA) instrument in 193 Å from Solar Dynamics Observatory. H-alpha images were processed by imaging softwares, namely Iris 5.59 and ImageJ, to enhance the signal to noise ratio and to identify the filament features associated with coronal hole. For images observed on October 12, 2011, November 14, 2011 and January 2, 2012, we identified distinct features of coronal holes above the quiescent filaments. This associated coronal holes have filament-like morphology with a thick long thread as it's `spine', defined as Deep Coronal Hole. Because of strong magnetic field of sunspot, these filaments and coronal holes emerged far from active region and lasted for several days. It is interesting as for segmented filament, deep coronal holes above the filaments lasted for a quite long period of time and merged. This association between filament and deep coronal hole can be explained by filament magnetic loop.

  8. Bootstrapping the Coronal Magnetic Field with STEREO

    Science.gov (United States)

    Aschwanden, Markus J.

    2010-05-01

    The 3D coronal magnetic field obtained from stereoscopically triangulated loops has been compared with standard photospheric magnetogram extrapolations. We found a large misalignment of 20-40 deg, depending on the complexity of an AR (Sandman et al. 2009; DeRosa et al. 2009). These studies prove that the magnetic field in the photosphere is not force-free and fundamentally cannot reproduce the coronal magnetic field. Bootstrapping with coronal loop 3D geometries are required to improve modeling of the coronal field. Such coronal field bootstrapping methods are currently developed using stereoscopically triangulated loops from STEREO/EUVI and preliminary results show already a significantly reduced misalignment of 10-20 deg.

  9. Blind Stereoscopy of the Coronal Magnetic Field

    CERN Document Server

    Aschwanden, Markus J; Malanushenko, Anna

    2015-01-01

    We test the feasibility of 3D coronal-loop tracing in stereoscopic EUV image pairs, with the ultimate goal of enabling efficient 3D reconstruction of the coronal magnetic field that drives flares and coronal mass ejections (CMEs). We developed an automated code designed to perform triangulation of coronal loops in pairs (or triplets) of EUV images recorded from different perspectives. The automated (or blind) stereoscopy code includes three major tasks: (i) automated pattern recognition of coronal loops in EUV images, (ii) automated pairing of corresponding loop patterns from two different aspect angles, and (iii) stereoscopic triangulation of 3D loop coordinates. We perform tests with simulated stereoscopic EUV images and quantify the accuracy of all three procedures. In addition we test the performance of the blind stereoscopy code as a function of the spacecraft-separation angle and as a function of the spatial resolution. We also test the sensitivity to magnetic non-potentiality. The automated code develo...

  10. The Inconvenient Truth About Coronal Dimmings

    CERN Document Server

    McIntosh, Scott W

    2008-01-01

    We investigate the occurrence of a coronal dimming using a combination of high resolution spectro-polarimetric, spectral and broadband images which span from the deep photosphere into the corona. These observations reinforce the belief that coronal dimmings, or transient coronal holes as they are also known, are indeed the locations of open magnetic flux in the corona resulting from the launch of a CME. We will see that, as open magnetic regions, they must act just as coronal holes and be sources of the fast solar wind, but only temporarily. An inescapable question therefore arises - what impact does this source of fast wind have on the propagation and in-flight characteristics of the CME that initiates the coronal dimming in the first place?

  11. EIT waves and coronal magnetic field diagnostics

    Institute of Scientific and Technical Information of China (English)

    CHEN PengFei

    2009-01-01

    Magnetic field in the solar lower atmosphere can be measured by the use of the Zeeman and Hanle effects. By contrast, the coronal magnetic field well above the solar surface, which directly controls various eruptive phenomena, can not be precisely measured with the traditional techniques. Several attempts are being made to probe the coronal magnetic field, such as force-free extrapolation based on the photospheric magnetograms, gyroresonance radio emissions, and coronal seismology based on MHD waves in the corona. Compared to the waves trapped in the localized coronal loops, EIT waves are the only global-scale wave phenomenon, and thus are the ideal tool for the coronal global seismology. In this paper, we review the observations and modelings of EIT waves, and illustrate how they can be applied to probe the global magnetic field in the corona.

  12. Network Coronal Bright Points: Coronal Heating Concentrations Found in the Solar Magnetic Network

    Science.gov (United States)

    Falconer, D. A.; Moore, R. L.; Porter, J. G.; Hathaway, D. H.

    1998-01-01

    We examine the magnetic origins of coronal heating in quiet regions by combining SOHO/EIT Fe xii coronal images and Kitt Peak magnetograms. Spatial filtering of the coronal images shows a network of enhanced structures on the scale of the magnetic network in quiet regions. Superposition of the filtered coronal images on maps of the magnetic network extracted from the magnetograms shows that the coronal network does indeed trace and stem from the magnetic network. Network coronal bright points, the brightest features in the network lanes, are found to have a highly significant coincidence with polarity dividing lines (neutral lines) in the network and are often at the feet of enhanced coronal structures that stem from the network and reach out over the cell interiors. These results indicate that, similar to the close linkage of neutral-line core fields with coronal heating in active regions (shown in previous work), low-lying core fields encasing neutral lines in the magnetic network often drive noticeable coronal heating both within themselves (the network coronal bright points) and on more extended field lines rooted around them. This behavior favors the possibility that active core fields in the network are the main drivers of the heating of the bulk of the quiet corona, on scales much larger than the network lanes and cells.

  13. Recent advances in coronal heating

    CERN Document Server

    De Moortel, Ineke

    2015-01-01

    The solar corona, the tenuous outer atmosphere of the Sun, is orders of magnitude hotter than the solar surface. This 'coronal heating problem' requires the identification of a heat source to balance losses due to thermal conduction, radiation and (in some locations) convection. The review papers in this Theo Murphy meeting issue present an overview of recent observational findings, large- and small-scale numerical modelling of physical processes occurring in the solar atmosphere and other aspects which may affect our understanding of the proposed heating mechanisms. At the same time, they also set out the directions and challenges which must be tackled by future research. In this brief introduction, we summarize some of the issues and themes which reoccur throughout this issue.

  14. Coronal Mass Ejections travel time

    Science.gov (United States)

    Braga, Carlos Roberto; Souza de Mendonça, Rafael Rodrigues; Dal Lago, Alisson; Echer, Ezequiel

    2017-10-01

    Coronal mass ejections (CMEs) are the main source of intense geomagnetic storms when they are earthward directed. Studying their travel time is a key-point to understand when the disturbance will be observed at Earth. In this work, we study the CME that originated the interplanetary disturbance observed on 2013/10/02. According to the observations, the CME that caused the interplanetary disturbance was ejected on 2013/09/29. We obtained the CME speed and estimate of the time of arrival at the Lagrangian Point L1 using the concept of expansion speed. We found that observed and estimated times of arrival of the shock differ between 2 and 23 hours depending on method used to estimate the radial speed.

  15. FORWARD: A toolset for multiwavelength coronal magnetometry

    Directory of Open Access Journals (Sweden)

    Sarah eGibson

    2016-03-01

    Full Text Available Determining the 3D coronal magnetic field is a critical, but extremely difficult problem to solve. Since different types of multiwavelength coronal data probe different aspects of the coronal magnetic field, ideally these data should be used together to validate and constrain specifications of that field. Such a task requires the ability to create observable quantities at a range of wavelengths from a distribution of magnetic field and associated plasma -- i.e., to perform forward calculations. In this paper we describe the capabilities of the FORWARD SolarSoft IDL package, a uniquely comprehensive toolset for coronal magnetometry. FORWARD is a community resource that may be used both to synthesize a broad range of coronal observables, and to access and compare synthetic observables to existing data. It enables forward fitting of specific observations, and helps to build intuition into how the physical properties of coronal magnetic structures translate to observable properties. FORWARD can also be used to generate synthetic test beds from MHD simulations in order to facilitate the development of coronal magnetometric inversion methods, and to prepare for the analysis of future large solar telescope data.

  16. FORWARD: A toolset for multiwavelength coronal magnetometry

    Science.gov (United States)

    Gibson, Sarah; Kucera, Therese; White, Stephen; Dove, James; Fan, Yuhong; Forland, Blake; Rachmeler, Laurel; Downs, Cooper; Reeves, Katharine

    2016-03-01

    Determining the 3D coronal magnetic field is a critical, but extremely difficult problem to solve. Since different types of multiwavelength coronal data probe different aspects of the coronal magnetic field, ideally these data should be used together to validate and constrain specifications of that field. Such a task requires the ability to create observable quantities at a range of wavelengths from a distribution of magnetic field and associated plasma -- i.e., to perform forward calculations. In this paper we describe the capabilities of the FORWARD SolarSoft IDL package, a uniquely comprehensive toolset for coronal magnetometry. FORWARD is a community resource that may be used both to synthesize a broad range of coronal observables, and to access and compare synthetic observables to existing data. It enables forward fitting of specific observations, and helps to build intuition into how the physical properties of coronal magnetic structures translate to observable properties. FORWARD can also be used to generate synthetic test beds from MHD simulations in order to facilitate the development of coronal magnetometric inversion methods, and to prepare for the analysis of future large solar telescope data.

  17. Observational features of equatorial coronal hole jets

    Directory of Open Access Journals (Sweden)

    G. Zimbardo

    2010-03-01

    Full Text Available Collimated ejections of plasma called "coronal hole jets" are commonly observed in polar coronal holes. However, such coronal jets are not only a specific features of polar coronal holes but they can also be found in coronal holes appearing at lower heliographic latitudes. In this paper we present some observations of "equatorial coronal hole jets" made up with data provided by the STEREO/SECCHI instruments during a period comprising March 2007 and December 2007. The jet events are selected by requiring at least some visibility in both COR1 and EUVI instruments. We report 15 jet events, and we discuss their main features. For one event, the uplift velocity has been determined as about 200 km s−1, while the deceleration rate appears to be about 0.11 km s−2, less than solar gravity. The average jet visibility time is about 30 min, consistent with jet observed in polar regions. On the basis of the present dataset, we provisionally conclude that there are not substantial physical differences between polar and equatorial coronal hole jets.

  18. Space weather and coronal mass ejections

    CERN Document Server

    Howard, Tim

    2013-01-01

    Space weather has attracted a lot of attention in recent times. Severe space weather can disrupt spacecraft, and on Earth can be the cause of power outages and power station failure. It also presents a radiation hazard for airline passengers and astronauts. These ""magnetic storms"" are most commonly caused by coronal mass ejections, or CMES, which are large eruptions of plasma and magnetic field from the Sun that can reach speeds of several thousand km/s. In this SpringerBrief, Space Weather and Coronal Mass Ejections, author Timothy Howard briefly introduces the coronal mass ejection, its sc

  19. Slipping magnetic reconnection in coronal loops.

    Science.gov (United States)

    Aulanier, Guillaume; Golub, Leon; Deluca, Edward E; Cirtain, Jonathan W; Kano, Ryouhei; Lundquist, Loraine L; Narukage, Noriyuki; Sakao, Taro; Weber, Mark A

    2007-12-07

    Magnetic reconnection of solar coronal loops is the main process that causes solar flares and possibly coronal heating. In the standard model, magnetic field lines break and reconnect instantaneously at places where the field mapping is discontinuous. However, another mode may operate where the magnetic field mapping is continuous but shows steep gradients: The field lines may slip across each other. Soft x-ray observations of fast bidirectional motions of coronal loops, observed by the Hinode spacecraft, support the existence of this slipping magnetic reconnection regime in the Sun's corona. This basic process should be considered when interpreting reconnection, both on the Sun and in laboratory-based plasma experiments.

  20. Relating magnetic reconnection to coronal heating.

    Science.gov (United States)

    Longcope, D W; Tarr, L A

    2015-05-28

    It is clear that the solar corona is being heated and that coronal magnetic fields undergo reconnection all the time. Here we attempt to show that these two facts are related--i.e. coronal reconnection generates heat. This attempt must address the fact that topological change of field lines does not automatically generate heat. We present one case of flux emergence where we have measured the rate of coronal magnetic reconnection and the rate of energy dissipation in the corona. The ratio of these two, [Formula: see text], is a current comparable to the amount of current expected to flow along the boundary separating the emerged flux from the pre-existing flux overlying it. We can generalize this relation to the overall corona in quiet Sun or in active regions. Doing so yields estimates for the contribution to coronal heating from magnetic reconnection. These estimated rates are comparable to the amount required to maintain the corona at its observed temperature.

  1. Microwave Enhancement in Coronal Holes: Statistical Properties

    Indian Academy of Sciences (India)

    Ν. Gopalswamy; Κ. Shibasaki; Μ. Salem

    2000-09-01

    We report on the statistical properties of the microwave enhancement (brightness temperature, area, fine structure, life time and magnetic field strength) in coronal holes observed over a period of several solar rotations.

  2. Observational Consequences of Coronal Heating Mechanisms

    Science.gov (United States)

    Winebarger, Amy R.; Cirtain, Jonathan C.; Golub, Leon; Kobayashi, Ken

    2014-01-01

    The coronal heating problem remains unsolved today, 80 years after its discovery, despite 50 years of suborbital and orbital coronal observatories. Tens of theoretical coronal heating mechanisms have been suggested, but only a few have been able to be ruled out. In this talk, we will explore the reasons for the slow progress and discuss the measurements that will be needed for potential breakthrough, including imaging the solar corona at small spatial scales, measuring the chromospheric magnetic fields, and detecting the presence of high temperature, low emission measure plasma. We will discuss three sounding rocket instruments developed to make these measurements: the High resolution Resolution Coronal Imager (Hi-C), the Chromospheric Lyman-Alpha Spectropolarimeter (CLASP), and the Marshall Grazing Incidence X-ray Spectrometer (MaGIXS).

  3. Multidimensional modeling of coronal rain dynamics

    CERN Document Server

    Fang, X; Keppens, R

    2013-01-01

    We present the first multidimensional, magnetohydrodynamic simulations which capture the initial formation and the long-term sustainment of the enigmatic coronal rain phenomenon. We demonstrate how thermal instability can induce a spectacular display of in-situ forming blob-like condensations which then start their intimate ballet on top of initially linear force-free arcades. Our magnetic arcades host chromospheric, transition region, and coronal plasma. Following coronal rain dynamics for over 80 minutes physical time, we collect enough statistics to quantify blob widths, lengths, velocity distributions, and other characteristics which directly match with modern observational knowledge. Our virtual coronal rain displays the deformation of blobs into $V$-shaped like features, interactions of blobs due to mostly pressure-mediated levitations, and gives the first views on blobs which evaporate in situ, or get siphoned over the apex of the background arcade. Our simulations pave the way for systematic surveys o...

  4. Coronal Magnetism and Forward Solarsoft Idl Package

    Science.gov (United States)

    Gibson, S. E.

    2014-12-01

    The FORWARD suite of Solar Soft IDL codes is a community resource for model-data comparison, with a particular emphasis on analyzing coronal magnetic fields. FORWARD may be used both to synthesize a broad range of coronal observables, and to access and compare to existing data. FORWARD works with numerical model datacubes, interfaces with the web-served Predictive Science Inc MAS simulation datacubes and the Solar Soft IDL Potential Field Source Surface (PFSS) package, and also includes several analytic models (more can be added). It connects to the Virtual Solar Observatory and other web-served observations to download data in a format directly comparable to model predictions. It utilizes the CHIANTI database in modeling UV/EUV lines, and links to the CLE polarimetry synthesis code for forbidden coronal lines. FORWARD enables "forward-fitting" of specific observations, and helps to build intuition into how the physical properties of coronal magnetic structures translate to observable properties.

  5. Observational Properties of Coronal Mass Ejections

    Science.gov (United States)

    2006-01-01

    2003. Peameis, D.V., Magntetic topology of imspumlsive assd gradutal solar energetic particle Xic. H., L. Ofmran, and G. Lawvrence, Cone model for...425, 1097, 2004. Yashiro, S., N. Gopalssvamy, G. Michalek, assd R.A. Hosvard, Properties of narrow coronal Sltatstnigara~jU, A., Y.-i. Mootn, M. Dryer...G.M.,’FTit relatiomtslip hetwseen prominence ermtptions assd coronal mnass ejections.. 107(A8), 1223, doi: 10. 1029/2001 JAOO9 143, 2002. .1. Atssnn.s

  6. MULTIDIMENSIONAL MODELING OF CORONAL RAIN DYNAMICS

    Energy Technology Data Exchange (ETDEWEB)

    Fang, X.; Xia, C.; Keppens, R. [Centre for mathematical Plasma Astrophysics, Department of Mathematics, KU Leuven, B-3001 Leuven (Belgium)

    2013-07-10

    We present the first multidimensional, magnetohydrodynamic simulations that capture the initial formation and long-term sustainment of the enigmatic coronal rain phenomenon. We demonstrate how thermal instability can induce a spectacular display of in situ forming blob-like condensations which then start their intimate ballet on top of initially linear force-free arcades. Our magnetic arcades host a chromospheric, transition region, and coronal plasma. Following coronal rain dynamics for over 80 minutes of physical time, we collect enough statistics to quantify blob widths, lengths, velocity distributions, and other characteristics which directly match modern observational knowledge. Our virtual coronal rain displays the deformation of blobs into V-shaped features, interactions of blobs due to mostly pressure-mediated levitations, and gives the first views of blobs that evaporate in situ or are siphoned over the apex of the background arcade. Our simulations pave the way for systematic surveys of coronal rain showers in true multidimensional settings to connect parameterized heating prescriptions with rain statistics, ultimately allowing us to quantify the coronal heating input.

  7. Observational features of equatorial coronal hole jets

    CERN Document Server

    Nistico', G; Patsourakos, S; Zimbardo, G

    2010-01-01

    Collimated ejections of plasma called "coronal hole jets" are commonly observed in polar coronal holes. However, such coronal jets are not only a specific features of polar coronal holes but they can also be found in coronal holes appearing at lower heliographic latitudes. In this paper we present some observations of "equatorial coronal hole jets" made up with data provided by the STEREO/SECCHI instruments during a period comprising March 2007 and December 2007. The jet events are selected by requiring at least some visibility in both COR1 and EUVI instruments. We report 15 jet events, and we discuss their main features. For one event, the uplift velocity has been determined as about 200 km/s, while the deceleration rate appears to be about 0.11 km/s2, less than solar gravity. The average jet visibility time is about 30 minutes, consistent with jet observed in polar regions. On the basis of the present dataset, we provisionally conclude that there are not substantial physical differences between polar and eq...

  8. Coronal rain in magnetic bipolar weak fields

    Science.gov (United States)

    Xia, C.; Keppens, R.; Fang, X.

    2017-07-01

    Aims: We intend to investigate the underlying physics for the coronal rain phenomenon in a representative bipolar magnetic field, including the formation and the dynamics of coronal rain blobs. Methods: With the MPI-AMRVAC code, we performed three dimensional radiative magnetohydrodynamic (MHD) simulation with strong heating localized on footpoints of magnetic loops after a relaxation to quiet solar atmosphere. Results: Progressive cooling and in-situ condensation starts at the loop top due to radiative thermal instability. The first large-scale condensation on the loop top suffers Rayleigh-Taylor instability and becomes fragmented into smaller blobs. The blobs fall vertically dragging magnetic loops until they reach low-β regions and start to fall along the loops from loop top to loop footpoints. A statistic study of the coronal rain blobs finds that small blobs with masses of less than 1010 g dominate the population. When blobs fall to lower regions along the magnetic loops, they are stretched and develop a non-uniform velocity pattern with an anti-parallel shearing pattern seen to develop along the central axis of the blobs. Synthetic images of simulated coronal rain with Solar Dynamics Observatory Atmospheric Imaging Assembly well resemble real observations presenting dark falling clumps in hot channels and bright rain blobs in a cool channel. We also find density inhomogeneities during a coronal rain "shower", which reflects the observed multi-stranded nature of coronal rain. Movies associated to Figs. 3 and 7 are available at http://www.aanda.org

  9. An Estimate of Solar Wind Density and Velocity Profiles in a Coronal Hole and a Coronal Streamer

    Science.gov (United States)

    Patzold, M.; Tsurutani, B. T.; Bird, M. K.

    1996-01-01

    Using the total electron content data obtained by the Ulysses Solar Corona Experiment (SCE) during the first solar conjunction in summer 1991, two data sets were selected, one associated with a coronal hole and the other associated with coronal streamer crossings. In order to determine coronal streamer density profiles, the electron content of the tracking passes embedded in a coronal streamer were corrected for the contributions from coronal hole densities.

  10. Estudo retrospectivo-sistemático da matriz extracelular de tumores mamários caninos

    Directory of Open Access Journals (Sweden)

    Ana Maria Cristina Rabello Pinto da Fonseca Martins

    2002-01-01

    Full Text Available A finalidade do presente trabalho foi efetuar um estudo retrospectivo, de 1932 à 1999 , afim de se estabelecer a casuística desses tumores nos arquivos do Departamento de Patologia da Faculdade de Medicina Veterinária - USP , bem como a freqüência de desmoplasia, metaplasia cartilaginosa e óssea em 578 desses tumores. Entre os 537 tumores malignos, 13.05% foram adenocarcinomas tubulares simples, 3.91% foram adenocarcinomas tubulares compostos, 7.26% adenocarcinomas papilíferos simples, 4.28% adenocarcinomas papilíferos compostos, 23.27% cistoadenocarcinomas papilíferos simples, 8.37% cistoadenocarcinomas papilíferos compostos, 16.38% adenocarcinomas sólidos simples, 6.70% adenocarcinomas sólidos compostos, 2.04% carcinomas de células espinhosas simples, 1.11% carcinomas de células espinhosas compostos, 2.79% carcinomas mucinosos ,8.19% carcinomas anaplásicos ,0.93% carcinomas escamosos, 1.30% fibrossarcomas,.0.18% condrossarcoma, 0.18% osteossarcoma e entre os 41 tumores benignos ,51.21% foram adenomas, 12.19% cistadenomas pailíferos,7.31% papilomas, 4.87% fibroadenomas e 24.39% foram fibroadenomas. Tanto a desmoplasia como a metaplasia foi um achado freqüente nas neoplasias benignas e malignas, mas foram mais freqüentes entre os adenocarcinomas tubulares compostos: 38% apresentaram desmoplasia, 57% metaplasia cartilaginosa e 28% metaplasia óssea. Entre as neoplasias benignas, adenoma apresentou a maior frequência: 14 % com desmoplasia, 29% com metaplasia cartilaginosa e 24% com metaplasia óssea. Os resultados deste estudo enfatizam a complexidade da inter-relação entre as macromoléculas da matriz extracelular e as células tumorais.

  11. Tratamento cirúrgico da laringomalácia grave: estudo retrospectivo de 11 casos

    Directory of Open Access Journals (Sweden)

    José Antonio Pinto

    2013-10-01

    Full Text Available A laringomalácia é a anomalia congênita da laringe mais frequente, sendo responsável por cerca de 60% a 75% dos casos de estridor congênito. Apesar de seu curso benigno e autolimitado, 10% dos casos necessitam de intervenção. Atualmente, as supraglotoplastias são consideradas o tratamento padrão da laringomalácia grave. OBJETIVO: Descrever a experiência adquirida pelos autores no tratamento cirúrgico dos pacientes com laringomalácia grave. Metodologia: Estudo retrospectivo. MÉTODO: Os prontuários de 11 casos consecutivos de laringomalácia grave, submetidos ao tratamento cirúrgico entre 2003 e 2012, foram analisados quanto à idade, gênero, sintomas, doenças associadas, técnica cirúrgica adotada, tempo de extubação, complicações cirúrgicas, tempo de internação e evolução clínica. RESULTADOS: Dos 11 casos de laringomalácia grave, seis pacientes (54,5% foram operados com o uso do laser de CO2 e em cinco pacientes (45,5% foram realizadas a técnica a frio. Apenas um paciente (9,1% necessitou reabordagem cirúrgica. Não foram observados casos de complicações cirúrgicas. Todos os pacientes apresentaram melhora clínica importante. CONCLUSÃO: A supraglotoplastia mostrou-se um procedimento eficaz e seguro no tratamento da laringomalácia grave.

  12. Characteristics of Coronal Mass Ejections

    Science.gov (United States)

    Talukder, F.; Marchese, A. K.; Tulsee, T.

    2014-12-01

    A coronal mass ejection (CME) is a release of charged particles resulting from solar activity. These charged particles can affect electronics on spacecraft, airplanes, global positioning systems, and communication satellites. The purpose of this research was to study CME data from satellites and correlate these to other properties. Solar wind data collected by STEREO A/B and ACE satellites were analyzed. The data consisted of solar wind flux for various elements (helium through iron), as well as the components of the interplanetary magnetic field. CME events are known to cause a surge in the helium flux, as well as other particles. It is hypothesized that a CME event will cause an increase in the number of lighter elements relative to heavier particles. This is because for a given input of energy, lighter elements are expected to be accelerated to a greater extent than heavier elements. A significant increase was observed in the ratio between helium to oxygen (He/O) prior to intense CMEs. A CME event on November 4, 2003 caused an eleven-fold increase in the He/O ratio, while for another event on April 2, 2001 the He/O ratio increased from 80 to 700. A significant increase in He/O ratio is not observed during weaker CMEs. Furthermore, it was also observed that not all increases in the ratio were accompanied by CMEs. The increase in He/O ratio prior to the CME arrival might be used as a way to predict future events.

  13. Disfunção intestinal em pacientes com lesão cerebral decorrente de acidente vascular cerebral e traumatismo craniencefálico: estudo retrospectivo de uma série de casos

    Directory of Open Access Journals (Sweden)

    Cinthia Carlos Dourado

    2012-01-01

    Full Text Available La disfunción del intestino es una queja común entre los pacientes con daño cerebral debido a una lesión cerebral traumática y accidente cerebrovascular. Este estudio tuvo como objetivo investigar la prevalencia de disfunción del intestino (incontinencia y constipación en pacientes con daño cerebral debido a una lesión cerebral traumática y accidente cerebrovascular admitidos para la rehabilitación. Este es un estudio retrospectivo de una serie de casos a partir del análisis de los datos de 138 expedientes de los pacientes ingresados en el primer semestre de 2009. La prevalencia de disfunción del intestino fue de 41%, siendo 33 (24% incontinencia anal y 37 (27%, constipación. El comprometimiento motor, ayuda a la movilidad, cambios en la memoria y la comunicación se asocian con la presencia de la incontinencia anal. La prevalencia de disfunción del intestino es alta en esta población, identificar en forma temprana los factores relacionados, y promover el reentrenamiento intestinal pueden ayudar a mejorar la calidad de sus vidas.

  14. Estudio comparativo de las maloclusiones de clase III tratadas con y sin cirugía

    OpenAIRE

    Martínez Asúnsolo, Pascual

    2014-01-01

    El objetivo de la presente tesis fue determinar si existen diferencias en la inclinación de los incisivos superiores e inferiores en pacientes de clase III tratados con cirugía o únicamente con “camuflaje ortodóncico”, así como su repercusión en la relación esquelética final. Para ello se realizó un estudio clínico comparativo y retrospectivo en la unidad docente de Ortodoncia del departamento de Estomatología de la Universidad de Valencia. La muestra consistió en 56 pacientes que cump...

  15. Estudio comparativo de las maloclusiones de clase III tratadas con y sin cirugía

    OpenAIRE

    Martínez Asúnsolo, Pascual

    2014-01-01

    El objetivo de la presente tesis fue determinar si existen diferencias en la inclinación de los incisivos superiores e inferiores en pacientes de clase III tratados con cirugía o únicamente con “camuflaje ortodóncico”, así como su repercusión en la relación esquelética final. Para ello se realizó un estudio clínico comparativo y retrospectivo en la unidad docente de Ortodoncia del departamento de Estomatología de la Universidad de Valencia. La muestra consistió en 56 pacientes que cump...

  16. Fracturas faciales en un centro de referencia de traumatismos nivel i. Estudio descriptivo

    OpenAIRE

    2015-01-01

    Objetivo: Recopilar información del traumatismo maxilofacial, específicamente en pacientes adultos, en el periodo de 3 años en un centro chileno de referencia de traumatismos. Materiales y métodos: Se realizó un estudio descriptivo retrospectivo en todos los casos de fracturas faciales que asistieron al Servicio de Cirugía Maxilofacial del Hospital Clínico Mutual de Seguridad C.Ch.C., Santiago de Chile, en el periodo de 3 años (enero de 2009-diciembre de 2011). Fueron analizadas las variab...

  17. ESPECTRO CLÍNICO DE LA PREECLAMPSIA: ESTUDIO COMPARATIVO DE SUS DIVERSOS GRADOS DE SEVERIDAD

    OpenAIRE

    Parra C,Mauro; San Martín O,Alfredo; Valdés R,Enrique; Hasbún H,Jorge; Quiroz V,Lorena; Schepeler S,Manuel; Pérez B,Sebastián; Rau M,Carlos; Miranda 0,Juan Pablo

    2007-01-01

    Objetivo: Comparar los resultados maternos y perinatales en embarazadas que cursaron con preeclampsia (PE) en sus diversas presentaciones en el período 2001 -2005. Material y Método: Estudio retrospectivo de 7.205 partos asistidos en la maternidad del Hospital Clínico de la Universidad de Chile. 204 mujeres presentaron PE/eclampsia, dividiéndose en 3 grupos: PE modera, severa y síndrome de HELLP. Se analizaron las variables clínicas y de laboratorio de la embarazada y del recién nacido. Se co...

  18. Coronal "wave": Magnetic Footprint Of A Cme?

    Science.gov (United States)

    Attrill, Gemma; Harra, L. K.; van Driel-Gesztelyi, L.; Demoulin, P.; Wuelser, J.

    2007-05-01

    We propose a new mechanism for the generation of "EUV coronal waves". This work is based on new analysis of data from SOHO/EIT, SOHO/MDI & STEREO/EUVI. Although first observed in 1997, the interpretation of coronal waves as flare-induced or CME-driven remains a debated topic. We investigate the properties of two "classical" SOHO/EIT coronal waves in detail. The source regions of the associated CMEs possess opposite helicities & the coronal waves display rotations in opposite senses. We observe deep dimmings near the flare site & also widespread diffuse dimming, accompanying the expansion of the EIT wave. We report a new property of these EIT waves, namely, that they display dual brightenings: persistent ones at the outermost edge of the core dimming regions & simultaneously diffuse brightenings constituting the leading edge of the coronal wave, surrounding the expanding diffuse dimmings. We show that such behaviour is consistent with a diffuse EIT wave being the magnetic footprint of a CME. We propose a new mechanism where driven magnetic reconnections between the skirt of the expanding CME & quiet-Sun magnetic loops generate the observed bright diffuse front. The dual brightenings & widespread diffuse dimming are identified as innate characteristics of this process. In addition we present some of the first analysis of a STEREO/EUVI limb coronal wave. We show how the evolution of the diffuse bright front & dimmings can be understood in terms of the model described above. We show that an apparently stationary part of the bright front can be understood in terms of magnetic interchange reconnections between the expanding CME & the "open" magnetic field of a low-latitude coronal hole. We use both the SOHO/EIT & STEREO/EUVI events to demonstrate that through successive reconnections, this new model provides a natural mechanism via which CMEs can become large-scale in the lower corona.

  19. Ectopic folliculosebaceous units at the coronal sulcus.

    Science.gov (United States)

    Fernandez-Flores, Angel

    2014-12-01

    Tyson glands were described in the 17th century as modified sebaceous glands of the coronal sulcus of the penis. However, this description and other early texts supporting the existence of Tyson glands were not accompanied by illustrations. The existence of such glands has been passing through the literature without adequate graphical demonstration, which has contributed to controversial debates. Herein we present a case of a partial penectomy performed on a 65-year-old man with a squamous cell carcinoma of the penis. In this case we identified sebaceous glands as well as folliculosebaceous units in the coronal sulcus. We also comparatively examined 12 cases of partial penectomy to search for sebaceous glands or folliculosebaceous units in the coronal sulcus or the preputium. We found neither sebaceous glands nor folliculosebaceous units at the coronal sulcus or the mucosal aspect of the prepuce. We conclude that: (1) folliculosebaceous units are possible in the coronal sulcus, as the current case illustrates for the first time in literature and (2) the current case is an oddity, probably induced by the accompanying squamous cell carcinoma, and therefore it may represent an ectopic folliculosebaceous unit rather than an anatomic variation.

  20. Coronal Jet Plasma Properties and Acceleration Mechanisms

    Science.gov (United States)

    Farid, Samaiyah; Reeves, Kathy; Savcheva, Antonia; Soto, Natalia

    2017-08-01

    Coronal jets are transient eruptions of plasma typically characterized by aprominent long spire and a bright base, and sometimes accompanied by a small filament. Jets are thought to be produced by magnetic reconnection when small-scale bipolar magnetic fields emerge into an overlying coronal field or move into a locally unipolar region. Coronal jets are commonly divided into two categories: standard jets and blowout jets, and are found in both quiet and active regions. The plasma properties of jets vary across type and location, therefore understanding the underlying acceleration mechanisms are difficult to pin down. In this work, we examine both blow-out and standard jets using high resolution multi-wavelength data. Although reconnection is commonly accepted as the primary acceleration mechanism, we also consider the contribution chromospheric evaporation to jet formation. We use seven coronal channels from SDO/AIA , Hinode/XRT Be-thin and IRIS slit-jaw data. In addition, we separate the Fe-XVIII line from the SDO/94Å channel. We calculate plasma properties including velocity, Alfven speed, and density as a function of wavelength and Differential Emission Measure (DEM). Finally, we explore the magnetic topology of the jets using Coronal Modeling System (CMS) to construct potential and non-linear force free models based on the flux rope insertion method.

  1. Estudo retrospectivo de 66 casos de urolitíase obstrutiva em ovinos

    Directory of Open Access Journals (Sweden)

    Janaina Azevedo Guimarães

    2012-09-01

    Full Text Available Objetivou-se realizar um estudo retrospectivo dos principais achados epidemiológicos, clínicos, patológicos e laboratoriais de ovinos acometidos por urolitíase obstrutiva, atendidos na Clínica de Bovinos, Campus Garanhuns/ UFRPE. Para isso, foram analisadas 66 fichas clínicas de ovinos, todos machos não castrados, com idade entre dois meses e cinco anos. A maioria dos casos (79,63% ocorreu na época chuvosa. A maioria dos animais (87,88% era criada intensivamente e todos eram alimentados com concentrados. Os sinais clínicos mais importantes foram as manifestações de dor, congestão de mucosas, hipertermia e aumento da tensão abdominal associados a obstrução do trato urinário. Metade dos animais apresentou obstrução total da uretra. Destes, 69,70% morreram, enquanto nos casos de obstrução parcial, 30,30% morreram. Nos exames laboratoriais verificou-se neutrofilia e desvio à esquerda regenerativo, hiperfibrinogenemia e azotemia. Na urinálise constatou-se hematúria em 89,29% dos casos e pH ácido em 46,43%. Na sedimentoscopia predominaram hemácias, leucócitos, células de descamação do epitélio uretral e cristais de urato amorfo. Os achados necroscópicos renais mais frequentes foram pielonefrite (61,54% dos casos e hidronefrose (50%. Nos ureteres foram visualizados ureterite e hidroureter. Na bexiga foi mais evidente a cistite hemorrágica difusa (50% e a presença de urólitos (57,69%. Na uretra observaram-se urólitos (61,54% e uretrite hemorrágica difusa (57,69%. Quanto à composição dos urólitos predominaram os compostos por oxalato de cálcio hidratado. Conclui-se que no Agreste de Pernambuco a urolitiase é uma doença importante de ovinos, com alta letalidade, estando associada à alimentação rica em concentrados e sal mineral.

  2. Coronal heating in multiple magnetic threads

    CERN Document Server

    Tam, K V; Browning, P K; Cargill, P J

    2015-01-01

    Context. Heating the solar corona to several million degrees requires the conversion of magnetic energy into thermal energy. In this paper, we investigate whether an unstable magnetic thread within a coronal loop can destabilise a neighbouring magnetic thread. Aims. By running a series of simulations, we aim to understand under what conditions the destabilisation of a single magnetic thread can also trigger a release of energy in a nearby thread. Methods. The 3D magnetohydrodynamics code, Lare3d, is used to simulate the temporal evolution of coronal magnetic fields during a kink instability and the subsequent relaxation process. We assume that a coronal magnetic loop consists of non-potential magnetic threads that are initially in an equilibrium state. Results. The non-linear kink instability in one magnetic thread forms a helical current sheet and initiates magnetic reconnection. The current sheet fragments, and magnetic energy is released throughout that thread. We find that, under certain conditions, this ...

  3. The Fundamental Structure of Coronal Loops

    Science.gov (United States)

    Winebarger, Amy; Warren, Harry; Cirtain, Jonathan; Kobayashi, Ken; Korreck, Kelly; Golub, Leon; Kuzin, Sergey; Walsh, Robert; DePontieu, Bart; Title, Alan; Weber, Mark

    2012-01-01

    During the past ten years, solar physicists have attempted to infer the coronal heating mechanism by comparing observations of coronal loops with hydrodynamic model predictions. These comparisons often used the addition of sub ]resolution strands to explain the observed loop properties. On July 11, 2012, the High Resolution Coronal Imager (Hi ]C) was launched on a sounding rocket. This instrument obtained images of the solar corona was 0.2 ]0.3'' resolution in a narrowband EUV filter centered around 193 Angstroms. In this talk, we will compare these high resolution images to simultaneous density measurements obtained with the Extreme Ultraviolet Imaging Spectrograph (EIS) on Hinode to determine whether the structures observed with Hi ]C are resolved.

  4. A unified theory of coronal heating

    Science.gov (United States)

    Ionson, J. A.

    1985-01-01

    Solar coronal heating mechanisms are analyzed within the framework of a unified theory of heating processes. The theory is based on the standing wave equation of Ionson (1982) for the global current driven by emfs from the convection Beta less than 1. The equation has the same form as a driven LRC equation in which the equivalent inductance is scaled with the coronal loop length. The theory is used to classify various heating mechanisms inside the coronal loops. It is shown that the total global current can be obtained from an integration of the local currents, the degree of coherency between local currents being the dominant factor governing the global current amplitude. Active region loops appear to be heated by electrodynamic coupling to p-mode oscillations in the convection Beta less than 1.

  5. A Contemporary View of Coronal Heating

    CERN Document Server

    Parnell, Clare E; 10.1098/rsta.2012.0113

    2012-01-01

    Determining the heating mechanism (or mechanisms) that causes the outer atmosphere of the Sun, and many other stars, to reach temperatures orders of magnitude higher than their surface temperatures has long been a key problem. For decades the problem has been known as the coronal heating problem, but it is now clear that `coronal heating' cannot be treated or explained in isolation and that the heating of the whole solar atmosphere must be studied as a highly coupled system. The magnetic field of the star is known to play a key role, but, despite significant advancements in solar telescopes, computing power and much greater understanding of theoretical mechanisms, the question of which mechanism or mechanisms are the dominant supplier of energy to the chromosphere and corona is still open. Following substantial recent progress, we consider the most likely contenders and discuss the key factors that have made, and still make, determining the actual (coronal) heating mechanism (or mechanisms) so difficult.

  6. Free Magnetic Energy and Coronal Heating

    Science.gov (United States)

    Winebarger, Amy; Moore, Ron; Falconer, David

    2012-01-01

    Previous work has shown that the coronal X-ray luminosity of an active region increases roughly in direct proportion to the total photospheric flux of the active region's magnetic field (Fisher et al. 1998). It is also observed, however, that the coronal luminosity of active regions of nearly the same flux content can differ by an order of magnitude. In this presentation, we analyze 10 active regions with roughly the same total magnetic flux. We first determine several coronal properties, such as X-ray luminosity (calculated using Hinode XRT), peak temperature (calculated using Hinode EIS), and total Fe XVIII emission (calculated using SDO AIA). We present the dependence of these properties on a proxy of the free magnetic energy of the active region

  7. DIRECT OBSERVATION OF SOLAR CORONAL MAGNETIC FIELDS BY VECTOR TOMOGRAPHY OF THE CORONAL EMISSION LINE POLARIZATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Kramar, M. [Physics Department, The Catholic University of America, 620 Michigan Avenue NE, Washington, DC 20064 (United States); Lin, H. [Institute for Astronomy, University of Hawaii at Manoa, 34 Ohia Ku Street, Pukalani, Maui, HI 96768 (United States); Tomczyk, S., E-mail: kramar@cua.edu, E-mail: lin@ifa.hawaii.edu, E-mail: tomczyk@ucar.edu [High Altitude Observatory, 3080 Center Green Drive, Boulder, CO 80301 (United States)

    2016-03-10

    We present the first direct “observation” of the global-scale, 3D coronal magnetic fields of Carrington Rotation (CR) Cycle 2112 using vector tomographic inversion techniques. The vector tomographic inversion uses measurements of the Fe xiii 10747 Å Hanle effect polarization signals by the Coronal Multichannel Polarimeter (CoMP) and 3D coronal density and temperature derived from scalar tomographic inversion of Solar Terrestrial Relations Observatory (STEREO)/Extreme Ultraviolet Imager (EUVI) coronal emission lines (CELs) intensity images as inputs to derive a coronal magnetic field model that best reproduces the observed polarization signals. While independent verifications of the vector tomography results cannot be performed, we compared the tomography inverted coronal magnetic fields with those constructed by magnetohydrodynamic (MHD) simulations based on observed photospheric magnetic fields of CR 2112 and 2113. We found that the MHD model for CR 2112 is qualitatively consistent with the tomography inverted result for most of the reconstruction domain except for several regions. Particularly, for one of the most noticeable regions, we found that the MHD simulation for CR 2113 predicted a model that more closely resembles the vector tomography inverted magnetic fields. In another case, our tomographic reconstruction predicted an open magnetic field at a region where a coronal hole can be seen directly from a STEREO-B/EUVI image. We discuss the utilities and limitations of the tomographic inversion technique, and present ideas for future developments.

  8. Analgesia e Anestesia Obstétricas na Maternidade do Hospital D. Estefânia: Estudo Retrospectivo

    OpenAIRE

    Gaspar, S.; Gonçalves, C; Gonçalves, AL

    2010-01-01

    Resumo: Por intermédio deste estudo, pretendeu-se verificar qual a realidade em termos de analgesia e anestesia obstétricas na Maternidade do Hospital D. Estefânia, ao longo de 4 anos. Para isso, foi realizado um estudo retrospectivo no período entre Janeiro de 2005 e Dezembro de 2008. Foram avaliados a classificação ASA das parturientes, o número total de partos, o número de parturientes submetidas a técnicas locorregionais e suas complicações, número de cesarianas e a necessidade de conv...

  9. Analgesia e Anestesia Obstétricas na Maternidade do Hospital D. Estefânia: Estudo Retrospectivo

    OpenAIRE

    Gaspar,S.; Gonçalves, C; Gonçalves, AL

    2010-01-01

    Resumo: Por intermédio deste estudo, pretendeu-se verificar qual a realidade em termos de analgesia e anestesia obstétricas na Maternidade do Hospital D. Estefânia, ao longo de 4 anos. Para isso, foi realizado um estudo retrospectivo no período entre Janeiro de 2005 e Dezembro de 2008. Foram avaliados a classificação ASA das parturientes, o número total de partos, o número de parturientes submetidas a técnicas locorregionais e suas complicações, número de cesarianas e a necessidade de conv...

  10. Estudo retrospectivo de 3055 animais atendidos no ODONTOVET® (Centro Odontológico Veterinário) durante 44 meses

    OpenAIRE

    Michele Alice Françoise Anita Venturini

    2007-01-01

    Este levantamento retrospectivo teve por objetivos verificar quais animais de companhia foram levados para atendimento odontológico, avaliar quais foram as afecções mais freqüentes na cavidade oral destes animais, avaliar o grau de conscientização dos proprietários e a metodologia de preenchimento dos prontuários. As 3055 fichas cadastradas em um período de 44 meses foram analisadas de forma seqüencial. Os dados coletados foram espécie, raça, sexo, idade, peso, realização de consulta prévia a...

  11. Magnetohydrodynamic Modeling of Coronal Evolution and Disruption

    Science.gov (United States)

    Linker, Jon

    2002-01-01

    Flux cancellation, defined observationally as the mutual disappearance of magnetic fields of opposite polarity at the neutral line separating them, has been found to occur frequently at the site of filaments (called prominences when observed on the limb of the Sun). During the second year of this project, we have studied theoretically the role that flux cancellation may play in prominence formation, prominence eruption, and the initiation of coronal mass ejections. This work has been in published in two papers: "Magnetic Field Topology in Prominences" by Lionello, Mikic, Linker, and Amari and "Flux Cancellation and Coronal Mass Ejections" by Linker, Mikic, Riley, Lionello, Amari, and Odstrcil.

  12. Aneurismas poplíteos: estudo retrospectivo Popliteal Aneurysms: retrospective study

    Directory of Open Access Journals (Sweden)

    Ana Baptista

    2010-12-01

    Full Text Available Introdução: Os autores elaboraram um estudo retrospectivo de todos os casos clínicos admitidos no seu Serviço com o diagnóstico de aneurisma poplíteo ao longo de 5 anos. Material e Métodos: Para atingir esse objectivo, procederam à consulta dos processos hospitalares de todos os doentes admitidos com o diagnóstico de aneurisma poplíteo entre 01 de Janeiro de 2004 e 31 de Dezembro de 2008. Resultados: De um total de 61 doentes, 37 (60,7% apresentavam aneurismas bilaterais. Desses 61 doentes, 58 eram do sexo masculino e 3 do feminino, sendo a média de idades de 66,9 ± 11,6 anos. 36,1% dos doentes apresentavam também aneurismas noutras localizações. Os aneurismas eram, na sua maioria, assintomáticos. Quando sintomáticos, a forma de apresentação mais frequente foi a isquémia aguda por trombose do aneurisma. Dentro da totalidade dos aneurismas poplíteos (n=98, 37 foram operados electivamente, 29 de urgência e 32 não foram operados. As intervenções cirúrgicas de eleição foram a exclusão do aneurisma através de bypass femoro-poplíteo distal com veia safena interna (n=48 ou com prótese (n=16. As taxas de patência primária aos 30 dias foram de 98% com o uso de veia e de 68,8% com prótese, tendo motivado 3 amputações supracondilianas. Conclusões: Os aneurismas poplíteos são mais prevalentes no sexo masculino, frequentemente bilaterais, e existe uma forte relação entre estes e aneurismas noutras localizações/megadistrofia arterial generalizada. O tratamento cirúrgico ideal é o realizado electivamente com material autólogo, sendo as taxas de patência com o recurso a material protésico bastante inferiores.Introduction: The authors performed a 5-year retrospective study of all the case reports admitted in their Department with the diagnosis of popliteal aneurysm. Material and Methods: To achieve that purpose, the clinical files of all the patients admitted with the diagnosis of popliteal aneurysm between

  13. Histerectomias: estudo retrospectivo de 554 casos Hysterectomies: a retrospective study of 554 cases

    Directory of Open Access Journals (Sweden)

    Eddie Fernando Cândido Murta

    2000-10-01

    Full Text Available OBJETIVO: A histerectomia é uma operação muito realizada, entretanto há poucos trabalhos na literatura nacional sobre suas indicações, técnica e complicações. O objetivo deste trabalho é avaliar estes procedimentos realizados na Disciplina de Ginecologia e Obstetrícia da Faculdade de Medicina do Triângulo Mineiro. MÉTODO: Estudo retrospectivo de 470 histerectomias abdominais e 84 vaginais foi conduzido analisando as indicações, tempo de cirurgia e internação, tipo de incisão e morbidez. RESULTADOS: As principais indicações foram o mioma uterino e o prolapso uterino para as histerectomias abdominais e vaginais, respectivamente. As complicações intra-operatórias aconteceram em 3,4% e as pós-operatórias em 2,4% do total de casos. Nenhuma diferença estatística foi encontrada no número de complicações em relação ao tipo de incisão (vertical ou transversal. O tempo de cirurgia e o de hospitalização foram estatisticamente maiores nas incisões verticais. A hemorragia foi a mais freqüente complicação intra-operatória e a infecção da incisão operatória foi a mais freqüente no pós-operatório. CONCLUSÕES: A histerectomia é um procedimento de baixo risco, no entanto, a realização de revisões sobre indicações e complicações, e a pesquisa de melhores técnicas cirúrgicas são necessárias para torná-la cada vez mais segura.OBJECTIVE: Hysterectomy is a frequently performed surgery, but national literature gives limited information regarding indications, technique and complications. The aim of this study is to evaluate our results with this operation performed by the Discipline of Gynecology and Obstetrics of the Faculty of Medicine of "Triângulo Mineiro". METHODS: A retrospective study of 470 abdominal and 84 vaginal hysterectomies was conducted in which the indications, operation time, abdominal approach, hospitalization time, and morbidity were analyzed. RESULTS: Uterine myoma and uterine prolapse

  14. Coronal temperature profiles obtained from kinetic models and from coronal brightness measurements obtained during solar eclipses

    CERN Document Server

    Pierrard, V; Lemaire, J F

    2012-01-01

    Coronal density, temperature and heat flux distributions for the equatorial and polar corona have been deduced by Lemaire [2012] from Saito's model of averaged coronal white light (WL) brightness and polarization observations. They are compared with those determined from a kinetic collisionless/exospheric model of the solar corona. This comparison indicates rather similar distributions at large radial distances (> 7 Rs) in the collisionless region. However, rather important differences are found close to the Sun in the acceleration region of the solar wind. The exospheric heat flux is directed away from the Sun, while that inferred from all WL coronal observations is in the opposite direction, i.e., conducting heat from the inner corona toward the chromosphere. This could indicate that the source of coronal heating rate extends up into the inner corona where it maximizes at r > 1.5 Rs well above the transition region.

  15. Large-scale Globally Propagating Coronal Waves

    Directory of Open Access Journals (Sweden)

    Alexander Warmuth

    2015-09-01

    Full Text Available Large-scale, globally propagating wave-like disturbances have been observed in the solar chromosphere and by inference in the corona since the 1960s. However, detailed analysis of these phenomena has only been conducted since the late 1990s. This was prompted by the availability of high-cadence coronal imaging data from numerous spaced-based instruments, which routinely show spectacular globally propagating bright fronts. Coronal waves, as these perturbations are usually referred to, have now been observed in a wide range of spectral channels, yielding a wealth of information. Many findings have supported the “classical” interpretation of the disturbances: fast-mode MHD waves or shocks that are propagating in the solar corona. However, observations that seemed inconsistent with this picture have stimulated the development of alternative models in which “pseudo waves” are generated by magnetic reconfiguration in the framework of an expanding coronal mass ejection. This has resulted in a vigorous debate on the physical nature of these disturbances. This review focuses on demonstrating how the numerous observational findings of the last one and a half decades can be used to constrain our models of large-scale coronal waves, and how a coherent physical understanding of these disturbances is finally emerging.

  16. Coronal bright points associated with minifilament eruptions

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Junchao; Jiang, Yunchun; Yang, Jiayan; Bi, Yi; Li, Haidong [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China); Yang, Bo; Yang, Dan, E-mail: hjcsolar@ynao.ac.cn [Also at Graduate School of Chinese Academy of Sciences, Beijing, China. (China)

    2014-12-01

    Coronal bright points (CBPs) are small-scale, long-lived coronal brightenings that always correspond to photospheric network magnetic features of opposite polarity. In this paper, we subjectively adopt 30 CBPs in a coronal hole to study their eruptive behavior using data from the Atmospheric Imaging Assembly (AIA) and the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory. About one-quarter to one-third of the CBPs in the coronal hole go through one or more minifilament eruption(s) (MFE(s)) throughout their lifetimes. The MFEs occur in temporal association with the brightness maxima of CBPs and possibly result from the convergence and cancellation of underlying magnetic dipoles. Two examples of CBPs with MFEs are analyzed in detail, where minifilaments appear as dark features of a cool channel that divide the CBPs along the neutral lines of the dipoles beneath. The MFEs show the typical rising movements of filaments and mass ejections with brightenings at CBPs, similar to large-scale filament eruptions. Via differential emission measure analysis, it is found that CBPs are heated dramatically by their MFEs and the ejected plasmas in the MFEs have average temperatures close to the pre-eruption BP plasmas and electron densities typically near 10{sup 9} cm{sup –3}. These new observational results indicate that CBPs are more complex in dynamical evolution and magnetic structure than previously thought.

  17. Observing coronal nanoflares in active region moss

    CERN Document Server

    Testa, Paola; Martinez-Sykora, Juan; DeLuca, Ed; Hansteen, Viggo; Cirtain, Jonathan; Winebarger, Amy; Golub, Leon; Kobayashi, Ken; Korreck, Kelly; Kuzin, Sergey; Walsh, Robert; DeForest, Craig; Title, Alan; Weber, Mark

    2013-01-01

    The High-resolution Coronal Imager (Hi-C) has provided Fe XII 193A images of the upper transition region moss at an unprecedented spatial (~0.3-0.4 arcsec) and temporal (5.5s) resolution. The Hi-C observations show in some moss regions variability on timescales down to ~15s, significantly shorter than the minute scale variability typically found in previous observations of moss, therefore challenging the conclusion of moss being heated in a mostly steady manner. These rapid variability moss regions are located at the footpoints of bright hot coronal loops observed by SDO/AIA in the 94A channel, and by Hinode/XRT. The configuration of these loops is highly dynamic, and suggestive of slipping reconnection. We interpret these events as signatures of heating events associated with reconnection occurring in the overlying hot coronal loops, i.e., coronal nanoflares. We estimate the order of magnitude of the energy in these events to be of at least a few $10^{23}rg, also supporting the nanoflare scenario. These Hi-C...

  18. OBSERVING CORONAL NANOFLARES IN ACTIVE REGION MOSS

    Energy Technology Data Exchange (ETDEWEB)

    Testa, Paola; DeLuca, Ed; Golub, Leon; Korreck, Kelly; Weber, Mark [Smithsonian Astrophysical Observatory, 60 Garden street, MS 58, Cambridge, MA 02138 (United States); De Pontieu, Bart; Martinez-Sykora, Juan; Title, Alan [Lockheed Martin Solar and Astrophysics Lab, Org. A021S, Bldg. 252, 3251 Hanover Street, Palo Alto, CA 94304 (United States); Hansteen, Viggo [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, N-0315 Oslo (Norway); Cirtain, Jonathan; Winebarger, Amy; Kobayashi, Ken [NASA Marshall Space Flight Center, ZP 13, Huntsville, AL 35812 (United States); Kuzin, Sergey [P. N. Lebedev Physical institute of the Russian Academy of Sciences, Leninskii prospekt, 53, 119991 Moscow (Russian Federation); Walsh, Robert [University of Central Lancashire, Lancashire, Preston PR1 2HE (United Kingdom); DeForest, Craig, E-mail: ptesta@cfa.harvard.edu [Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302 (United States)

    2013-06-10

    The High-resolution Coronal Imager (Hi-C) has provided Fe XII 193A images of the upper transition region moss at an unprecedented spatial ({approx}0.''3-0.''4) and temporal (5.5 s) resolution. The Hi-C observations show in some moss regions variability on timescales down to {approx}15 s, significantly shorter than the minute-scale variability typically found in previous observations of moss, therefore challenging the conclusion of moss being heated in a mostly steady manner. These rapid variability moss regions are located at the footpoints of bright hot coronal loops observed by the Solar Dynamics Observatory/Atmospheric Imaging Assembly in the 94 A channel, and by the Hinode/X-Ray Telescope. The configuration of these loops is highly dynamic, and suggestive of slipping reconnection. We interpret these events as signatures of heating events associated with reconnection occurring in the overlying hot coronal loops, i.e., coronal nanoflares. We estimate the order of magnitude of the energy in these events to be of at least a few 10{sup 23} erg, also supporting the nanoflare scenario. These Hi-C observations suggest that future observations at comparable high spatial and temporal resolution, with more extensive temperature coverage, are required to determine the exact characteristics of the heating mechanism(s).

  19. Role of Magnetic Carpet in Coronal Heating

    Indian Academy of Sciences (India)

    S. R. Verma; Diksha Chaudhary

    2008-03-01

    One of the fundamental questions in solar physics is how the solar corona maintains its high temperature of several million Kelvin above photosphere with a temperature of 6000 K. Observations show that solar coronal heating problem is highly complex with many different facts. It is likely that different heating mechanisms are at work in the solar corona. The separate kinds of coronal loops may also be heated by different mechanisms. Using data from instruments onboard the Solar and Heliospheric Observatory (SOHO) and from the more recent Transition Region and Coronal Explorer (TRACE) scientists have identified small regions of mixed polarity, termed magnetic carpet contributing to solar activity on a short time scale. Magnetic loops of all sizes rise into the solar corona, arising from regions of opposite magnetic polarity in the photosphere. Energy released when oppositely directed magnetic fields meet in the corona is one likely cause for coronal heating. There is enough energy coming up from the loops of the “magnetic carpet” to heat the corona to its known temperature.

  20. Magnetic Topology of Coronal Hole Linkages

    Science.gov (United States)

    Titov, V. S.; Mikic, Z.; Linker, J. A.; Lionello, R.; Antiochos, S. K.

    2010-01-01

    In recent work, Antiochos and coworkers argued that the boundary between the open and closed field regions on the Sun can be extremely complex with narrow corridors of open ux connecting seemingly disconnected coronal holes from the main polar holes, and that these corridors may be the sources of the slow solar wind. We examine, in detail, the topology of such magnetic configurations using an analytical source surface model that allows for analysis of the eld with arbitrary resolution. Our analysis reveals three important new results: First, a coronal hole boundary can join stably to the separatrix boundary of a parasitic polarity region. Second, a single parasitic polarity region can produce multiple null points in the corona and, more important, separator lines connecting these points. Such topologies are extremely favorable for magnetic reconnection, because it can now occur over the entire length of the separators rather than being con ned to a small region around the nulls. Finally, the coronal holes are not connected by an open- eld corridor of finite width, but instead are linked by a singular line that coincides with the separatrix footprint of the parasitic polarity. We investigate how the topological features described above evolve in response to motion of the parasitic polarity region. The implications of our results for the sources of the slow solar wind and for coronal and heliospheric observations are discussed.

  1. Estudio descriptivo retrospectivo de pacientes candidatos a trasplante de hígado (TH) de la Fundación Hospitalaria San Vicente de Paúl (FHSVP)

    OpenAIRE

    Correa Gonzalo; Juan Carlos Restrepo; Beatriz Uribe; Germán Useche; Jairo Casas

    2001-01-01

    El trasplante hepático (TH) es el tratamiento de elección para pacientes con enfermedad hepática avanzada (EHA). El objetivo fue
    identificar mediante la aplicación de un flujograma establecido por el
    Grupo los pacientes que necesitan un TH y sus características clínicas y demográficas más importantes.

  2. Radiotherapy treatment results of bladder cancer: study of 458 patients. Resultados del tratamiento radioterapico en cancer de vejiga: estudio retrospectivo de 458 pacientes

    Energy Technology Data Exchange (ETDEWEB)

    Vara Santos, J.; Torre Tomas, A. de la; Romero Fernandez, J.; Regueiro Otero, C.; Clavo Varas, B.; Magallan Sebastian, R.; Valcarcel Sancho, F.; Polo Tolosana, E.; Aragon de la Cruz, G.

    1994-01-01

    Between 1964 to 1990, 458 patients diagnosed of bladder cancer have been treated with radical radiotherapy in our department. The 5-years and 10-years actuarial survival rates were 37% and 27% respectively. The 5-years and 10-years actuarial local control rates, evaluated in 404 patients, were 41% and 38%. In regard to survival, T stage (p=0.013), advanced intravesical extension or multicentrity (p>0.0001), and squamous differentiation (p<0.0001), reached statistical significance as adverse prognostic factors. In 248 patients, with invasive transitional carcinoma, radical radiotherapy alone was used. In this group of patients, T stage (p=0.006) and advanced intravesical extension or multicentrity (p=0.0002) were adverse prognostic factors for survival. Our results suggest that radical radiotherapy must be considered and alternative to surgery in management of bladder cancer. On the basis of prognostic factors evidenced in this series a subgroup of patients with low probability of survival when treated with exclusive radiotherapy are defined. This patients must be included in clinical research protocols. (Author) 44 refs.

  3. Psoriasis y síndrome metabólico: Estudio retrospectivo sobre 22 casos Psoriasis And Metabolic Syndrome: Retrospective Study About 22 Clinical Cases

    Directory of Open Access Journals (Sweden)

    E Carbo Amoroso

    2010-03-01

    Full Text Available La Psoriasis es una enfermedad crónica inmunomediada, que se caracteriza por lesiones eritematoescamosas, asociada en ocasiones con afectación articular. Existe una gran cantidad de evidencia que demuestra, un proceso inflamatorio sistémico subyacente patogénico. Un nuevo patrón de respuesta de linfocitos T se ha propuesto como es la Th17, acompañando a una respuesta Th1 y una posible disfunción de células T reguladoras. En los últimos años se la asociado a otros procesos inflamatorios crónicos como: la enfermedad de Crohn, EPOC, síndrome metabólico, arterioesclerosis y sus complicaciones cardiovasculares. El objetivo de nuestro trabajo fue evaluar la severidad de los pacientes con Psoriasis que concurren al consultorio de Dermatología, en el Hospital Cullen de la ciudad de Santa Fe, Argentina y determinar la prevalencia de aquellos con Síndrome metabólico. Para determinar la extensión / severidad de la enfermedad se utilizó el score de PASI y para el diagnóstico del Síndrome metabólico la definición de ATPIII. El 36% de los participantes se incluyeron dentro de la definición de la enfermedad, al cumplir con tres de los cinco criterios para su diagnóstico. A partir de los datos aportados sugerimos el screening de factores de riesgo cardiovasculares, en pacientes con Psoriasis.Psoriasis is a chronic, immune mediated disease, characterized by erythematous scamous lesions, often associated with articular involvement. A large body of evidence demonstrates an underlying systemic inflammatory process, which is pathogenic. A new pattern of response of Th17 lymphocytes has been proposed as the accompanying Th1 and a possible dysfunction of regulatory Tcells. In recent years, the association with other chronic inflammatory conditions such as Crohn's disease, COPD, metabolic syndrome, atherosclerosis and cardiovascular complications. The aim of our study was to assess the severity of psoriasis patients who fulfilled the office of Dermatology at the Cullen Hospital of Santa Fe - Argentina and to determine the prevalence of those with metabolic syndrome. To determine the extent / severity of disease was used PASI score and the diagnosis of metabolic syndrome using the ATPIII definition. The 36% of participants were included within the definition of the disease for meet three of the five criteria for its diagnosis. From the data, we suggest the screening of cardiovascular risk factors in psoriasis patients.

  4. Estudio descriptivo retrospectivo de pacientes candidatos a trasplante de hígado (TH de la Fundación Hospitalaria San Vicente de Paúl (FHSVP

    Directory of Open Access Journals (Sweden)

    Correa Gonzalo

    2001-04-01

    Full Text Available El trasplante hepático (TH es el tratamiento de elección para pacientes con enfermedad hepática avanzada (EHA. El objetivo fue
    identificar mediante la aplicación de un flujograma establecido por el
    Grupo los pacientes que necesitan un TH y sus características clínicas y demográficas más importantes.

  5. Fracturas de cadera de trazo basicervical con inestabilidad rotacional: estudio retrospectivo de la eficacia de dos sistemas de incremento de la estabilidad mecánica del implante

    OpenAIRE

    Escudero Marcos, Roberto

    2015-01-01

    Se han evaluado los patrones más inestables de fractura extracapsular de cadera y cómo se pueden reducir las tasas de complicaciones mecánicas, en una muestra de 301 pacientes tratados con clavo endomedular de hoja espiral, de forma aislada o asociada a sistemas antirrotación (tornillo canulado adicional o cementación). Las complicaciones mecánicas fueron menores con un tip apex distance < 25mm, posición centro-centro de la espiral y utilización de sistemas antirrotación las fractur...

  6. Acute hepatitis C in Spain: a retrospective study of 131 cases Hepatitis aguda C en España: estudio retrospectivo de 131 casos

    OpenAIRE

    Ramón Pérez-Álvarez; Javier García-Samaniego; Ricard Solà; Rosa Pérez-López; Rafael Bárcena; Ramón Planas; Nuria Cañete; María Luisa Manzano; María Luisa Gutiérrez; Luis Morano; Luis Rodrigo

    2012-01-01

    Background and aims: the management of acute hepatitis C (AHC) is controversial. We have conducted a retrospective study to determine the epidemiological and biochemical aspects, the genotypes, the spontaneous clearance of HCV (SVC), and the treatment responses in patients with AHC. Methods: we have retrospectively collected data from 131 patients with AHC from 18 Spanish hospitals. Results: the mean age was 43 ± 16 years (17-83), 69% were symptomatic. The causes of infection were noso...

  7. Descompresión orbitaria grasa para la enfermedad orbitaria tiroidea: estudio retrospectivo de casos para la selección del óptimo paciente

    OpenAIRE

    Calsina Prat, Marta

    2016-01-01

    La enfermedad orbitaria tiroidea (EOT) produce una inflamación, expansión y cicatrización del tejido blando. Durante la fase aguda de la enfermedad, la grasa orbitaria, los músculos extraoculares y la glándula lagrimal pueden ser infiltrados por linfocitos y glicosaminoglicanos. Tanto los músculos extraoculares y la grasa orbitaria se expanden en niveles variables. La fase aguda de EOT se resuelve después de un período de 6 meses a 2 años, seguido de una fase estable de la EOT. Los signos clí...

  8. Relevancia clínica de la interacción de la warfarina y del acetaminofén: estudio de cohortes retrospectivo

    Directory of Open Access Journals (Sweden)

    Mauricio Ceballos

    2016-09-01

    Conclusión: El uso concomitante de la warfarina y el acetaminofén está asociado a un aumento del INR igual o mayor de 0,5 unidades, lo cual podría generar un mayor efecto anticoagulante y, por tanto, un mayor riesgo potencial de sangrado.

  9. Genesis Solar Wind Interstream, Coronal Hole and Coronal Mass Ejection Samples: Update on Availability and Condition

    Science.gov (United States)

    Allton, J. H.; Gonzalez, C. P.; Allums, K. K.

    2017-01-01

    Recent refinement of analysis of ACE/SWICS data (Advanced Composition Explorer/Solar Wind Ion Composition Spectrometer) and of onboard data for Genesis Discovery Mission of 3 regimes of solar wind at Earth-Sun L1 make it an appropriate time to update the availability and condition of Genesis samples specifically collected in these three regimes and currently curated at Johnson Space Center. ACE/SWICS spacecraft data indicate that solar wind flow types emanating from the interstream regions, from coronal holes and from coronal mass ejections are elementally and isotopically fractionated in different ways from the solar photosphere, and that correction of solar wind values to photosphere values is non-trivial. Returned Genesis solar wind samples captured very different kinds of information about these three regimes than spacecraft data. Samples were collected from 11/30/2001 to 4/1/2004 on the declining phase of solar cycle 23. Meshik, et al is an example of precision attainable. Earlier high precision laboratory analyses of noble gases collected in the interstream, coronal hole and coronal mass ejection regimes speak to degree of fractionation in solar wind formation and models that laboratory data support. The current availability and condition of samples captured on collector plates during interstream slow solar wind, coronal hole high speed solar wind and coronal mass ejections are de-scribed here for potential users of these samples.

  10. Using coronal seismology to estimate the magnetic field strength in a realistic coronal model

    CERN Document Server

    Chen, Feng

    2015-01-01

    Coronal seismology is extensively used to estimate properties of the corona, e.g. the coronal magnetic field strength are derived from oscillations observed in coronal loops. We present a three-dimensional coronal simulation including a realistic energy balance in which we observe oscillations of a loop in synthesised coronal emission. We use these results to test the inversions based on coronal seismology. From the simulation of the corona above an active region we synthesise extreme ultraviolet (EUV) emission from the model corona. From this we derive maps of line intensity and Doppler shift providing synthetic data in the same format as obtained from observations. We fit the (Doppler) oscillation of the loop in the same fashion as done for observations to derive the oscillation period and damping time. The loop oscillation seen in our model is similar to imaging and spectroscopic observations of the Sun. The velocity disturbance of the kink oscillation shows an oscillation period of 52.5s and a damping tim...

  11. Nonlinear Force-free Coronal Magnetic Stereoscopy

    Science.gov (United States)

    Chifu, Iulia; Wiegelmann, Thomas; Inhester, Bernd

    2017-03-01

    Insights into the 3D structure of the solar coronal magnetic field have been obtained in the past by two completely different approaches. The first approach are nonlinear force-free field (NLFFF) extrapolations, which use photospheric vector magnetograms as boundary condition. The second approach uses stereoscopy of coronal magnetic loops observed in EUV coronal images from different vantage points. Both approaches have their strengths and weaknesses. Extrapolation methods are sensitive to noise and inconsistencies in the boundary data, and the accuracy of stereoscopy is affected by the ability of identifying the same structure in different images and by the separation angle between the view directions. As a consequence, for the same observational data, the 3D coronal magnetic fields computed with the two methods do not necessarily coincide. In an earlier work (Paper I) we extended our NLFFF optimization code by including stereoscopic constrains. The method was successfully tested with synthetic data, and within this work, we apply the newly developed code to a combined data set from SDO/HMI, SDO/AIA, and the two STEREO spacecraft. The extended method (called S-NLFFF) contains an additional term that monitors and minimizes the angle between the local magnetic field direction and the orientation of the 3D coronal loops reconstructed by stereoscopy. We find that when we prescribe the shape of the 3D stereoscopically reconstructed loops, the S-NLFFF method leads to a much better agreement between the modeled field and the stereoscopically reconstructed loops. We also find an appreciable decrease by a factor of two in the angle between the current and the magnetic field. This indicates the improved quality of the force-free solution obtained by S-NLFFF.

  12. A Two-Fluid, MHD Coronal Model

    Science.gov (United States)

    Suess, S. T.; Wang, A.-H.; Wu, S. T.; Poletto, G.; McComas, D. J.

    1999-01-01

    We describe first results from a numerical two-fluid MHD model of the global structure of the solar Corona. The model is two-fluid in the sense that it accounts for the collisional energy exchange between protons and electrons. As in our single-fluid model, volumetric heat and Momentum sources are required to produce high speed wind from Corona] holes, low speed wind above streamers, and mass fluxes similar to the empirical solar wind. By specifying different proton and electron heating functions we obtain a high proton temperature in the coronal hole and a relatively low proton temperature above the streamer (in comparison with the electron temperature). This is consistent with inferences from SOHO/UltraViolet Coronagraph Spectrometer instrument (UVCS), and with the Ulysses/Solar Wind Observations Over the Poles of the Sun instrument (SWOOPS) proton and electron temperature measurements which we show from the fast latitude scan. The density in the coronal hole between 2 and 5 solar radii (2 and 5 R(sub S)) is similar to the density reported from SPARTAN 201.-01 measurements by Fisher and Guhathakurta [19941. The proton mass flux scaled to 1 AU is 2.4 x 10(exp 8)/sq cm s, which is consistent with Ulysses observations. Inside the closed field region, the density is sufficiently high so that the simulation gives equal proton and electron temperatures due to the high collision rate. In open field regions (in the coronal hole and above the streamer) the proton and electron temperatures differ by varying amounts. In the streamer the temperature and density are similar to those reported empirically by Li et al. [1998], and the plasma beta is larger than unity everywhere above approx. 1.5 R(sub S), as it is in all other MHD coronal streamer models [e.g., Steinolfson et al., 1982; also G. A. Gary and D. Alexander, Constructing the coronal magnetic field, submitted to Solar Physics, 1998].

  13. Standing sausage modes in curved coronal slabs

    Science.gov (United States)

    Pascoe, D. J.; Nakariakov, V. M.

    2016-09-01

    Context. Magnetohydrodynamic waveguides such as dense coronal loops can support standing modes. The ratios of the periods of oscillations for different longitudinal harmonics depend on the dispersive nature of the waveguide and so may be used as a seismological tool to determine coronal parameters. Aims: We extend models of standing sausage modes in low β coronal loops to include the effects of loop curvature. The behaviour of standing sausage modes in this geometry is used to explain the properties of observed oscillations that cannot be accounted for using straight loop models. Methods: We perform 2D numerical simulations of an oscillating coronal loop, modelled as a dense slab embedded in a potential magnetic field. The loop is field-aligned and so experiences expansion with height in addition to being curved. Standing sausage modes are excited by compressive perturbations of the loop and their properties are studied. Results: The spatial profiles of standing sausage modes are found to be modified by the expanding loop geometry typical for flaring loops and modelled by a potential magnetic field in our simulations. Longitudinal harmonics of order n > 1 have anti-nodes that are shifted towards the loop apex and the amplitude of anti-nodes near the loop apex is smaller than those near the loop footpoints. Conclusions: We find that the observation of standing sausage modes by the Nobeyama Radioheliograph in a flaring coronal loop on 12 January 2000 is consistent with interpretation in terms of the global mode (n = 1) and third harmonic (n = 3). This interpretation accounts for the period ratio and spatial structure of the observed oscillations.

  14. Estudio del horizonte local

    OpenAIRE

    Ros Ferré, Rosa Maria

    2009-01-01

    El estudio del horizonte es fundamental para poder facilitar las primeras observaciones de los alumnos en un centro educativo. Un simple modelo, que debe realizarse para cada centro, nos permite facilitar el estudio y la comprensión de los primeros rudimentos astronómicos. El modelo construido se presenta a su vez como un sencillo modelo de reloj ecuatorial y a partir de él se pueden construir otros modelos (horizontal y vertical).

  15. Los estudios longitudinales en la prevención de las enfermedades cardiovasculares

    Directory of Open Access Journals (Sweden)

    Ignacio Balaguer Vintró

    2004-01-01

    Full Text Available Los estudios longitudinales de cohortes bien definidas han contribuido a la identificación de los factores de riesgo de la cardiopatía coronaria y otras complicaciones clínicas de la aterosclerosis. Después de comentar las conclusiones de los estudios de la aterosclerosis experimental y los factores de riesgo sugeridos por el estudio de una serie de infartos de miocardio en adultos jóvenes en comparación con controles apareados, se expone la metodología, el desarrollo y los resultados de los estudios longitudinales realizados en Estados Unidos desde 1949: Twin Cities, Framingham, Pooling Project, Western Collaborative, Puerto Rico, Evans County, NI-HONSAN, San Francisco, Harvard, Bogalusa y CARDIA. Se presta especial atención a las hipótesis propuestas al inicio del estudio de Framingham y a los obstáculos y cambios para continuar el proyecto después de los primeros veinticuatro años. A continuación se expone el Seven Countries Study, ideado y dirigido por Ancel Keys y primer estudio realizado con metodología centralizada en varios países, y los estudios longitudinales realizados en diversos países de Europa: Whitehall, Manresa, París, British Regional, Northwick Park, Caerphilly, Speedwell, PROCAM. Se analiza el papel de los estudios longitudinales en la metodología de los estudios posteriores: hijos e hijas de los participantes en Framingham, estudios longitudinales basados en cuestionarios, estudios de otros posibles factores de riesgo, prevalencia de factores de riesgo en estudios retrospectivos, ensayos de intervención primaria (MRFT, WHO European Collaborative Trial y el de Goteburgo y la participación de los equipos entrenados en el Proyecto MONICA. Se señalan los temas todavía en debate en relación con la metodología y los resultados de los estudios longitudinales: exámenes periódicos de los participantes en las cohortes de los estudios epidemiológicos, cambios en la definición de nuevos casos de accidentes

  16. Periodic Variations in the Coronal Green Line Intensity and their Connection with the White-light Coronal Structures

    Indian Academy of Sciences (India)

    Milan Minarovjech; Milan Rybansky; Vojtech Rusin

    2000-09-01

    We present an analysis of short time-scale intensity variations in the coronal green line as obtained with high time resolution observations. The observed data can be divided into two groups. The first one shows periodic intensity variations with a period of 5 min. the second one does not show any significant intensity variations. We studied the relation between regions of coronal intensity oscillations and the shape of whitelight coronal structures. We found that the coronal green-line oscillations occur mainly in regions where open white-light coronal structures are located.

  17. Metodología de los escenarios para estudios prospectivos

    Directory of Open Access Journals (Sweden)

    Alexandra V. Cely B.

    2011-02-01

    Full Text Available Existen diferentes formas de aproximarse al futuro, siendo la prospectiva la única que lo aborda como una realidad múltiple e indeterminada, obtenida como resultado de las inf'mitas posibilidades de acción humana, reflejada en los diferentes proyectos (acciones concretas, anhelos y temores de los grupos sociales. Para desarrollar estudios de prospectiva existen diferentes metodologías entre las que se encuentra la de escenarios, cuyo uso se ha venido generalizando durante los últimos diez años gracias a la claridad en la presentación de los resultados y a la articulación de los mismos con la intencionalidad de la acción humana. Esta metodología se desarrolla en tres fases: análisis estructural, análisis del juego de actores y elaboración de escenarios, cuyo propósito es analizar el fenómeno en estudio desde un punto de vista retrospectivo y actual, teniendo en cuenta la influencia de los grupos sociales gestores de su desarrollo para, posteriormente, presentar la realidad futura en forma de escenarios. En este artículo se pretende hacer una descripción clara y detallada de dicha metodología, así como de las diferentes herramientas que utiliza.

  18. The Coronal Global Evolutionary Model (CGEM)

    Science.gov (United States)

    Fisher, George H.; DeRosa, M. L.; Hoeksema, J. T.

    2013-07-01

    The Coronal Global Evolutionary Model, or CGEM, is a collaborative effort from the UC Berkeley Space Sciences Laboratory (SSL), Stanford University, and Lockheed-Martin. In work that led up to the selection of this project, the team demonstrated its capability to use sequences of vector magnetograms and Dopplergrams from the Helioseismic and Magnetic Imager (HMI) instrument aboard the SDO to drive a magnetofrictional (MF) model of the coronal magnetic field in AR 11158, which produced an X2.2 flare. We will implement this MF model in spherical coordinates to enable real-time, long-term modeling of the non-potential coronal magnetic field, both globally and for individual active region (ARs). The model's Earth-facing hemisphere will be driven using electric fields derived from the observed evolution of photospheric line-of-sight magnetic fields and electric currents. Far-side data inputs will be from an existing flux transport code, combined with HMI far-side observations of new active regions, with empirical parametrizations of orientation and flux. Because this model includes large-scale coronal electric currents, it is a substantial improvement over existing real-time global coronal models, which assume potential fields. Data products available from the model will include: 1) the evolving photospheric electric field, Poynting flux, and helicity flux; 2) estimates of coronal free energy and non-potential geometry and topology; 3) initial and time-dependent boundary conditions for MHD modeling of active regions; and 4) time-dependent boundary conditions and flux tube expansion factors for MHD and empirical solar wind models. Unstable configurations found from MF models will be dynamically evolved with local and global MHD codes. Modules used to derive surface electric fields from magnetic evolution will be incorporated into the SDO/HMI data pipeline, and data products will be distributed through the Joint Science Operations Center (JSOC) and directly to space

  19. Reconnection and Spire Drift in Coronal Jets

    Science.gov (United States)

    Moore, Ronald; Sterling, Alphonse; Falconer, David

    2015-04-01

    It is observed that there are two morphologically-different kinds of X-ray/EUV jets in coronal holes: standard jets and blowout jets. In both kinds: (1) in the base of the jet there is closed magnetic field that has one foot in flux of polarity opposite that of the ambient open field of the coronal hole, and (2) in coronal X-ray/EUV images of the jet there is typically a bright nodule at the edge of the base. In the conventional scenario for jets of either kind, the bright nodule is a compact flare arcade, the downward product of interchange reconnection of closed field in the base with impacted ambient open field, and the upper product of this reconnection is the jet-outflow spire. It is also observed that in most jets of either kind the spire drifts sideways away from the bright nodule. We present the observed bright nodule and spire drift in an example standard jet and in two example blowout jets. With cartoons of the magnetic field and its reconnection in jets, we point out: (1) if the bright nodule is a compact flare arcade made by interchange reconnection, then the spire should drift toward the bright nodule, and (2) if the bright nodule is instead a compact flare arcade made, as in a filament-eruption flare, by internal reconnection of the legs of the erupting sheared-field core of a lobe of the closed field in the base, then the spire, made by the interchange reconnection that is driven on the outside of that lobe by the lobe’s internal convulsion, should drift away from the bright nodule. Therefore, from the observation that the spire usually drifts away from the bright nodule, we infer: (1) in X-ray/EUV jets of either kind in coronal holes the interchange reconnection that generates the jet-outflow spire usually does not make the bright nodule; instead, the bright nodule is made by reconnection inside erupting closed field in the base, as in a filament eruption, the eruption being either a confined eruption for a standard jet or a blowout eruption (as

  20. Estudio piloto sobre la prescripción en situaciones excepcionales. Uso de medicamentos de humana en medicina veterinaria

    OpenAIRE

    Lobo, M.; Díaz, M. J.; García, J.; Frejo, M. T.

    2011-01-01

    En este trabajo se ha realizado una revisión de los medicamentos de uso humano prescritos para animales de compañía (perros y gatos) con el fin de comprobar el cumplimiento por parte del veterinario del supuesto de “prescripción excepcional”. Para ello se llevó a cabo un estudio piloto transversal retrospectivo durante un periodo de 2 años de los medicamentos de uso humano prescritos para animales de compañía y su alternativa en medicina veterinaria. Los datos han sido obtenidos a partir de l...

  1. Estudio de la plastia de ligamento cruzado anterior, autóloga vs heteróloga

    OpenAIRE

    Cases Cases, Manuel Javier

    2012-01-01

    Objetivo Evaluar el porcentaje de pacientes intervenidos de plastia de LCA autóloga que vuelven a la actividad deportiva previa. Método Estudio retrospectivo de 512 pacientes intervenidos de rotura aguda de LCA, mediante plastia autóloga bajo las mismas condiciones de quirófano y personal. Se han evaluado variables de tipo clínicas, epidemiológicas, diagnosticas, quirúrgicas, tratamiento, complicaciones y de seguimiento. Resultados Únicamente el 70% de los paciente de rotura LC...

  2. Demografía industrial: un estudio sobre relocalización de firmas en Colombia, 1995-2012

    Directory of Open Access Journals (Sweden)

    Charle Londoño

    2015-01-01

    Full Text Available Este trabajo realiza un estudio retrospectivo sobre la relocalización de firmas en Colombia. Para ello, se evalúa la incidencia de variables financieras, tributarias, territoriales y de accesibilidad en la relocalización de empresas, utilizando un modelo de regresión logística y una muestra de 36.235 compañías en el periodo 1995-2012. Se encuentra que la tributación es un factor neurálgico para las decisiones de localización.

  3. ESTUDIO DESCRIPTIVO DE LA ACTIVIDAD DE LAS COMISIONES DE DEONTOLOGÍA PROVINCIALES HOY EN ESPAÑA

    OpenAIRE

    JULIO GARCÍA-GUERRERO; ERNESTO TARAZONA LÓPEZ; BLANCA MARTÍNEZ CALDUCH; ENRIQUE JESÚS VERA-REMARTÍNEZ; MARÍA ANTONIA JIMÉNEZ DE ALDASORO; VICENTE BOIX RAJADELL; MARIO VENTURA LÓPEZ

    2016-01-01

    Objetivo: Describir las características de los expedientes que dirimen las comisiones de deontología de los colegios de médicos provinciales (CdDP). Material y método: Estudio descriptivo, retrospectivo de la tipología de las reclamaciones llegadas a las CdDP entre 01-06-2013 y 31-05-2014. Selección de los colegios mediante muestreo aleatorio estratificado simple. Se recogieron variables relacionadas con el origen de la queja, capítulo del Código de Deontología (CD) afectado,...

  4. Magnetic Topology of Coronal Hole Linkages

    CERN Document Server

    Titov, V S; Linker, J A; Lionello, R; Antiochos, S K

    2010-01-01

    In recent work, Antiochos and coworkers argued that the boundary between the open and closed field regions on the Sun can be extremely complex with narrow corridors of open flux connecting seemingly disconnected coronal holes from the main polar holes, and that these corridors may be the sources of the slow solar wind. We examine, in detail, the topology of such magnetic configurations using an analytical source surface model that allows for analysis of the field with arbitrary resolution. Our analysis reveals three important new results: First, a coronal hole boundary can join stably to the separatrix boundary of a parasitic polarity region. Second, a single parasitic polarity region can produce multiple null points in the corona and, more important, separator lines connecting these points. It is known that such topologies are extremely favorable for magnetic reconnection, because they allow this process to occur over the entire length of the separators rather than being confined to a small region around the...

  5. Solar Coronal Jets: Observations, Theory, and Modeling

    CERN Document Server

    Raouafi, N E; Pariat, E; Young, P R; Sterling, A C; Savcheva, A; Shimojo, M; Moreno-Insertis, F; DeVore, C R; Archontis, V; Török, T; Mason, H; Curdt, W; Meyer, K; Dalmasse, K; Matsui, Y

    2016-01-01

    Coronal jets represent important manifestations of ubiquitous solar transients, which may be the source of significant mass and energy input to the upper solar atmosphere and the solar wind. While the energy involved in a jet-like event is smaller than that of "nominal" solar flares and coronal mass ejections (CMEs), jets share many common properties with these phenomena, in particular, the explosive magnetically driven dynamics. Studies of jets could, therefore, provide critical insight for understanding the larger, more complex drivers of the solar activity. On the other side of the size-spectrum, the study of jets could also supply important clues on the physics of transients close or at the limit of the current spatial resolution such as spicules. Furthermore, jet phenomena may hint to basic process for heating the corona and accelerating the solar wind; consequently their study gives us the opportunity to attack a broad range of solar-heliospheric problems.

  6. Solar coronal observations at high frequencies

    CERN Document Server

    Katsiyannis, A C; Phillips, K J H; Williams, D R; Keenan, F P

    2001-01-01

    The Solar Eclipse Coronal Imaging System (SECIS) is a simple and extremely fast, high-resolution imaging instrument designed for studies of the solar corona. Light from the corona (during, for example, a total solar eclipse) is reflected off a heliostat and passes via a Schmidt-Cassegrain telescope and beam splitter to two CCD cameras capable of imaging at 60 frames a second. The cameras are attached via SCSI connections to a purpose-built PC that acts as the data acquisition and storage system. Each optical channel has a different filter allowing observations of the same events in both white light and in the green line (Fe XIV at 5303 A). Wavelet analysis of the stabilized images has revealed high frequency oscillations which may make a significant contribution on the coronal heating process. In this presentation we give an outline of the instrument and its future development.

  7. Chemical Fractionation and Abundances in Coronal Plasma

    CERN Document Server

    Drake, J J

    2003-01-01

    Much of modern astrophysics is grounded on the observed chemical compositions of stars and the diffuse plasma that pervades the space between stars, galaxies and clusters of galaxies. X-ray and EUV spectra of the hot plasma in the outer atmospheres of stars have demonstrated that these environments are subject to chemical fractionation in which the abundances of elements can be enhanced and depleted by an order of magnitude or more. These coronal abundance anomalies are discussed and some of the physical mechanisms that might be responsible for producing them are examined. It is argued that coronal abundances can provide important new diagnostics on physical processes at work in solar and stellar coronae. It seems likely that other hot astrophysical plasmas will be subject to similar effects.

  8. Microflares as Possible Sources for Coronal Heating

    Indian Academy of Sciences (India)

    Meera Gupta; Rajmal Jain; Jayshree Trivedi; A. P. Mishra

    2008-03-01

    We present a preliminary study of 27 microflares observed by Solar X-ray Spectrometer (SOXS) mission during July 2003 to August 2006. We found that all 27 microflares show the Fe-line feature peaking around 6.7 keV, which is an indicator of the presence of coronal plasma temperature ≥ 9 MK. On the other hand, the spectra of microflares showhybrid model of thermal and non-thermal emission, which further supports them as possible sources of coronal heating. Our results based on the analysis show that the energy relapsed by the microflares is good enough for heating of the active corona. We discuss our results in the light of the hybrid model of microflares production.

  9. Damped transverse oscillations of interacting coronal loops

    CERN Document Server

    Soler, Roberto

    2015-01-01

    Damped transverse oscillations of magnetic loops are routinely observed in the solar corona. This phenomenon is interpreted as standing kink magnetohydrodynamic waves, which are damped by resonant absorption owing to plasma inhomogeneity across the magnetic field. The periods and damping times of these oscillations can be used to probe the physical conditions of the coronal medium. Some observations suggest that interaction between neighboring oscillating loops in an active region may be important and can modify the properties of the oscillations compared to those of an isolated loop. Here we theoretically investigate resonantly damped transverse oscillations of interacting non-uniform coronal loops. We provide a semi-analytic method, based on the T-matrix theory of scattering, to compute the frequencies and damping rates of collective oscillations of an arbitrary configuration of parallel cylindrical loops. The effect of resonant damping is included in the T-matrix scheme in the thin boundary approximation. ...

  10. Selamento coronário em Endodontia

    OpenAIRE

    Oliveira, Rui Pedro Barra de Sá

    2016-01-01

    Introdução: A Endodontia é a especialidade da Medicina Dentária responsável pelo estudo e tratamento da câmara pulpar, de todo o sistema de canais radiculares e dos tecidos periapicais, bem como das doenças que os afetam. O selamento da porção coronária dos dentes alvo de tratamento endodôntico apresenta-se como um critério determinante no sucesso ou insucesso do tratamento. São vários os fatores que podem proporcionar um correto selamento coronário evitando assim a microinfiltração de ...

  11. Coronal Mass Ejections of Solar Cycle 23

    Indian Academy of Sciences (India)

    Nat Gopalswamy

    2006-06-01

    I summarize the statistical, physical, and morphological properties of coronal mass ejections (CMEs) of solar cycle 23, as observed by the Solar and Heliospheric Observatory (SOHO) mission. The SOHO data is by far the most extensive data, which made it possible to fully establish the properties of CMEs as a phenomenon of utmost importance to Sun–Earth connection as well as to the heliosphere. I also discuss various subsets of CMEs that are of primary importance for their impact on Earth.

  12. Interchange Reconnection and Coronal Hole Dynamics

    Science.gov (United States)

    2010-05-01

    calculate the time-dependent dynamics of coronal hole boundaries rigorously and test our conjectures. We describe below our numerical simulations of...radiation and thermal conduction are needed in order to test such a model. It is tempting to conjecture that this process of releasing the closed-field... HTP , TR&T, and SR&T Programs, and has benefited greatly from the authors’ participation in the NASA TR&T focused science team on the solar

  13. Coronal Plumes in the Fast Solar Wind

    Science.gov (United States)

    Velli, Marco; Lionello, Roberto; Linker, Jon A.; Mikic, Zoran

    2011-01-01

    The expansion of a coronal hole filled with a discrete number of higher density coronal plumes is simulated using a time-dependent two-dimensional code. A solar wind model including an exponential coronal heating function and a flux of Alfven waves propagating both inside and outside the structures is taken as a basic state. Different plasma plume profiles are obtained by using different scale heights for the heating rates. Remote sensing and solar wind in situ observations are used to constrain the parameter range of the study. Time dependence due to plume ignition and disappearance is also discussed. Velocity differences of the order of approximately 50 km/s, such as those found in microstreams in the high-speed solar wind, may be easily explained by slightly different heat deposition profiles in different plumes. Statistical pressure balance in the fast wind data may be masked by the large variety of body and surface waves which the higher density filaments may carry, so the absence of pressure balance in the microstreams should not rule out their interpretation as the extension of coronal plumes into interplanetary space. Mixing of plume-interplume material via the Kelvin-Helmholtz instability seems to be possible within the parameter ranges of the models defined here, only at large di stances from the Sun, beyond 0.2-0.3 AU. Plasma and composition measurements in the inner heliosphere, such as those which will become available with Solar Orbiter and Solar Probe Plus, should therefore definitely be able to identify plume remnants in the solar wind.

  14. Topics on shock waves and coronal seismology

    Energy Technology Data Exchange (ETDEWEB)

    Costa, A, E-mail: acosta@mail.oac.uncor.edu [Instituto de AstronomIa Teorica y Experimental, CONICET-Cordoba, Laprida 922, 5000 Cordoba (Argentina); Facultad de Ciencias Exactas, Fisica y Naturales, Universidad Nacional de Cordoba, Av. Velez Sarsfield 1611, 5000 Cordoba (Argentina)

    2011-07-15

    The usual strong and sudden energy release sources that necessarily lead to mode excitation suggest the importance of shocks and nonlinear waves in the corona. We discuss the importance of nonlinear waves as an alternative capable of accurately matching the observational cases of coronal seismology usually interpreted as linear waves. We present two case studies where we explore the goodness of the shock wave interpretation in magnetic structures of the low corona.

  15. Earth-Affecting Coronal Mass Ejections Without Obvious Low Coronal Signatures

    Science.gov (United States)

    Nitta, Nariaki V.; Mulligan, Tamitha

    2017-09-01

    We present a study of the origin of coronal mass ejections (CMEs) that were not accompanied by obvious low coronal signatures (LCSs) and yet were responsible for appreciable disturbances at 1 AU. These CMEs characteristically start slowly. In several examples, extreme ultraviolet (EUV) images taken by the Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory reveal coronal dimming and a post-eruption arcade when we make difference images with long enough temporal separations, which are commensurate with the slow initial development of the CME. Data from the EUV imager and COR coronagraphs of the Sun Earth Connection Coronal and Heliospheric Investigation onboard the Solar Terrestrial Relations Observatory, which provide limb views of Earth-bound CMEs, greatly help us limit the time interval in which the CME forms and undergoes initial acceleration. For other CMEs, we find similar dimming, although only with lower confidence as to its link to the CME. It is noted that even these unclear events result in unambiguous flux rope signatures in in situ data at 1 AU. There is a tendency that the CME source regions are located near coronal holes or open field regions. This may have implications for both the initiation of the stealthy CME in the corona and its outcome in the heliosphere.

  16. Bridging the Gap between Coronal and Non-Coronal Evolved Stars

    Science.gov (United States)

    Carpenter, Kenneth G.; Nielsen, Krister E.; Kober, Gladys V.

    2017-01-01

    The Hubble Space Telescope (HST) Treasury Program "Advanced Spectral Library (ASTRAL)" enables investigations of a broad range of problems including the character and dynamics of the wind and chromosphere of cool stars. This paper presents an investigation of the change in spectral characteristics when transitioning from the cool non-coronal objects with fluorescent emission spectra from the iron group elements, molecular hydrogen, and carbon monoxide to the warmer stars on the blue side of the Linsky-Haish dividing line in the HR diagram. These warmer objects exhibit chromospheric emission from significantly hotter environments in addition to coronal signatures, while the hybrid stars overlap in the HR-diagram with some of the non-coronal objects and share many spectral characteristics but show differences in the wind properties. We show how the wind, fluorescent features, and hot stellar signatures dramatically change with spectral class by comparing the already analyzed non-coronal objects (Alpha Ori, Gamma Cru) with the hybrid stars (Gamma Dra, Beta Gem and Alpha Aqr) and the coronal object Beta Dra. We aim to gain understanding of the physical processes in these objects' outer atmospheres and their evolutionary tracks.

  17. Relationship of EUV Irradiance Coronal Dimming Slope and Depth to Coronal Mass Ejection Speed and Mass

    CERN Document Server

    Mason, James Paul; Webb, David F; Thompson, Barbara J; Colaninno, Robin C; Vourlidas, Angelos

    2016-01-01

    Extreme ultraviolet (EUV) coronal dimmings are often observed in response to solar eruptive events. These phenomena can be generated via several different physical processes. For space weather, the most important of these is the temporary void left behind by a coronal mass ejection (CME). Massive, fast CMEs tend to leave behind a darker void that also usually corresponds to minimum irradiance for the cooler coronal emissions. If the dimming is associated with a solar flare, as is often the case, the flare component of the irradiance light curve in the cooler coronal emission can be isolated and removed using simultaneous measurements of warmer coronal lines. We apply this technique to 37 dimming events identified during two separate two-week periods in 2011, plus an event on 2010 August 7 analyzed in a previous paper, to parameterize dimming in terms of depth and slope. We provide statistics on which combination of wavelengths worked best for the flare-removal method, describe the fitting methods applied to t...

  18. The Lower Chromosphere in a Coronal Hole

    Science.gov (United States)

    Teplitskaya, R. B.; Turova, I. P.; Ozhogina, O. A.

    2007-07-01

    We study the Ca ii K, H, and λ 849.8 nm line profiles in two regions of the quiet Sun, one being located in the extensive low-latitude coronal hole observed on 3 through 5 August 2003, and the other being located outside the coronal hole. Comparison of the profiles was carried out separately for cells and cell boundaries of the chromospheric network. Our principal result is that space- and time-averaged profiles of the central self-reversal in the coronal hole sites differ from those outside of the hole: Intensities of the K3 and H3 central depressions are increased in the cells but are unchanged in the network; the height of the K2 peaks is reduced in the cells and particularly in the network; the central self-reversal asymmetry is intensified in the network. Distinctions appear at a high confidence level. Line wings as well as average characteristics of the infrared line remain practically unchanged. We discuss probable causes for this behavior of the lower chromosphere lines.

  19. Coronal Heating Observed with Hi-C

    Science.gov (United States)

    Winebarger, Amy R.

    2013-01-01

    The recent launch of the High-Resolution Coronal Imager (Hi-C) as a sounding rocket has offered a new, different view of the Sun. With approx 0.3" resolution and 5 second cadence, Hi-C reveals dynamic, small-scale structure within a complicated active region, including coronal braiding, reconnection regions, Alfven waves, and flows along active region fans. By combining the Hi-C data with other available data, we have compiled a rich data set that can be used to address many outstanding questions in solar physics. Though the Hi-C rocket flight was short (only 5 minutes), the added insight of the small-scale structure gained from the Hi-C data allows us to look at this active region and other active regions with new understanding. In this talk, I will review the first results from the Hi-C sounding rocket and discuss the impact of these results on the coronal heating problem.

  20. Characteristics of polar coronal hole jets

    CERN Document Server

    Chandrashekhar, K; Banerjee, D; Gupta, G R; Teriaca, L

    2013-01-01

    High spatial- and temporal-resolution images of coronal hole regions show a dynamical environment where mass flows and jets are frequently observed. These jets are believed to be important for the coronal heating and the acceleration of the fast solar wind. We studied the dynamics of two jets seen in a polar coronal hole with a combination of imaging from EIS and XRT onboard Hinode. We observed drift motions related to the evolution and formation of these small-scale jets, which we tried to model as well. We found observational evidence that supports the idea that polar jets are very likely produced by multiple small-scale reconnections occurring at different times in different locations. These eject plasma blobs that flow up and down with a motion very similar to a simple ballistic motion. The associated drift speed of the first jet is estimated to be $\\approx$ 27 km s$^{-1}$. The average outward speed of the first jet is $\\approx 171$ km s$^{-1}$, well below the escape speed, hence if simple ballistic motio...

  1. Dynamics of Coronal-Hole Boundaries

    CERN Document Server

    Higginson, A K; DeVore, C R; Wyper, P F; Zurbuchen, T H

    2016-01-01

    Remote and in-situ observations suggest that the slow solar wind consists of plasma from the hot, closed-field corona that is released onto open magnetic field lines. The Separatrix-Web (S-Web) theory for the slow wind proposes that photospheric motions, at the scale of supergranules, are responsible for generating dynamics at coronal-hole boundaries, which result in the inferred necessary transfer of plasma from closed to open field lines. We use 3D magnetohydrodynamic (MHD) simulations to determine the effect of photospheric flows on the open and closed magnetic flux of a model corona with a dipole magnetic field and an isothermal solar wind. We find that a supergranular-scale photospheric motion at the boundary between the coronal hole and helmet streamer results in prolific and efficient interchange reconnection between open and closed flux. This reconnection acts to smooth the large- and small-scale structure introduced by the photospheric flows. Magnetic flux near the coronal-hole boundary experiences m...

  2. A Mechanism for Coronal Hole Jets

    CERN Document Server

    Mueller, D A N

    2008-01-01

    Bald patches are magnetic topologies in which the magnetic field is concave up over part of a photospheric polarity inversion line. A bald patch topology is believed to be the essential ingredient for filament channels and is often found in extrapolations of the observed photospheric field. Using an analytic source-surface model to calculate the magnetic topology of a small bipolar region embedded in a global magnetic dipole field, we demonstrate that although common in closed-field regions close to the solar equator, bald patches are unlikely to occur in the open-field topology of a coronal hole. Our results give rise to the following question: What happens to a bald patch topology when the surrounding field lines open up? This would be the case when a bald patch moves into a coronal hole, or when a coronal hole forms in an area that encompasses a bald patch. Our magnetostatic models show that, in this case, the bald patch topology almost invariably transforms into a null point topology with a spine and a fa...

  3. Coronal Structure of Low-Mass Stars

    CERN Document Server

    Lang, Pauline; Donati, Jean-Francois; Morin, Julien; Vidotto, Aline

    2012-01-01

    We investigate the change in stellar magnetic topology across the fully-convective boundary and its effects on coronal properties. We consider both the magnitude of the open flux that influences angular momentum loss in the stellar wind and X-ray emission measure. We use reconstructed maps of the radial magnetic field at the stellar surface and the potential-field source surface method to extrapolate a 3D coronal magnetic field for a sample of early-to-mid M dwarfs. During the magnetic reconstruction process it is possible to force a solution towards field geometries that are symmetric or antisymmetric about the equator but we demonstrate that this has only a modest impact on the coronal tracers mentioned above. We find that the dipole component of the field, which governs the large-scale structure, becomes increasingly strong as the stellar mass decreases, while the magnitude of the open (wind-bearing) magnetic flux is proportional to the magnitude of the reconstructed magnetic flux. By assuming a hydrostati...

  4. The formation of an equatorial coronal hole

    Science.gov (United States)

    Yang, Liheng; Jiang, Yunchun; Zhang, Jun

    2010-02-01

    The formation of an equatorial coronal hole (CH) from 2006 January 9 to 12 was simultaneously observed by GOES-12/SXI, SOHO/EIT and SOHO/MDI instruments. The varieties of soft X-ray and EUV brightness, coronal temperature, and total magnetic flux in the CH were examined and compared with that of a quiet-sun (QS) region nearby. The following results are obtained. (1) A preexisting dark lane appeared on the location of the followed CH and was reinforced by three enhanced networks. (2) The CH gradually formed in about 81 hours and was predominated by positive magnetic flux. (3) During the formation, the soft X-ray and EUV brightness, coronal temperature, and total magnetic flux obviously decreased in the CH, but were almost no change in the QS region. The decrease of the total magnetic flux may be the result of magnetic reconnection between the open and closed magnetic lines, probably indicating the physical mechanism for the birth of the CH.

  5. Propagating magnetohydrodynamics waves in coronal loops.

    Science.gov (United States)

    De Moortel, I

    2006-02-15

    High cadence Transition Region and Coronal Explorer (TRACE) observations show that outward propagating intensity disturbances are a common feature in large, quiescent coronal loops, close to active regions. An overview is given of measured parameters of such longitudinal oscillations in coronal loops. The observed oscillations are interpreted as propagating slow magnetoacoustic waves and are unlikely to be flare-driven. A strong correlation, between the loop position and the periodicity of the oscillations, provides evidence that the underlying oscillations can propagate through the transition region and into the corona. Both a one- and a two-dimensional theoretical model of slow magnetoacoustic waves are presented to explain the very short observed damping lengths. The results of these numerical simulations are compared with the TRACE observations and show that a combination of the area divergence and thermal conduction agrees well with the observed amplitude decay. Additionally, the usefulness of wavelet analysis is discussed, showing that care has to be taken when interpreting the results of wavelet analysis, and a good knowledge of all possible factors that might influence or distort the results is a necessity.

  6. Standing Slow-Mode Waves in Hot Coronal Loops: Observations, Modeling, and Coronal Seismology

    CERN Document Server

    Wang, Tongjiang

    2010-01-01

    Strongly damped Doppler shift oscillations are observed frequently associated with flarelike events in hot coronal loops. In this paper, a review of the observed properties and the theoretical modeling is presented. Statistical measurements of physical parameters (period, decay time, and amplitude) have been obtained based on a large number of events observed by SOHO/SUMER and Yohkoh/BCS. Several pieces of evidence are found to support their interpretation in terms of the fundamental standing longitudinal slow mode. The high excitation rate of these oscillations in small- or micro-flares suggest that the slow mode waves are a natural response of the coronal plasma to impulsive heating in closed magnetic structure. The strong damping and the rapid excitation of the observed waves are two major aspects of the waves that are poorly understood, and are the main subject of theoretical modeling. The slow waves are found mainly damped by thermal conduction and viscosity in hot coronal loops. The mode coupling seems ...

  7. A unified theory of electrodynamic coupling in coronal magnetic loops - The coronal heating problem

    Science.gov (United States)

    Ionson, J. A.

    1984-01-01

    The coronal heating problem is studied, and it is demonstrated that Ionson's (1982) LRC approach results in a unified theory of coronal heating which unveils a variety of new heating mechanisms and which links together previously proposed mechanisms. Ionson's LRC equation is rederived, focusing on various aspects that were not clarified in the original article and incorporating new processes that were neglected. A parameterized heating rate is obtained. It is shown that Alfvenic surface wave heating, stochastic magnetic pumping, resonant electrodynamic heating, and dynamical dissipation emerge as special cases of a much more general formalism. This generalized theory is applied to solar coronal loops and it is found that active region and large scale loops are underdamped systems. Young active region loops and (possibly) bright points are found to be overdamped systems.

  8. The acceleration of electrons at a spherical coronal shock in a streamer-like coronal field

    Science.gov (United States)

    Kong, Xiangliang; Chen, Yao; Guo, Fan

    2016-03-01

    We study the effect of large-scale coronal magnetic field on the electron acceleration at a spherical coronal shock using a test-particle method. The coronal field is approximated by an analytical solution with a streamer-like magnetic field featured by partially open magnetic field and a current sheet at the equator atop the closed region. It shows that the closed field plays the role of a trapping agency of shock-accelerated electrons, allowing for repetitive reflection and acceleration, therefore can greatly enhance the shock-electron acceleration efficiency. It is found that, with an ad hoc pitch-angle scattering, electron injected in the open field at the shock flank can be accelerated to high energies as well. In addition, if the shock is faster or stronger, a relatively harder electron energy spectrum and a larger maximum energy can be achieved.

  9. Simulations of Emerging Magnetic Flux. II. The Formation of Unstable Coronal Flux Ropes and the Initiation of Coronal Mass Ejections

    Science.gov (United States)

    Leake, James E.; Linton, Mark G.; Antiochos, Spiro K.

    2014-01-01

    We present results from three-dimensional magnetohydrodynamic simulations of the emergence of a twisted convection zone flux tube into a pre-existing coronal dipole field. As in previous simulations, following the partial emergence of the sub-surface flux into the corona, a combination of vortical motions and internal magnetic reconnection forms a coronal flux rope. Then, in the simulations presented here, external reconnection between the emerging field and the pre-existing dipole coronal field allows further expansion of the coronal flux rope into the corona. After sufficient expansion, internal reconnection occurs beneath the coronal flux rope axis, and the flux rope erupts up to the top boundary of the simulation domain (approximately 36 Mm above the surface).We find that the presence of a pre-existing field, orientated in a direction to facilitate reconnection with the emerging field, is vital to the fast rise of the coronal flux rope. The simulations shown in this paper are able to self-consistently create many of the surface and coronal signatures used by coronal mass ejection (CME) models. These signatures include surface shearing and rotational motions, quadrupolar geometry above the surface, central sheared arcades reconnecting with oppositely orientated overlying dipole fields, the formation of coronal flux ropes underlying potential coronal field, and internal reconnection which resembles the classical flare reconnection scenario. This suggests that proposed mechanisms for the initiation of a CME, such as "magnetic breakout," are operating during the emergence of new active regions.

  10. Estudio de caso

    OpenAIRE

    Maciel-González-Durán, Gabriela

    2015-01-01

    El presente trabajo es un estudio de caso de acompañamiento emocional y psicoterapéutico. Se muestra el contexto general y el proceso de la consultante. El motivo principal de consulta fue una experiencia de secuestro y violación que ocasionó un cuadro de estrés post-traumático. Dentro del apartado del estudio de caso se hace referencia a las vivencias, significados y contexto de la consultante, se pretende demostrar el desarrollo que se fue llevando a cabo en la consultante, y se comparten f...

  11. Segmentation of Coronal Holes Using Active Contours Without Edges

    CERN Document Server

    Boucheron, L E; McAteer, R T J

    2016-01-01

    An application of active contours without edges is presented as an efficient and effective means of extracting and characterizing coronal holes. Coronal holes are regions of low-density plasma on the Sun with open magnetic field lines. As the source of the fast solar wind, the detection and characterization of these regions is important for both testing theories of their formation and evolution and from a space weather perspective. Coronal holes are detected in full disk extreme ultraviolet (EUV) images of the corona obtained with the Solar Dynamics Observatory Atmospheric Imaging Assembly (SDO/AIA). The proposed method detects coronal boundaries without determining any fixed intensity value in the data. Instead, the active contour segmentation employs an energy-minimization in which coronal holes are assumed to have more homogeneous intensities than surrounding active regions and quiet Sun. The segmented coronal holes tend to correspond to unipolar magnetic regions, are consistent with concurrent solar wind ...

  12. Análisis retrospectivo sobre la utilidad de las herramientas de valoración funcional, en las dolencias lumbares a nivel del ámbito laboral (Regional Canarias de Fremap, Año 2012

    Directory of Open Access Journals (Sweden)

    Alexander Vera Vicuña

    2014-01-01

    Full Text Available Introducción: La lumbalgia o dolor lumbar (DL, constituye uno de los síndromes que provocan más consultas en el sistema sanitario, constituyendo la causa más importante de desembolso compensatorio económico, bien sea por entidades públicas como la Seguridad Social o entidades aseguradoras laborales como las mutuas. Objetivo: Determinar la posible influencia de aplicar las herramientas de valoración funcional (Nedlumb/IBV 1.0 en el seguimiento de los procesos de baja laboral por dolor lumbar, en la disminución en el tiempo de baja por dolencias lumbares, así como el ahorro en los coste por compensación de días de baja laboral. Materiales y métodos: Se realizó un estudio retrospectivo, transversal, determinando el número total de paciente con diagnóstico de Lumbalgia en la Regional Canarias de Fremap en el año 2012, extrapolando el tiempo promedio de duración de nuestras baja por dicha dolencia en Contingencia Profesional (CP, con respecto al grupo II del estudio realizado por Asepeyo en Sant Cugat en 2009, denominando a nuestro grupo de estudio, Grupo-II Fremap (Lumbalgias sin valoración funcional, que se comparó con el grupo I de dicho estudio (Lumbalgias con valoración funcional. Se estudio la correlación entre ambos grupo y si el resultado de la valoración funcional, tiene un valor pronóstico, sobre el período restante de baja posterior, en cuanto a disminución del tiempo de baja o al coste económico de la misma. Resultado: Tras comparar nuestro grupo, Grupo II-Fremap, con el Grupo I, como si se hubiera realizado la valoración funcional con el Nedlumb/IBV 1.0 a los 50 días de la baja, los resultado evidenciaron una reducción total de 758.54 días de baja, que sí se correlacionaban con el ahorro del coste diario de compensación de baja (36.3€/día, se demostraba, que se podía haber conseguido un ahorro de 27.535€ en bajas por CP por patología lumbar en la Regional Canarias en el año 2012. Además, si tambi

  13. THE COOLING OF CORONAL PLASMAS. IV. CATASTROPHIC COOLING OF LOOPS

    Energy Technology Data Exchange (ETDEWEB)

    Cargill, P. J. [Space and Atmospheric Physics, The Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom); Bradshaw, S. J., E-mail: p.cargill@imperial.ac.uk [Department of Physics and Astronomy, Rice University, Houston, TX 77005 (United States)

    2013-07-20

    We examine the radiative cooling of coronal loops and demonstrate that the recently identified catastrophic cooling is due to the inability of a loop to sustain radiative/enthalpy cooling below a critical temperature, which can be >1 MK in flares, 0.5-1 MK in active regions, and 0.1 MK in long tenuous loops. Catastrophic cooling is characterized by a rapid fall in coronal temperature, while the coronal density changes by a small amount. Analytic expressions for the critical temperature are derived and show good agreement with numerical results. This effect considerably limits the lifetime of coronal plasmas below the critical temperature.

  14. Resumen estudios sobre tabaquismo

    OpenAIRE

    Gónzalez, M.M. (M.)

    2009-01-01

    Este documento se realizó para publicar en la página Web de la Gerencia de Atención primaria del Área III. Este documento es una recopilación de estudios sobre tabaquismo. Gerencia de Atención Primaria Área III

  15. de estudios observacionales

    Directory of Open Access Journals (Sweden)

    Erik von Elm

    2008-01-01

    un documento de explicación y elaboración al que puede accederse libremente en los sitios web de PLoS Medicine, Annals of Internal Medicine y Epidemiology. Esperamos que la declaración STROBE contribuya a mejorar la calidad de la publicación de los estudios observacionales.

  16. Retrato de estudio. Sacerdote.

    OpenAIRE

    Ansede y Juanes

    2010-01-01

    1 fot.; papel; imagen 12,6 x 20 cm. - Retrato de estudio. Sacerdote. (2 copias. Gelatina D. O. P. mate montada sobre cartulina, medida total 12,6 x 20. Sello troquelado impreso del fotógrafo con letras doradas en ángulo inferior derecho de cartulina: "Ansede y Juanes - Salamanca"). - Procedencia: fondo Miguel de Unamuno. - Buena Conservación.

  17. Contribución del estudio neurofisiológico al diagnóstico y control evolutivo de la enfermedad de Charcot-Marie-Tooth en la provincia de Las Palmas

    OpenAIRE

    Navarro Rivero, Beatriz

    2015-01-01

    Programa de doctorado: Patología Quirúrgica [ES]En la presente tesis se estudian los diferentes tipos gnéticos de CMT en la provincia de Las Palmas mediante un estudio transversal, descriptivo y retrospectivo entre los años 2008-2012; valorando la importancia del estudio neurofisiológico y su posible correlación de los parámetros neurofiosológicos con diferentes nervios respecto a discapacidad clínica, tiempos de evolución de la enfer...

  18. Lesiones pigmentadas buco-faciales más frecuentes: Estudio clínico y correlación histopatológica The most frequent buccofacial pigmented injuries: Clinical study and histopathological correlation

    OpenAIRE

    Rafael Delgado Fernández; Rosa María Segismundo Rodríguez; Katia Barceló López

    2005-01-01

    Las lesiones pigmentadas de la piel y la mucosa bucal constituyen alteraciones que aparecen frecuentemente en la clínica estomatológica; por sus características y las diferentes formas de presentarse, su diagnóstico clínico con frecuencia discrepa del estudio morfológico. Por la importancia clínica de algunas de estas lesiones, nos propusimos hacer un estudio retrospectivo desde el punto de vista clínico y morfológico en 6 años (1998-2003), en los archivos de biopsias del Departamento de Pato...

  19. Solar jet-coronal hole collision and a related coronal mass ejection

    CERN Document Server

    Zheng, Ruisheng; Du, Guohui; Li, Chuanyang

    2016-01-01

    Jets are defined as impulsive, well-collimated upflows, occurring in different layers of the solar atmosphere with different scales. Their relationship with coronal mass ejections (CMEs), another type of solar impulsive events, remains elusive. Using the high-quality imaging data of AIA/SDO, here we show a well-observed coronal jet event, in which part of the jets, with the embedding coronal loops, runs into a nearby coronal hole (CH) and gets bounced towards the opposite direction. This is evidenced by the flat-shape of the jet front during its interaction with the CH and the V-shaped feature in the time-slice plot of the interaction region. About a half-hour later, a CME initially with a narrow and jet-like front is observed by the LASCO C2 coronagraph, propagating along the direction of the post-collision jet. We also observe some 304 A dark material flowing from the jet-CH interaction region towards the CME. We thus suggest that the jet and the CME are physically connected, with the jet-CH collision and t...

  20. SOLAR JET–CORONAL HOLE COLLISION AND A CLOSELY RELATED CORONAL MASS EJECTION

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Ruisheng; Chen, Yao; Du, Guohui; Li, Chuanyang, E-mail: ruishengzheng@sdu.edu.cn [Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, and Institute of Space Sciences, Shandong University, 264209, Weihai (China)

    2016-03-10

    Jets are defined as impulsive, well-collimated upflows, occurring in different layers of the solar atmosphere with different scales. Their relationship with coronal mass ejections (CMEs), another type of solar impulsive events, remains elusive. Using high-quality imaging data from the Atmospheric Imaging Assembly/Solar Dynamics Observatory, we show a well-observed coronal jet event, in which the part of the jet with embedding coronal loops runs into a nearby coronal hole (CH) and gets bounced in the opposite direction. This is evidenced by the flat shape of the jet front during its interaction with the CH and the V-shaped feature in the time-slice plot of the interaction region. About a half-hour later, a CME with an initially narrow and jet-like front is observed by the LASCO C2 coronagraph propagating along the direction of the post-collision jet. We also observe some 304 Å dark material flowing from the jet–CH interaction region toward the CME. We thus suggest that the jet and the CME are physically connected, with the jet–CH collision and the large-scale magnetic topology of the CH being important in defining the eventual propagating direction of this particular jet–CME eruption.

  1. Observing coronal nanoflares in active region moss

    OpenAIRE

    Testa, Paola; De Pontieu, Bart; Martinez-Sykora, Juan; DeLuca, Ed; Hansteen, Viggo; Cirtain, Jonathan; Winebarger, Amy; Golub, Leon; Kobayashi, Ken; Korreck, Kelly; Kuzin, Sergey; Walsh, Robert; DeForest, Craig; Title, Alan; Weber, Mark

    2013-01-01

    The High-resolution Coronal Imager (Hi-C) has provided Fe XII 193A images of the upper transition region moss at an unprecedented spatial (~0.3-0.4 arcsec) and temporal (5.5s) resolution. The Hi-C observations show in some moss regions variability on timescales down to ~15s, significantly shorter than the minute scale variability typically found in previous observations of moss, therefore challenging the conclusion of moss being heated in a mostly steady manner. These rapid variability moss r...

  2. Solar coronal observations at high frequencies

    OpenAIRE

    Katsiyannis, A. C.; Mathioudakis, M.; Phillips, K. J. H.; Williams, D. R.; F. P. Keenan

    2001-01-01

    The Solar Eclipse Coronal Imaging System (SECIS) is a simple and extremely fast, high-resolution imaging instrument designed for studies of the solar corona. Light from the corona (during, for example, a total solar eclipse) is reflected off a heliostat and passes via a Schmidt-Cassegrain telescope and beam splitter to two CCD cameras capable of imaging at 60 frames a second. The cameras are attached via SCSI connections to a purpose-built PC that acts as the data acquisition and storage syst...

  3. Análisis retrospectivo de 23 años de necrólisis epidérmica tóxica en la Unidad de Quemados de Alicante, España

    Directory of Open Access Journals (Sweden)

    F.I. Castillo-Muñoz

    2014-09-01

    Full Text Available El Síndrome de Lyell o Necrólisis Epidérmica Tóxica (NET se encuadra dentro del espectro de reacciones cutáneas adversas graves y se caracteriza por presentar una baja incidencia pero una elevada mortalidad. La mayoría de los casos de NET se relacionan con una reacción medicamentosa idiosincrática. El objetivo de este trabajo es reflejar la experiencia clínica con esta entidad en la Unidad de Quemados del Hospital General Universitario de Alicante, España, durante los últimos 23 años. Realizamos un estudio retrospectivo recogiendo los datos epidemiológicos, agentes causales probables, pruebas complementarias, patologías concomitantes, tratamiento y evolución clínica. En total recogimos 16 pacientes con una media de edad de 53,19 años, 68,75% mujeres y 31,25% varones. Los antibióticos fueron los fármacos más comúnmente implicados (31,25%, seguidos de los AINES (25%. Durante el ingreso hospitalario, el 43,75% de los pacientes recibió corticoides sistémicos, el 37,5% exclusivamente tratamiento de soporte y el 25% inmunoglobulinas intravenosas. El 56,25% sufrió algún tipo de secuela, siendo la afectación ocular la más frecuente (18,75%. Calculamos el SCORTEN (Severity of illness score for toxic epidermal necrolisys para todos los pacientes en las primeras 24 horas de ingreso, siendo la suma de las probabilidades predichas de morir por NET de un 32%, cifra superior a los datos reales (mortalidad del 25%. La utilización de corticoides sistémicos sigue siendo controvertida, apareciendo en nuestro estudio un mayor número de infecciones y una mayor mortalidad asociada a dicho tratamiento. La retirada inmediata del fármaco sospechoso, el ingreso precoz en una Unidad de Quemados o de Cuidados Intensivos, el tratamiento de soporte y la reposición hidroelectrolítica, siguen siendo medidas cruciales y de primera línea en el tratamiento de estos pacientes. A pesar de que están descritos diferentes tipos de tratamiento

  4. Relationship of EUV Irradiance Coronal Dimming Slope and Depth to Coronal Mass Ejection Speed and Mass

    Science.gov (United States)

    Mason, James Paul; Woods, Thomas N.; Webb, David F.; Thompson, Barbara J.; Colaninno, Robin C.; Vourlidas, Angelos

    2016-10-01

    Extreme ultraviolet (EUV) coronal dimmings are often observed in response to solar eruptive events. These phenomena can be generated via several different physical processes. For space weather, the most important of these is the temporary void left behind by a coronal mass ejection (CME). Massive, fast CMEs tend to leave behind a darker void that also usually corresponds to minimum irradiance for the cooler coronal emissions. If the dimming is associated with a solar flare, as is often the case, the flare component of the irradiance light curve in the cooler coronal emission can be isolated and removed using simultaneous measurements of warmer coronal lines. We apply this technique to 37 dimming events identified during two separate two-week periods in 2011 plus an event on 2010 August 7, analyzed in a previous paper to parameterize dimming in terms of depth and slope. We provide statistics on which combination of wavelengths worked best for the flare-removal method, describe the fitting methods applied to the dimming light curves, and compare the dimming parameters with corresponding CME parameters of mass and speed. The best linear relationships found are \\begin{eqnarray*}{v}{CME} ≤ft[\\displaystyle \\frac{{km}}{{{s}}}\\right] & ≈ & 2.36× {10}6 ≤ft[\\displaystyle \\frac{{km}}{ % }\\right]× {s}\\dim ≤ft[\\displaystyle \\frac{ % }{{{s}}}\\right]\\ {m}{CME} [{{g}}] & ≈ & 2.59× {10}15≤ft[\\displaystyle \\frac{g}{ % }\\right]× \\sqrt{{d}\\dim } [ % ].\\end{eqnarray*} These relationships could be used for space weather operations of estimating CME mass and speed using near-real-time irradiance dimming measurements.

  5. Evaluation of the Minifilament-Eruption Scenario for Solar Coronal Jets in Polar Coronal Holes

    Science.gov (United States)

    Baikie, Tomi K.; Sterling, Alphonse C.; Falconer, David; Moore, Ronald L.; Savage, Sabrina L.

    2016-01-01

    Solar coronal jets are suspected to result from magnetic reconnection low in the Sun's atmosphere. Sterling et al. (2015) looked as 20 jets in polar coronal holes, using X-ray images from the Hinode/X-Ray Telescope (XRT) and EUV images from the Solar Dynamics Observatory (SDO) Atmospheric Imaging Assembly (AIA). They suggested that each jet was driven by the eruption of twisted closed magnetic field carrying a small-scale filament, which they call a 'minifilament', and that the jet was produced by reconnection of the erupting field with surrounding open field. In this study, we carry out a more extensive examination of polar coronal jets. From 180 hours of XRT polar coronal hole observations spread over two years (2014-2016), we identified 130 clearly-identifiable X-ray jet events and thus determined an event rate of over 17 jets per day per in the Hinode/XRT field of view. From the broader set, we selected 25 of the largest and brightest events for further study in AIA 171, 193, 211, and 304 Angstrom images. We find that at least the majority of the jets follow the minifilament-eruption scenario, although for some cases the evolution of the minifilament in the onset of its eruption is more complex than presented in the simplified schematic of Sterling et al. (2015). For all cases in which we could make a clear determination, the spire of the X-ray jet drifted laterally away from the jet-base-edge bright point; this spire drift away from the bright point is consistent with expectations of the minifilament-eruption scenario for coronal-jet production. This work was supported with funding from the NASA/MSFC Hinode Project Office, and from the NASA HGI program.

  6. Modified Homogeneous Data Set of Coronal Intensities

    Science.gov (United States)

    Dorotovič, I.; Minarovjech, M.; Lorenc, M.; Rybanský, M.

    2014-07-01

    The Astronomical Institute of the Slovak Academy of Sciences has published the intensities, recalibrated with respect to a common intensity scale, of the 530.3 nm (Fe xiv) green coronal line observed at ground-based stations up to the year 2008. The name of this publication is Homogeneous Data Set (HDS). We have developed a method that allows one to successfully substitute the ground-based observations by satellite observations and, thus, continue with the publication of the HDS. For this purpose, the observations of the Extreme-ultraviolet Imaging Telescope (EIT), onboard the Solar and Heliospheric Observatory (SOHO) satellite, were exploited. Among other data the EIT instrument provides almost daily 28.4 nm (Fe xv) emission-line snapshots of the corona. The Fe xiv and Fe xv data (4051 observation days) taken in the period 1996 - 2008 have been compared and good agreement was found. The method to obtain the individual data for the HDS follows from the correlation analysis described in this article. The resulting data, now under the name of Modified Homogeneous Data Set (MHDS), are identical up to 1996 to those in the HDS. The MHDS can be used further for studies of the coronal solar activity and its cycle. These data are available at http://www.suh.sk.

  7. Energetics of Solar Coronal Mass Ejections

    CERN Document Server

    Subramanian, P; Subramanian, Prasad; Vourlidas, Angelos

    2007-01-01

    Aims: To investigate if solar coronal mass ejections are driven mainly by coupling to the ambient solar wind, or through the release of internal magnetic energy. Methods: We examine the energetics of 39 flux-rope like coronal mass ejections (CMEs) from the Sun using data in the distance range $\\sim$ 2--20 $R_{{\\o}dot}$ from the Large Angle Spectroscopic Coronograph (LASCO) aboard the Solar and Heliospheric Observatory (SOHO). This comprises a complete sample of the best examples of flux-rope CMEs observed by LASCO in 1996-2001. Results: We find that 69% of the CMEs in our sample experience a clearly identifiable driving power in the LASCO field of view. For these CMEs which are driven, we examine if they might be deriving most of their driving power by coupling to the solar wind. We do not find conclusive evidence in favor of this hypothesis. On the other hand, we find that their internal magnetic energy is a viable source of the required driving power. We have estimated upper and lower limits on the power th...

  8. SAUSAGE OSCILLATIONS OF CORONAL PLASMA STRUCTURES

    Energy Technology Data Exchange (ETDEWEB)

    Nakariakov, V. M.; Hornsey, C. [Physics Department, University of Warwick, Coventry CV4 7AL (United Kingdom); Melnikov, V. F., E-mail: V.Nakariakov@warwick.ac.uk [Central Astronomical Observatory at Pulkovo of the Russian Academy of Sciences, 196140 St Petersburg (Russian Federation)

    2012-12-20

    The dependence of the period of sausage oscillations of coronal loops on length together with the depth and steepness of the radial profile are determined. We performed a parametric study of linear axisymmetric fast magnetoacoustic (sausage) oscillations of coronal loops modeled as a field-aligned low-{beta} plasma cylinder with a smooth inhomogeneity of the plasma density in the radial direction. The density decreases smoothly in the radial direction. Sausage oscillations are impulsively excited by a perturbation of the radial velocity, localized at the cylinder axis and with a harmonic dependence on the longitudinal coordinate. The initial perturbation results in either a leaky or a trapped sausage oscillation, depending upon whether the longitudinal wavenumber is smaller or greater than a cutoff value, respectively. The period of the sausage oscillations was found to always increase with increasing longitudinal wavelength, with the dependence saturating in the long-wavelength limit. Deeper and steeper radial profiles of the Alfven speed correspond to more efficient trapping of sausage modes: the cutoff value of the wavelength increases with the steepness and the density (or Alfven speed) contrast ratio. In the leaky regime, the period is always longer than the period of a trapped mode of a shorter wavelength in the same cylinder. For shallow density profiles and shorter wavelengths, the period increases with wavelength. In the long-wavelength limit, the period becomes independent of the wavelength and increases with the depth and steepness of the radial profile of the Alfven speed.

  9. Analytical investigations on the Coronation Gospels manuscript

    Science.gov (United States)

    Aceto, Maurizio; Agostino, Angelo; Fenoglio, Gaia; Idone, Ambra; Crivello, Fabrizio; Griesser, Martina; Kirchweger, Franz; Uhlir, Katharina; Puyo, Patricia Roger

    2017-01-01

    The Coronation Gospels or Krönungsevangeliar is a manuscript kept in Vienna at the Kunsthistorisches Museum Wien, datable to the end of VIII century A.D. and produced at Charlemagne court. It is an example of a purple codex, i.e. its parchment is coloured in purple. It has to be considered as one of the most important medieval codices, according to its use to take oath in the coronation ceremony of kings and emperors of the Holy Roman Empire up to 1792. In order to gather information of the manufacture of the manuscript and its present conservation state, a diagnostic investigation campaign has been carried out in situ with totally non-invasive techniques. X-ray Fluorescence Spectrometry (XRF), UV-visible diffuse reflectance spectrophotometry with optical fibres (FORS), spectrofluorimetry, optical microscopy and multispectral analysis have been applied in order to identify the colourants used in the decoration of the manuscript, with the main concern to the dye used to impart the purple hue to the parchment. The information collected was useful in order to address some of the questions raised by art historians concerning its history.

  10. A Moreton Wave and its Coronal Counterparts

    Science.gov (United States)

    Francile, Carlos N.; Mandrini, Cristina H.; Long, David; Cremades, Hebe; Lopez, Fernando M.; Luoni, Maria Luisa

    2016-07-01

    On 29 March 2014, a Moreton wave was detected in AR 12017 with the Halpha Solar Telescope for Argentina (HASTA) in association with an X1 flare. Several phenomena took place in various regimes in connection with this event, such as low coronal waves and a coronal mass ejection (CME). We investigate their role and relationship with the Moreton wave to shed light on issues so far under debate. We analyze its connection with waves observed in the low corona with the Atmospheric Imaging Assembly aboard the Solar Dynamics Observatory (SDO/AIA), as well as with the ensuing CME, via kinematics analyses. We build stack plots from sequences of images obtained at different wavelengths to track wave fronts along several directions and find links between the features observed in the chromosphere and low corona, as well as in the associated CME. We also derive the shock front properties. We propose a geometrical model of the wave to explain the observed wave fronts as the photospheric and chromospheric traces of an expanding and outward-traveling bubble intersecting the Sun.

  11. Association of solar coronal loops to photospheric magnetic field

    Science.gov (United States)

    Pradeep Chitta, Lakshmi; Peter, Hardi; Solanki, Sami

    2017-08-01

    Magnetic connectivity and its evolution from the solar photosphere to the corona will play a crucial role in the energetics of the solar atmosphere. To explore this connectivity, we use high spatial resolution magnetic field observations of an active region from the balloon-borne SUNRISE telescope, in combination with the observations of coronal loops imaged in extreme ultraviolet by SDO/AIA. We show that photospheric magnetic field at the base of coronal loops is rapidly evolving through small-scale flux emergence and cancellation events with rates on the order of 10^15 Mx/s. When observed at high spatial resolution better than 0.5 arcsec, we find that basically all coronal loops considered so far are rooted in the photosphere above small-scale opposite polarity magnetic field patches. In the photosphere, the magnetic field threading coronal loops is interacting with opposite polarity parasitic magnetic concentrations leading to dynamic signatures in the upper atmosphere. Chromospheric small-scale jets aligned to coronal loops are observed at these locations. We will present preliminary results from 3D MHD simulations of coronal loops driven by realistic magneto-convection and discuss what role the magnetic interactions at coronal loop footpoints could play in the evolution of coronal loops and their heating.

  12. Segmentation of Coronal Holes Using Active Contours Without Edges

    Science.gov (United States)

    Boucheron, L. E.; Valluri, M.; McAteer, R. T. J.

    2016-10-01

    An application of active contours without edges is presented as an efficient and effective means of extracting and characterizing coronal holes. Coronal holes are regions of low-density plasma on the Sun with open magnetic field lines. The detection and characterization of these regions is important for testing theories of their formation and evolution, and also from a space weather perspective because they are the source of the fast solar wind. Coronal holes are detected in full-disk extreme ultraviolet (EUV) images of the corona obtained with the Solar Dynamics Observatory Atmospheric Imaging Assembly (SDO/AIA). The proposed method detects coronal boundaries without determining any fixed intensity value in the data. Instead, the active contour segmentation employs an energy-minimization in which coronal holes are assumed to have more homogeneous intensities than the surrounding active regions and quiet Sun. The segmented coronal holes tend to correspond to unipolar magnetic regions, are consistent with concurrent solar wind observations, and qualitatively match the coronal holes segmented by other methods. The means to identify a coronal hole without specifying a final intensity threshold may allow this algorithm to be more robust across multiple datasets, regardless of data type, resolution, and quality.

  13. Segmentation of Coronal Holes Using Active Contours Without Edges

    Science.gov (United States)

    Boucheron, L. E.; Valluri, M.; McAteer, R. T. J.

    2016-09-01

    An application of active contours without edges is presented as an efficient and effective means of extracting and characterizing coronal holes. Coronal holes are regions of low-density plasma on the Sun with open magnetic field lines. The detection and characterization of these regions is important for testing theories of their formation and evolution, and also from a space weather perspective because they are the source of the fast solar wind. Coronal holes are detected in full-disk extreme ultraviolet (EUV) images of the corona obtained with the Solar Dynamics Observatory Atmospheric Imaging Assembly (SDO/AIA). The proposed method detects coronal boundaries without determining any fixed intensity value in the data. Instead, the active contour segmentation employs an energy-minimization in which coronal holes are assumed to have more homogeneous intensities than the surrounding active regions and quiet Sun. The segmented coronal holes tend to correspond to unipolar magnetic regions, are consistent with concurrent solar wind observations, and qualitatively match the coronal holes segmented by other methods. The means to identify a coronal hole without specifying a final intensity threshold may allow this algorithm to be more robust across multiple datasets, regardless of data type, resolution, and quality.

  14. Assessment of Coronal Radiographic Parameters of the Spine in the Treatment of Adolescent Idiopathic Scoliosis

    Directory of Open Access Journals (Sweden)

    Mohsen Karami

    2016-10-01

    Preoperative coronal balance is very important to make a balanced spine after surgery. Other parameters like Lenke classification or main thoracic overcorrection did not affect postoperative coronal decompensation.

  15. Bootstrapping the Coronal Magnetic Field with STEREO/EUVI

    Science.gov (United States)

    Aschwanden, Markus; Sandman, Anne

    2010-05-01

    The 3D coronal magnetic field obtained from stereoscopically triangulated loops has been compared with standard photospheric magnetogram extrapolations. We found a large misalignment of 20-40 deg, depending on the complexity of an AR (Sandman et al. 2009; DeRosa et al. 2009). These studies prove that the magnetic field in the photosphere is not force-free and fundamentally cannot reproduce the coronal magnetic field. Bootstrapping with coronal loop 3D geometries are required to improve modeling of the coronal field. Such coronal field bootstrapping methods are currently developed using stereoscopically triangulated loops from STEREO/EUVI and preliminary results show already a significantly reduced misalignment of 10-20 deg.

  16. Stellar Coronal Response to Differential Rotation and Flux Emergence

    CERN Document Server

    Gibb, G P S; Jardine, M M; Yeates, A R

    2016-01-01

    We perform a numerical parameter study to determine what effect varying differential rotation and flux emergence has on a star's non-potential coronal magnetic field. In particular we consider the effects on the star's surface magnetic flux, open magnetic flux, mean azimuthal field strength, coronal free magnetic energy, coronal heating and flux rope eruptions. To do this, we apply a magnetic flux transport model to describe the photospheric evolution, and couple this to the non-potential coronal evolution using a magnetofrictional technique. A flux emergence model is applied to add new magnetic flux onto the photosphere and into the corona. The parameters of this flux emergence model are derived from the solar flux emergence profile, however the rate of emergence can be increased to represent higher flux emergence rates than the Sun's. Overall we find that flux emergence has a greater effect on the non-potential coronal properties compared to differential rotation, with all the aforementioned properties incr...

  17. Observing Episodic Coronal Heating Events Rooted in Chromospheric Activity

    CERN Document Server

    McIntosh, Scott W

    2009-01-01

    We present results of a multi-wavelength study of episodic plasma injection into the corona of AR 10942. We exploit long-exposure images of the Hinode and Transition Region and Coronal Explorer (TRACE) spacecraft to study the properties of faint, episodic, "blobs" of plasma that are propelled upward along coronal loops that are rooted in the AR plage. We find that the source location and characteristic velocities of these episodic upflow events match those expected from recent spectroscopic observations of faint coronal upflows that are associated with upper chromospheric activity, in the form of highly dynamic spicules. The analysis presented ties together observations from coronal and chromospheric spectrographs and imagers, providing more evidence of the connection of discrete coronal mass heating and injection events with their source, dynamic spicules, in the chromosphere.

  18. Solar Wind Associated with Near Equatorial Coronal Hole

    Indian Academy of Sciences (India)

    M. Hegde; K. M. Hiremath; Vijayakumar H. Doddamani; Shashanka R. Gurumath

    2015-09-01

    Present study probes temporal changes in the area and radiative flux of near equatorial coronal hole associated with solar wind parameters such as wind speed, density, magnetic field and temperature. Using high temporal resolution data from SDO/AIA for the two wave-lengths 193 Å and 211 Å, area and radiative flux of coronal holes are extracted and are examined for the association with high speed solar wind parameters. We find a strong association between different parameters of coronal hole and solar wind. For both the wavelength bands, we also compute coronal hole radiative energy near the earth and it is found to be of similar order as that of solar wind energy. However, for the wavelength 193 Å, owing to almost similar magnitudes of energy emitted by coronal hole and energy due to solar wind, it is conjectured that solar wind might have originated around the same height where 193 Å line is formed in the corona.

  19. Observaciones de la corona solar interior con un coronógrafo de espejo

    Science.gov (United States)

    Stenborg, G.; Schwenn, R.; Francile, C.; Rovira, M.

    El plasma de la corona solar es un buen indicador de las líneas de fuerza del campo magnético. Por lo tanto, el análisis de estructuras coronales cuasiestacionarias en la corona da importante información sobre el campo magnético y la actividad asociada. Se trata de poner límites a los modelos teóricos existentes mediante el estudio de distintas estructuras en la corona interior. En agosto de 1997 comenzó a operar el coronógrafo solar (MICA) en El Leoncito como parte del Observatorio Solar Alemán-Argentino. Desde su instalación obtiene imágenes de la corona solar (1.05 a 2.0 radios solares) en 2 líneas espectrales correspondientes a la emisión de Fe XIV y Fe X. El instrumento puede obtener imágenes cada minuto por lo que es ideal para estudiar procesos rápidos. Presentamos observaciones recientes que muestran la capacidad del coronógrafo así como la evolución de algunos eventos dinámicos observados por MICA.

  20. An Estimate of Solar Wind Velocity Profiles in a Coronal Hole and Coronal Streamer Area (6-40R)

    Science.gov (United States)

    Patzold, M.; Tsurutani, B. T.; Bird, M. K.

    1995-01-01

    Using the total electron content data obtained by the Ulysses Solar Corona Experiment during the first solar conjunction in summer 1991 (Bird et al., 1994), an estimate is presented of solar wind velocity profiles in a coronal hole and a coronal streamer area in the range between 6 and 40 solar radii.

  1. Estudio de la pérdida dental en pacientes diagnosticados de periodontitis, tratados y controlados con terapia periodontal de soporte

    OpenAIRE

    Estefanía Fresco, Ruth

    2016-01-01

    173 p. Los objetivos son analizar la pérdida dental en los pacientes diagnosticados de periodontitis crónica o agresiva, tratados y mantenidos durante un mínimo de 5 años, así como reconocer cuáles son los factores de riesgo involucrados en la pérdida dental en estos pacientes. Para ello se diseñó un estudio retrospectivo y observacional, con un tamaño muestral de 175 pacientes. Los datos se recogieron revisando la historia clínica y los registros radiográficos, mediante una entrevista con...

  2. Estudio de los resultados del tratamiento con fármacos inmunomoduladores biológicos en la enfermedad autoinmune ocular

    OpenAIRE

    2014-01-01

    Establecer la e\\icacia y seguridad de los fármacos biológicos etenercept, in\\liximab, adalimumab y rituximab en la enfermedad autoinmune ocular en la Unidad de Inmunología Ocular del Hospital Clínico Universitario de Valladolid (HCUV) Diseño: Estudio retrospectivo de investigación clínica observacional. Material y método: Treinta y tres pacientes con enfermedad autoinmune ocular tratados con in\\liximab, adalimumab, etanercept y rituximab fueron identi\\icados de la Unidad de I...

  3. Estudio de los factores de riesgo de amputación en el pie diabético, evolución en una serie de 120 pacientes

    OpenAIRE

    Tomalá Pantaleón, Tito Peter

    2013-01-01

    Las amputaciones de los miembros inferiores por pie diabético son una de las dificultades más temidas por los pacientes que presentan Diabetes Mellitus. Se realizó un estudio descriptivo retrospectivo para comprobar la prevalencia de las amputaciones de los miembros inferiores en pacientes con diagnóstico de pie diabético, y su evolución en la Clínica Santa Gema de la Ciudad de Guayaquil, una evolución de 120 pacientes desde el año 2008 al 2011, en los resultados se ...

  4. Cushing pituitario dependiente: estudio comparativo del corticotropinoma y la secreción de ACTH y a-MSH según sexo y edad en el perro

    OpenAIRE

    Gallelli, María Florencia; Cabrera Blatter, María Fernanda; Castillo, Víctor Alejandro

    2010-01-01

    Existen pocos reportes acerca de la distribución de la Enfermedad de Cushing según edad y sexo en el perro, así como de las características morfológicas y funcionales del corticotropinoma en esta especie. Por lo tanto se realizó un estudio retrospectivo transversal en base a historias clínicas de perros con EC confirmada, atendidos en el periodo 2003-2008 en la Unidad de Endocrinología del Hospital Escuela de la Facultad de Ciencias Veterinarias, Universidad de Buenos Aires. Trabajo galard...

  5. La mamografía y la ecografía en el estudio de la patología mamaria en el varón

    OpenAIRE

    Muñoz Carrasco, Rafaela

    2011-01-01

    Objetivo: Valorar las variables clínicas que pueden ser útiles para diferenciar patología mamaria benigna de maligna y analizar la contribución de la mamografía y la ecografía en la evaluación de la mama masculina. Material y métodos: Estudio retrospectivo que incluye todos los pacientes varones que tuvieran realizada mamografía o ecografía entre 1993 y 2006 en nuestro hospital. Se comparan las características clínicas de los pacientes con patología mamaria benigna y maligna. Los hallazgos...

  6. Estudio de los factores de riesgo de amputación en el pie diabético, evolución en una serie de 120 pacientes

    OpenAIRE

    Tomalá Pantaleón, Tito Peter

    2013-01-01

    Las amputaciones de los miembros inferiores por pie diabético son una de las dificultades más temidas por los pacientes que presentan Diabetes Mellitus. Se realizó un estudio descriptivo retrospectivo para comprobar la prevalencia de las amputaciones de los miembros inferiores en pacientes con diagnóstico de pie diabético, y su evolución en la Clínica Santa Gema de la Ciudad de Guayaquil, una evolución de 120 pacientes desde el año 2008 al 2011, en los resultados se ...

  7. La Diabetes Mellitus tipo 1 en menores de 14 años. Estudio epidemiológico en Extremadura (1996-2011)

    OpenAIRE

    Fuentes Bolaños, Noemi Auxiliadora

    2016-01-01

    El aumento global de la incidencia de diabetes tipo 1 pone de manifiesto la necesidad de una monitorización continua de la epidemiología de esta enfermedad. Objetivos. 1. Analizar la incidencia de diabetes tipo 1 en la población pediátrica de Extremadura desde 1996 hasta 2011. 2. Definir las características clínico-epidemiológicas de este grupo poblacional. Sujetos y método. Estudio retrospectivo sobre la población menor de 14 años de edad que fue diagnosticada de diabetes tipo 1 en Extremadu...

  8. Magnetic structure of Coronal Mass Ejections

    CERN Document Server

    Lyutikov, Maxim

    2012-01-01

    We present several models of the magnetic structure of solar coronal mass ejections (CMEs). First, we model CMEs as expanding force-free magnetic structures. While keeping the internal magnetic field structure of the stationary solutions, expansion leads to complicated internal velocities and rotation, while the field structures remain force-free. Second, expansion of a CME can drive resistive dissipation within the CME changing the ionization states of different ions. We fit in situ measurements of ion charge states to the resistive spheromak solutions. Finally, we consider magnetic field structures of fully confined stable magnetic clouds containing both toroidal and poloidal magnetic fields and having no surface current sheets. Expansion of such clouds may lead to sudden onset of reconnection events.

  9. Coronal Mass Ejections: From Sun to Earth

    Science.gov (United States)

    Patsourakos, S.

    2016-06-01

    Coronal Mass Ejections (CMEs) are gigantic expulsions of magnetized plasmas from the solar corona into the interplanetary (IP) space. CMEs spawn ~ 1015 gr of mass and reach speeds ranging between several hundred to a few thousand km/s (e.g., Gopalswamy et al. 2009; Vourlidas et al. 2010). It takes 1-5 days for a CME to reach Earth. CMEs are one of the most energetic eruptive manifestations in the solar system and are major drivers of space weather via their magnetic fields and energetic particles, which are accelerated by CME-driven shocks. In this review we give a short account of recent, mainly observational, results on CMEs from the STEREO and SDO missions which include the nature of their pre-eruptive and eruptive configurations and the CME propagation from Sun to Earth. We conclude with a discussion of the exciting capabilities in CME studies that will soon become available from new solar and heliospheric instrumentation.

  10. Periodicities in Solar Coronal Mass Ejections

    CERN Document Server

    Lou, Y Q; Fan, Z; Wang, S; Wang, J

    2003-01-01

    Mid-term quasi-periodicities in solar coronal mass ejections (CMEs) during the most recent solar maximum cycle 23 are reported here for the first time using the four-year data (February 5, 1999 to February 10, 2003) of the Large Angle Spectrometric Coronagraph (LASCO) onboard the Solar and Heliospheric Observatory (SOHO). In parallel, mid-term quasi-periodicities in solar X-ray flares (class >M5.0) from the Geosynchronous Operational Environment Satellites (GOES) and in daily averages of Ap index for geomagnetic disturbances from the World Data Center (WDC) at the International Association for Geomagnetism and Aeronomy (IAGA) are also examined for the same four-year time span. Several conceptual aspects of possible equatorially trapped Rossby-type waves at and beneath the solar photosphere are discussed.

  11. Kinematical properties of coronal mass ejections

    CERN Document Server

    Temmer, Manuela

    2016-01-01

    Coronal mass ejections (CMEs) are the most dynamic phenomena in our solar system. They abruptly disrupt the continuous outflow of solar wind by expelling huge clouds of magnetized plasma into interplanetary space with velocities enabling to cross the Sun-Earth distance within a few days. Earth-directed CMEs may cause severe geomagnetic storms when their embedded magnetic fields and the shocks ahead compress and reconnect with the Earth's magnetic field. The transit times and impacts in detail depend on the initial CME velocity, size, and mass, as well as on the conditions and coupling processes with the ambient solar wind flow in interplanetary space. The observed CME parameters may be severly affected by projection effects and the constant changing environmental conditions are hard to derive. This makes it difficult to fully understand the physics behind CME evolution, preventing to do a reliable forecast of Earth-directed events. This short review focusing on observational data, shows recent methods which w...

  12. Coronal Neutrino Emission in Hypercritical Accretion Flows

    CERN Document Server

    Kawabata, R; Kawanaka, N

    2007-01-01

    Hypercritical accretion flows onto stellar mass black holes (BHs) are commonly considered as a promising model of central engines of gamma-ray bursts (GRBs). In this model a certain fraction of gravitational binding energy of accreting matter is deposited to the energy of relativistic jets via neutrino annihilation and/or magnetic fields. However, some recent studies have indicated that the energy deposition rate by neutrino annihilation is somewhat smaller than that needed to power a GRB. To overcome this difficulty, Ramirez-Ruiz & Socrates (2005) proposed that high energy neutrinos from hot corona above the accretion disk might enhance the efficiency of energy deposition. We elucidate the disk corona model in the context of hypercritical accretion flows. From the energy balance in the disk and the corona, we can calculate the disk and coronal temperature, Td and Tc, and neutrino spectra, taking into account the neutrino cooling processes by neutrino-electron scatterings and neutrino pair productions. Th...

  13. A magnetohydrodynamic theory of coronal loop transients

    Science.gov (United States)

    Yeh, T.

    1982-01-01

    The physical and geometrical characteristics of solar coronal loop transients are described in an MHD model based on Archimedes' MHD buoyancy force. The theory was developed from interpretation of coronagraphic data, particularly from Skylab. The brightness of a loop is taken to indicate the electron density, and successive pictures reveal the electron enhancement in different columns. The forces which lift the loop off the sun surface are analyzed as an MHD buoyancy force affecting every mass element by imparting an inertial force necessary for heliocentrifugal motion. Thermal forces are responsible for transferring the ambient stress to the interior of the loop to begin the process. The kinematic and hydrostatic buoyancy overcome the gravitational force, and a flux rope can then curve upward, spiralling like a corkscrew with varying cross section around the unwinding solar magnetic field lines.

  14. Solar Eruptions: Coronal Mass Ejections and Flares

    Science.gov (United States)

    Gopalswamy, Nat

    2012-01-01

    This lecture introduces the topic of Coronal mass ejections (CMEs) and solar flares, collectively known as solar eruptions. During solar eruptions, the released energy flows out from the Sun in the form of magnetized plasma and electromagnetic radiation. The electromagnetic radiation suddenly increases the ionization content of the ionosphere, thus impacting communication and navigation systems. Flares can be eruptive or confined. Eruptive flares accompany CMEs, while confined flares hav only electromagnetic signature. CMEs can drive MHD shocks that accelerate charged particles to very high energies in the interplanetary space, which pose radiation hazard to astronauts and space systems. CMEs heading in the direction of Earth arrive in about two days and impact Earth's magnetosphere, producing geomagnetic storms. The magnetic storms result in a number of effects including induced currnts that can disrupt power grids, railroads, and underground pipelines

  15. Stealthy but Geoeffective Coronal Mass Ejections

    Science.gov (United States)

    Nitta, Nariaki; Mulligan, Tamitha

    2017-08-01

    We have long known about the existence of "problem" geomagnetic storms whose origins are elusive. In more general terms, not all the 1 AU disturbances can be clearly attributed to coronal mass ejections (CMEs), high speed streams (HSSs) or corotation interaction regions (CIRs.) When interplanetary CME (ICME) signatures are found in in situ data, there is not always a flare or filament eruption on the Sun or even an obvious CME observed close to the Sun that correlates with the ICME within a reasonable time range. These ICMEs sometimes result in intense storms. Furthermore, there is a possibility that some of the more severe storms could be partly contributed by such ICMEs of unclear origin. Therefore space weather prediction will remain incomplete without properly understanding these ICMEs. Even if the ICME is paired with a CME, it is sometimes difficult to find where the latter comes from. This is often called the “stealth CME” that apparently lacks low coronal signatures (LCSs). STEREO's second and third view points have tremendously helped us determine its front-side origin and find when and where it forms and accelerates, which is important for isolating possible LCSs. Although SDO/AIA has been continuously taking full-disk EUV images in a wide temperature range since 2010, there are still a number of stealthy CMEs whose LCSs are unclear or ambiguous. It is assumed that they start at high altitudes, leaving weak or negligible LCSs. Some of them seem to involve multiple magnetic domains, and weak or open field regions. We present AIA observations of several stealthy CMEs, including recent ones, that were responsible for geomagnetic storms, emphasizing the need to compare images with long time differences and to find the periods at which the CME forms and accelerates. We also discuss uncertainties in interpreting in situ data as to whether a CME is present when data are dominated by other solar wind features, such as HSS and CIR.

  16. Numerical Simulation of DC Coronal Heating

    Science.gov (United States)

    Dahlburg, Russell B.; Einaudi, G.; Taylor, Brian D.; Ugarte-Urra, Ignacio; Warren, Harry; Rappazzo, A. F.; Velli, Marco

    2016-05-01

    Recent research on observational signatures of turbulent heating of a coronal loop will be discussed. The evolution of the loop is is studied by means of numerical simulations of the fully compressible three-dimensional magnetohydrodynamic equations using the HYPERION code. HYPERION calculates the full energy cycle involving footpoint convection, magnetic reconnection, nonlinear thermal conduction and optically thin radiation. The footpoints of the loop magnetic field are convected by random photospheric motions. As a consequence the magnetic field in the loop is energized and develops turbulent nonlinear dynamics characterized by the continuous formation and dissipation of field-aligned current sheets: energy is deposited at small scales where heating occurs. Dissipation is non-uniformly distributed so that only a fraction of thecoronal mass and volume gets heated at any time. Temperature and density are highly structured at scales which, in the solar corona, remain observationally unresolved: the plasma of the simulated loop is multi thermal, where highly dynamical hotter and cooler plasma strands are scattered throughout the loop at sub-observational scales. Typical simulated coronal loops are 50000 km length and have axial magnetic field intensities ranging from 0.01 to 0.04 Tesla. To connect these simulations to observations the computed number densities and temperatures are used to synthesize the intensities expected in emission lines typically observed with the Extreme ultraviolet Imaging Spectrometer (EIS) on Hinode. These intensities are then employed to compute differential emission measure distributions, which are found to be very similar to those derived from observations of solar active regions.

  17. The Dynamics of Coronal-Hole Boundaries

    Science.gov (United States)

    Higginson, A. K.; Antiochos, S. K.; DeVore, C. R.; Wyper, P. F.; Zurbuchen, T.

    2015-12-01

    The source of the slow solar wind at the Sun is the subject of intense debate in solar and heliospheric physics. Because the majority of the solar wind observed at Earth is slow wind, understanding its origin is essential for understanding and predicting Earth's space weather environment. In-situ and remote observations show that, compared to the fast wind, the slow solar wind corresponds to higher freeze-in temperatures, as indicated by charge-state ratios, and more corona-like elemental abundances. These results indicate that the most likely source for the slow wind is the hot plasma in the closed-field corona; however, the release mechanism for the wind from the closed-field regions is far from understood. Here we present the first fully dynamic, 3D MHD simulations of a coronal-hole boundary driven by photospheric convective flows. We determine in detail the opening and closing of coronal flux due to photospheric motions at the base of a helmet streamer. These changes should lead to the release of plasma from the closed magnetic field at the edge of the streamer. Our analysis demonstrates that the bulk of the release is due to interchange reconnection. We calculate the effective of numerical Lundquist number on the dynamics and discuss the implications of our results for theories of slow-wind origin, in particular the S-Web model. We also discuss the implications of our results for observations, in particular from the upcoming Solar Orbiter and Solar Probe Plus missions. This work was supported by the NASA SR&T and TR&T Programs.

  18. PROMINENCE ACTIVATION BY CORONAL FAST MODE SHOCK

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Takuya [Department of Astronomy, Kyoto University, Sakyo, Kyoto, 606-8502 (Japan); Asai, Ayumi [Unit of Synergetic Studies for Space, Kyoto University, Yamashina, Kyoto 607-8471 (Japan); Shibata, Kazunari, E-mail: takahashi@kwasan.kyoto-u.ac.jp [Kwasan and Hida Observatories, Kyoto University, Yamashina, Kyoto 607-8471 (Japan)

    2015-03-01

    An X5.4 class flare occurred in active region NOAA11429 on 2012 March 7. The flare was associated with a very fast coronal mass ejection (CME) with a velocity of over 2500 km s{sup −1}. In the images taken with the Solar Terrestrial Relations Observatory-B/COR1, a dome-like disturbance was seen to detach from an expanding CME bubble and propagated further. A Type-II radio burst was also observed at the same time. On the other hand, in extreme ultraviolet images obtained by the Solar Dynamic Observatory/Atmospheric Imaging Assembly (AIA), the expanding dome-like structure and its footprint propagating to the north were observed. The footprint propagated with an average speed of about 670 km s{sup −1} and hit a prominence located at the north pole and activated it. During the activation, the prominence was strongly brightened. On the basis of some observational evidence, we concluded that the footprint in AIA images and the ones in COR1 images are the same, that is, the MHD fast mode shock front. With the help of a linear theory, the fast mode Mach number of the coronal shock is estimated to be between 1.11 and 1.29 using the initial velocity of the activated prominence. Also, the plasma compression ratio of the shock is enhanced to be between 1.18 and 2.11 in the prominence material, which we consider to be the reason for the strong brightening of the activated prominence. The applicability of linear theory to the shock problem is tested with a nonlinear MHD simulation.

  19. Fisioterapia na paralisia facial periférica: estudo retrospectivo Physical therapy in peripheral facial paralysis: retrospective study

    Directory of Open Access Journals (Sweden)

    Márcia Regina Garanhani

    2007-02-01

    Full Text Available A paralisia facial periférica requer tratamento especializado. A fisioterapia tem como objetivo restabelecer a mímica facial. O objetivo deste estudo foi descrever e analisar os resultados da fisioterapia para indivíduos com paralisia facial periférica. FORMA DE ESTUDO: Retrospectivo. MÉTODO: Foi realizado um estudo retrospectivo em um Hospital Universitário, com autorização do Serviço de Atendimento Médico e Estatístico, no período de 1999 a 2003. Os dados são apresentados em forma descritiva, com utilização de média e mediana para variáveis numéricas e freqüência para variáveis categóricas. RESULTADOS: Foram analisados 23 prontuários durante quatro anos. Foi identificado o predomínio do sexo feminino e a média de idade foi de 32,3 anos (DP±16,5; 14 casos idiopáticas e cinco traumáticas; 12, com comprometimento motor total e 11, parcial; nos 12 casos com avaliação final, sete evoluíram para recuperação parcial e cinco para total. A fisioterapia utilizada foi cinesioterapia e orientações. CONCLUSÃO: Neste estudo os indivíduos são similares a outras populações. Foram tratados com cinesioterapia, como sugerido pela literatura científica e evoluíram com recuperação.Peripheral facial paralysis requires specialized treatment. Physical therapy aims at reestablishing facial movements. The aim of this study was to describe and to analyze physical therapy results for individuals with peripheral facial paralysis. STUDY DESIGN: Retrospective study. METHOD: A retrospective study was carried out at the University Hospital, authorized by the Statistics and Medical File Services, from 1999 to 2003. Data are presented in descriptive form with mean and median values for numeric variables and frequency for categorical variables. RESULTS: Twenty-three files were analyzed during four years. Females predominated and the average age was of 32.3 years (SD±16.5; 14 idiopathic and five trauma cases; 12 with total motor

  20. Coronal loops above an Active Region - observation versus model

    CERN Document Server

    Bourdin, Philippe-A; Peter, Hardi

    2014-01-01

    We conducted a high-resolution numerical simulation of the solar corona above a stable active region. The aim is to test the field-line braiding mechanism for a sufficient coronal energy input. We also check the applicability of scaling laws for coronal loop properties like the temperature and density. Our 3D-MHD model is driven from below by Hinode observations of the photosphere, in particular a high-cadence time series of line-of-sight magnetograms and horizontal velocities derived from the magnetograms. This driving applies stress to the magnetic field and thereby delivers magnetic energy into the corona, where currents are induced that heat the coronal plasma by Ohmic dissipation. We compute synthetic coronal emission that we directly compare to coronal observations of the same active region taken by Hinode. In the model, coronal loops form at the same places as they are found in coronal observations. Even the shapes of the synthetic loops in 3D space match those found from a stereoscopic reconstruction ...

  1. Transverse Oscillations in a Coronal Loop Triggered by a Jet

    Science.gov (United States)

    Sarkar, S.; Pant, V.; Srivastava, A. K.; Banerjee, D.

    2016-11-01

    We detect and analyse transverse oscillations in a coronal loop, lying at the south-east limb of the Sun as seen from the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO). The jet is believed to trigger transverse oscillations in the coronal loop. The jet originates from a region close to the coronal loop on 19 September 2014 at 02:01:35 UT. The length of the loop is estimated to be between 377 - 539 Mm. Only one complete oscillation is detected with an average period of about 32±5 min. Using magnetohydrodynamic (MHD) seismologic inversion techniques, we estimate the magnetic field inside the coronal loop to be between 2.68 - 4.5 G. The velocity of the hot and cool components of the jet is estimated to be 168 km s^{-1} and 43 km s^{-1}, respectively. The energy density of the jet is found to be greater than the energy density of the oscillating coronal loop. We therefore conclude that the jet triggered transverse oscillations in the coronal loop. To our knowledge, this is the first coronal loop seismology study using the properties of a jet propagation to trigger oscillations.

  2. Retrospective study of ocular disorders in Amazon parrots Estudo retrospectivo das alterações oculares observadas em papagaios

    Directory of Open Access Journals (Sweden)

    Ana Paula Hvenegaard

    2009-12-01

    Full Text Available A retrospective study was conducted to identify the occurrence and types of ocular disorders in 57 Amazon parrots admitted to the Ophthalmology Service, Veterinary Teaching Hospital, School of Veterinary Medicine, University of São Paulo, Brazil from 1997 to 2006. The most frequent observed disorder was cataracts, present in 24 of the 114 examined eyes (57 parrots. Uveitis, ulcerative keratitis and keratoconjunctivitis were frequently diagnosed as well. The cornea was the most affected ocular structure, with 28 reported disorders. Uveal disorders also were commonly observed. Conjunctiva and eyelid disorders were diagnosed in lower frequency. Results suggest that cataracts are common and that cornea, lens and uvea are the most affected ocular structures in Amazon parrots.Realizou-se estudo retrospectivo para identificar a ocorrência e os tipos de alterações oculares observadas em 57 papagaios atendidos no Serviço de Oftalmologia do Hospital Veterinário da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo (USP, de 1997-2006. Catarata em diferentes estágios de evolução foi a alteração ocular mais frequentemente diagnosticada, sendo observada em 24 dos 114 olhos examinados. Uveíte, ceratite ulcerativa e ceratoconjuntivite foram também diagnosticadas. A córnea foi a estrutura ocular mais acometida (28 registros. Alterações uveais foram frequentemente observadas. Alterações das pálpebras e conjuntiva foram observadas em menor freqüência. Concluí-se que catarata foi a alteração mais frequentemente observada e que a córnea, lente e úvea são as estruturas oculares mais susceptíveis a alterações em papagaios.

  3. Electroweak Hall Effect of Neutrino and Coronal Heating

    CERN Document Server

    Ishikawa, Kenzo

    2015-01-01

    The inversion of temperature at the solar corona is hard to understand from classical physics, and the coronal heating mechanism remains unclear. The heating in the quiet region seems contradicting with the thermodynamics and is a keen problem for physicists. A new mechanism for the coronal heating based on the neutrino radiative transition unique in the corona region is studied. The probability is enormously amplified by an electroweak Chern-Simons form and overlapping waves, and the sufficient energy is transfered. Thus the coronal heating is understood from the quantum effects of the solar neutrino.

  4. Magnetohydrodynamic waves and coronal seismology: an overview of recent results.

    Science.gov (United States)

    De Moortel, Ineke; Nakariakov, Valery M

    2012-07-13

    Recent observations have revealed that magnetohydrodynamic (MHD) waves and oscillations are ubiquitous in the solar atmosphere, with a wide range of periods. We give a brief review of some aspects of MHD waves and coronal seismology that have recently been the focus of intense debate or are newly emerging. In particular, we focus on four topics: (i) the current controversy surrounding propagating intensity perturbations along coronal loops, (ii) the interpretation of propagating transverse loop oscillations, (iii) the ongoing search for coronal (torsional) Alfvén waves, and (iv) the rapidly developing topic of quasi-periodic pulsations in solar flares.

  5. MHD Waves and Coronal Seismology: an overview of recent results

    CERN Document Server

    De Moortel, Ineke

    2012-01-01

    Recent observations have revealed that MHD waves and oscillations are ubiquitous in the solar atmosphere, with a wide range of periods. We give a brief review of some aspects of MHD waves and coronal seismology which have recently been the focus of intense debate or are newly emerging. In particular, we focus on four topics: (i) the current controversy surrounding propagating intensity perturbations along coronal loops, (ii) the interpretation of propagating transverse loop oscillations, (iii) the ongoing search for coronal (torsional) Alfven waves and (iv) the rapidly developing topic of quasi-periodic pulsations (QPP) in solar flares.

  6. Formation of the current sheet in a coronal streamer

    CERN Document Server

    Abbo, Lucia; Lionello, Roberto; Mikić, Zoran; Riley, Pete

    2011-01-01

    The present work is on the study of a coronal streamer observed in March 2008 at high spectral and spatial resolution by the Ultraviolet Coronagraph Spectrometer (UVCS) onboard SOHO. On the basis of a spectroscopic analysis of the O VI doublet, the solar wind plasma parameters are inferred in the extended corona. The analysis accounts for the coronal magnetic topology, extrapolated through a 3D magneto-hydrodynamic model. The results of the analysis show indications on the formation of the current sheet, one of the source regions of the slow coronal wind.

  7. Case report: pre-eruptive intra-coronal radiolucencies revisited.

    LENUS (Irish Health Repository)

    Counihan, K P

    2012-08-01

    Pre-eruptive intra-coronal radiolucency (PEIR) describes a radiolucent lesion located in the coronal dentine, just beneath the enamel-dentine junction of unerupted teeth. The prevalence of this lesion varies depending on the type and quality of radiographic exposure and age of patients used for assessment. The aetiology of pre-eruptive intra-coronal radiolucent lesions is not fully understood, but published clinical and histological evidence suggest that these lesions are resorptive in nature. Issues around the diagnosis, treatment planning and clinical management of this lesion are explored using previously unreported cases.

  8. un estudio comparativo

    Directory of Open Access Journals (Sweden)

    Federico Varona

    2007-01-01

    Full Text Available La comunicación efectiva es uno de los mayores retos que tienen hoy las organizaciones y empresas tanto a nivel nacional como internacional (global. Este artículo presenta los resultados de la investigación realizada por un equipo internacional de investigadores interesados en descubrir y comparar las conductas comunicativas o estilos de comunicación de los empleados finlandeses y mexicanos cuando interactúan con sus superiores. Para ello presentamos: primero, un breve marco teórico del estudio; segundo, la metodología; tercero, los resultados del análisis estadístico comparativo entre los empleados de Finlandia y México; cuarto, las conclusiones generales y su explicación cultural; y quinto, las implicaciones teóricas y prácticas de este estudio con respecto a las competencias comunicativas necesarias para la comunicación efectiva entre empleados y superiores tanto en organizaciones nacionales como internacionales (globales.

  9. Photospheric magnetic field of an eroded-by-solar-wind coronal mass ejection

    Science.gov (United States)

    Palacios, J.; Cid, C.; Saiz, E.; Guerrero, A.

    2017-10-01

    We have investigated the case of a coronal mass ejection that was eroded by the fast wind of a coronal hole in the interplanetary medium. When a solar ejection takes place close to a coronal hole, the flux rope magnetic topology of the coronal mass ejection (CME) may become misshapen at 1 AU as a result of the interaction. Detailed analysis of this event reveals erosion of the interplanetary coronal mass ejection (ICME) magnetic field. In this communication, we study the photospheric magnetic roots of the coronal hole and the coronal mass ejection area with HMI/SDO magnetograms to define their magnetic characteristics.

  10. Standing Slow MHD Waves in Radiatively Cooling Coronal Loops

    CERN Document Server

    Al-Ghafri, Khalil Salim

    2015-01-01

    The standing slow magneto-acoustic oscillations in cooling coronal loops are investigated. There are two damping mechanisms which are considered to generate the standing acoustic modes in coronal magnetic loops namely thermal conduction and radiation. The background temperature is assumed to change temporally due to optically thin radiation. In particular, the background plasma is assumed to be radiatively cooling. The effects of cooling on longitudinal slow MHD modes is analytically evaluated by choosing a simple form of radiative function that ensures the temperature evolution of the background plasma due to radiation coincides with the observed cooling profile of coronal loops. The assumption of low-beta plasma leads to neglect the magnetic field perturbation and eventually reduces the MHD equations to a 1D system modelling longitudinal MHD oscillations in a cooling coronal loop. The cooling is assumed to occur on a characteristic time scale much larger than the oscillation period that subsequently enables...

  11. Jet phenomena above null points of the coronal magnetic field

    Science.gov (United States)

    Filippov, B.; Koutchmy, S.; Golub, L.

    2009-12-01

    Short-lived plasma jets of various scales, from giant X-ray jets more than 300 Mm in extent to numerous small jets with sizes typical of macrospicules, are the phenomena observed in the solar corona in extreme ultraviolet and X-ray emission. Small jets are particularly prominent in polar coronal holes. They are close neighbors of tiny bright loops and coincide in time with their sudden brightening and increase in size. The geometric shape of the jets and their location suggest that they arise near singular null points of the coronal magnetic field. These points appear in coronal holes due to the emergence of small bipolar or unipolar magnetic structures within large-scale unipolar cells. Polar jets show a distinct vertical plasma motion in a coronal hole that introduces significant momentum and mass into the solar wind flow. Investigating the dynamics of polar jets can elucidate certain details in the problem of fast solar wind acceleration.

  12. The coronal magnetic field reversal observed by the SOLARC instrument

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    High-sensitivity measurements for mapping coronal magnetic field have become possible since the recent development of infrared detection techniques. One urgent task that arises from the routine infrared observations is to interpret what the Stokes signals could indicate for coronal magnetic fields. It is the first time for us to successfully reveal the coronal field structure above a simple and stable sunspot on the photosphere using profiles of full Stokes parameters. In this paper, the author further points out the deficiency in any conclusions/judgements just based on incomplete polarization data. A magnetic flux reversal feature, observed from circular polarization data, may correspond to one or more coronal tubes with their front or farside arching apex there, more complicated than people imagined before. To exactly locate the infrared radiation sources, we need both circular and linear polarization data for an integrated analysis of them.

  13. Cyclical Variation of the Quiet Corona and Coronal Holes

    Indian Academy of Sciences (India)

    Takashi Sakurai

    2000-09-01

    Recent advances in the understanding of the quiet corona and coronal holes are reviewed. The review is based on long-term accumulation of data from eclipse observations, coronagraph observations, helium 10830 Å spectroheliograms, and X-ray observations.

  14. Anticipating the Geoeffectiveness of Coronal Mass Ejections Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Coronal Mass Ejections (CMEs) are responsible for some of the most severe space weather at Earth. Major geomagnetic storms arise when CMEs carry large amounts of...

  15. Standing sausage modes in coronal loops with plasma flow

    CERN Document Server

    Li, Bo; Xia, Li-Dong; Yu, Hui

    2014-01-01

    Magnetohydrodynamic waves are important for diagnosing the physical parameters of coronal plasmas. Field-aligned flows appear frequently in coronal loops.We examine the effects of transverse density and plasma flow structuring on standing sausage modes trapped in coronal loops, and examine their observational implications. We model coronal loops as straight cold cylinders with plasma flow embedded in a static corona. An eigen-value problem governing propagating sausage waves is formulated, its solutions used to construct standing modes. Two transverse profiles are distinguished, one being the generalized Epstein distribution (profile E) and the other (N) proposed recently in Nakariakov et al.(2012). A parameter study is performed on the dependence of the maximum period $P_\\mathrm{max}$ and cutoff length-to-radius ratio $(L/a)_{\\mathrm{cutoff}}$ in the trapped regime on the density parameters ($\\rho_0/\\rho_\\infty$ and profile steepness $p$) and flow parameters (magnitude $U_0$ and profile steepness $u$). For e...

  16. DE AGUA. ESTUDIO PRELIMINAR

    Directory of Open Access Journals (Sweden)

    Esther E. Pellizzari

    2015-01-01

    Full Text Available El objetivo del presente estudio fue investigar la resistencia al arsénico en cultivos puros de Pseudomonas aeruginosa , aislada de aguas subterráneas de Presidencia Roque Sáenz Peña, provincia de Chaco y evaluar la posibilidad de su uso para la remoción de este contaminante presente en las aguas subterráneas. Las cepas fueron inmovilizadas en piedra natural y se cu ltivaron en caldo de sales y 1 mgAs/L . Se observó la resistencia al arsénico y la formación de biofilm , logrando la interacción entre la s células, roca y arsénico . L a remoción de arsénico se evaluó durante 3 meses y el porcentaje de eliminación de arsénico al final del experimento fue 60%.

  17. Dos estudios de casos

    Directory of Open Access Journals (Sweden)

    Hernán Guillermo Salazar Morales

    1989-04-01

    Full Text Available RESUMEN A continuación se presenta dos casos de estudio en donde se puede apreciar a la forma  como se establecen  las relaciones en una organización y lo que una DECISION  puede llegar a incidir en el desarrollo de las operaciones de una empresa. Decisiones basadas en la intuición, o en corazonadas, frecuentemente conducen en dirección equivocada, ocasionando pérdidas en tiempo, personal y dinero. El proceso de toma de decisiones deben ser TAREAS ESTRUCTURADAS que se sustenten con hechos. Su ejecución debe hacerse secuencialmente y cumplir con cada uno de sus pasos. El diseño de los  casos está orientado para que  sirvan como material de aplicación en la asignatura de  taller de planeación.

  18. Coronal Dynamics at Recent Total Solar Eclipses

    Science.gov (United States)

    Pasachoff, J. M.; Lu, M.; Davis, A. B.; Demianski, M.; Rusin, V.; Saniga, M.; Seaton, D. B.; Lucas, R.; Babcock, B. A.; Dantowitz, R.; Gaintatzis, P.; Seeger, C. H.; Malamut, C.; Steele, A.

    2014-12-01

    Our composite images of the solar corona based on extensive imaging at the total solar eclipses of 2010 (Easter Island), 2012 (Australia), and 2013 (Gabon) reveal several coronal mass ejections and other changes in coronal streamers and in polar plumes. Our resultant spatial resolution is finer than that available in imaging from spacecraft, including that from SOHO/LASCO or STEREO. We trace the eruptions back to their footpoints on the sun using imaging from SDO and SWAP, and follow them upwards through the corona, measuring velocities. The high-resolution computer compositing by Miloslav Druckmüller and Hana Druckmüllerová (2010 and 2013) and Pavlos Gaintatzis (2012) allows comparison of our images with those taken at intervals of minutes or hours along the totality path. Williams College's 2013 eclipse expedition was supported in part by grant 9327-13 from National Geographic Society/Committee for Research and Exploration. Our work on the 2012 eclipse is supported in part by grant AGS-1047726 from Solar Terrestrial Research/NSF AGS. V.R. and M.S. were partially supported by the VEGA grant agency project 2/0098/10 and 2/0003/13 (Slovak Academy of Sciences) and Grant 0139-12 from NG/CRE, and Hana Druckmüllerová by grant 205/09/1469 of the Czech Science Foundation. M.L. was supported by Sigma Xi. C.M. was a Keck Northeast Astronomy Consortium Summer Fellow, supported at Williams College by REU/NSF grant AST-1005024. Partial support was provided by U.S. Department of Defense's ASSURE program. J.M.P. thanks Caltech's Planetary Sciences Department for hospitality. Support for D.B.S. and SWAP came from PRODEX grant C90345 managed by ESA in collaboration with the Belgian Federal Science Policy Office (BELSPO) in support of the PROBA2/SWAP mission, and from the EC's Seventh Framework Programme (FP7/2007-2013) under grant 218816 (SOTERIA project, www.soteria-space.eu). SWAP is a project of the Centre Spatial de Liège and the Royal Observatory of Belgium funded by

  19. Exploración del modelo coronal MHD de Uchida

    Science.gov (United States)

    Francile, C.; Castro, J. I.; Flores, M.

    We present an analysis of the MHD model of an isothermal solar corona with radially symmetrical magnetic field and gravity. The solution in the approximation "WKB" was presented by Uchida (1968). The model is ex- plored for different coronal conditions and heights of initial perturbation to study the propagation of coronal waves and reproduce the observed char- acteristics of phenomena such as Moreton waves. Finally we discuss the obtained results. FULL TEXT IN SPANISH

  20. Observing the formation of flare-driven coronal rain

    OpenAIRE

    Scullion, E.; Rouppe van der Voort, L.; Antolin, P.; Wedemeyer, S.; Vissers, G.; E. P. Kontar; Gallagher, P

    2016-01-01

    PA. GV are funded by the European Research Council under the European Union Seventh Framework Programme (FP7/2007-2013) / ERC grant agreement nr. 291058 Flare-driven coronal rain can manifest from rapidly cooled plasma condensations near coronal loop-tops in thermally unstable post-flare arcades. We detect 5 phases that characterise the post-flare decay:heating, evaporation, conductive cooling dominance for ~120 s, radiative/ enthalpy cooling dominance for ~4700 s and finally catastrophic ...

  1. Are Spicules the Primary Source of Hot Coronal Plasma?

    Science.gov (United States)

    Klimchuk, James A.

    2011-01-01

    The recent discovery of Type II spicules has generated considerable excitement. It has even been suggested that these ejections can account for a majority of the hot plasma observed in the corona, thus obviating the need for "coronal" heating. If this is the case, however, then there should be observational consequences. We have begun to examine some of these consequences and find reason to question the idea that spicules are the primary source of hot coronal plasma.

  2. Culex coronator Dyar and Knab: a new Florida species record.

    Science.gov (United States)

    Smith, John P; Walsh, Jimmy D; Cope, Eric H; Tennant, Richard A; Kozak, John A; Darsie, Richard F

    2006-06-01

    We report the first finding of Culex coronator Dyar and Knab in Florida, based on multiple adult collections from several locations in the western panhandle of Florida. GPS coordinates and habitat descriptions are given and disease implications are discussed. These records extend the known distribution of Cx. coronator from six other states (Arizona, Louisiana, Mississippi, New Mexico, Oklahoma, and Texas), and from Mexico to Argentina.

  3. MHD Modeling of Differential Rotation in Coronal Holes

    Science.gov (United States)

    Lionello, Roberto; Linker, Jon A.; Mikic, Zoran; Riley, Pete

    2004-01-01

    The photosphere and the magnetic flux therein undergo differential rotation. Coronal holes appear to rotate almost rigidly. Magnetic reconnection has been invoked to reconcile these phenomena. Mechanism relevant to the formation of the slow solar wind. We have used our MHD model in spherical coordinates to study the effect of differential rotation on coronal holes. We have imposed a magnetic flux distribution similar to and applied differential rotation for the equivalent of 5 solar rotations.

  4. Mitochondrial genomes and comparative analyses of Culex camposi, Culex coronator, Culex usquatus and Culex usquatissimus (Diptera:Culicidae), members of the coronator group

    National Research Council Canada - National Science Library

    Demari-Silva, Bruna; Foster, Peter G; de Oliveira, Tatiane M P; Bergo, Eduardo S; Sanabani, Sabri S; Pessôa, Rodrigo; Sallum, Maria Anice M

    2015-01-01

    The Coronator Group currently encompasses six morphologically similar species (Culex camposi Dyar, Culex coronator Dyar and Knab, Culex covagarciai Forattini, Culex usquatus Dyar, Culex usquatissimus Dyar, and Culex ousqua Dyar...

  5. Estudio de competencias del teleformador

    OpenAIRE

    Marcelo, Carlos

    2005-01-01

    El Servicio Andaluz de Empleo de la Consejeria de Empleo de la Junta de Andalucia ha realizado un Estudio de Competencias del Teleformador. Este estudio establece un análisis de competencias necesarias para el diseño, desarrollo y gestión de acciones de e-Learning.

  6. Interação medicamentosa associada à reinternação hospitalar: estudo retrospectivo em um hospital geral

    Directory of Open Access Journals (Sweden)

    Cristiano Soares de Moura

    2012-12-01

    Full Text Available OBJETIVO: Analisar a relação entre interação medicamentosa potencial e reinternação hospitalar. MÉTODOS: Estudo retrospectivo com 1.487 pacientes maiores de 18 anos admitidos em um hospital geral em Vitória da Conquista, BA, de janeiro a dezembro de 2007. Os dados foram extraídos da Autorização de Internação Hospitalar do Sistema de Informação Hospitalar do Sistema Único de Saúde. O relacionamento probabilístico foi empregado para combinar múltiplas autorizações de uma mesma internação em um único registro e para identificar readmissões. Informações sobre prescrições foram agregadas manualmente aos registros do Sistema de Informação Hospitalar. Regressão logística foi utilizada para quantificar a influência de interação medicamentosa potencial e reinternação. Regressão de Cox foi empregada para testar a influência dessa variável no tempo até a primeira reinternação. RESULTADOS: Foram identificadas 99 readmissões (7% dos pacientes. Interação medicamentosa potencial foi encontrada em 35% das prescrições analisadas. Pacientes com potencial de interação medicamentosa na admissão prévia foram mais propensos à reinternação. A razão de chance ajustada indicou que esses pacientes tinham chance 2,4 vezes maior de readmissão; a taxa de risco ajustada mostrou que em pacientes com interação medicamentosa esse risco foi 79% maior (p < 0,01. CONCLUSÕES: Os resultados encontrados neste trabalho sugerem associação entre exposição à interação em internação prévia e risco aumentado de reinternação. Os profissionais de saúde devem atentar para os riscos potenciais de certas combinações medicamentosas e monitorar cuidadosamente pacientes em maior risco, como aqueles com insuficiência renal ou idosos.

  7. The Contribution of Coronal Jets To The Solar Wind

    CERN Document Server

    Lionello, R; Titov, V S; Leake, J E; MikiĆ, Z; Linker, J A; Linton, M G

    2016-01-01

    Transient collimated plasma eruptions in the solar corona, commonly known as coronal (or X-ray) jets, are among the most interesting manifestations of solar activity. It has been suggested that these events contribute to the mass and energy content of the corona and solar wind, but the extent of these contributions remains uncertain. We have recently modeled the formation and evolution of coronal jets using a three-dimensional (3D) magnetohydrodynamic (MHD) code with thermodynamics in a large spherical domain that includes the solar wind. Our model is coupled to 3D MHD flux-emergence simulations, i.e, we use boundary conditions provided by such simulations to drive a time-dependent coronal evolution. The model includes parametric coronal heating, radiative losses, and thermal conduction, which enables us to simulate the dynamics and plasma properties of coronal jets in a more realistic manner than done so far. Here we employ these simulations to calculate the amount of mass and energy transported by coronal j...

  8. Evolving Coronal Holes and Interplanetary Erupting Stream Disturbances

    Indian Academy of Sciences (India)

    Rajendra Shelke

    2006-06-01

    Coronal holes and interplanetary disturbances are important aspects of the physics of the Sun and heliosphere. Interplanetary disturbances are identified as an increase in the density turbulence compared with the ambient solar wind. Erupting stream disturbances are transient large-scale structures of enhanced density turbulence in the interplanetary medium driven by the high-speed flows of low-density plasma trailing behind for several days. Here, an attempt has been made to investigate the solar cause of erupting stream disturbances, mapped by Hewish & Bravo (1986) from interplanetary scintillation (IPS) measurements made between August 1978 and August 1979 at 81.5 MHz. The position of the sources of 68 erupting stream disturbances on the solar disk has been compared with the locations of newborn coronal holes and/or the areas that have been coronal holes previously. It is found that the occurrence of erupting stream disturbances is linked to the emergence of newcoronal holes at the eruption site on the solar disk. A coronal hole is indicative of a radial magnetic field of a predominant magnetic polarity. The newborn coronal hole emerges on the Sun, owing to the changes in magnetic field configuration leading to the opening of closed magnetic structure into the corona. The fundamental activity for the onset of an erupting stream seems to be a transient opening of pre-existing closed magnetic structures into a new coronal hole, which can support high-speed flow trailing behind the compression zone of the erupting stream for several days.

  9. Transverse oscillations in a coronal loop triggered by a jet

    CERN Document Server

    Sarkar, S; Srivastava, A K; Banerjee, D

    2016-01-01

    We detect and analyse transverse oscillations in a coronal loop, lying at the south east limb of the Sun as seen from the \\textit{{Atmospheric Imaging Assembly}} (AIA) onboard \\textit{{Solar Dynamics Observatory}} (SDO). The jet is believed to trigger transverse oscillations in the coronal loop. The jet originates from a region close to the coronal loop on 19$^{\\rm th}$ September 2014 at 02:01:35 UT. The length of the loop is estimated to be between 377-539~Mm. Only one complete oscillation is detected with an average period of about $32\\pm5$~min. Using MHD seismologic inversion techniques, we estimate the magnetic field inside the coronal loop to be between $2.68 -4.5$~G. The velocity of the hot and cool components of the jet is estimated to be 168~km~s$^{-1}$ and 43~km~s$^{-1}$, respectively. The energy density of the jet is found to be greater than the energy density of the oscillating coronal loop. Therefore, we conclude that the jet {triggered} transverse oscillations in the coronal loop. To our knowledg...

  10. Resultados del estudio PROMESA I: eficacia y seguridad de la aplicación de una dieta de muy bajo aporte calórico y reeducación alimentaria posterior mediante el método PronoKal® en el tratamiento del exceso de peso

    OpenAIRE

    Amparo Martínez-Riquelme; Ignacio Sajoux; Joan Fondevila

    2014-01-01

    Introducción y Objetivos: El objetivo de este estudio fue evaluar la eficacia en la reducción de peso con la utilización de dieta de muy bajo aporte calórico cetogénica y posterior reeducación alimentaria según el método PronoKal® en pacientes con sobrepeso y obesidad, y la seguridad durante su aplicación. Métodos: Estudio multicéntrico observacional, retrospectivo en que se analizaron estadísticamente variables descriptivas de los pacientes, variables relacionadas con el cambio ponderal, cir...

  11. Stellar Differential Rotation and Coronal Timescales

    CERN Document Server

    Gibb, G P S; Mackay, D H

    2014-01-01

    We investigate the timescales of evolution of stellar coronae in response to surface differential rotation and diffusion. To quantify this we study both the formation time and lifetime of a magnetic flux rope in a decaying bipolar active region. We apply a magnetic flux transport model to prescribe the evolution of the stellar photospheric field, and use this to drive the evolution of the coronal magnetic field via a magnetofrictional technique. Increasing the differential rotation (i.e. decreasing the equator-pole lap time) decreases the flux rope formation time. We find that the formation time is dependent upon the geometric mean of the lap time and the surface diffusion timescale. In contrast, the lifetime of flux ropes are proportional to the lap time. With this, flux ropes on stars with a differential rotation of more than eight times the solar value have a lifetime of less than two days. As a consequence, we propose that features such as solar-like quiescent prominences may not be easily observable on s...

  12. Radio-quiet Fast Coronal Mass Ejections

    Science.gov (United States)

    Gopalswamy, N.; Aguilar-Rodriguez, E.; Kaiser, M. L.; Howard, R. A.

    2004-12-01

    Coronal mass ejections (CMEs) drive shocks in the interplanetary medium that produce type II radio emission. These CMEs are faster and wider on the average, than the general population of CMEs. However, when we start from fast (speed > 900 km/s) and wide (angular width > 60 degrees), more than half of them are not associated with radio bursts. In order to understand why these CMEs are radio quiet, we collected all the fast and wide (FW) CMEs detected by the Solar and Heliospheric Observatory (SOHO) mission's Large Angle and Spectrometric Coronagraph (LASCO) and isolated those without associated type II radio bursts. The radio bursts were identified in the dynamic spectra of the Radio and Plasma Wave (WAVES) Experiment on board the Wind spacecraft. We also checked the list against metric type II radio bursts reported in Solar Geophysical Data and isolated those without any radio emission. This exercise resulted in about 140 radio-quiet FW CMEs. We identified the source regions of these CMEs using the Solar Geophysical Data listings, cross-checked against the eruption regions in the SOHO/EIT movies. We explored a number of possibilities for the radio-quietness: (i) Source region being too far behind the limb, (ii) flare size, (iii) brightness of the CME, and (iv) the density of the ambient medium. We suggest that a combination of CME energy and the Alfven speed profile of the ambient medium is primarily responsible for the radio-quietness of these FW CMEs.

  13. Anatomy of Depleted Interplanetary Coronal Mass Ejections

    Science.gov (United States)

    Kocher, M.; Lepri, S. T.; Landi, E.; Zhao, L.; Manchester, W. B., IV

    2017-01-01

    We report a subset of interplanetary coronal mass ejections (ICMEs) containing distinct periods of anomalous heavy-ion charge state composition and peculiar ion thermal properties measured by ACE/SWICS from 1998 to 2011. We label them “depleted ICMEs,” identified by the presence of intervals where C6+/C5+ and O7+/O6+ depart from the direct correlation expected after their freeze-in heights. These anomalous intervals within the depleted ICMEs are referred to as “Depletion Regions.” We find that a depleted ICME would be indistinguishable from all other ICMEs in the absence of the Depletion Region, which has the defining property of significantly low abundances of fully charged species of helium, carbon, oxygen, and nitrogen. Similar anomalies in the slow solar wind were discussed by Zhao et al. We explore two possibilities for the source of the Depletion Region associated with magnetic reconnection in the tail of a CME, using CME simulations of the evolution of two Earth-bound CMEs described by Manchester et al.

  14. Multiscale Modeling of Solar Coronal Magnetic Reconnection

    Science.gov (United States)

    Antiochos, Spiro K.; Karpen, Judith T.; DeVore, C. Richard

    2010-01-01

    Magnetic reconnection is widely believed to be the primary process by which the magnetic field releases energy to plasma in the Sun's corona. For example, in the breakout model for the initiation of coronal mass ejections/eruptive flares, reconnection is responsible for the catastrophic destabilizing of magnetic force balance in the corona, leading to explosive energy release. A critical requirement for the reconnection is that it have a "switch-on' nature in that the reconnection stays off until a large store of magnetic free energy has built up, and then it turn on abruptly and stay on until most of this free energy has been released. We discuss the implications of this requirement for reconnection in the context of the breakout model for CMEs/flares. We argue that it imposes stringent constraints on the properties of the flux breaking mechanism, which is expected to operate in the corona on kinetic scales. We present numerical simulations demonstrating how the reconnection and the eruption depend on the effective resistivity, i.e., the effective Lundquist number, and propose a model for incorporating kinetic flux-breaking mechanisms into MHO calculation of CMEs/flares.

  15. Potential Method of Predicting Coronal Mass Ejection

    Science.gov (United States)

    Imholt, Timothy

    2001-10-01

    Coronal Mass Ejections (CME) may be described as a blast of gas and highly charged solar mass fragments ejected into space. These ejections, when directed toward Earth, have many different effects on terrestrial systems ranging from the Aurora Borealis to changes in wireless communication. The early prediction of these solar events cannot be overlooked. There are several models currently accepted and utilized to predict these events, however, with earlier prediction of both the event and the location on the sun where the event occurs allows us to have earlier warnings as to when they will affect man-made systems. A better prediction could perhaps be achieved by utilizing low angular resolution radio telescope arrays to catalog data from the sun at different radio frequencies on a regular basis. Once this data is cataloged a better predictor for these CME’s could be found. We propose a model that allows a prediction to be made that appears to be longer than 24 hours.

  16. Are Coronal Loops Isothermal or Multithermal? Yes!

    CERN Document Server

    Schmelz, J T; Rightmire, L A; Kimble, J A; Del Zanna, G; Cirtain, J W; DeLuca, E E; Mason, H E

    2009-01-01

    Surprisingly few solar coronal loops have been observed simultaneously with TRACE and SOHO/CDS, and even fewer analyses of these loops have been conducted and published. The SOHO Joint Observing Program 146 was designed in part to provide the simultaneous observations required for in-depth temperature analysis of active region loops and determine whether these loops are isothermal or multithermal. The data analyzed in this paper were taken on 2003 January 17 of AR 10250. We used TRACE filter ratios, emission measure loci, and two methods of differential emission measure analysis to examine the temperature structure of three different loops. TRACE and CDS observations agree that Loop 1 is isothermal with Log T $=$ 5.85, both along the line of sight as well as along the length of the loop leg that is visible in the CDS field of view. Loop 2 is hotter than Loop 1. It is multithermal along the line of sight, with significant emission between 6.2 $<$ Log T $<$ 6.4, but the loop apex region is out of the CDS ...

  17. Geometric Model of a Coronal Cavity

    Science.gov (United States)

    Kucera, Therese A.; Gibson, S. E.; Ratawicki, D.; Dove, J.; deToma, G.; Hao, J.; Hudson, H. S.; Marque, C.; McIntosh, P. S.; Reeves, K. K.; hide

    2010-01-01

    We observed a coronal cavity from August 8-18 2007 during a multi-instrument observing campaign organized under the auspices of the International Heliophysical Year (IHY). Here we present initial efforts to model the cavity with a geometrical streamer-cavity model. The model is based the white-light streamer mode] of Gibson et a]. (2003 ), which has been enhanced by the addition of a cavity and the capability to model EUV and X-ray emission. The cavity is modeled with an elliptical cross-section and Gaussian fall-off in length and width inside the streamer. Density and temperature can be varied in the streamer and cavity and constrained via comparison with data. Although this model is purely morphological, it allows for three-dimensional, multi-temperature analysis and characterization of the data, which can then provide constraints for future physical modeling. Initial comparisons to STEREO/EUVI images of the cavity and streamer show that the model can provide a good fit to the data. This work is part of the effort of the International Space Science Institute International Team on Prominence Cavities

  18. Surface Flux Emergence and Coronal Eruption

    Science.gov (United States)

    Fang, Fang

    2016-05-01

    Among various active regions, delta-sunspots of aggregated spots of opposite polarities, are of particular interest due to their high productivity in energetic and recurrent eruptive events, such as X-class flares and homologous eruptions. We here study the formation of such complex magnetic structures by numerical simulations of magnetic flux emergence from the convection zone into the corona in an active-region scale domain. In our simulation, two pairs of bipolar sunspots form on the surface, originating from two buoyant segments of a single subsurface twisted flux rope. Expansion and rotation of the emerging fields in the two bipoles drive the two opposite polarities into each other with apparent rotating motion, producing a compact delta-sunspot with a sharp polarity inversion line (PIL). The formation of the delta-sunspot in such a realistic-scale domain produces emerging patterns similar to those formed in observations, e.g. the inverted polarity against Hale’s law, the curvilinear motion of the spot, strong transverse field with highly sheared magnetic and velocity fields at the PIL. Strong current builds up at the PIL, giving rise to reconnection, which produces a complex coronal magnetic connectivity with non-potential fields in the delta-spot overlaid by more relaxed fields connecting the two polarities at the two ends.

  19. Coronal activity from the ASAS eclipsing binaries

    CERN Document Server

    Szczygiel, D M; Paczynski, B; Pojmanski, G; Pilecki, B

    2008-01-01

    We combine the catalogue of eclipsing binaries from the All Sky Automated Survey (ASAS) with the ROSAT All Sky Survey (RASS). The combination results in 836 eclipsing binaries that display coronal activity and is the largest sample of active binary stars assembled to date. By using the (V-I) colors of the ASAS eclipsing binary catalogue, we are able to determine the distances and thus bolometric luminosities for the majority of eclipsing binaries that display significant stellar activity. A typical value for the ratio of soft X-ray to bolometric luminosity is L_X/L_bol ~ a few x 10^-4, similar to the ratio of soft X-ray to bolometric flux F_X/F_bol in the most active regions of the Sun. Unlike rapidly rotating isolated late-type dwarfs -- stars with significant outer convection zones -- a tight correlation between Rossby number and activity of eclipsing binaries is absent. We find evidence for the saturation effect and marginal evidence for the so-called "super-saturation" phenomena. Our work shows that wide-...

  20. Geometric Model of a Coronal Cavity

    Science.gov (United States)

    Kucera, Therese A.; Gibson, S. E.; Ratawicki, D.; Dove, J.; deToma, G.; Hao, J.; Hudson, H. S.; Marque, C.; McIntosh, P. S.; Reeves, K. K.; Schmidt, D. J.; Sterling, A. C.; Tripathi, D. K.; Williams, D. R.; Zhang, M.

    2010-01-01

    We observed a coronal cavity from August 8-18 2007 during a multi-instrument observing campaign organized under the auspices of the International Heliophysical Year (IHY). Here we present initial efforts to model the cavity with a geometrical streamer-cavity model. The model is based the white-light streamer mode] of Gibson et a]. (2003 ), which has been enhanced by the addition of a cavity and the capability to model EUV and X-ray emission. The cavity is modeled with an elliptical cross-section and Gaussian fall-off in length and width inside the streamer. Density and temperature can be varied in the streamer and cavity and constrained via comparison with data. Although this model is purely morphological, it allows for three-dimensional, multi-temperature analysis and characterization of the data, which can then provide constraints for future physical modeling. Initial comparisons to STEREO/EUVI images of the cavity and streamer show that the model can provide a good fit to the data. This work is part of the effort of the International Space Science Institute International Team on Prominence Cavities

  1. Why are halo coronal mass ejections faster?

    Institute of Scientific and Technical Information of China (English)

    Qing-Min Zhang; Yang Guo; Peng-Fei Chen; Ming-De Ding; Cheng Fang

    2010-01-01

    Halo coronal mass ejections(CMEs)have been to be significantly faster than normal CMEs,which is a long-standing puzzle.In order to solve the puzzle,we first investigate the observed properties of 31 limb CMEs that clearly display loopshaped frontal loops.The observational results show a strong tendency that slower CMEs are weaker in white-light intensity.Then,we perform a Monte Carlo simulation of 20000 artificial limb CMEs that have an average velocity of~523 km s-1.The Thomson scattering of these events is calculated when they are assumed to be observed as limb and halo events,respectively.It is found that the white-light intensity of many slow CMEs becomes remarkably reduced when they turn from being viewed as a limb event to being viewed as a halo event.When the intensity is below the background solar wind fluctuation,it is assumed that they would be missed by coronagraphs.The average velocity of"detectable"halo CMEs is~922 km s-1,very close to the observed value.This also indicates that wider events are more likely to be recorded.The results soundly suggest that the higher average velocity of halo CMEs is due to that a majority of slow events and some of narrow fast events carrying less material are so faint that they are blended with the solar wind fluctuations,and therefore are not observed.

  2. Active Longitude and Coronal Mass Ejection Occurrences

    Science.gov (United States)

    Gyenge, N.; Singh, T.; Kiss, T. S.; Srivastava, A. K.; Erdélyi, R.

    2017-03-01

    The spatial inhomogeneity of the distribution of coronal mass ejection (CME) occurrences in the solar atmosphere could provide a tool to estimate the longitudinal position of the most probable CME-capable active regions in the Sun. The anomaly in the longitudinal distribution of active regions themselves is often referred to as active longitude (AL). In order to reveal the connection between the AL and CME spatial occurrences, here we investigate the morphological properties of active regions. The first morphological property studied is the separateness parameter, which is able to characterize the probability of the occurrence of an energetic event, such as a solar flare or CME. The second morphological property is the sunspot tilt angle. The tilt angle of sunspot groups allows us to estimate the helicity of active regions. The increased helicity leads to a more complex buildup of the magnetic structure and also can cause CME eruption. We found that the most complex active regions appear near the AL and that the AL itself is associated with the most tilted active regions. Therefore, the number of CME occurrences is higher within the AL. The origin of the fast CMEs is also found to be associated with this region. We concluded that the source of the most probably CME-capable active regions is at the AL. By applying this method, we can potentially forecast a flare and/or CME source several Carrington rotations in advance. This finding also provides new information for solar dynamo modeling.

  3. A Catalog of Coronal "EIT Wave" Transients

    Science.gov (United States)

    Thompson, B. J.; Myers, D. C.

    2009-01-01

    Solar and Heliospheric Observatory (SOHO) Extreme ultraviolet Imaging Telescope (EIT) data have been visually searched for coronal "EIT wave" transients over the period beginning from 1997 March 24 and extending through 1998 June 24. The dates covered start at the beginning of regular high-cadence (more than one image every 20 minutes) observations, ending at the four-month interruption of SOHO observations in mid-1998. One hundred and seventy six events are included in this catalog. The observations range from "candidate" events, which were either weak or had insufficient data coverage, to events which were well defined and were clearly distinguishable in the data. Included in the catalog are times of the EIT images in which the events are observed, diagrams indicating the observed locations of the wave fronts and associated active regions, and the speeds of the wave fronts. The measured speeds of the wave fronts varied from less than 50 to over 700 km s(exp -1) with "typical" speeds of 200-400 km s(exp -1).

  4. Energy Release in Driven Twisted Coronal Loops

    Science.gov (United States)

    Bareford, M. R.; Gordovskyy, M.; Browning, P. K.; Hood, A. W.

    2016-01-01

    We investigate magnetic reconnection in twisted magnetic fluxtubes, representing coronal loops. The main goal is to establish the influence of the field geometry and various thermodynamic effects on the stability of twisted fluxtubes and on the size and distribution of heated regions. In particular, we aim to investigate to what extent the earlier idealised models, based on the initially cylindrically symmetric fluxtubes, are different from more realistic models, including the large-scale curvature, atmospheric stratification, thermal conduction and other effects. In addition, we compare the roles of Ohmic heating and shock heating in energy conversion during magnetic reconnection in twisted loops. The models with straight fluxtubes show similar distribution of heated plasma during the reconnection: it initially forms a helical shape, which subsequently becomes very fragmented. The heating in these models is rather uniformly distributed along fluxtubes. At the same time, the hot plasma regions in curved loops are asymmetric and concentrated close to the loop tops. Large-scale curvature has a destabilising influence: less twist is needed for instability. Footpoint convergence normally delays the instability slightly, although in some cases, converging fluxtubes can be less stable. Finally, introducing a stratified atmosphere gives rise to decaying wave propagation, which has a destabilising effect.

  5. Análise retrospectiva dos registros de enfermagem em uma unidade especializada Análisis retrospectivo de los registros de enfermaría en una unidad especializada Retrospective analysis of nursing records at a specialized unit

    Directory of Open Access Journals (Sweden)

    Kattia Ochoa-Vigo

    2003-03-01

    Full Text Available Estudo retrospectivo longitudinal, realizado em unidade especializada do interior do Brasil, teve como objetivo verificar as diferenças dos registros de enfermagem quanto ao modo de documentar a assistência oferecida ao paciente, em três períodos relacionados com a implementação do Processo de Enfermagem. Coletaram-se os dados em 20% dos prontuários de pacientes acima de15 anos, selecionados aleatoriamente, segundo distribuição proporcional, que foram transcritos integralmente, no instrumento construído para essa finalidade, e classificados a partir das propostas do referencial. Para a análise, utilizou-se o Teste Binomial a 0,05% de significância. Nos resultados, observou-se tendência para melhoria nos registros quanto à intelecção da escrita e descrição completa de sinais/sintomas no segundo período. Concluiu-se que houve diferença entre os períodos inicial e de pré-implementação, fato que expressa necessidade de rever o modo de desenvolver-se o Processo de Enfermagem como responsabilidade de toda a equipe de enfermagem.Estudio retrospectivo longitudinal, realizado en una unidad especializada en el interior del Brasil que tuvo como objetivo verificar las diferencias en los registros de enfermería cuanto al modo de documentar la asistencia ofrecida al paciente en tres periodos relacionados con la implementación del Proceso de Enfermería. Se colectaron datos del 20% de las historias clínicas de pacientes mayores de 15 años, seleccionados aleatoriamente según distribución proporcional, que fueron transcritos íntegramente en un instrumento construido para esta finalidad e clasificados a partir de las propuestas del referencial. Para el análisis se utilizó el Test Binomial a 0,05% de significancia. En los resultados se observó tendencia para mejoría en los registros cuanto a la intelección de la escritura y descripción de signos/síntomas en el segundo periodo. Se concluye que hubo diferencia entre los per

  6. Estrabismo em idade ambliogénica: estudo retrospectivo de 12 meses consecutivos de referenciação oftalmológica hospitalar

    OpenAIRE

    Monteiro, Sílvia

    2017-01-01

    Introdução: O objectivo deste trabalho é a análise do estado actual da referenciação oftalmológica hospitalar de casos de estrabismo em idade pediátrica.Métodos: Estudo retrospectivo e descritivo dos processos clínicos das crianças com idade menor ou igual a 10 anos referenciadas à Consulta de Oftalmologia Pediátrica do Centro Hospitalar do Porto entre Julho de 2011 e Julho de 2012.Resultados: Das 649 crianças referenciadas, 267 (41.1%) foram por suspeita de estrabismo. Em 109 (40.8%) dessas ...

  7. ON THE RELATIONSHIP BETWEEN THE CORONAL MAGNETIC DECAY INDEX AND CORONAL MASS EJECTION SPEED

    Energy Technology Data Exchange (ETDEWEB)

    Xu Yan; Liu Chang; Jing Ju; Wang Haimin, E-mail: yx2@njit.edu [Space Weather Research Lab, Center for Solar-Terrestrial Research, New Jersey Institute of Technology, 323 Martin Luther King Boulevard, Newark, NJ 07102-1982 (United States)

    2012-12-10

    Numerical simulations suggest that kink and torus instabilities are two potential contributors to the initiation and prorogation of eruptive events. A magnetic parameter called the decay index (i.e., the coronal magnetic gradient of the overlying fields above the eruptive flux ropes) could play an important role in controlling the kinematics of eruptions. Previous studies have identified a threshold range of the decay index that distinguishes between eruptive and confined configurations. Here we advance the study by investigating if there is a clear correlation between the decay index and coronal mass ejection (CME) speed. Thirty-eight CMEs associated with filament eruptions and/or two-ribbon flares are selected using the H{alpha} data from the Global H{alpha} Network. The filaments and flare ribbons observed in H{alpha} associated with the CMEs help to locate the magnetic polarity inversion line, along which the decay index is calculated based on the potential field extrapolation using Michelson Doppler Imager magnetograms as boundary conditions. The speeds of CMEs are obtained from the LASCO C2 CME catalog available online. We find that the mean decay index increases with CME speed for those CMEs with a speed below 1000 km s{sup -1} and stays flat around 2.2 for the CMEs with higher speeds. In addition, we present a case study of a partial filament eruption, in which the decay indices show different values above the erupted/non-erupted part.

  8. MAGNETIC FLUX SUPPLEMENT TO CORONAL BRIGHT POINTS

    Energy Technology Data Exchange (ETDEWEB)

    Mou, Chaozhou; Huang, Zhenghua; Xia, Lidong; Li, Bo; Fu, Hui; Jiao, Fangran; Hou, Zhenyong [Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, Institute of Space Sciences, Shandong University, Weihai, 264209 Shandong (China); Madjarska, Maria S., E-mail: z.huang@sdu.edu.cn [Armagh Observatory, College Hill, Armagh BT61 9DG (United Kingdom)

    2016-02-10

    Coronal bright points (BPs) are associated with magnetic bipolar features (MBFs) and magnetic cancellation. Here we investigate how BP-associated MBFs form and how the consequent magnetic cancellation occurs. We analyze longitudinal magnetograms from the Helioseismic and Magnetic Imager to investigate the photospheric magnetic flux evolution of 70 BPs. From images taken in the 193 Å passband of the Atmospheric Imaging Assembly (AIA) we dermine that the BPs’ lifetimes vary from 2.7 to 58.8 hr. The formation of the BP MBFs is found to involve three processes, namely, emergence, convergence, and local coalescence of the magnetic fluxes. The formation of an MBF can involve more than one of these processes. Out of the 70 cases, flux emergence is the main process of an MBF buildup of 52 BPs, mainly convergence is seen in 28, and 14 cases are associated with local coalescence. For MBFs formed by bipolar emergence, the time difference between the flux emergence and the BP appearance in the AIA 193 Å passband varies from 0.1 to 3.2 hr with an average of 1.3 hr. While magnetic cancellation is found in all 70 BPs, it can occur in three different ways: (I) between an MBF and small weak magnetic features (in 33 BPs); (II) within an MBF with the two polarities moving toward each other from a large distance (34 BPs); (III) within an MBF whose two main polarities emerge in the same place simultaneously (3 BPs). While an MBF builds up the skeleton of a BP, we find that the magnetic activities responsible for the BP heating may involve small weak fields.

  9. Forecasting Coronal Mass Ejections from Vector Magnetograms

    Science.gov (United States)

    Falconer, D. A.; Moore, R. L.; Gary, G. A.; Six, N. Frank (Technical Monitor)

    2002-01-01

    In a 17 vector magnetogram study of 12 bipolar active regions (Falconer, Moore, & Gary, 2002, ApJ in press), we correlated four quantitative global magnetic measures with the Coronal Mass Ejections (CME) productivity of the active region. The global measures included a measure of active region size, the total magnetic flux phi and three measures of an active region global nonpotentiality 1) the net current (I (sub N)), 2) the length of the strong-shear, strong-field main neutral line (L(sub SS)) and 3) and the normalized twist (alpha = muIN/PHI). The CME productivity was determined from YOHKOH/SXT observations, Geostationary Operational Environmental Satellite (GOES), and when possible Solar and Heliospheric Observatory/Large Angle and Spectrometric Coronagraph Experiment (SOHO/LASCO) observations within 12 days of the day of the magnetogram. We found that the three measures of global nonpotentiality (I(sub N), L(sub SS), alpha) were all well correlated (greater than 99% confidence level) with an active region's CME productivity. The sample size was to small to confirm if there was a statistical significant correlation of the globally nonscientist measures with future CME activity (i.e. from the date of the magnetogram forward). We are doubling our sample, and will report on the statistical significance of global nonpotentiality as a predictor of future CME productivity. The new active regions are all from the first year of the upgraded MSFC vector magnetograms. This work, is funded by NSF through the Space Weather Program, by NASA through the Living with the Star, Targeted Research and Technology, and by NASA Solar Physics Supporting Research and Technology Program. The upgrade to the MSFC vector magnetograph was supported by the High Energy Solar Spectroscopic Imager (HESSI) mission.

  10. Nanodust dynamics during a coronal mass ejection

    Science.gov (United States)

    Czechowski, Andrzej; Kleimann, Jens

    2017-09-01

    The dynamics of nanometer-sized grains (nanodust) is strongly affected by electromagnetic forces. High-velocity nanodust was proposed as an explanation for the voltage bursts observed by STEREO. A study of nanodust dynamics based on a simple time-stationary model has shown that in the vicinity of the Sun the nanodust is trapped or, outside the trapped region, accelerated to high velocities. We investigate the nanodust dynamics for a time-dependent solar wind and magnetic field configuration in order to find out what happens to nanodust during a coronal mass ejection (CME). The plasma flow and the magnetic field during a CME are obtained by numerical simulations using a 3-D magnetohydrodynamic (MHD) code. The equations of motion for the nanodust particles are solved numerically, assuming that the particles are produced from larger bodies moving in near-circular Keplerian orbits within the circumsolar dust cloud. The charge-to-mass ratios for the nanodust particles are taken to be constant in time. The simulation is restricted to the region within 0.14 AU from the Sun. We find that about 35 % of nanodust particles escape from the computational domain during the CME, reaching very high speeds (up to 1000 km s-1). After the end of the CME the escape continues, but the particle velocities do not exceed 300 km s-1. About 30 % of all particles are trapped in bound non-Keplerian orbits with time-dependent perihelium and aphelium distances. Trapped particles are affected by plasma ion drag, which causes contraction of their orbits.

  11. Endometriose de cicatriz cirúrgica: estudo retrospectivo de 72 casos Scar endometriosis: a retrospective study of 72 patients

    Directory of Open Access Journals (Sweden)

    Nilo Sérgio Nominato

    2007-08-01

    Full Text Available OBJETIVO: avaliar a freqüência e fatores associados à endometriose de cicatriz cirúrgica. MÉTODOS: foi realizado estudo observacional, tipo coorte retrospectivo, a partir da revisão de prontuários de pacientes do Hospital das Clínicas da Universidade Federal de Minas Gerais (UFMG com diagnóstico anatomopatológico de endometriose de cicatriz cirúrgica, no período de maio de 1978 a dezembro de 2003. RESULTADOS: foram encontrados 72 pacientes com diagnóstico de endometriose de cicatriz. A incidência de endometriose de cicatriz após cesariana foi significativamente maior do que após parto normal (0,2 e 0,06%, respectivamente; pPURPOSE: to identify the incidence and associated factors of surgical scar endometriosis. METHODS: a retrospective cohort observational study performed from the medical records of female patients attended at the Clinical Hospital of Univesidade Federal de Minas Gerais (UFMG with histopathological diagnosis of scar endometriosis from May 1978 to December 2003. RESULTS: a total of 72 patients were included in the study. The incidence of scar endometriosis after cesarean section was significantly higher than after episiotomy (0.2% and 0.06%, respectively; p<0.00001 with relative risk of 3.3. The women’s age, when diagnosed, ranged from 16 to 48 years old, (mean=30.8 years old. The scar location varied according to the previous surgery: 46 scars after cesarean sections, one after hysterectomy and one after abdominal surgery (48 lesions in the abdominal wall; 19 scars after episiotomy, one because of relapse and two after pelvic floor surgeries (22 pelvic wounds; two women had not been submitted to previous gynecological surgery (one umbilical endometrioma and one lesion in the posterior vaginal wall. Pain was the most frequent symptom (80%, followed by a node (79% and, in more than 40%, the pain and the node suffered modification with menstruation. Other less frequent complaints were: dyspareunia, secondary

  12. Toxoplasmose em primatas neotropicais: estudo retrospectivo de sete casos Toxoplasmosis in New World primates: Retrospective study of seven cases

    Directory of Open Access Journals (Sweden)

    Renata A. Casagrande

    2013-01-01

    Full Text Available A toxoplasmose é considerada uma doença parasitária fatal em primatas neotropicais. O objetivo deste trabalho foi descrever, através de um estudo retrospectivo, os casos de toxoplasmose em primatas neotropicais. No período de 1999-2009 foram realizados 86 exames anatomopatológicos em primatas e a toxoplasmose foi a enfermidade mais comum (7/86, relatando-se um caso em sagui-do-tufo-preto (Callithrix penicillata e seis em bugio-ruivo (Alouatta guariba. Dois animais foram encontrados mortos e cinco morreram em poucos dias. Os sinais clínicos mais frequentes foram apatia e anorexia (5/7, distensão abdominal (4/7 e febre (3/7. Na necropsia observou-se esplenomegalia (4/7, hemorragia do trato digestório, linfonodos e bexiga (4/7, pulmões avermelhados (3/7 e hepatomegalia (2/7. No exame histopatológico evidenciou-se hepatite (7/7, esplenite (3/7, miocardite (2/7, enterite (2/7, linfadenite (1/7 e sialite (1/7 necróticas e, pneumonia intersticial (4/7. Em fígado, pulmões, baço, coração, linfonodos e glândula salivar havia taquizoítos de Toxoplasma gondii que foram também detectados pelo exame de imuno-histoquímica anti-T. gondii em fígado, baço e pulmões (5/7. A toxoplasmose pode causar alta mortalidade em colônias de primatas neotropicais e representar mais uma ameaça à conversação dessas espécies em cativeiro. Sendo assim, medidas preventivas devem ser tomadas para evitar a contaminação desses animais.Toxoplasmosis is considered to be a fatal parasitic disease in New World primates. The objective of this report was to describe, through a retrospective study, the toxoplasmosis cases in New World primates. From 1999 to 2009 eighty-six anatomopathological exams was performed in primates and toxoplasmosis was the most common disease (7/86. One case occurred in Black-Tufted-Marmoset (Callithrix penicillata and six in Brown-Howler monkeys (Alouatta guariba. Two monkeys were found death and five died within few days. The most

  13. y casos de estudios

    Directory of Open Access Journals (Sweden)

    Esteban Valenzuela Van Treek

    2006-01-01

    latinoamericanas, adentrándose en las problemáticas de la más relevantes, así como reflexionar sobre el presente de ellas, tomando para esto algunos casos de estudio.. “En el caso de las áreas metropolitanas, la concentración y el crecimiento de las grandes ciudades con fenómenos de nuevas barriadas, de municipios limítrofes y de ciudades dormitorios, dentro o fuera del término de la gran ciudad, demandan soluciones administrativas de conjunto que superen los esquemas municipales tradicionales” (Barrero, 1993. Esto lleva a definir el problema de estudio de como la aglomeración de población en áreas superiores a las ciudades tradicionales en América Latina, constituyen formas diferentes a los planos nacionales y municipales, por lo que urge crear condiciones para el bienestar de sus ciudadanos. Es necesario para esto, el comprender el sistema político de manera dinámica y variable, el cual esta íntimamente ligado a la constitución a la deriva estructural de las sociedades, pero sobretodo al gobierno de la ciudad, elemento fundante de la civilización occidental en la cual estamos situados.

  14. Standing Slow MHD Waves in Radiatively Cooling Coronal Loops

    Indian Academy of Sciences (India)

    K. S. Al-Ghafri

    2015-06-01

    The standing slow magneto-acoustic oscillations in cooling coronal loops are investigated. There are two damping mechanisms which are considered to generate the standing acoustic modes in coronal magnetic loops, namely, thermal conduction and radiation. The background temperature is assumed to change temporally due to optically thin radiation. In particular, the background plasma is assumed to be radiatively cooling. The effects of cooling on longitudinal slow MHD modes is analytically evaluated by choosing a simple form of radiative function, that ensures the temperature evolution of the background plasma due to radiation, coincides with the observed cooling profile of coronal loops. The assumption of low-beta plasma leads to neglecting the magnetic field perturbation and, eventually, reduces the MHD equations to a 1D system modelling longitudinal MHD oscillations in a cooling coronal loop. The cooling is assumed to occur on a characteristic time scale, much larger than the oscillation period that subsequently enables using the WKB theory to study the properties of standing wave. The governing equation describing the time-dependent amplitude of waves is obtained and solved analytically. The analytically derived solutions are numerically evaluated to give further insight into the evolution of the standing acoustic waves. We find that the plasma cooling gives rise to a decrease in the amplitude of oscillations. In spite of the reduction in damping rate caused by rising the cooling, the damping scenario of slow standing MHD waves strongly increases in hot coronal loops.

  15. Standing Kink modes in three-dimensional coronal loops

    Energy Technology Data Exchange (ETDEWEB)

    Pascoe, D. J.; De Moortel, I., E-mail: dpascoe@mcs.st-andrews.ac.uk [School of Mathematics and Statistics, University of St. Andrews, St. Andrews KY16 9SS (United Kingdom)

    2014-04-01

    So far, the straight flux tube model proposed by Edwin and Roberts is the most commonly used tool in practical coronal seismology, in particular, to infer values of the (coronal) magnetic field from observed, standing kink mode oscillations. In this paper, we compare the period predicted by this basic model with three-dimensional (3D) numerical simulations of standing kink mode oscillations, as the period is a crucial parameter in the seismological inversion to determine the magnetic field. We perform numerical simulations of standing kink modes in both straight and curved 3D coronal loops and consider excitation by internal and external drivers. The period of oscillation for the displacement of dense coronal loops is determined by the loop length and the kink speed, in agreement with the estimate based on analytical theory for straight flux tubes. For curved coronal loops embedded in a magnetic arcade and excited by an external driver, a secondary mode with a period determined by the loop length and external Alfvén speed is also present. When a low number of oscillations is considered, these two periods can result in a single, non-resolved (broad) peak in the power spectrum, particularly for low values of the density contrast for which the two periods will be relatively similar. In that case (and for this particular geometry), the presence of this additional mode would lead to ambiguous seismological estimates of the magnetic field strength.

  16. MEXCODE* CASO DE ESTUDIO

    Directory of Open Access Journals (Sweden)

    Gabriel Arturo García Gómez

    2000-01-01

    Full Text Available El caso plantea la reactivación de un proyecto que se presentó en el año 1995 como alternativa para el desarrollo del centro del Valle y mejora de la eficiencia en el manejo del comercio exterior de la Cuenca Pacífica. El proyecto se revivió a raíz de la necesidad de la compañía patrocinadora de mejorar sus flujos de caja proyectados y la reciente autorización para su funcionamiento. El proyecto es el popularmente denominado “Puerto Seco” de la ciudad de Guadalajara de Buga, internamente nombrado Mexcode. Los estudios iniciales estaban encaminados a que el proyecto fuera manejado por el municipio de Buga, sin embargo, posteriormente se vio la necesidad de buscar que pasara a manos de la empresa privada. El municipio, después de analizar las propuestas de varios inversionistas de la región en las cuales se evaluaba la ubicación dentro de la zona de los predios de sus empresas, su área, proximidad a la línea férrea y a la doble calzada Buga-Tuluá (sitio de paso del 80% de la carga de importación y exportación por Buenaventura y evaluar aspectos relativos a su trayectoria empresarial y compromiso con el desarrollo de la región, decidió otorgarle el proyecto al Grupo Empresarial Agri-Supplies S.A.

  17. Estudio del CH interestelar

    Science.gov (United States)

    Olano, C.; Lemarchand, G.; Sanz, A. J.; Bava, J. A.

    El objetivo principal de este proyecto consiste en el estudio de la distribución y abundancia del CH en nubes interestelares a través de la observación de las líneas hiperfinas del CH en 3,3 GHz. El CH es una molécula de amplia distribución en el espacio interestelar y una de las pocas especies que han sido observadas tanto con técnicas de radio como ópticas. Desde el punto de vista tecnológico se ha desarrollado un cabezal de receptor que permitirá la realización de observaciones polarimétricas en la frecuencia de 3,3 GHz, con una temperatura del sistema de 60 K y un ancho de banda de 140 MHz, y que será instalado en el foco primario de la antena parabólica del IAR. El cabezal del receptor es capaz de detectar señales polarizadas, separando las componentes de polarización circular derecha e izquierda. Para tal fin el cabezal consta de dos ramas receptoras que amplificarán la señal y la trasladarán a una frecuencia más baja (frecuencia intermedia), permitiendo de esa forma un mejor transporte de la señal a la sala de control para su posterior procesamiento. El receptor además de tener características polarimétricas, podrá ser usado en el continuo y en la línea, utilizando las ventajas observacionales y de procesamiento de señal que actualmente posee el IAR.

  18. The Search for Stellar Coronal Mass Ejections

    Science.gov (United States)

    Villadsen, Jacqueline Rose

    2017-05-01

    Coronal mass ejections (CMEs) may dramatically impact habitability and atmospheric composition of planets around magnetically active stars, including young solar analogs and many M dwarfs. Theoretical predictions of such effects are limited by the lack of observations of stellar CMEs. This thesis addresses this gap through a search for the spectral and spatial radio signatures of CMEs on active M dwarfs. Solar CMEs produce radio bursts with a distinctive spectral signature, narrow-band plasma emission that drifts to lower frequency as a CME expands outward. To search for analogous events on nearby stars, I worked on system design, software, and commissioning for the Starburst project, a wideband single-baseline radio interferometry backend dedicated to stellar observations. In addition, I led a survey of nearby active M dwarfs with the Karl G. Jansky Very Large Array (VLA), detecting coherent radio bursts in 13 out of 23 epochs, over a total of 58 hours. This survey's ultra-wide bandwidth (0.23-6.0 GHz) dynamic spectroscopy, unprecedented for stellar observations, revealed diverse behavior in the time-frequency plane. Flare star UV Ceti produced complex, luminous events reminiscent of brown dwarf aurorae; AD Leo sustained long-duration, intense, narrow-band "storms"; and YZ CMi emitted a burst with substructure with rapid frequency drift, resembling solar Type III bursts, which are attributed to electrons moving at speeds of order 10% of the speed of light. To search for the spatial signature of CMEs, I led 8.5-GHz observations with the Very Long Baseline Array simultaneous to 24 hours of the VLA survey. This program detected non-thermal continuum emission from the stars in all epochs, as well as continuum flares on AD Leo and coherent bursts on UV Ceti, enabling measurement of the spatial offset between flaring and quiescent emission. These observations demonstrate the diversity of stellar transients that can be expected in time-domain radio surveys, especially

  19. The Search for Stellar Coronal Mass Ejections

    Science.gov (United States)

    Villadsen, Jacqueline; Hallinan, Gregg; Monroe, Ryan; Bourke, Stephen; Starburst Program Team

    2017-01-01

    Coronal mass ejections (CMEs) may dramatically impact habitability and atmospheric composition of planets around magnetically active stars, including young solar analogs and many M dwarfs. Theoretical predictions of such effects are limited by the lack of observations of stellar CMEs. My thesis addresses this gap through a search for the spectral and spatial radio signatures of CMEs on active M dwarfs.Solar CMEs produce radio bursts with a distinctive spectral signature, narrow-band plasma emission that drifts to lower frequency as a CME expands outward. To search for analogous events on nearby stars, I worked on system design, software, and commissioning for the Starburst project, a wideband single-baseline radio interferometry backend dedicated to stellar observations. In addition, I led a survey of nearby active M dwarfs with the Karl G. Jansky Very Large Array (JVLA), detecting 12 bright (>10 mJy) radio bursts in 58 hours. This survey’s ultra-wide bandwidth (0.23-6.0 GHz) dynamic spectroscopy, unprecedented for stellar observations, revealed diverse behavior in the time-frequency plane. Flare star UV Ceti produced complex, luminous events reminiscent of brown dwarf aurorae; AD Leo sustained long-duration, intense, narrow-band "storms"; and YZ CMi emitted a burst with substructure with rapid frequency drift, resembling solar Type III bursts, which are attributed to electrons moving at speeds of order 10% of the speed of light.To search for the spatial signature of CMEs, I led 8.5-GHz observations with the Very Long Baseline Array simultaneous to 24 hours of the JVLA survey. This program detected non-thermal continuum emission from the stars in all epochs, as well as continuum flares on AD Leo and coherent bursts on UV Ceti, enabling measurement of the spatial offset between flaring and quiescent emission.These observations demonstrate the diversity of stellar transients that can be expected in time-domain radio surveys, especially with the advent of large low

  20. Mechanisms of Plasma Acceleration in Coronal Jets

    Science.gov (United States)

    Soto, N.; Reeves, K.; Savcheva, A. S.

    2016-12-01

    Jets are small explosions that occur frequently in the Sun possibly driven by the local reconfiguration of the magnetic field, or reconnection. There are two types of coronal jets: standard jets and blowout jets. The purpose of this project is to determine which mechanisms accelerate plasma in two different jets, one that occurred in January 17, 2015 at the disk of the sun and another in October 24, 2015 at the limb. Two possible acceleration mechanisms are chromospheric evaporation and magnetic acceleration. Using SDO/AIA, Hinode/XRT and IRIS data, we create height-time plots, and calculate the velocities of each wavelength for both jets. We calculate the potential magnetic field of the jet and the general region around it to gain a more detailed understanding of its structure, and determine if the jet is likely to be either a standard or blowout jet. Finally, we calculate the magnetic field strength for different heights along the jet spire, and use differential emission measures to calculate the plasma density. Once we have these two values, we calculate the Alfven speed. When analyzing our results we are looking for certain patterns in our velocities. If the plasma in a jet is accelerated by chromospheric evaporation, we expect the velocities to increase as function of temperature, which is what we observed in the October 24th jet. The magnetic models for this jet also show the Eiffel Tower shaped structure characteristic of standard jets, which tend to have plasma accelerated by this mechanism. On the other hand, if the acceleration mechanism were magnetic acceleration, we would expect the velocities to be similar regardless of temperature. For the January 17th jet, we saw that along the spire, the velocities where approximately 200 km/s in all wavelengths, but the velocities of hot plasma detected at the base were closer to the Alfven speed, which was estimated to be about 2,000 km/s. These observations suggest that the plasma in the January 17th jet is

  1. Characterizing the Properties of Coronal Magnetic Null Points

    Science.gov (United States)

    Barnes, Graham; DeRosa, Marc; Wagner, Eric

    2015-08-01

    The topology of the coronal magnetic field plays a role in a wide range of phenomena, from Coronal Mass Ejections (CMEs) through heating of the corona. One fundamental topological feature is the null point, where the magnetic field vanishes. These points are natural sites of magnetic reconnection, and hence the release of energy stored in the magnetic field. We present preliminary results of a study using data from the Helioseismic and Magnetic Imager aboard NASA's Solar Dynamics Observatory to characterize the properties and evolution of null points in a Potential Field Source Surface model of the coronal field. The main properties considered are the lifetime of the null points, their distribution with height, and how they form and subsequently vanish.This work is supported by NASA/LWS Grant NNX14AD45G, and by NSF/SHINE grant 1357018.

  2. Ultraviolet Spectroscopic Observations of Coronal Streamers in the SOHO Era

    Indian Academy of Sciences (India)

    Leonard Strachan

    2008-03-01

    Measurements made with the Ultraviolet Coronagraph Spectrometer (UVCS) on the Solar and Heliospheric Observatory can be used to determine physical parameters in the solar corona such as hydrogen and ion kinetic temperatures, electron densities, and absolute elemental abundances. Hydrogen and ion outflow velocities can be determined by combining the UV spectroscopic measurements with white light polarized brightness measurements. These combined measurements can be used to reveal physical characteristics of coronal streamers. To date we have studied plasma properties, such as the variation of plasma outflows in quiescent streamers, primarily in classic helmet streamers at solar minimum. Outflows have not been observed in the centers of coronal streamers suggesting that these are closed magnetic field regions.We propose to study all of the coronal streamers in the UVCS synoptic dataset in order to investigate different types of streamers and their long-term evolution.

  3. Determination of coronal temperatures from electron density profiles

    CERN Document Server

    Lemaire, J F

    2011-01-01

    The most popular method for determining coronal temperatures is the scale-height-method (shm). It is based on electron density profiles inferred from White Light (WL) brightness measurements of the corona during solar eclipses. This method has been applied to several published coronal electron density models. The calculated temperature distributions reach a maximum at r > 1.3 RS, and therefore do not satisfy one of the conditions for applying the shm method. Another method is the hydrostatic equilibrium method (hst), which enables coronal temperature distributions to be determined, providing solutions to the hydrostatic equilibrium equation. The temperature maximas using the hst method are almost equal to those obtained using the shm method, but the temperature peak is always at significantly lower altitude when the hst-method is used than when the shm-method is used. A third and more recently developed method, dyn, can be used for the same published electron density profiles. The temperature distributions ob...

  4. Influence of coronal holes on CMEs in causing SEP events

    Institute of Scientific and Technical Information of China (English)

    Cheng-Long Shen; Jia Yao; Yu-Ming Wang; Pin-Zhong Ye; Xue-Pu Zhao; Shui Wang

    2010-01-01

    The issue of the influence of coronal holes(CHs)on coronal mass ejections(CMEs)in causing solar energetic particle(SEP)events is revisited.It is a continuation and extension of our previous work,in which no evident effects of CHs on CMEs in generating SEPs were found by statistically investigating 56 CME events.This result is consistent with the conclusion obtained by Kahler in 2004.We extrapolate the coronal magnetic field,define CHs as the regions consisting of only open magnetic field lines and perform a similar analysis on this issue for 76 events in total by extending the study interval to the end of 2008.Three key parameters,CH proximity,CH area and CH relative position,are involved in the analysis.The new result confirms the previous conclusion that CHs did not show any evident effect on CMEs in causing SEP events.

  5. A data driven kinetic approach to coronal heating

    CERN Document Server

    Toutountzi, A; Isliker, H; Moraitis, K; Georgoulis, M; Chintzoglou, G

    2016-01-01

    Coronal heating through the explosive release of magnetic energy remains an open problem in solar physics. Several one-dimensional hydrodynamical models have been developed over the last decade, using simple approaches for the way energy is deposited and transported in the coronal plasma, namely by inserting 'nanoflares' in the form of 'hot spots' at random sites and times. Our aim in this work is to investigate the problem from a different perspective. With the help of a nonlinear force-free extrapolation method we reconstruct the coronal magnetic field of a well-studied solar active region using an observed photospheric vector magnetogram of the region as the required boundary condition. We then determine the locations, energy contents, and volumes of unstable areas within the active-region corona. These areas include strong gradients in the magnetic field and are naturally connected to three-dimensional current sheets. The statistical distributions of these volumes, their fractal structure and correspondin...

  6. Characteristics of EUV coronal jets observed with STEREO/SECCHI

    CERN Document Server

    Nistico, G; Patsourakos, S; Zimbardo, G

    2009-01-01

    In this paper we present the first comprehensive statistical study of EUV coronal jets observed with the SECCHI imaging suites of the two STEREO spacecraft. A catalogue of 79 polar jets is presented, identified from simultaneous EUV and white-light coronagraph observations, taken during the time period March 2007 to April 2008. The appearances of the coronal jets were always correlated with underlying small-scale chromospheric bright points. A basic characterisation of the morphology and identification of the presence of helical structure were established with respect to recently proposed models for their origin and temporal evolution. A classification of the events with respect to previous jet studies shows that amongst the 79 events there were 37 Eiffel tower-type jet events commonly interpreted as a small-scale (about 35 arcsec) magnetic bipole reconnecting with the ambient unipolar open coronal magnetic fields at its looptops, and 12 lambda-type jet events commonly interpreted as reconnection with the amb...

  7. Damping of Slow Magnetoacoustic Waves in an Inhomogeneous Coronal Plasma

    Indian Academy of Sciences (India)

    Nagendra Kumar; Pradeep Kumar; Shiv Singh; Anil Kumar

    2008-03-01

    We study the propagation and dissipation of slow magnetoacoustic waves in an inhomogeneous viscous coronal loop plasma permeated by uniform magnetic field. Only viscosity and thermal conductivity are taken into account as dissipative processes in the coronal loop. The damping length of slow-mode waves exhibit varying behaviour depending upon the physical parameters of the loop in an active region AR8270 observed by TRACE. The wave energy flux associated with slow magnetoacoustic waves turns out to be of the order of 106 erg cm-2 s-1 which is high enough to replace the energy lost through optically thin coronal emission and the thermal conduction belowto the transition region. It is also found that only those slow-mode waves which have periods more than 240 s provide the required heating rate to balance the energy losses in the solar corona. Our calculated wave periods for slow-mode waves nearly match with the oscillation periods of loop observed by TRACE.

  8. Coronal Loop Evolution Observed with AIA and Hi-C

    Science.gov (United States)

    Mulu-Moore, Fana; Winebarger, A.; Cirtain, J.; Kobayashi, K.; Korreck, K.; Golub, L.; Kuzin. S.; Walsh, R.; DeForest, C.; DePontieu, B.; Weber, M.

    2012-01-01

    Despite much progress toward understanding the dynamics of the solar corona, the physical properties of coronal loops are not yet fully understood. Recent investigations and observations from different instruments have yielded contradictory results about the true physical properties of coronal loops. In the past, the evolution of loops has been used to infer the loop substructure. With the recent launch of High Resolution Coronal Imager (Hi-C), this inference can be validated. In this poster we discuss the first results of loop analysis comparing AIA and Hi-C data. We find signatures of cooling in a pixel selected along a loop structure in the AIA multi-filter observations. However, unlike previous studies, we find that the cooling time is much longer than the draining time. This is inconsistent with previous cooling models.

  9. Examining the Properties of Jets in Coronal Holes

    Science.gov (United States)

    Gaulle, Owen; Adams, Mitzi L.; Tennant, A. F.

    2012-01-01

    We examined both X-ray and Magnetic field data in order to determine if there is a correlation between emerging magnetic flux and the production of Coronal jets. It was proposed that emerging flux can be a trigger to a coronal jet. The jet is thought to be caused when local bipoles reconnect or when a region of magnetic polarity emerges through a uniform field. In total we studied 15 different jets that occurred over a two day period starting 2011-02-27 00:00:00 UTC and ending 2011-02-28 23:59:55 UTC. All of the jets were contained within a coronal hole that was centered on the disk. Of the 15 that we studied 6 were shown to have an increase of magnetic flux within one hour prior to the creation of the jet and 10 were within 3 hours before the event.

  10. Transverse, Propagating Velocity Perturbations in Solar Coronal Loops

    CERN Document Server

    De Moortel, I; Wright, A N; Hood, A W

    2015-01-01

    This short review paper gives an overview of recently observed transverse, propagating velocity perturbations in coronal loops. These ubiquitous perturbations are observed to undergo strong damping as they propagate. Using 3D numerical simulations of footpoint-driven transverse waves propagating in a coronal plasma with a cylindrical density structure, in combination with analytical modelling, it is demonstrated that the observed velocity perturbations can be understood in terms of coupling of different wave modes in the inhomogeneous boundaries of the loops. Mode coupling in the inhomogeneous boundary layers of the loops leads to the coupling of the transversal (kink) mode to the azimuthal (Alfven) mode, observed as the decay of the transverse kink oscillations. Both the numerical and analytical results show the spatial profile of the damped wave has a Gaussian shape to begin with, before switching to exponential decay at large heights. In addition, recent analysis of CoMP (Coronal Multi-channel Polarimeter)...

  11. Using Coronal Hole Maps to Constrain MHD Models

    Science.gov (United States)

    Caplan, Ronald M.; Downs, Cooper; Linker, Jon A.; Mikic, Zoran

    2017-08-01

    In this presentation, we explore the use of coronal hole maps (CHMs) as a constraint for thermodynamic MHD models of the solar corona. Using our EUV2CHM software suite (predsci.com/chd), we construct CHMs from SDO/AIA 193Å and STEREO-A/EUVI 195Å images for multiple Carrington rotations leading up to the August 21st, 2017 total solar eclipse. We then contruct synoptic CHMs from synthetic EUV images generated from global thermodynamic MHD simulations of the corona for each rotation. Comparisons of apparent coronal hole boundaries and estimates of the net open flux are used to benchmark and constrain our MHD model leading up to the eclipse. Specifically, the comparisons are used to find optimal parameterizations of our wave turbulence dissipation (WTD) coronal heating model.

  12. Relation between incremental lines and tensile strength of coronal dentin.

    Science.gov (United States)

    Inoue, Toshiko; Saito, Makoto; Yamamoto, Masato; Nishimura, Fumio; Miyazaki, Takashi

    2012-01-01

    In one aspect, this study examined the tensile strength of coronal dentin, as a function of the location of incremental lines, in two types of teeth: human molar versus bovine incisor. In another aspect, tensile strength in coronal dentin was examined with tensile loading in two different orientations to the incremental lines: parallel versus perpendicular. There were four experimental groups in this study: HPa, human molar dentin with tensile orientation parallel to the incremental lines; HPe, human molar dentin with tensile orientation perpendicular to the incremental lines; BPa, bovine incisor dentin with tensile orientation parallel to the incremental lines; BPe, bovine incisor dentin with tensile orientation perpendicular to the incremental lines. Tensile strengths of the parallel group (HPa and BPa) were significantly higher (pincremental lines, was thus confirmed in coronal dentin. However, there were no differences in anisotropy effect between the two tooth types.

  13. The Nature of CME-Flare Associated Coronal Dimming

    CERN Document Server

    Cheng, J X

    2016-01-01

    Coronal mass ejections (CMEs) are often accompanied by coronal dimming evident in extreme ultraviolet (EUV) and soft X-ray observations. The locations of dimming are sometimes considered to map footpoints of the erupting flux rope. As the emitting material expands in the corona, the decreased plasma density leads to reduced emission observed in spectral and irradiance measurements. Therefore, signatures of dimming may reflect properties of CMEs in the early phase of its eruption. In this study, we analyze the event of flare, CME, and coronal dimming on December 26, 2011. We use the data from the Atmospheric Imaging Assembly (AIA) on Solar Dynamics Observatories (SDO) for disk observations of the dimming, and analyze images taken by EUVI, COR1, and COR2 onboard the Solar Terrestrial Relations Observatories to obtain the height and velocity of the associated CMEs observed at the limb. We also measure magnetic reconnection rate from flare observations. Dimming occurs in a few locations next to the flare ribbons,...

  14. Flux Rope Formation Preceding Coronal Mass Ejection Onset

    CERN Document Server

    Green, L M

    2009-01-01

    We analyse the evolution of a sigmoidal (S shaped) active region toward eruption, which includes a coronal mass ejection (CME) but leaves part of the filament in place. The X-ray sigmoid is found to trace out three different magnetic topologies in succession: a highly sheared arcade of coronal loops in its long-lived phase, a bald-patch separatrix surface (BPSS) in the hours before the CME, and the first flare loops in its major transient intensity enhancement. The coronal evolution is driven by photospheric changes which involve the convergence and cancellation of flux elements under the sigmoid and filament. The data yield unambiguous evidence for the existence of a BPSS, and hence a flux rope, in the corona prior to the onset of the CME.

  15. Polarisation of microwave emission from reconnecting twisted coronal loops

    CERN Document Server

    Gordovskyy, Mykola; Kontar, Eduard

    2016-01-01

    Magnetic reconnection and particle acceleration due to the kink instability in twisted coronal loops can be a viable scenario for confined solar flares. Detailed investigation of this phenomenon requires reliable methods for observational detection of magnetic twist in solar flares, which may not be possible solely through extreme UV and soft X-ray thermal emission. The gradient of microwave polarisation across flaring loops can serve as one of the detection criteria. The aim of this study is to investigate the effect of magnetic twist in flaring coronal loops on the polarisation of gyro-synchrotron microwave emission, and determine whether microwave emission polarisation could provide a means for observational detection. We use time-dependent magnetohydrodynamic and test-particle models, developed using LARE3D and GCA codes to investigate twisted coronal loops relaxing following the kink-instability, and calculate synthetic microwave emission maps (I and V Stokes components) using GX simulator. It is found t...

  16. Aproximación bibliográfica a los estudios de Semántica estructural en España: Tesis defendidas en universidades españolas (1968-2002)

    OpenAIRE

    Pablo Núñez, Luis

    2006-01-01

    Se ofrece una aproximación crítica a las tesis de Semántica estructural publicadas e inéditas realizadas en España. El objetivo de la recopilación pretende ser un complemento del artículo de Eugenio Coseriu "La Semántica estructural en España", con el fin de ofrecer un panorama retrospectivo de la vitalidad de estos estudios en la Lingüística española moderna.

  17. Actitudes y significados acerca de la jubilación: un estudio comparativo de acuerdo al género en adultos mayores / Attitudes and meanings regarding retirement: a comparative study according to gender in older adults

    OpenAIRE

    Paula Daniela Hermida; María Florencia Tartaglini; Dorina Stefani

    2016-01-01

    RESUMEN: El objetivo del estudio es evaluar si las expectativas sociales de «rol» diferencial de género influyen en la adaptación de los adultos mayores a la jubilación, a través de los significados y actitudes hacia el retiro laboral. Se empleó un diseño ex post facto, de carácter retrospectivo simple. Participaron 300 adultos mayores autoválidos de clase media, 150 varones y 150 mujeres, residentes en la Ciudad Autónoma de Buenos Aires y conurbano bonaerense (República Argentina). Se admini...

  18. Revisión y estudio de las manifestaciones paleopatológicas en los homininos del plio-pleistoceno, con especial referencia a algunos fósiles de la Sierra de Atapuerca

    OpenAIRE

    2015-01-01

    La paleopatología es la disciplina que estudia las enfermedades del pasado a través del análisis del registro fósil para definir el perfil de morbosidad sufrido por el individuo o el conjunto de la población. Para ello utiliza un diagnóstico retrospectivo, extrapolando las consecuencias de la enfermedad para conocer sus causas. El patrón de enfermedad que afecta a una población es el resultado del estrés al que está sujeta dicha población. Los estudios de evolución humana requieren de otras ...

  19. Estudio clínico, anatomopatológico y de biología molecular de cuadros entéricos en cerdos de crecimiento y terminación

    OpenAIRE

    Pérez, Estefanía Marisol

    2016-01-01

    Se evaluó la participación de Lawsonia intracellularis, Brachyspira hyodysenteriae, Brachyspira pilosicoli y Salmonella spp. en el desarrollo de infecciones clínicas y subclínicas en cerdos de la etapa de engorde. Se realizó un estudio retrospectivo histopatológico de casos de archivo en el que se relacionaron las lesiones histopatológicas con los agentes etiológicos identificados por IHQ, WS y PCR a partir de tejidos embebidos en parafina. Se detectó asociación estadística entre las lesiones...

  20. Estudio del manejo anestésico perioperatorio en los pacientes intervenidos por metástasis hepáticas de cáncer colorrectal: Anestesia general "versus" anestesia combinada

    OpenAIRE

    Pérez Navarro, Guillermo Ignacio; Serrablo Requejo, Alejandro; Martínez Ubieto, Javier; Borrego Estella, Vicente Manuel

    2013-01-01

    Introducción: En la actualidad, existe suficiente experiencia acumulada en estudios retrospectivos y prospectivos como para considerar la resección hepática como el tratamiento de elección para algunos pacientes con metástasis hepáticas de cáncer colorrectal. La técnica anestésica combinada (Anestesia general asociada a técnica analgésica epidural) es una opción anestésico-analgésica aceptada y utilizada frecuentemente para el manejo perioperatorio de cirugía abdominal mayor, torácica y cardi...

  1. Kinematics and amplitude evolution of global coronal extreme ultraviolet waves

    Institute of Scientific and Technical Information of China (English)

    Ting Li; Jun Zhang; Shu-Hong Yang; Wei Liu

    2012-01-01

    With the observations of the Solar-Terrestrial Relations Observatory (STEREO) and the Solar Dynamics Observatory (SDO),we analyze in detail the kinematics of global coronal waves together with their intensity amplitudes (so-called "perturbation profiles").We use a semi-automatic method to investigate the perturbation profiles of coronal waves.The location and amplitude of the coronal waves are calculated over a 30° sector on the sphere,where the wave signal is strongest.The position with the strongest perturbation at each time is considered as the location of the wave front.In all four events,the wave velocities vary with time for most of their lifetime,up to 15 min,while in the event observed by the Atmospheric Imaging Assembly there is an additional early phase with a much higher velocity.The velocity varies greatly between different waves from 216 to 440 km s-1.The velocity of the two waves initially increases,subsequently decreases,and then increases again.Two other waves show a deceleration followed by an acceleration.Three categories of amplitude evolution of global coronal waves are found for the four events.The first is that the amplitude only shows a decrease.The second is that the amplitude initially increases and then decreases,and the third is that the amplitude shows an orderly increase,a decrease,an increase again and then a decrease.All the extreme ultraviolet waves show a decrease in amplitude while propagating farther away,probably because the driver of the global coronal wave (coronal mass ejection) is moving farther away from the solar surface.

  2. SIMULATIONS OF SOLAR JETS CONFINED BY CORONAL LOOPS

    Energy Technology Data Exchange (ETDEWEB)

    Wyper, P. F. [Oak Ridge Associated Universities, Heliophysics Science Division, NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD 20771 (United States); DeVore, C. R., E-mail: peter.f.wyper@nasa.gov, E-mail: c.richard.devore@nasa.gov [Heliophysics Science Division, NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD 20771 (United States)

    2016-03-20

    Coronal jets are collimated, dynamic events that occur over a broad range of spatial scales in the solar corona. In the open magnetic field of coronal holes, jets form quasi-radial spires that can extend far out into the heliosphere, while in closed-field regions the jet outflows are confined to the corona. We explore the application of the embedded-bipole model to jets occurring in closed coronal loops. In this model, magnetic free energy is injected slowly by footpoint motions that introduce twist within the closed dome of the jet source region, and is released rapidly by the onset of an ideal kink-like instability. Two length scales characterize the system: the width (N) of the jet source region and the footpoint separation (L) of the coronal loop that envelops the jet source. We find that both the conditions for initiation and the subsequent dynamics are highly sensitive to the ratio L/N. The longest-lasting and most energetic jets occur along long coronal loops with large L/N ratios, and share many of the features of open-field jets, while smaller L/N ratios produce shorter-duration, less energetic jets that are affected by reflections from the far-loop footpoint. We quantify the transition between these behaviors and show that our model replicates key qualitative and quantitative aspects of both quiet Sun and active-region loop jets. We also find that the reconnection between the closed dome and surrounding coronal loop is very extensive: the cumulative reconnected flux at least matches the total flux beneath the dome for small L/N, and is more than double that value for large L/N.

  3. Automatic measurement of orbital volume in unilateral coronal synostosis

    DEFF Research Database (Denmark)

    Dahl, Vedrana Andersen; Einarsson, Gudmundur; Darvann, Tron Andre;

    2016-01-01

    Premature fusion of the coronal suture on one side of the calvaria (unilateral coronal synostosis, UCS) results in asymmetric craniofacial development and the deformation of the orbits. Often this necessitates surgery, where CT scanning is employed to obtain measures of the bony orbit...... segmentations. We obtain similar measures, as well as high Dice scores, compared to the experts. The run time for the proposed approach with a prototype implementation is around 3 minutes on a standard laptop, making the method suitable for rapid evaluation of orbital volume in UCS....

  4. Coronal seismology waves and oscillations in stellar coronae

    CERN Document Server

    Stepanov, Alexander; Nakariakov, Valery M

    2012-01-01

    This concise and systematic account of the current state of this new branch of astrophysics presents the theoretical foundations of plasma astrophysics, magneto-hydrodynamics and coronal magnetic structures, taking into account the full range of available observation techniques -- from radio to gamma. The book discusses stellar loops during flare energy releases, MHD waves and oscillations, plasma instabilities and heating and charged particle acceleration. Current trends and developments in MHD seismology of solar and stellar coronal plasma systems are also covered, while recent p

  5. Comparison of Two Coronal Magnetic Field Models to Reconstruct a Sigmoidal Solar Active Region with Coronal Loops

    Science.gov (United States)

    Duan, Aiying; Jiang, Chaowei; Hu, Qiang; Zhang, Huai; Gary, G. Allen; Wu, S. T.; Cao, Jinbin

    2017-06-01

    Magnetic field extrapolation is an important tool to study the three-dimensional (3D) solar coronal magnetic field, which is difficult to directly measure. Various analytic models and numerical codes exist, but their results often drastically differ. Thus, a critical comparison of the modeled magnetic field lines with the observed coronal loops is strongly required to establish the credibility of the model. Here we compare two different non-potential extrapolation codes, a nonlinear force-free field code (CESE-MHD-NLFFF) and a non-force-free field (NFFF) code, in modeling a solar active region (AR) that has a sigmoidal configuration just before a major flare erupted from the region. A 2D coronal-loop tracing and fitting method is employed to study the 3D misalignment angles between the extrapolated magnetic field lines and the EUV loops as imaged by SDO/AIA. It is found that the CESE-MHD-NLFFF code with preprocessed magnetogram performs the best, outputting a field that matches the coronal loops in the AR core imaged in AIA 94 Å with a misalignment angle of ˜10°. This suggests that the CESE-MHD-NLFFF code, even without using the information of the coronal loops in constraining the magnetic field, performs as good as some coronal-loop forward-fitting models. For the loops as imaged by AIA 171 Å in the outskirts of the AR, all the codes including the potential field give comparable results of the mean misalignment angle (˜30°). Thus, further improvement of the codes is needed for a better reconstruction of the long loops enveloping the core region.

  6. Estudios longitudinales: concepto y particularidades

    Directory of Open Access Journals (Sweden)

    Miguel Delgado Rodríguez

    2004-01-01

    Full Text Available En la presente revisión se analiza el concepto de estudio longitudinal. Los libros de texto de epidemiología actuales en general no lo definen, mientras que sí lo hacen los tratados de estadística. Se habla más de «datos longitudinales» que de «estudios longitudinales». El estudio longitudinal implica la existencia de medidas repetidas (más de dos a lo largo de un seguimiento. Sería pues un subtipo de estudio de cohortes que, a diferencia de los de tipo tabla de vida, permite inferencias a nivel individual y analizar cambios en diferentes variables (exposiciones y efectos y transiciones entre diferentes estados de salud. Las particularidades de este tipo de diseño hace que se tenga que prestar atención especial al control de calidad durante su ejecución, a los abandonos durante el seguimiento, y a los datos perdidos en algunas de las mediciones. El análisis debe tener en cuenta las medidas repetidas y esto es lo que confiere finalmente a un estudio su carácter longitudinal.

  7. Evolution of an equatorial coronal hole structure and the released coronal hole wind stream: Carrington rotations 2039 to 2050

    Science.gov (United States)

    Heidrich-Meisner, Verena; Peleikis, Thies; Kruse, Martin; Berger, Lars; Wimmer-Schweingruber, Robert F.

    2017-07-01

    Context. The Sun is a highly dynamic environment that exhibits dynamic behavior on many different timescales. Variability is observed both in closed and in open field line regions in the solar corona. In particular, coronal holes exhibit temporal and spatial variability. Signatures of these coronal dynamics are inherited by the coronal hole wind streams that originate in these regions and can effect the Earth's magnetosphere. Both the cause of the observed variabilities and how these translate to fluctuations in the in situ observed solar wind is not yet fully understood. Aims: During solar activity minimum the structure of the magnetic field typically remains stable over several Carrington rotations (CRs). But how stable is the solar magnetic field? Here, we address this question by analyzing the evolution of a coronal hole structure and the corresponding coronal hole wind stream emitted from this source region over 12 consecutive CRs in 2006. Methods: To this end, we link in situ observations of Solar Wind Ion Composition Spectrometer (SWICS) onboard the Advanced Composition Explorer (ACE) with synoptic maps of Michelson Doppler imager (MDI) on the Solar and Heliospheric Observatory (SOHO) at the photospheric level through a combination of ballistic back-mapping and a potential field source surface (PFSS) approach. Together, these track the evolution of the open field line region that is identified as the source region of a recurring coronal hole wind stream. Under the assumptions of the freeze-in scenario for charge states in the solar wind, we derive freeze-in temperatures and determine the order in which the different charge state ratios of ion pairs appear to freeze-in. We call the combination of freeze-in temperatures derived from in situ observed ion density ratios and freeze-in order a minimal electron temperature profile and investigate its variability. Results: The in situ properties and the PFSS model together probe the lateral magnetic field

  8. Characteristics of Low-latitude Coronal Holes near the Maximum of Solar Cycle 24

    DEFF Research Database (Denmark)

    Hofmeister, Stefan J.; Veronig, Astrid; Reiss, Martin A.

    2017-01-01

    of the coronal holes is predominantly concentrated in magnetic flux tubes: 38% (81%) of the unbalanced magnetic flux of coronal holes arises from only 1% (10%) of the coronal hole area, clustered in magnetic flux tubes with field strengths >50 G (10 G). The average magnetic field density and the unbalanced...

  9. Estudio de Rodilla Flotante en pacientes del Hospital Clinico Viedma

    Directory of Open Access Journals (Sweden)

    Omar Marcelo Vargas Fuentes

    2011-06-01

    Full Text Available Se denomina “Rodilla Flotante” a la combinación de fractura de fémur y tibia ipsilaterales. La incidencia exacta se desconoce, pero tiene un abordaje terapéutico complejo, una alta tasa de complicaciones y una elevada mortalidad.El presente estudio busca determinar los aspectos relacionados con esta patología en nuestro medio y analizarlos de una manera integral, realizándose para esto un estudio descriptivo y longitudinal retrospectivo abarcando 18 meses (de julio 2008 a diciembre 2009 que incluye a 17 pacientes con diagnóstico de “Rodilla Flotante” ingresados en el Servicio de Ortopedia y Traumatología del Hospital Clínico Viedma. Los resultados mostraronque esta lesión equivale al 1,9 % de los casos atendidos por este servicio. Siendo el 82,35% hombres. La edad promedio fue de 34 años. El mecanismo de producción más frecuente: accidentes en motocicleta (41,2%, seguido de atropellados (29,4%. En cuanto a la clasificación la mayor parte fue tipo I de Fraser (68,8%. El tratamiento quirúrgico definitivo se aplicó entre el 5° y 14° día en el 73.3%, mayormente usando clavos centro medulares en fémur y tibia. Los resultados del tratamiento fueron: excelentes 40%, buenos 33.3%, regulares 20% y pobres en el 6,6% según la escala de Karlstrom y Olerud. Las lesiones asociadas: TEC (80%, fracturas de pelvis (60%, trauma abdominal cerrado (60% y trauma de tórax (33,3%. Dentro de las complicaciones, un paciente falleció por fallamultiorgánica, otro concluyó en amputación, y cinco presentaron infección.Por lo que se concluye que en general los aspectos relacionados con esta patología, su presentación y tratamiento en nuestro medio, son similares a los que se encuentran descritos en la literatura médica.

  10. un objeto de estudio emergente

    Directory of Open Access Journals (Sweden)

    Vanesa Aidée Ramírez Vázquez

    2007-01-01

    Full Text Available El interés de este artículo es mostrar, de manera muy general, los textos que la revista Estudios sobre las Culturas Contemporáneas (ESCC ha publicado desde su creación refi eridas al campo de las Tecnologías de Información y Comunicación (TIC. No se incluyen los estudios sobre la radio y la televisión pues se considera que merecen un tratamiento especial como medios masivos de comunicación con mayor tiempo en el escenario social; se centra, en cambio, en los estudios relativos a las computadoras, Internet, videojuegos, celulares, satélites, redes, chat, lo que se ha dado en llamar Nuevas Tecnologías de Información y Comunicación (NTIC.

  11. Competition between shock and turbulent heating in coronal loop system

    Science.gov (United States)

    Matsumoto, Takuma

    2016-11-01

    2.5-dimensional magnetohydrodynamic (MHD) simulations are performed with high spatial resolution in order to distinguish between competing models of the coronal heating problem. A single coronal loop powered by Alfvén waves excited in the photosphere is the target of this study. The coronal structure is reproduced in our simulations as a natural consequence of the transportation and dissipation of Alfvén waves. Further, the coronal structure is maintained as the spatial resolution is changed from 25 to 3 km, although the temperature at the loop top increases with the spatial resolution. The heating mechanisms change gradually across the magnetic canopy at a height of 4 Mm. Below the magnetic canopy, both the shock and the MHD turbulence are dominant heating processes. Above the magnetic canopy, the shock heating rate reduces to less than 10 per cent of the total heating rate while the MHD turbulence provides significant energy to balance the radiative cooling and thermal conduction loss or gain. The importance of compressibility shown in this study would significantly impact on the prospects of successful MHD turbulence theory in the solar chromosphere.

  12. The Relationship of Coronal Mass Ejections to Streamers

    CERN Document Server

    Subramanian, P; Rich, N B; Howard, R A; Subramanian, Prasad

    1999-01-01

    We have examined images from the Large Angle Spectroscopic Coronagraph (LASCO) to study the relationship of Coronal Mass Ejections (CMEs) to coronal streamers. We wish to test the suggestion (Low 1996) that CMEs arise from flux ropes embedded in a streamer erupting, thus disrupting the streamer. The data span a period of two years near sunspot minimum through a period of increased activity as sunspot numbers increased. We have used LASCO data from the C2 coronagraph which records Thomson scattered white light from coronal electrons at heights between 1.5 and 6R_sun. Maps of the coronal streamers have been constructed from LASCO C2 observations at a height of 2.5R_sun at the east and west limbs. We have superposed the corresponding positions of CMEs observed with the C2 coronagraph onto the synoptic maps. We identified the different kinds of signatures CMEs leave on the streamer structure at this height (2.5R_sun). We find four types of CMEs with respect to their effect on streamers: 1. CMEs that disrupt the s...

  13. Measurements of outflow from the base of solar coronal holes

    Science.gov (United States)

    Rottman, G. J.; Orrall, F. Q.; Klimchuk, J. A.

    1982-01-01

    New evidence is presented that EUV emission lines formed at the levels of the base of the corona and the transition region are systematically shifted to shorter wavelengths within coronal holes relative to the rest of the solar disk, and that moreover this shift increases with height in the atmosphere. Measurements were made with a rocket-borne EUV spectrometer having high spectroscopic resolution and stability flown on July 15, 1980. Repeated measurements were made along a chord of the solar disk that crossed a compact coronal hole near sun center identified on gamma 10830 He I spectroheliograms. The maximum measured shift corresponded to a velocity of 12 km/sec in gamma 625 Mg X and 7 km/sec in gamma 629 O V. If these velocities correspond to a true mass flux, they provide important data on the acceleration of coronal plasma in open magnetic field regions. These observed Doppler displacements are a strong and significant signature of coronal holes, now measured on three rocket flights.

  14. Closed-Field Coronal Heating Driven by Wave Turbulence

    CERN Document Server

    Downs, Cooper; Mikić, Zoran; Linker, Jon A; Velli, Marco

    2016-01-01

    To simulate the energy balance of coronal plasmas on macroscopic scales, we often require the specification of the coronal heating mechanism in some functional form. To go beyond empirical formulations and to build a more physically motivated heating function, we investigate the wave-turbulence-driven (WTD) phenomenology for the heating of closed coronal loops. Our implementation is designed to capture the large-scale propagation, reflection, and dissipation of wave turbulence along a loop. The parameter space of this model is explored by solving the coupled WTD and hydrodynamic evolution in 1D for an idealized loop. The relevance to a range of solar conditions is also established by computing solutions for over one hundred loops extracted from a realistic 3D coronal field. Due to the implicit dependence of the WTD heating model on loop geometry and plasma properties along the loop and at the footpoints, we find that this model can significantly reduce the number of free parameters when compared to traditiona...

  15. Coronal heating by resonant absorption: The effects of chromospheric coupling

    NARCIS (Netherlands)

    Belien, A. J. C.; Martens, P. C. H.; Keppens, R.

    1999-01-01

    We present the first 2.5 dimensional numerical model calculations of the nonlinear wave dynamics and heating by resonant absorption in coronal loops with thermal structuring of the transition region and higher chromosphere. The numerical calculations were done with the Versatile Advection Code. The

  16. A Bayesian Approach to Period Searching in Solar Coronal Loops

    Science.gov (United States)

    Scherrer, Bryan; McKenzie, David

    2017-03-01

    We have applied a Bayesian generalized Lomb–Scargle period searching algorithm to movies of coronal loop images obtained with the Hinode X-ray Telescope (XRT) to search for evidence of periodicities that would indicate resonant heating of the loops. The algorithm makes as its only assumption that there is a single sinusoidal signal within each light curve of the data. Both the amplitudes and noise are taken as free parameters. It is argued that this procedure should be used alongside Fourier and wavelet analyses to more accurately extract periodic intensity modulations in coronal loops. The data analyzed are from XRT Observation Program #129C: “MHD Wave Heating (Thin Filters),” which occurred during 2006 November 13 and focused on active region 10293, which included coronal loops. The first data set spans approximately 10 min with an average cadence of 2 s, 2″ per pixel resolution, and used the Al-mesh analysis filter. The second data set spans approximately 4 min with a 3 s average cadence, 1″ per pixel resolution, and used the Al-poly analysis filter. The final data set spans approximately 22 min at a 6 s average cadence, and used the Al-poly analysis filter. In total, 55 periods of sinusoidal coronal loop oscillations between 5.5 and 59.6 s are discussed, supporting proposals in the literature that resonant absorption of magnetic waves is a viable mechanism for depositing energy in the corona.

  17. Data-driven coronal evolutionary model of active region 11944.

    Science.gov (United States)

    Kazachenko, M.

    2014-12-01

    Recent availability of systematic measurements of vector magnetic fields and Doppler velocities has allowed us to utilize a data-driven approach for modeling observed active regions (AR), a crucial step for understanding the nature of solar flare initiation. We use a sequence of vector magnetograms and Dopplergrams from the Helioseismic and Magnetic Imager (HMI) aboard the SDO to drive magnetofrictional (MF) model of the coronal magnetic field in the the vicinity of AR 11944, where an X1.2 flare on January 7 2014 occurred. To drive the coronal field we impose a time-dependent boundary condition based on temporal sequences of magnetic and electric fields at the bottom of the computational domain, i.e. the photosphere. To derive the electric fields we use a recently improved poloidal-toroidal decomposition (PTD), which we call the ``PTD-Doppler-FLCT-Ideal'' or PDFI technique. We investigate the results of the simulated coronal evolution, compare those with EUV observations from Atmospheric Imaging Assembly (AIA) and discuss what we could learn from them. This work is a a collaborative effort from the UC Berkeley Space Sciences Laboratory (SSL), Stanford University, and Lockheed-Martin and is a part of Coronal Global Evolutionary (CGEM) Model, funded jointly by NASA and NSF.

  18. Quantifying the Significance of Substructure in Coronal Loops

    Science.gov (United States)

    McKeough, K. B. D.; Kashyap, V.; McKillop, S.

    2014-12-01

    A method to infer the presence of small-scale substructure in SDO/AIA (Atmospheric Imaging Assembly on the Solar Dynamics Observatory) images of coronal loops is developed. We can classify visible loop structure based on this propensity to show substructure which puts constraints on contemporary solutions to the coronal heating problem. The method uses the Bayesian algorithm Low-count Image Reconstruction and Analysis (LIRA) to infer the multi-scale component of the loops which describes deviations from a smooth model. The increase in contrast of features in this multi-scale component is determined using a statistic that estimates the sharpness across the image. Regions with significant substructure are determined using p-value upper bounds. We are able to locate substructure visible in Hi-C (High-Resolution Coronal Imager) data that are not salient features in the corresponding AIA image. Looking at coronal loops at different regions of the Sun (e.g., low-lying structure and loops in the upper corona) we are able to map where detectable substructure exists and thus the influence of the nanoflare heating process. We acknowledge support from AIA under contract SP02H1701R from Lockheed-Martin to SAO.

  19. Arthroscopic Treatment of Medial Femoral Condylar Coronal Fractures and Nonunions

    Science.gov (United States)

    Ercin, Ersin; Bilgili, M. Gokhan; Basaran, S. Hakan; Baca, Emre; Kural, Cemal; Avkan, M. Cevdet

    2013-01-01

    Nonunion of medial femoral condylar coronal fractures are uncommon. In neglected Hoffa fractures despite nonunion, there is a risk of missing accompanying ligamentous and intra-articular injuries. Neither preoperative clinical examination nor magnetic resonance imaging showed these injuries before arthroscopy. Arthroscopy before internal fixation gives additional information and changes the surgical protocol for these fractures and nonunions. PMID:24400191

  20. Investigation of Coronal Large Scale Structures Utilizing Spartan 201 Data

    Science.gov (United States)

    Guhathakurta, Madhulika

    1998-01-01

    Two telescopes aboard Spartan 201, a small satellite has been launched from the Space Shuttles, on April 8th, 1993, September 8th, 1994, September 7th, 1995 and November 20th, 1997. The main objective of the mission was to answer some of the most fundamental unanswered questions of solar physics-What accelerates the solar wind and what heats the corona? The two telescopes are 1) Ultraviolet Coronal Spectrometer (UVCS) provided by the Smithsonian Astrophysical Observatory which uses ultraviolet emissions from neutral hydrogen and ions in the corona to determine velocities of the coronal plasma within the solar wind source region, and the temperature and density distributions of protons and 2) White Light Coronagraph (WLC) provided by NASA's Goddard Space Flight Center which measures visible light to determine the density distribution of coronal electrons within the same region. The PI has had the primary responsibility in the development and application of computer codes necessary for scientific data analysis activities, end instrument calibration for the white-light coronagraph for the entire Spartan mission. The PI was responsible for the science output from the WLC instrument. PI has also been involved in the investigation of coronal density distributions in large-scale structures by use of numerical models which are (mathematically) sufficient to reproduce the details of the observed brightness and polarized brightness distributions found in SPARTAN 201 data.

  1. Competition between shock and turbulent heating in coronal loop system

    CERN Document Server

    Matsumoto, Takuma

    2016-01-01

    2.5-dimensional magnetohydrodynamic (MHD) simulations are performed with high spatial resolution in order to distinguish between competing models of the coronal heating problem. A single coronal loop powered by Alfv\\'{e}n waves excited in the photosphere is the target of the present study. The coronal structure is reproduced in our simulations as a natural consequence of the transportation and dissipation of Alfv\\'{e}n waves. Further, the coronal structure is maintained as the spatial resolution is changed from 25 to 3 km, although the temperature at the loop top increases with the spatial resolution. The heating mechanisms change gradually across the magnetic canopy at a height of 4 Mm. Below the magnetic canopy, both the shock and the MHD turbulence are dominant heating processes. Above the magnetic canopy, the shock heating rate reduces to less than 10 % of the total heating rate while the MHD turbulence provides significant energy to balance the radiative cooling and thermal conduction loss or gain. The i...

  2. Prevalência de cistos e tumores odontogênicos em pacientes atendidos na Fundação Assistencial da Paraíba: estudo retrospectivo

    OpenAIRE

    Pereira, Jozinete Vieira; Figueirêdo, Danillo Urquiza de; Souza, Emmanuel Albuquerque; Holmes, Tatiana Stuart Vieira; Gomes, Daliana Queiroga de Castro; Cavalcanti, Alessandro Leite

    2016-01-01

    Avaliar a prevalência de cistos e tumores odontogênicos em pacientes atendidos na Fundação Assistencial da Paraíba (FAP). Foi realizado um estudo observacional, epidemiológico e retrospectivo, por meio da análise de 2.268 prontuários odontológicos de pacientes atendidos no período de janeiro de 1999 a dezembro de 2008. Os dados foram coletados por um único examinador e registrados em ficha específica, sendo analisadas as variáveis: gênero, faixa etária, tipo de lesão (cisto ou tumor) e locali...

  3. Coronal Jets from Minifilament Eruptions in Active Regions

    Science.gov (United States)

    Sterling, A. C.; Martinez, F.; Falconer, D. A.; Moore, R. L.

    2016-12-01

    Solar coronal jets are transient (frequently of lifetime 10 min) features that shoot out from near the solar surface, become much longer than their width, and occur in all solar regions, including coronal holes, quiet Sun, and active regions (e.g., Shimojo et al. 1996, Certain et al. 2007). Sterling et al. (2015) and other studies found that in coronal holes and in quiet Sun the jets result when small-scale filaments, called ``minifilaments,'' erupt onto nearby open or high-reaching field lines. Additional studies found that coronal-jet-onset locations (and hence presumably the minifilament-eruption-onset locations) coincided with locations of magnetic-flux cancellation. For active region (AR) jets however the situation is less clear. Sterling et al. (2016) studied jets in one active region over a 24-hour period; they found that some AR jets indeed resulted from minifilament eruptions, usually originating from locations of episodes of magnetic-flux cancelation. In some cases however they could not determine whether flux was emerging or canceling at the polarity inversion line from which the minifilament erupted; and for other jets of that region minifilaments were not conclusively apparent prior to jet occurrence. Here we further study AR jets, by observing them in a single AR over a one-week period, using X-ray images from Hinode/XRT and EUV/UV images from SDO/AIA, and line-of-sight magnetograms and white-light intensity-grams from SDO/HMI. We initially identified 13 prominent jets in the XRT data, and examined corresponding AIA and HMI data. For at least several of the jets, our findings are consistent with the jets resulting from minifilament eruptions, and originating from sights of magnetic-field cancelation. Thus our findings support that, at least in many cases, AR coronal jets result from the same physical processes that produce coronal jets in quiet-Sun and coronal-hole regions. FM was supportedby the Research Experience for Undergraduates (REU) program at

  4. Magnetic Field in the Gravitationally Stratified Coronal Loops

    Indian Academy of Sciences (India)

    B. N. Dwivedi; A. K. Srivastava

    2015-03-01

    We study the effect of gravitational stratification on the estimation of magnetic fields in the coronal loops. By using the method of MHD seismology of kink waves for the estimation of magnetic field of coronal loops, we derive a new formula for the magnetic field considering the effect of gravitational stratification. The fast-kink wave is a potential diagnostic tool for the estimation of magnetic field in fluxtubes. We consider the eleven kink oscillation cases observed by TRACE between July 1998 and June 2001. We calculate magnetic field in the stratified loops (str) and compare them with the previously calculated absolute magnetic field (abs). The gravitational stratification efficiently affects the magnetic field estimation in the coronal loops as it affects also the properties of kink waves. We find ≈22% increment in the magnetic field for the smallest ( = 72 Mm) while ≈42% increment in the absolute magnetic field for the longest ( = 406 Mm) coronal loops. The magnetic fields str and abs also increase with the number density, if the loop length does not vary much. The increment in the magnetic field due to gravitational stratification is small at the lower number densities, however, it is large at the higher number densities. We find that damping time of kink waves due to phase-mixing is less in the case of gravitationally stratified loops compared to nonstratified ones. This indicates the more rapid damping of kink waves in the stratified loops. In conclusion, we find that the gravitational stratification efficiently affects the estimation of magnetic field and damping time estimation especially in the longer coronal loops.

  5. Dichotomy of Solar Coronal Jets: Standard Jets and Blowout Jets

    Science.gov (United States)

    Moore, R. L.; Cirtain, J. W.; Sterling, A. C.; Falconer, D. A.

    2010-01-01

    By examining many X-ray jets in Hinode/XRT coronal X-ray movies of the polar coronal holes, we found that there is a dichotomy of polar X-ray jets. About two thirds fit the standard reconnection picture for coronal jets, and about one third are another type. We present observations indicating that the non-standard jets are counterparts of erupting-loop H alpha macrospicules, jets in which the jet-base magnetic arch undergoes a miniature version of the blowout eruptions that produce major CMEs. From the coronal X-ray movies we present in detail two typical standard X-ray jets and two typical blowout X-ray jets that were also caught in He II 304 Angstrom snapshots from STEREO/EUVI. The distinguishing features of blowout X-ray jets are (1) X-ray brightening inside the base arch in addition to the outside bright point that standard jets have, (2) blowout eruption of the base arch's core field, often carrying a filament of cool (T 10(exp 4) - 10(exp 5) K) plasma, and (3) an extra jet-spire strand rooted close to the bright point. We present cartoons showing how reconnection during blowout eruption of the base arch could produce the observed features of blowout X-ray jets. We infer that (1) the standard-jet/blowout-jet dichotomy of coronal jets results from the dichotomy of base arches that do not have and base arches that do have enough shear and twist to erupt open, and (2) there is a large class of spicules that are standard jets and a comparably large class of spicules that are blowout jets.

  6. Comorbilidad psicopatológica en el alcoholismo: un estudio descriptivo

    Directory of Open Access Journals (Sweden)

    Natalia Landa

    2006-01-01

    Full Text Available En este estudio se lleva a cabo un análisis del perfil de bebida y de la comorbilidad psicopatológica en 50 pacientes alcohólicos que acuden en busca de tratamiento a un programa ambulatorio de Proyecto Hombre de Navarra. Para ello, se lleva a cabo un estudio ex post facto, de carácter retrospectivo y con un grupo cuasi control. Se utilizan los criterios diagnósticos del DSM-IV-TR para la dependencia alcohólica, el Müncher Alkoholismus Test (MALT para valorar la gravedad del alcoholismo y el SCL-90-R como medida de la sintomatología asociada. Los resultados obtenidos muestran la presencia de numerosa sintomatología psicopatológica, con elevaciones significativas en la mayoría de las dimensiones del SCL-90-R, tanto en los hombres como en las mujeres de la muestra. La comparación con las muestras normativas refleja que los alcohólicos de la muestra presentan más síntomas psicopatológicos que la población normal, pero menos que la población psiquiátrica. Asimismo, la gravedad del alcoholismo se relaciona de forma significativa con la mayor presencia e intensidad de comorbilidad. Por último, se comentan las implicaciones de este estudio para la práctica clínica y para la investigación futura.

  7. On the nature of transverse coronal waves revealed by wavefront dislocations

    CERN Document Server

    Ariste, A López; Arregui, I; Khomenko, E; Collados, M

    2015-01-01

    Coronal waves are an important aspect of the dynamics of the plasma in the corona. Wavefront dislocations are topological features of most waves in nature and also of magnetohydrodynamic waves. Are there dislocations in coronal waves? The finding and explanation of dislocations may shed light on the nature and characteristics of the propagating waves, their interaction in the corona and in general on the plasma dynamics. We positively identify dislocations in coronal waves observed by the Coronal Multi-channel Polarimeter (CoMP) as singularities in the Doppler shifts of emission coronal lines. We study the possible singularities that can be expected in coronal waves and try to reproduce the observed dislocations in terms of localization and frequency of appearance. The observed dislocations can only be explained by the interference of a kink and a sausage wave modes propagating with different frequencies along the coronal magnetic field. In the plane transverse to the propagation, the cross-section of the osc...

  8. Characteristics of EUV Coronal Jets Observed with STEREO/SECCHI

    Science.gov (United States)

    Nisticò, G.; Bothmer, V.; Patsourakos, S.; Zimbardo, G.

    2009-10-01

    In this paper we present the first comprehensive statistical study of EUV coronal jets observed with the SECCHI (Sun Earth Connection Coronal and Heliospheric Investigation) imaging suites of the two STEREO spacecraft. A catalogue of 79 polar jets is presented, identified from simultaneous EUV and white-light coronagraph observations, taken during the time period March 2007 to April 2008, when solar activity was at a minimum. The twin spacecraft angular separation increased during this time interval from 2 to 48 degrees. The appearances of the coronal jets were always correlated with underlying small-scale chromospheric bright points. A basic characterization of the morphology and identification of the presence of helical structure were established with respect to recently proposed models for their origin and temporal evolution. Though each jet appeared morphologically similar in the coronagraph field of view, in the sense of a narrow collimated outward flow of matter, at the source region in the low corona the jet showed different characteristics, which may correspond to different magnetic structures. A classification of the events with respect to previous jet studies shows that amongst the 79 events there were 37 Eiffel tower-type jet events, commonly interpreted as a small-scale (˜35 arc sec) magnetic bipole reconnecting with the ambient unipolar open coronal magnetic fields at its loop tops, and 12 lambda-type jet events commonly interpreted as reconnection with the ambient field happening at the bipole footpoints. Five events were termed micro-CME-type jet events because they resembled the classical coronal mass ejections (CMEs) but on much smaller scales. The remaining 25 cases could not be uniquely classified. Thirty-one of the total number of events exhibited a helical magnetic field structure, indicative for a torsional motion of the jet around its axis of propagation. A few jets are also found in equatorial coronal holes. In this study we present sample

  9. Standing sausage modes in coronal loops with plasma flow

    Science.gov (United States)

    Li, Bo; Chen, Shao-Xia; Xia, Li-Dong; Yu, Hui

    2014-08-01

    Context. Magnetohydrodynamic waves are important for diagnosing the physical parameters of coronal plasmas. Field-aligned flows appear frequently in coronal loops. Aims: We examine the effects of transverse density and plasma flow structuring on standing sausage modes trapped in coronal loops, and examine their observational implications in the context of coronal seismology. Methods: We model coronal loops as straight cold cylinders with plasma flow embedded in a static corona. An eigen-value problem governing propagating sausage waves is formulated and its solutions are employed to construct standing modes. Two transverse profiles are distinguished, and are called profiles E and N. A parameter study is performed on the dependence of the maximum period Pmax and cutoff length-to-radius ratio (L/a)cutoff in the trapped regime on the density parameters (ρ0/ρ∞ and profile steepness p) and the flow parameters (its magnitude U0 and profile steepness u). Results: For either profile, introducing a flow reduces Pmax obtainable in the trapped regime relative to the static case. The value of Pmax is sensitive to p for profile N, but is insensitive to p for profile E. By far the most important effect a flow introduces is to reduce the capability for loops to trap standing sausage modes: (L/a)cutoff may be substantially reduced in the case with flow relative to the static one. In addition, (L/a)cutoff is smaller for a stronger flow, and for a steeper flow profile when the flow magnitude is fixed. Conclusions: If the density distribution can be described by profile N, then measuring the sausage mode period can help deduce the density profile steepness. However, this practice is not feasible if profile E more accurately describes the density distribution. Furthermore, even field-aligned flows with magnitudes substantially smaller than the ambient Alfvén speed can make coronal loops considerably less likely to support trapped standing sausage modes. Appendix A is available in

  10. Coronal Abundance Anomalies in Solar-Like Stars

    Science.gov (United States)

    Laming, John

    We propose to model the trend of coronal abundance anomalies observed in a sample of solar-like stars by Wood & Linsky (2010). Dwarf stars of similar spectral type to the Sun show what has become known as a FIP (First Ionization Potential) Effect, where elements with first ionization potential below about 10 eV are enhanced in abundance in the corona by a factor of about 3 - 4. Stars of later spectral type show a diminished FIP effect, with the anomaly disappearing at about K5 spectral type. Beyond this, M dwarf stars show an inverse FIP effect, with the low FIP ions becoming depleted in the stellar corona, by factors of order 2.5 - 3. The solar case of positive FIP effect has been successfully interpreted as being due to the action of the ponderomotive force associated with chromospheric Alfven waves. In conditions in which upgoing Alfven waves are transmitted into coronal loops, or in which coronally generated waves reflect at loop footpoints, the ponderomotive force is directed upwards, and accelerates chromospheric ions (the low FIP elements) into the corona. Neutral atoms are not affected. The inverse FIP effect can arise when upward propagating chromospheric Alfven waves are reflected back down again at coronal loop footpoints, due to a mismatch between the wave frequency and the loop resonance. We propose to study stars for which parameters like asteroseismic oscillation frequencies, coronal abundance anomalies, and chromospheric structure are known. As well as constraining coronal magnetic fields and loop resonances in these stars, we expect important insights into the nature of stellar dynamos since the M dwarfs in the sample (with inverse FIP effect) are at or near the fully convective limit. Finally, we will be able to assess potential fractionation in the O/Ne abundance ratio. Drake & Testa (2005) argued that Ne is depleted in the solar corona relative to O, but not in the coronae of more active stars. Our FIP models provide some support for this in the

  11. Analisis retrospectivo de las pruebas diagnosticas de leptospirosis bovina procesadas en La Unidad de Investigacion y Diagnostico de Leptospirosis de la Universidad del Zulia, 1998-2001

    National Research Council Canada - National Science Library

    Van Balen, Joany; Hoet, Armando; D'Pool, Gerardo; Gil, Marcelo; Escalona, Freddys; Diaz, Dubraska

    2009-01-01

    En el presente estudio se analizaron los resultados de sueros de bovinos procesados en la Unidad de Investigacion y Diagnostico de Leptospirosis de la Universidad del Zulia durante el periodo 1998-2001...

  12. Estudios de investigación experimentales

    OpenAIRE

    Serra Añó, Pilar

    2016-01-01

    En este vídeo se explican las principales características de los estudios de investigación experimentales, en cuanto a diseño y procedimientos. En concreto se consideran los estudios experimentales (ensayos clínicos aleatorizados y no aleatorizados) y los estudios cuasi-experimentales (diseño de series temporales y experimentos cruzados).

  13. Coronal Structures as Tracers of Sub-Surface Processes

    Indian Academy of Sciences (India)

    Alexei A. PevtSOV; Richard C. Canfield

    2000-09-01

    The solar corona - one of the most spectacular celestial shows and yet one of the most challenging puzzles - exhibits a spectrum of structures related to both the quiet Sun and active regions. In spite of dramatic differences in appearance and physical processes, all these structures share a common origin: they are all related to the solar magnetic field. The origin of the field is beneath the turbulent convection zone, where the magnetic field is not a master but a slave, and one can wonder how much the coronal magnetic field ``remembers" its dynamo origin. Surprisingly, it does. We will describe several observational phenomena that indicate a close relationship between coronal and sub-photospheric processes.

  14. Turbulent coronal heating and the distribution of nanoflares

    CERN Document Server

    Dmitruk, P; Dmitruk, Pablo; Gomez, Daniel O.

    1997-01-01

    We perform direct numerical simulations of an externally driven two-dimensional magnetohydrodynamic system over extended periods of time to simulate the dynamics of a transverse section of a solar coronal loop. A stationary and large-scale magnetic forcing was imposed, to model the photospheric motions at the magnetic loop footpoints. A turbulent stationary regime is reached, which corresponds to energy dissipation rates consistent with the heating requirements of coronal loops. The temporal behavior of quantities such as the energy dissipation rate show clear indications of intermittency, which are exclusively due to the strong nonlinearity of the system. We tentatively associate these impulsive events of magnetic energy dissipation to the so-called nanoflares. A statistical analysis of these events yields a power law distribution as a function of their energies with a negative slope of 1.5, which is consistent with those obtained for flare energy distributions reported from X-ray observations.

  15. Coronal Streamers and Their Associated Solar Wind Streams

    Science.gov (United States)

    Miralles, M. P.; Landi, E.; Cranmer, S. R.; Cohen, O.; Raymond, J. C.

    2012-12-01

    We use the EUV spectrometers aboard SOHO and Hinode and white-light coronagraphs to characterize the physical properties of coronal streamers during Earth/Ulysses quadrature configurations for the previous two solar minimum periods. In addition, comparisons between coronal observations and in situ measurements of solar wind plasma properties are being used to further characterize the origins of slow wind streams. In order to investigate slow solar wind heating and acceleration, we also compare with predictions from three-dimensional MHD models. We aim to use the empirical measurements to distinguish between different proposed physical processes for slow wind acceleration (e.g., waves/turbulence versus reconnection). This work is supported by NASA grant NNX10AQ58G to the Smithsonian Astrophysical Observatory.

  16. Polar Coronal Holes During Solar Cycles 22 and 23

    Institute of Scientific and Technical Information of China (English)

    Jun Zhang; J. Woch; S. Solanki

    2005-01-01

    Data from the Solar Wind Ion Composition Spectrometer (SWICS) on Ulysses and synoptic maps from Kitt Peak are used to analyze the polar coronal holes of solar activity cycles 22 and 23 (from 1990 to end of 2003). In the beginning of the declining phase of solar cycles 22 and 23, the north polar coronal holes (PCHs) appear about one year earlier than the ones in the south polar region.The solar wind velocity and the solar wind ionic charge composition exhibit a characteristic dependence on the solar wind source position within a PCH. From the center toward the boundary of a young PCH, the solar wind velocity decreases,coinciding with a shift of the ionic charge composition toward higher charge states.However, for an old PCH, the ionic charge composition does not show any obvious change, although the latitude evolution of the velocity is similar to that of a young PCH.

  17. Global Alfven Waves in Solar Physics: Coronal Heating

    Science.gov (United States)

    de Azevedo, C. A.; de Assis, A. S.

    1990-11-01

    RESUMEN. Se ha demostrado que Ia onda discreta de Alfven puede generar por lo memos un 20% de la energia coronal requerida con densidad de flujo de lO- erg 5 . Las ondas discretas de Alfven son una nueva clase `de ondas de Alfven las cuales pueden describirse por el modelo con que incluye un i6n finito, con frecuencia ciclotr6nica ( /uci # 0) y los efectos del equilibrio de plasma mostrados por Appert, Vaclavik and Villar 1984. ABSTRACT. It has been shown that the Discrete Alfven wave can power at least 20% of the required coronal energy flux density iO- Discrete Alfven waves are a new class of Alfven waves wich can be described by the model with the inclusion of finite ion cyclotron frequency (w/wci 0) and the equilibrium plasma current effects as shown by Appert, Vaclavik and Villar 1984. o,t :, HYDROMAGNETICS - SUN-CORONA

  18. Stellar Activity and Coronal Heating: an overview of recent results

    CERN Document Server

    Testa, Paola; Drake, Jeremy

    2015-01-01

    Observations of the coronae of the Sun and of solar-like stars provide complementary information to advance our understanding of stellar magnetic activity, and of the processes leading to the heating of their outer atmospheres. While solar observations allow us to study the corona at high spatial and temporal resolution, the study of stellar coronae allows us to probe stellar activity over a wide range of ages and stellar parameters. Stellar studies therefore provide us with additional tools for understanding coronal heating processes, as well as the long-term evolution of solar X-ray activity. We discuss how recent studies of stellar magnetic fields and coronae contribute to our understanding of the phenomenon of activity and coronal heating in late-type stars.

  19. Doente coronário agudo, um retrato global

    OpenAIRE

    Ivo, Rita Maria Mendes Duarte Gomes

    2012-01-01

    Introdução: Na União Europeia, quase metade das mortes ocorrem devido a doenças cardiovasculares e destas, cerca de um terço é causada por doenças coronárias agudas. São uma causa importante de incapacidade e de aumento dos custos da saúde de um país. A identificação dos fatores de risco cardiovascular presentes numa população, adquire um papel preponderante para a prevenção destas patologias. O objetivo principal deste estudo é elaborar um retrato global do doente coronário agudo tratado no ...

  20. Nonlinear Dynamics of the Parker Scenario for Coronal Heating

    CERN Document Server

    Rappazzo, A F; Einaudi, G; Dahlburg, R B

    2007-01-01

    The Parker or field line tangling model of coronal heating is studied comprehensively via long-time high-resolution simulations of the dynamics of a coronal loop in cartesian geometry within the framework of reduced magnetohydrodynamics (RMHD). Slow photospheric motions induce a Poynting flux which saturates by driving an anisotropic turbulent cascade dominated by magnetic energy. In physical space this corresponds to a magnetic topology where magnetic field lines are barely entangled, nevertheless current sheets (corresponding to the original tangential discontinuities hypothesized by Parker) are continuously formed and dissipated. Current sheets are the result of the nonlinear cascade that transfers energy from the scale of convective motions ($\\sim 1,000 km$) down to the dissipative scales, where it is finally converted to heat and/or particle acceleration. Current sheets constitute the dissipative structure of the system, and the associated magnetic reconnection gives rise to impulsive ``bursty'' heating ...

  1. On The Fourier And Wavelet Analysis Of Coronal Time Series

    CERN Document Server

    Auchère, F; Bocchialini, K; Buchlin, E; Solomon, J

    2016-01-01

    Using Fourier and wavelet analysis, we critically re-assess the significance of our detection of periodic pulsations in coronal loops. We show that the proper identification of the frequency dependence and statistical properties of the different components of the power spectra provies a strong argument against the common practice of data detrending, which tends to produce spurious detections around the cut-off frequency of the filter. In addition, the white and red noise models built into the widely used wavelet code of Torrence & Compo cannot, in most cases, adequately represent the power spectra of coronal time series, thus also possibly causing false positives. Both effects suggest that several reports of periodic phenomena should be re-examined. The Torrence & Compo code nonetheless effectively computes rigorous confidence levels if provided with pertinent models of mean power spectra, and we describe the appropriate manner in which to call its core routines. We recall the meaning of the default c...

  2. Stellar activity and coronal heating: an overview of recent results

    Science.gov (United States)

    Testa, Paola; Saar, Steven H.; Drake, Jeremy J.

    2015-01-01

    Observations of the coronae of the Sun and of solar-like stars provide complementary information to advance our understanding of stellar magnetic activity, and of the processes leading to the heating of their outer atmospheres. While solar observations allow us to study the corona at high spatial and temporal resolution, the study of stellar coronae allows us to probe stellar activity over a wide range of ages and stellar parameters. Stellar studies therefore provide us with additional tools for understanding coronal heating processes, as well as the long-term evolution of solar X-ray activity. We discuss how recent studies of stellar magnetic fields and coronae contribute to our understanding of the phenomenon of activity and coronal heating in late-type stars. PMID:25897087

  3. Estimate of Coronal Magnetic Field Strength Using Plasmoid Acceleration Measurement

    Science.gov (United States)

    Choe, G.; Lee, K.; Jang, M.

    2010-12-01

    A method of estimating the lower bound of coronal magnetic field strength in the neighborhood of an ejecting plasmoid is presented. Based on the assumption that the plasma ejecta is within a magnetic island, an analytical expression for the force acting on the ejecta is derived. A rather simple calculation shows that the vertical force acting on a cylinder-like volume, whose lateral surface is a flux surface and whose magnetic axis is parallel to the horizontal, is just the difference in total pressure (magnetic pressure plus plasma pressure) below and above the volume. The method is applied to a limb coronal mass ejection event, and a lower bound of the magnetic field strength just below the CME core is estimated. The method is expected to provide useful information on the strength of reconnecting magnetic field if applied to X-ray plasma ejecta.

  4. Coronal heating by the partial relaxation of twisted loops

    CERN Document Server

    Bareford, Michael; Browning, Philippa

    2012-01-01

    Context: Relaxation theory offers a straightforward method for estimating the energy that is released when a magnetic field becomes unstable, as a result of continual convective driving. Aims: We present new results obtained from nonlinear magnetohydrodynamic (MHD) simulations of idealised coronal loops. The purpose of this work is to determine whether or not the simulation results agree with Taylor relaxation, which will require a modified version of relaxation theory applicable to unbounded field configurations. Methods: A three-dimensional (3D) MHD Lagrangian-remap code is used to simulate the evolution of a line-tied cylindrical coronal loop model. This model comprises three concentric layers surrounded by a potential envelope; hence, being twisted locally, each loop configuration is distinguished by a piecewise-constant current profile. Initially, all configurations carry zero-net-current fields and are in ideally unstable equilibrium. The simulation results are compared with the predictions of helicity ...

  5. Spatial damping of propagating sausage waves in coronal cylinders

    CERN Document Server

    Guo, Ming-Zhe; Li, Bo; Xia, Li-Dong; Yu, Hui

    2015-01-01

    Sausage modes are important in coronal seismology. Spatially damped propagating sausage waves were recently observed in the solar atmosphere. We examine how wave leakage influences the spatial damping of sausage waves propagating along coronal structures modeled by a cylindrical density enhancement embedded in a uniform magnetic field. Working in the framework of cold magnetohydrodynamics, we solve the dispersion relation (DR) governing sausage waves for complex-valued longitudinal wavenumber $k$ at given real angular frequencies $\\omega$. For validation purposes, we also provide analytical approximations to the DR in the low-frequency limit and in the vicinity of $\\omega_{\\rm c}$, the critical angular frequency separating trapped from leaky waves. In contrast to the standing case, propagating sausage waves are allowed for $\\omega$ much lower than $\\omega_{\\rm c}$. However, while able to direct their energy upwards, these low-frequency waves are subject to substantial spatial attenuation. The spatial damping ...

  6. Coronal Mass Ejections and Non-recurrent Forbush Decreases

    Science.gov (United States)

    Belov, A.; Abunin, A.; Abunina, M.; Eroshenko, E.; Oleneva, V.; Yanke, V.; Papaioannou, A.; Mavromichalaki, H.; Gopalswamy, N.; Yashiro, S.

    2014-10-01

    Coronal mass ejections (CMEs) and their interplanetary counterparts (interplanetary coronal mass ejections, ICMEs) are responsible for large solar energetic particle events and severe geomagnetic storms. They can modulate the intensity of Galactic cosmic rays, resulting in non-recurrent Forbush decreases (FDs). We investigate the connection between CME manifestations and FDs. We used specially processed data from the worldwide neutron monitor network to pinpoint the characteristics of the recorded FDs together with CME-related data from the detailed online catalog based upon the Solar and Heliospheric Observatory (SOHO)/ Large Angle and Spectrometric Coronagraph (LASCO) data. We report on the correlations of the FD magnitude to the CME initial speed, the ICME transit speed, and the maximum solar wind speed. Comparisons between the features of CMEs (mass, width, velocity) and the characteristics of FDs are also discussed. FD features for halo, partial halo, and non-halo CMEs are presented and discussed.

  7. Energetic characterisation and statistics of solar coronal brightenings

    CERN Document Server

    Joulin, Vincent; Solomon, Jacques; Guennou, Chloé

    2016-01-01

    To explain the high temperature of the corona, much attention has been paid to the distribution of energy in dissipation events. Indeed, if the event energy distribution is steep enough, the smallest, unobservable events could be the largest contributors to the total energy dissipation in the corona. Previous observations have shown a wide distribution of energies but remain inconclusive about the precise slope. Furthermore, these results rely on a very crude estimate of the energy. On the other hand, more detailed spectroscopic studies of structures such as coronal bright points do not provide enough statistical information to derive their total contribution to heating. We aim at getting a better estimate of the distributions of the energy dissipated in coronal heating events using high-resolution, multi-channel Extreme Ultra-Violet (EUV) data. To estimate the energies corresponding to heating events and deduce their distribution, we detect brightenings in five EUV channels of the Atmospheric Imaging Assembl...

  8. Is Coronal X-ray Emission Energized By Electric Currents?

    Science.gov (United States)

    Ishibashi, Kazunori; Metcalf, T.; Lites, B.

    2007-05-01

    We examine the spatial correlation between coronal X-ray emission observed with the Hinode X-Ray Telescope and electric currents observed with the Hinode Solar Optical Telescope Spectro-polarimeter. We determine to what extent the X-ray brightness is correlated with electric current density and hence to what extent the hot corona is energized by electric currents which flow through the photosphere. We will also consider whether the currents reach the corona to heat the coronal plasma or whether they predominantly close below the corona. Hinode is an international project supported by JAXA, NASA, PPARC and ESA. We are grateful to the Hinode team for all their efforts in the design, development and operation of the mission.

  9. Inferring the Coronal Density Irregularity from EUV Spectra

    CERN Document Server

    Hahn, Michael

    2016-01-01

    Understanding the density structure of the solar corona is important for modeling both coronal heating and the solar wind. Direct measurements are difficult because of line-of-sight integration and possible unresolved structures. We present a new method for quantifying such structure using density-sensitive EUV line intensities to derive a density irregularity parameter, a relative measure of the amount of structure along the line of sight. We also present a simple model to relate the inferred irregularities to physical quantities, such as the filling factor and density contrast. For quiet Sun regions and interplume regions of coronal holes, we find a density contrast of at least a factor of three to ten and corresponding filling factors of about 10-20%. Our results are in rough agreement with other estimates of the density structures in these regions. The irregularity diagnostic provides a useful relative measure of unresolved structure in various regions of the corona.

  10. Factores de riesgo para morbilidad en neonatos con síndrome de Down. Estudio multicéntrico diciembre 2007 a julio 2009 / Risk factors for morbidity in neonatos with Down syndrome. Multicenter study december 2007 to july 2009

    OpenAIRE

    Franco Reina, Eliana Rocío

    2010-01-01

    El Síndrome de Down es la cromosomopatía más común y la más frecuente causa conocida de retardo mental. Cursa con anomalías, siendo las cardiopatías las más comunes y las asociadas a una mayor morbi-mortalidad. El objetivo de este estudio fue determinar factores de riesgo para la presentación y morbilidad en neonatos con síndrome de Down. Materiales y métodos: Se realizó un estudio de casos y controles retrospectivo, donde se incluyeron neonatos con síndrome de Down confirmados por cariotipo ...

  11. An Estimate of Solar Wind Velocity Profiles in a Coronal Hole and a Coronal Streamer Area (6-40 R(radius symbol)

    Science.gov (United States)

    Patzold, M.; Tsurutani, B. T.; Bird, M. K.

    1995-01-01

    Total electron content data obtained from the Ulysses Solar Corona Experiment (SCE) in 1991 were used to select two data sets, one associated with a coronal hole and the other with coronal streamer crossings. (This is largely equatorial data shortly after solar maximum.) The solar wind velocity profile is estimated for these areas.

  12. Estudio de la prevalencia de un tercer conducto en primeros premolares superiores mediante diafanización

    OpenAIRE

    Katherine Stephanie De la Rosa Fernández; Marcio Alejandro Farfán Chacha

    2016-01-01

    Existen fracasos endodónticos que son relacionados por diferentes causas como: obturación incompleta, filtración coronal y fallos por parte del clínico en identificar o localizar los conductos radiculares y sus ramificaciones. Por este motivo, es básico la noción de la anatomía interna dental y sobre todo es importante tener en cuenta las variaciones que pueden existir en las distintas piezas dentales. Objetivo: El propósito del presente estudio es conocer la cantidad de conductos existentes ...

  13. Projection Effects in Coronal Dimmings and Associated EUV Wave Event

    Science.gov (United States)

    Dissauer, K.; Temmer, M.; Veronig, A. M.; Vanninathan, K.; Magdalenić, J.

    2016-10-01

    We investigate the high-speed (v > 1000 km s‑1) extreme-ultraviolet (EUV) wave associated with an X1.2 flare and coronal mass ejection (CME) from NOAA active region 11283 on 2011 September 6 (SOL2011-09-06T22:12). This EUV wave features peculiar on-disk signatures in particular, we observe an intermittent “disappearance” of the front for 120 s in Solar Dynamics Observatory (SDO)/AIA 171, 193, 211 Å data, whereas the 335 Å filter, sensitive to hotter plasmas (T ∼ 2.5 MK), shows a continuous evolution of the wave front. The eruption was also accompanied by localized coronal dimming regions. We exploit the multi-point quadrature position of SDO and STEREO-A, to make a thorough analysis of the EUV wave evolution, with respect to its kinematics and amplitude evolution and reconstruct the SDO line-of-sight (LOS) direction of the identified coronal dimming regions in STEREO-A. We show that the observed intensities of the dimming regions in SDO/AIA depend on the structures that are lying along their LOS and are the combination of their individual intensities, e.g., the expanding CME body, the enhanced EUV wave, and the CME front. In this context, we conclude that the intermittent disappearance of the EUV wave in the AIA 171, 193, and 211 Å filters, which are channels sensitive to plasma with temperatures below ∼2 MK is also caused by such LOS integration effects. These observations clearly demonstrate that single-view image data provide us with limited insight to correctly interpret coronal features.

  14. EUV and Coronagraphic Observations of Coronal Mass Ejections

    Indian Academy of Sciences (India)

    Durgesh Tripathi

    2006-06-01

    The Large Angle Spectrometric Coronagraph (LASCO) and Extreme-ultraviolet Imaging Telescope (EIT) onboard Solar and Heliospheric Observatory (SOHO) provide us with unprecedented multi-wavelength observations helping us to understand different dynamic phenomena on the Sun and in the corona. In this paper we discuss the association between post-eruptive arcades (PEAs) detected by EIT and white-light coronal mass ejections (CMEs) detected by LASCO/C2 telescope.

  15. Energetic characterisation and statistics of solar coronal brightenings

    Science.gov (United States)

    Buchlin, Eric; Solomon, Jacques; Joulin, Vincent; Guennou, Chloé

    2016-07-01

    To explain the high temperature of the corona, much attention has been paid to the distribution of energy in dissipation events, which might be caused by turbulent reconnection. Indeed, if the event energy distribution is steep enough, the smallest, unobservable events could be the largest contributors to the total energy dissipation in the corona. Previous observations have shown a wide distribution of energies but remain inconclusive about the precise slope. Furthermore, these results rely on a very crude estimate of the energy. On the other hand, more detailed spectroscopic studies of structures such as coronal bright points do not provide enough statistical information to derive their total contribution to heating. We aim at getting a better estimate of the distributions of the energy dissipated in coronal heating events using high-resolution, multi-channel Extreme Ultra-Violet (EUV) data. To estimate the energies corresponding to heating events and deduce their distribution, we detect brightenings in five EUV channels of the Atmospheric Imaging Assembly (AIA) on-board the Solar Dynamics Observatory (SDO). We combine the results of these detections and we use maps of temperature and emission measure derived from the same observations to compute the energies. We obtain distributions of areas, durations, intensities, and energies (thermal, radiative, and conductive) of events. These distributions are power-laws, and we find also power-law correlations between event parameters. The energy distributions indicate that the energy from a population of events like the ones we detect represents a small contribution to the total coronal heating, even when extrapolating to smaller scales. The main explanations for this are how heating events can be extracted from observational data, and the incomplete knowledge of the thermal structure and processes in the coronal plasma attainable from available observations.

  16. Swift X-ray monitoring of stellar coronal variability

    Science.gov (United States)

    Miller, Brendan P.; Gallo, Elena; Wright, Jason; Hagen, Cedric

    2017-08-01

    We used California Planet Search Ca II H and K core emission measurements to identify and characterize chromospheric activity cycles in a sample of main-sequence FGK stars. About a dozen of these with existing ROSAT archival data were targeted with Swift to obtain a current epoch X-ray flux. We find that coronal variability by a factor of several is common on decade-long timescales (we attempt to link to the chromospheric cycle phase) but can also occur on short timescales between Swift visits to a given target, presumably related to stellar rotation and coronal inhomogeneity or to small flares.Additionally, we present new Swift monitoring observations of two M dwarfs with known exoplanets: GJ 15A and GJ 674. GJ 15A b is around 5.3 Earth masses with an 11.4 day orbital period, while GJ 674 is around 11.1 Earth masses with a 4.7 day orbital period. GJ 15A was observed several times in late 2014 and then monitored at approximately weekly intervals for several months in early 2016, for a total exposure of 18 ks. GJ 674 was monitored at approximately weekly intervals for most of 2016, for a total exposure of 40 ks. We provide light curves and hardness ratios for both sources, and also compare to earlier archival X-ray data. Both sources show significant X-ray variability, including between consecutive observations. We quantify the energy distribution for coronal flaring, and compare to optical results for M dwarfs from Kepler. Finally, we discuss the implications of M dwarf coronal activity for exoplanets orbiting within the nominal habitable zone.

  17. A Closer Look at the Alpha Persei Coronal Conundrum

    Science.gov (United States)

    Ayres, Thomas R.

    2017-03-01

    A ROSAT survey of the Alpha Per open cluster in 1993 detected its brightest star, the mid-F supergiant α Persei: the X-ray luminosity and spectral hardness were similar to coronally active late-type dwarf members. Later, in 2010, a Hubble Cosmic Origins Spectrograph SNAPshot of α Per found the far-ultraviolet (FUV) coronal-proxy Si iv unexpectedly weak. This, and a suspicious offset of the ROSAT source, suggested that a late-type companion might be responsible for the X-rays. Recently, a multifaceted program tested that premise. Ground-based optical coronography and near-UV imaging with Hubble Space Telescope (HST) Wide-Field Camera 3 searched for any close-in faint candidate coronal objects, but without success. Then, a Chandra pointing found the X-ray source single and coincident with the bright star. Significantly, the Si iv emissions of α Per, in a deeper FUV spectrum collected by the HST Cosmic Origin Spectrograph as part of the joint program, are aligned well with chromospheric atomic oxygen (which must be intrinsic to the luminous star), within the context of cooler late-F and early-G supergiants, including Cepheid variables. This pointed to the X-rays as the fundamental anomaly. The overluminous X-rays still support the case for a hyperactive dwarf secondary, albeit now spatially unresolved. However, an alternative is that α Per represents a novel class of coronal source. Resolving the first possibility now has become more difficult, because the easy solution—a well-separated companion—has been eliminated. Testing the other possibility will require a broader high-energy census of the early-F supergiants.

  18. Diagnostics of Coronal Heating in Active-region Loops

    Science.gov (United States)

    Fludra, A.; Hornsey, C.; Nakariakov, V. M.

    2017-01-01

    Understanding coronal heating remains a central problem in solar physics. Many mechanisms have been proposed to explain how energy is transferred to and deposited in the corona. We summarize past observational studies that attempted to identify the heating mechanism and point out the difficulties in reproducing the observations of the solar corona from the heating models. The aim of this paper is to study whether the observed extreme ultraviolet (EUV) emission in individual coronal loops in solar active regions can provide constraints on the volumetric heating function, and to develop a diagnostic for the heating function for a subset of loops that are found close to static thermal equilibrium. We reconstruct the coronal magnetic field from Solar Dynamics Observatory/HMI data using a nonlinear force-free magnetic field model. We model selected loops using a one-dimensional stationary model, with a heating rate dependent locally on the magnetic field strength along the loop, and we calculate the emission from these loops in various EUV wavelengths for different heating rates. We present a method to measure a power index β defining the dependence of the volumetric heating rate EH on the magnetic field, {E}H\\propto {B}β , and controlling also the shape of the heating function: concentrated near the loop top, uniform and concentrated near the footpoints. The diagnostic is based on the dependence of the electron density on the index β. This method is free from the assumptions of the loop filling factor but requires spectroscopic measurements of the density-sensitive lines. The range of applicability for loops of different length and heating distributions is discussed, and the steps to solving the coronal heating problem are outlined.

  19. Stellar Coronal Response to Differential Rotation and Flux Emergence

    OpenAIRE

    Gibb, G. P. S.; Mackay, D. H.; Jardine, M. M.; Yeates, A. R.

    2016-01-01

    GPSG would like to thank the STFC for financial support. DHM would like to thank the STFC and the Leverhulme Trust for financial support. Simulations were carried out on a STFC/SRIF funded UKMHD cluster at St Andrews. We perform a numerical parameter study to determine what effect varying differential rotation and flux emergence has on a star's non-potential coronal magnetic field. In particular we consider the effects on the star's surface magnetic flux, open magnetic flux, mean azimuthal...

  20. Projection effects in coronal dimmings and associated EUV wave event

    CERN Document Server

    Dissauer, Karin; Veronig, Astrid M; Vanninathan, Kamalam; Magdalenić, Jasmina

    2016-01-01

    We investigate the high-speed ($v >$ 1000 km s$^{-1}$) extreme-ultraviolet (EUV) wave associated with an X1.2 flare and coronal mass ejection (CME) from NOAA active region 11283 on 2011 September 6 (SOL2011-09-06T22:12). This EUV wave features peculiar on-disk signatures, in particular we observe an intermittent "disappearance" of the front for 120 s in SDO/AIA 171, 193, 211 {\\AA} data, whereas the 335 {\\AA} filter, sensitive to hotter plasmas (T$\\sim$2.5 MK), shows a continuous evolution of the wave front. The eruption was also accompanied by localized coronal dimming regions. We exploit the multi-point quadrature position of SDO and STEREO-A, to make a thorough analysis of the EUV wave evolution, with respect to its kinematics and amplitude evolution and reconstruct the SDO line-of-sight (LOS) direction of the identified coronal dimming regions in STEREO-A. We show that the observed intensities of the dimming regions in SDO/AIA depend on the structures that are lying along their LOS and are the combination ...

  1. MHD modeling of coronal loops: the transition region throat

    CERN Document Server

    Guarrasi, M; Orlando, S; Mignone, A; Klimchuk, J A

    2014-01-01

    The expansion of coronal loops in the transition region may considerably influence the diagnostics of the plasma emission measure. The cross sectional area of the loops is expected to depend on the temperature and pressure, and might be sensitive to the heating rate. The approach here is to study the area response to slow changes in the coronal heating rate, and check the current interpretation in terms of steady heating models. We study the area response with a time-dependent 2D MHD loop model, including the description of the expanding magnetic field, coronal heating and losses by thermal conduction and radiation from optically thin plasma. We run a simulation for a loop 50 Mm long and quasi-statically heated to about 4 MK. We find that the area can change substantially with the quasi-steady heating rate, e.g. by ~40% at 0.5 MK as the loop temperature varies between 1 and 4 MK, and, therefore, affects the interpretation of DEM(T) curves.

  2. Interpretation of the coronal magnetic field configuration of the Sun

    CERN Document Server

    Li, Bo; Yu, Hui

    2012-01-01

    The origin of the heliospheric magnetic flux on the Sun, and hence the origin of the solar wind, is a topic of hot debate.While the prevailing view is that the solar wind originates from outside coronal streamer helmets, there also exists the suggestion that the open magnetic field spans a far wider region.Without the definitive measurement of the coronal magnetic field, it is difficult to resolve the conflict between the two scenarios without doubt.We present two 2-dimensional, Alfv\\'enic-turbulence-based models of the solar corona and solar wind, one with and the other without a closed magnetic field region in the inner corona.The purpose of the latter model is to test whether it is possible to realize a picture suggested by polarimetric measurements of the corona using the FeXIII 10747\\AA\\ line, where open magnetic field lines seem to penetrate the streamer base.The boundary conditions at the coronal base are able to account for important observational constraints, especially those on the magnetic flux dis...

  3. Solar coronal plumes and the fast solar wind

    CERN Document Server

    Dwivedi, B N

    2015-01-01

    The spectral profiles of the coronal Ne viii line at 77 nm have different shapes in quiet-Sun regions and coronal holes (CHs). A single Gaussian fit of the line profile provides an adequate approximation in quiet-Sun areas, whereas a strong shoulder on the long-wavelength side is a systematic feature in CHs. Although this has been noticed since 1999, no physical reason for the peculiar shape could be given. In an attempt to identify the cause of this peculiarity, we address three problems that could not be conclusively resolved in a review article by a study team of the International Space Science Institute (ISSI; Wilhelm et al. 2011) : (1) The physical processes operating at the base and inside of plumes as well as their interaction with the solar wind (SW). (2) The possible contribution of plume plasma to the fast SW streams. (3) The signature of the first-ionization potential (FIP) effect between plumes and inter-plume regions (IPRs). Before the spectroscopic peculiarities in IPRs and plumes in polar coron...

  4. Disappearance of a coronal hole induced by a filament activation

    CERN Document Server

    Lin, Ma; Xiao-Li, Yan; Zhi-Ke, Xue

    2014-01-01

    We present a rare observation of direct magnetic interaction between an activating filament and a coronal hole (CH). The filament was a quiescent one located at the northwest of the CH. It underwent a nonradial activation, during which filament material constantly fell and intruded into the CH. As a result, the CH was clearly destroyed by the intrusion. Brightenings appeared at the boundaries and in the interior of the CH, meanwhile, its west boundaries began to retreat and the area gradually shrank. It is noted that the CH went on shrinking after the end of the intrusion and finally disappeared entirely. Following the filament activation, three coronal dimmings (D1-D3) were formed, among which D1 and D2 persisted throughout the complete disappearance of the CH. The derived coronal magnetic configuration shows that the filament was located below an extended loop system which obviously linked D1 to D2. By comparison with this result of extrapolation, our observations imply that the interaction between the fila...

  5. Bashful ballerina unveiled: Multipole analysis of the coronal magnetic field

    Science.gov (United States)

    Virtanen, I.; Mursula, K.

    2012-12-01

    Heliospheric current sheet (HCS) is the continuum of the coronal magnetic equator, dividing the heliospheric magnetic field (HMF) into two sectors (polarities). Because of its wavy structure, the HCS is often called the ballerina skirt. Several studies have proven that the HCS is southward shifted during about three years in the solar declining phase. This persistent phenomenon, called the bashful ballerina, has been verified by geomagnetic indices since 1930s, by OMNI data base since 1960s, by the WSO PFSS model since mid-1970s and by the Ulysses probe measurements during the fast latitude scans in 1994-1995 and 2007. We study here the Wilcox Solar Observatory measurements of the photospheric magnetic field and the PFSS extrapolation of the coronal magnetic field. We show that the quadrupole moment of the photospheric magnetic field, which is important for the HCS asymmetry (bashful ballerina), mainly arises from the difference between northern and southern polar field strengths. According to the WSO data the minimum time quadrupole is mainly due to the difference between the highest northern and southern latitude bins. Related studies imply that the southward shift of the HCS is related to the delayed development of southern coronal holes. We also discuss the suggested connection of the HCS asymmetry to sunspot hemispheric asymmetry.

  6. More of the Inconvenient Truth About Coronal Dimmings

    CERN Document Server

    McIntosh, Scott W; Leamon, Robert J

    2009-01-01

    We continue the investigation of a CME-driven coronal dimming from December 14 2006 using unique high resolution imaging of the chromosphere and corona from the Hinode spacecraft. Over the course of the dimming event we observe the dynamic increase of non-thermal line broadening of multiple emission lines as the CME is released and the corona opens; reaching levels seen in coronal holes. As the corona begins to close, refill and brighten, we see a reduction of the non-thermal broadening towards the pre-eruption level. The dynamic evolution of non-thermal broadening is consistent with the expected change of Alfven wave amplitudes in the magnetically open rarefied dimming region, compared to the dense closed corona prior to the CME. The presented data reinforce the belief that coronal dimmings must be temporary sources of the fast solar wind. It is unclear if such a rapid transition in the thermodynamics of the corona to a solar wind state has an effect on the CME itself.

  7. The Temperature-Dependent Nature of Coronal Dimmings

    CERN Document Server

    Robbrecht, Eva

    2010-01-01

    The opening-up of the magnetic field during solar eruptive events is often accompanied by a dimming of the local coronal emission. From observations of filament eruptions recorded with the Extreme-Ultraviolet Imager on STEREO during 2008-2009, it is evident that these dimmings are much more pronounced in 19.5 nm than in the lower-temperature line 17.1 nm, as viewed either on the disk or above the limb. We conclude that most of the cooler coronal plasma is not ejected but remains gravitationally bound when the loops open up. This result is consistent with Doppler measurements by Imada and coworkers, who found that the upflow speeds in a transient coronal hole increased dramatically above a temperature of 1 MK; it is also consistent with the quasistatic behavior of polar plumes, as compared with the hotter interplume regions that are the main source of the fast solar wind. When the open flux reconnects and closes down again, the trapped plasma is initially heated to such high temperatures that it is no longer v...

  8. Intermediate Inclinations of Type 2 Coronal-Line Forest AGN

    CERN Document Server

    Rose, Marvin; Crenshaw, Michael; Glidden, Ana

    2015-01-01

    Coronal-Line Forest Active Galactic Nuclei (CLiF AGN) are remarkable in the sense that they have a rich spectrum of dozens of coronal emission lines (e.g. [FeVII], [FeX] and [NeV]) in their spectra. Rose, Elvis & Tadhunter (2015) suggest that the inner obscuring torus wall is the most likely location of the coronal line region in CLiF AGN, and the unusual strength of the forbidden high ionization lines is due to a specific AGN-torus inclination angle. Here we test this suggestion using mid-IR colours (4.6$\\mu$m-22$\\mu$m) from the Wide-Field Infrared Survey Explorer (WISE) for the CLiF AGN. We use the Fischer et al. (2014) result that showed that as the AGN-torus inclination becomes more face on, the Spitzer 5.5$\\mu$m to 30$\\mu$m colours become bluer. We show that the [W2-W4] colours for the CLiF AGN ($\\langle$[W2-W4]$\\rangle$ = 5.92$\\pm$0.12) are intermediate between SDSS type 1 ($\\langle$[W2-W4]$\\rangle$ = 5.22$\\pm$0.01) and type 2 AGN ($\\langle$[W2-W4]$\\rangle$ = 6.35$\\pm$0.03). This implies that the AG...

  9. Current systems of coronal loops in 3D MHD simulations

    CERN Document Server

    Warnecke, Jörn; Bingert, Sven; Peter, Hardi

    2016-01-01

    We study the magnetic field and current structure associated with a coronal loop. Through this we investigate to what extent the assumptions of a force-free magnetic field break down. We analyse a three-dimensional MHD model of the solar corona in an emerging active region with the focus on the structure of the forming coronal loops. The lower boundary of this simulation is taken from a model of an emerging active region. As a consequence of the emerging magnetic flux a coronal loop formes self-consistently. We investigate the current density along magnetic field lines inside (and outside) this loop and study the magnetic and plasma properties in and around this loop. The loop is defined as the bundle of field lines that coincides with enhanced emission in extreme UV. We find that the total current along the emerging loop changes its sign from being antiparallel to parallel to the magnetic field. Around the loop the currents form a complex non-force-free helical structure. This is directly related to a bipola...

  10. The Density of Coronal Plasma in Active Stellar Coronae

    CERN Document Server

    Testa, P; Peres, G; Testa, Paola; Drake, Jeremy J.; Peres, Giovanni

    2004-01-01

    We have analyzed high-resolution X-ray spectra of a sample of 22 active stars observed with the High Energy Transmission Grating Spectrometer on {\\em Chandra} in order to investigate their coronal plasma density. Densities where investigated using the lines of the He-like ions O VII, Mg XI, and Si XIII. While Si XIII lines in all stars of the sample are compatible with the low-density limit, Mg XI lines betray the presence of high plasma densities ($> 10^{12}$ cm$^{-3}$) for most of the sources with higher X-ray luminosity ($> 10^{30}$ erg/s); stars with higher $L_X$ and $L_X/L_{bol}$ tend to have higher densities at high temperatures. Ratios of O VII lines yield much lower densities of a few $10^{10}$ cm$^{-3}$, indicating that the ``hot'' and ``cool'' plasma resides in physically different structures. Our findings imply remarkably compact coronal structures, especially for the hotter plasma emitting the Mg XI lines characterized by coronal surface filling factor, $f_{MgXI}$, ranging from $10^{-4}$ to $10^{-...

  11. Spatial damping of propagating sausage waves in coronal cylinders

    Science.gov (United States)

    Guo, Ming-Zhe; Chen, Shao-Xia; Li, Bo; Xia, Li-Dong; Yu, Hui

    2015-09-01

    Context. Sausage modes are important in coronal seismology. Spatially damped propagating sausage waves were recently observed in the solar atmosphere. Aims: We examine how wave leakage influences the spatial damping of sausage waves propagating along coronal structures modeled by a cylindrical density enhancement embedded in a uniform magnetic field. Methods: Working in the framework of cold magnetohydrodynamics, we solve the dispersion relation (DR) governing sausage waves for complex-valued, longitudinal wavenumber k at given real angular frequencies ω. For validation purposes, we also provide analytical approximations to the DR in the low-frequency limit and in the vicinity of ωc, the critical angular frequency separating trapped from leaky waves. Results: In contrast to the standing case, propagating sausage waves are allowed for ω much lower than ωc. However, while able to direct their energy upward, these low-frequency waves are subject to substantial spatial attenuation. The spatial damping length shows little dependence on the density contrast between the cylinder and its surroundings, and depends only weakly on frequency. This spatial damping length is of the order of the cylinder radius for ω ≲ 1.5vAi/a, where a and vAi are the cylinder radius and the Alfvén speed in the cylinder, respectively. Conclusions: If a coronal cylinder is perturbed by symmetric boundary drivers (e.g., granular motions) with a broadband spectrum, wave leakage efficiently filters out the low-frequency components.

  12. Fast-sausage oscillations in coronal loops with smooth boundary

    Science.gov (United States)

    Lopin, I.; Nagorny, I.

    2014-12-01

    Aims: The effect of the transition layer (shell) in nonuniform coronal loops with a continuous radial density profile on the properties of fast-sausage modes are studied analytically and numerically. Methods: We modeled the coronal waveguide as a structured tube consisting of a cord and a transition region (shell) embedded within a magnetic uniform environment. The derived general dispersion relation was investigated analytically and numerically in the context of frequency, cut-off wave number, and the damping rate of fast-sausage oscillations for various values of loop parameters. Results: The frequency of the global fast-sausage mode in the loops with a diffuse (or smooth) boundary is determined mainly by the external Alfvén speed and longitudinal wave number. The damping rate of such a mode can be relatively low. The model of coronal loop with diffuse boundary can support a comparatively low-frequency, global fast-sausage mode of detectable quality without involving extremely low values of the density contrast. The effect of thin transition layer (corresponds to the loops with steep boundary) is negligible and produces small reductions of oscillation frequency and relative damping rate in comparison with the case of step-function density profile. Seismological application of obtained results gives the estimated Alfvén speed outside the flaring loop about 3.25 Mm/s.

  13. An estimate of solar wind velocity profiles in an coronal hole and a coronal streamer area (6-40 solar radius)

    Science.gov (United States)

    Paetzold, M.; Tsurutani, B. T.; Bird, M. K.

    1995-01-01

    Using the total electron content data obtained by the Ulysses Solar Corona Experiment during the superior solar conjunction in summer 1991, we selected two data sets, one associated with a coronal hole and the other one with coronal streamer crossings. By doing this data splitting, we find two entirely different density profiles varying as r(exp -2.7) and r(exp -2.3) for the coronal hole and coronal streamers, respectively. Assuming mass flux conservation from the inner corona to one AU, an estimate for the velocity profiles or acceleration in these two different regions can be determined. The more negative exponent of the coronal hole density profile indicates a more extended heating and acceleration region or more flaring, or both. Various possible explanations will be discussed.

  14. Estudios de visitantes a museos

    Directory of Open Access Journals (Sweden)

    Keilyn Rodríguez Sánchez

    2011-01-01

    Full Text Available Este artículo ofrece un estudio bibliográfico en torno a las investigaciones sobre la relación entre la museografía y sus visitantes. El objetivo central de este documento consiste en elaborar una clasificación de esos estudios en programas de investigación de manera que sirva de punto de partida para la construcción de una pedagogía del Museo. Para este fin, se utiliza la propuesta de Schulman, sobre tipificación de estudios en programas de investigación y, al respecto, se plantean cuatro tipos: investigaciones centradas en lo museográfico, investigaciones centradas en el comportamiento museal, investigaciones centradas en la interacción dispositivo-visitantes y las investigaciones centradas en la evaluación museográfica. Se concluye que los resultados de investigación de estos programas, junto con el conocimiento de las técnicas de diseño y a la teoría educativa, serían la base central de un planteamiento sobre pedagogía museológica.

  15. estudio de un caso brasileño

    Directory of Open Access Journals (Sweden)

    Patricia Sampaio Silva

    2007-01-01

    Full Text Available El presente trabajo se basa en el estudio de tres grandes municipios del semiárido nordeste brasileño –Flores, Floresta y Villa Bella, pertenecientes a un valle particularmente pobre del interior del país–, desde el siglo XVIII hasta la década de 1930. Y tiene un doble objetivo; de un lado, considerar los municipios como actores históricos, con trayectorias propias, que conocen momentos de auge y de decadencia según las diferentes épocas. De otro, repensar el papel de los magistrados de las ciudades del interior, con el propósito de romper el cliché, por largo tiempo difundido, en virtud del cual todo magistrado, como todo funcionario público del interior del país, estaba “a los pies” de los potentados locales, los coronéis. Se trata pues de insertar la historia de los municipios en la transformación que tuvo lugar tanto a nivel local como regional, estableciendo un ir y venir entre la historia “de los municipios” y la historia “en los municipios”.

  16. Imaging solar coronal magnetic structures in 3D

    Science.gov (United States)

    Cartledge, N. P.

    The study of solar coronal structures and, in particular prominences, is a key part of understanding the highly complex physical mechanisms occurring in the Sun's atmosphere. Solar prominences are important in their own right and some of the most puzzling questions in solar theory have arisen through their study. For example, how do they form and how is their mass continuously replenished? How can the magnetic field provide their continuous support against gravity over time periods of several months? How can such cool, dense material exist in thermal equilibrium in the surrounding coronal environment? Why do they erupt? A study of their structure and that of the surrounding medium is important in determining the nature of the coronal plasma and magnetic field. Also, prominences are closely associated with other key phenomena such as coronal mass ejections and eruptive solar flares which occur as a prominence loses equilibrium and rises from the solar surface. Our current understanding of these fascinating structures is extremely limited and we know very little about their basic global structure. In fact, recent prominence observations have caused our basic paradigms to be challenged (Priest, 1996) and so we must set up new models in order to gain even a fundamental understanding. Prominences are highly nonlinear, three-dimensional structures. Large feet (or barbs) reach out from the main body of a prominence and reach down to the photosphere where the dense material continuously drains away. These provide a real clue to the three-dimensional nature of the coronal field and its relation to the photospheric field. It is important, therefore, to make stereographic observations of prominences in order to gain a basic understanding of their essentially three-dimensional nature and attempt to formulate new paradigms for their structure and evolution. There is no doubt that the study of prominences in three dimensions is a crucial exercise if we are to develop a better

  17. Field Topology Analysis of a Long-lasting Coronal Sigmoid

    Science.gov (United States)

    Savcheva, A. S.; van Ballegooijen, A. A.; DeLuca, E. E.

    2012-01-01

    We present the first field topology analysis based on nonlinear force-free field (NLFFF) models of a long-lasting coronal sigmoid observed in 2007 February with the X-Ray Telescope on Hinode. The NLFFF models are built with the flux rope insertion method and give the three-dimensional coronal magnetic field as constrained by observed coronal loop structures and photospheric magnetograms. Based on these models, we have computed horizontal maps of the current and the squashing factor Q for 25 different heights in the corona for all six days of the evolution of the region. We use the squashing factor to quantify the degree of change of the field line linkage and to identify prominent quasi-separatrix layers (QSLs). We discuss the major properties of these QSL maps and devise a way to pick out important QSLs since our calculation cannot reach high values of Q. The complexity in the QSL maps reflects the high degree of fragmentation of the photospheric field. We find main QSLs and current concentrations that outline the flux rope cavity and that become characteristically S-shaped during the evolution of the sigmoid. We note that, although intermittent bald patches exist along the length of the sigmoid during its whole evolution, the flux rope remains stable for several days. However, shortly after the topology of the field exhibits hyperbolic flux tubes (HFT) on February 7 and February 12 the sigmoid loses equilibrium and produces two B-class flares and associated coronal mass ejections (CMEs). The location of the most elevated part of the HFT in our model coincides with the inferred locations of the two flares. Therefore, we suggest that the presence of an HFT in a coronal magnetic configuration may be an indication that the system is ready to erupt. We offer a scenario in which magnetic reconnection at the HFT drives the system toward the marginally stable state. Once this state is reached, loss of equilibrium occurs via the torus instability, producing a CME.

  18. ESTUDIO RETROSPECTIVO DE LAS AFECCIONES OBSTRUCTIVAS DE LAS VÍAS AÉREAS SUPERIORES EN EQUINOS ADULTOS PRESENTADOS A LA CLÍNICA PARA GRANDES ANIMALES DE LA UNIVERSIDAD NACIONAL DE COLOMBIA ENTRE 1993 Y 2007

    Directory of Open Access Journals (Sweden)

    D. A. Martínez

    2012-01-01

    Full Text Available Se analizaron 44 historias de equinos admitidos en la Clínica de Grandes Animales de la Universidad Nacional de Colombia entre I-1993 y II-2007, para determinar las entidades obstructivas más prevalentes en el tracto respiratorio superior (cavidad nasal, faringe y laringe. Se determinó que el desplazamiento dorsal del paladar blando, la hemiplejia laríngea, la hiperplasia linfoide faríngea y las neoplasias fueron las entidades más prevalentes con 38,64%, 34,09%, 18,18% y 9,09%, respectivamente; el desplazamiento dorsal del paladar blando fue más común en animales de raza Paso Colombiano, lo que se atribuye a la posición recogida de cabeza y cuello durante el ejercicio. La hemiplejía laríngea, al igual que el desplazamiento, fue más común en animales de raza Paso Colombiano cuando se consideraron las razas individualmente; sin embargo, fueron los animales de las razas de deporte los más afectados (73,33%. Los hallazgos mencionados son semejantes a los reportados en la literatura.

  19. ESTUDIO RETROSPECTIVO DE LAS AFECCIONES OBSTRUCTIVAS DE LAS VÍAS AÉREAS SUPERIORES EN EQUINOS ADULTOS PRESENTADOS A LA CLÍNICA PARA GRANDES ANIMALES DE LA UNIVERSIDAD NACIONAL DE COLOMBIA ENTRE 1993 Y 2007

    OpenAIRE

    Martínez, D. A.; Oliver, O. J.

    2012-01-01

    Se analizaron 44 historias de equinos admitidos en la Clínica de Grandes Animales de la Universidad Nacional de Colombia entre I-1993 y II-2007, para determinar las entidades obstructivas más prevalentes en el tracto respiratorio superior (cavidad nasal, faringe y laringe). Se determinó que el desplazamiento dorsal del paladar blando, la hemiplejia laríngea, la hiperplasia linfoide faríngea y las neoplasias fueron las entidades más prevalentes con 38,64%, 34,09%, 18,18% y 9,09%, respectivamen...

  20. Estudio retrospectivo de las afecciones obstructivas de las vias aereas superiores en equinos adultos presentados a la clinica para grandes animales de la universidad nacional de colombia entre 1993 y 2007

    OpenAIRE

    Martínez, D. A.; Oliver, O. J.

    2012-01-01

    Un total de 44 historias de animales admitidos en la Clínica para Grandes Animales de la Universidad Nacional de Colombia fueron analizadas, para determinar cuales fueron las entidades más prevalentes en el tracto respiratorio superior (cavidad nasal, faringe y laringe) de estos equinos. Se determinó que el desplazamiento dorsal del paladar blando, la hemiplejia laríngea, la hiperplasia faríngea linfoide y las neoplasias fueron las mas prevalentes con 38.64%, 34.09%, 18.18% y 9.09% respectiva...

  1. Retrospective study of the calculation of doses by Monte Carlo in extracranial stereotactic; Estudio retrospectivo del calculo de dosis mediante Monte Carlo en radioterapia estereotaxica extracraneal (SBRT) de pulmon

    Energy Technology Data Exchange (ETDEWEB)

    Zucca Aparicio, D.; Perez Moreno, J. M.; Fernandez Leton, P.; Garcia Ruiz-Zorrilla, J.; Minambres Moro, A.

    2013-07-01

    The objective of this work consists of the evaluation of those clinical parameters described in RTOG 0813 and 0915 RTOG protocols relevant applicable to PTV, lung tissue and healthy normal, of those patients treated in our institution since April 2008, calculated initially through Pencil Beam and recalculated currently using Monte Carlo is interesting remark that the RTOG 0813 Protocol replaces the previous RTOG 0236 which expressly mentioned do not make corrections by heterogeneity in the calculation of dose in lung lesions. (Author)

  2. Colecistitis alitiásica: incidencia y factores de riesgo asociados, servicios de emergencias y medicina crítica del Hospital General Luis Vernaza, Enero 2008 - Diciembre 2010. Estudio retrospectivo de 100 casos

    OpenAIRE

    Carreño Cevallos, Johon César

    2012-01-01

    Antecedentes: La colecistitis alitiásica es la inflamación aguda, subaguda o crónica de la vesícula biliar sin la presencia de cálculos en su interior. Representa entre 5 y 12% de todos los casos de colecistitis. El diagnóstico sólo se sospecha tardiamente en pacientes críticos. Objetivos: 1. Determinar la incidencia de la Colecistitis Alitiásica en los servicios de Emergencias y Medicina Crítica del Hospital General Luis Vernaza. 2. Establecer si existe o no asoci...

  3. Pitiriasis liquenoide: estudio retrospectivo clínico epidemiológico de 49 pacientes pediátricos Pityriasis lichenoides: a retrospective clinical and epidemiological study of 49 pediatric patients

    Directory of Open Access Journals (Sweden)

    GP Sciancalepore

    Full Text Available La pitiriasis liquenoide (PL, entidad pápulo-escamosa, afecta principalmente a niños. Presenta una forma aguda, "pitiriasis liquenoide y varioliforme aguda" (PLEVA y otra crónica, la pitiriasis liquenoide crónica (PLC. Objetivo: describir las características de pacientes con diagnóstico clínico e histopatológico de PL. Comparar nuestros resultados con los hallados en la bibliografía. Materiales y Métodos: historias clínicas e informes anátomo-patológicos de 49 pacientes que consultaron entre marzo de 2000 a marzo de 2011. Se analizaron los datos obtenidos mediante el programa SPSS 11.5. Resultados: de 49 pacientes con PL, 17 presentaron PLEVA y 32 PLC. El promedio de edad de inicio de PLEVA fue de 6 años y de 10 años para PLC. Predominó el sexo masculino en PLEVA. Las formas generalizadas parecieran ser las predominantes. Las lesiones más frecuentemente halladas fueron: pápulas y pápulas eritematosas en PLEVA, escamas en PLC y las máculas hipocrómicas como discromía residual. 14 de 49 pacientes mostraron asociaciones mórbidas. Conclusiones: la PL puede ser dividida en aguda y crónica, a pesar de existir ambas clases de lesiones en un mismo paciente. PLEVA se presentó a edades más tempranas, predominando en varones. De los pacientes que presentaron co-morbilidades, la mayoría comprometía la inmunidad.Background: the pityriasis lichenoides (PL, a papulosquamous disease, affects mostly children. Present an acute form, pytiriasis lichenoides et varioliformis acute (PLEVA and other chronic, chronic lichenoid pytiriasis (PLC. Objetive: to describe the caracheristics of patients with clinic and histopathological diagnosis of PL. Compare our results with those found in the literature. Materials and Methods: clinical records and pathology reports of 49 patients who consulted between March 2000 and March 2011. Data were analyzed using SPSS 11.5. Results: of 49 patients with PL, 17 presented PLEVA and 32 PLC. The average age of onset of PLEVA was 6 years and 10 years for PLC. Males predominate in PLEVA. The lesions most frequently found were: papules and erythematous papules in PLEVA, scales in PLC and hypocromic macules as residual dyschromia. 14 of 49 patients showed morbid associations. Conclusions: the PL can be divided into acute and chronic forms, despite the existence of both types of lesions in the same patient. PLEVA was presented at younger age, predominantly in males. From the patients who had co-morbidities, the most of them, compromised immunity.

  4. Dose to patients in mammography. Retrospective study during more than 10 years of mammography screening program; Dosis a pacientes en mamografia. Estudio retrospectivo de mas de 10 anos de programa de cribado mamografico

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez Munoz, A.; Chapel Gomez, M. L.

    2010-07-01

    Breast screening programs include large number of women, most of them asymptomatic, receiving a significant absorbed dose. Under these circumstances, estimation of breast dose arises as a valuable tool to evaluate carcinogenic risk to the patient. Dose estimation can also become a tool for comparison of imaging systems, beam qualities and techniques for mammography. Mammographic systems have undergone many changes since its origins: new beam qualities have been introduced and digital mammography has replaced conventional systems. Data obtained from 2266 mammographic studies, during more than ten years of experience on the Canary Islands Breast Cancer Screening Program, have been analysed. Semi-automatic exposure control, completely automatic exposure control, screen-film and full field digital systems have been considered, Average glandular dose (the carcinogenic risk indicator) received by patients has been compared. A reduction in average glandular dose of full field digital mammography has been found. The optimisation of exposition parameters appears as critical factor on dose reduction. (Author) 26 refs.

  5. La calidad de los resúmenes de los artículos publicados en las revistas de enfermería españolas en 2015. Un protocolo de estudio observacional retrospectivo

    OpenAIRE

    García Romero, María Victoria

    2016-01-01

    Introducción: El resumen es la parte de un artículo científico más consultada por los investigadores en las búsquedas bibliográficas. Puesto que la profesión enfermera se centra en la práctica basada en la evidencia, resulta de gran importancia que los resúmenes de los artículos publicados en revistas de enfermería cuenten con unas pautas de calidad para facilitar la selección de los artículos de interés cuando se realizan búsquedas bibliográficas. El establecimiento de unos requisitos de cal...

  6. TIPSS (Shunt Portosistemático intrahepático transyugular) frente a las derivaciones portosistemáticas clásicas quirúrgicas. Estudio comparativo retrospectivo en Baleares.

    OpenAIRE

    Martín Franco, Miguel Ángel

    2006-01-01

    RESUMEN Introducción. La hipertensión portal supone un aumento patológico de la presión portal mayor de 15 mm de hg. Sus consecuencias son la aparición de HDA, ascitis, encefalopatía, y esplenomegalia. La incidencia es del 8%. El pronóstico de la misma lo determina la cuantía de la pérdida hemática y el grado de enfermedad hepática subyacente. En el tratamiento se incluye, las medidas generales, farmacoterapia (somatostatina, b-bloqueantes, octeótrido), taponamiento con balón esofágico ...

  7. 59. Estudio multicéntrico retrospectivo de comparación de dos dosis diferentes de ácido tranexámico en cirugía cardíaca

    Directory of Open Access Journals (Sweden)

    E. Martín

    2012-04-01

    Conclusiones: La pauta de AT del grupo A reduce significativamente el sangrado en las primeras 12 h del postoperatorio frente a la del grupo B, aunque no ha demostrado reducir las necesidades transfusionales.

  8. Estudio retrospectivo de las afecciones obstructivas de las vias aereas superiores en equinos adultos presentados a la clinica para grandes animales de la universidad nacional de colombia entre 1993 y 2007

    OpenAIRE

    Martínez, D. A.; Oliver, O. J.

    2012-01-01

    Un total de 44 historias de animales admitidos en la Clínica para Grandes Animales de la Universidad Nacional de Colombia fueron analizadas, para determinar cuales fueron las entidades más prevalentes en el tracto respiratorio superior (cavidad nasal, faringe y laringe) de estos equinos. Se determinó que el desplazamiento dorsal del paladar blando, la hemiplejia laríngea, la hiperplasia faríngea linfoide y las neoplasias fueron las mas prevalentes con 38.64%, 34.09%, 18.18% y 9.09% respectiva...

  9. ESTUDIO RETROSPECTIVO DE LAS AFECCIONES OBSTRUCTIVAS DE LAS VÍAS AÉREAS SUPERIORES EN EQUINOS ADULTOS PRESENTADOS A LA CLÍNICA PARA GRANDES ANIMALES DE LA UNIVERSIDAD NACIONAL DE COLOMBIA ENTRE 1993 Y 2007

    OpenAIRE

    Martínez, D. A.; Oliver, O. J.

    2012-01-01

    Se analizaron 44 historias de equinos admitidos en la Clínica de Grandes Animales de la Universidad Nacional de Colombia entre I-1993 y II-2007, para determinar las entidades obstructivas más prevalentes en el tracto respiratorio superior (cavidad nasal, faringe y laringe). Se determinó que el desplazamiento dorsal del paladar blando, la hemiplejia laríngea, la hiperplasia linfoide faríngea y las neoplasias fueron las entidades más prevalentes con 38,64%, 34,09%, 18,18% y 9,09%, respectivamen...

  10. Coronal structure analysis based on the potential field source surface modeling and total solar eclipse observation

    Science.gov (United States)

    Muhamad, Johan; Mumtahana, Farahhati; Sutastio, Heri; Imaduddin, Irfan; Putri, Gerhana P.

    2016-11-01

    We constructed global coronal magnetic fields of the Sun during the Total Solar Eclipse (TSE) 9 March 2016 by using Potential Field Source Surface (PFSS) model. Synoptic photospheric magnetogram data from Helioseismic and Magnetic Imager (HMI) onboard Solar Dynamics Observatory (SDO) was used as a boundary condition to extrapolate the coronal magnetic fields of the Sun. This extrapolated structure was analyzed by comparing the alignment of the fields from the model with coronal structure from the observation. We also used observational data of coronal structure during the total solar eclipse to know how well the model agree with the observation. As a result, we could identify several coronal streamers which were produced by the large closed loops in the lower regime of the corona. This result verified that the PFSS extrapolation can be used as a tool to model the inner corona with several constraints. We also discussed how the coronal structure can be used to deduce the phase of the solar cycle.

  11. Optimizing Global Coronal Magnetic Field Models Using Image-Based Constraints

    CERN Document Server

    Jones, Shaela I; Uritsky, Vadim M

    2015-01-01

    The coronal magnetic field directly or indirectly affects a majority of the phenomena studied in space physics. It provides energy for coronal heating, controls the release of coronal mass ejections (CMEs), and drives heliospheric and magnetospheric activity, yet the coronal magnetic field itself has proven difficult to measure. This difficulty has prompted a decades-long effort to develop accurate, timely, models of the field - an effort that continues today. We have developed a method for improving global coronal magnetic field models by incorporating the type of morphological constraints which could be derived from coronal images. Here we report promising initial tests of this approach on two theoretical problems, and discuss opportunities for application.

  12. El exilio como campo de estudios en ciencias sociales: análisis bibliométrico

    Directory of Open Access Journals (Sweden)

    José Hernando Ávila-Toscano

    2017-01-01

    Full Text Available Objetivo: formular una revisión bibliométrica de producciones científicas cuyo tema central de análisis es el exilio, con el fin de comprender el panorama de estudio actual en Ciencias Sociales en torno a dicho fenómeno. Método: a través de un diseño bibliométrico descriptivo, retrospectivo, fueron revisados 50 artículos publicados entre 2005 y 2015 en revistas Latinoamericanas. Los documentos se analizaron acorde con el país de producción, la coautoría, las áreas del conocimiento y los términos clave empleados, esto mediante análisis descriptivo y la construcción de grafos de redes. Resultados: sobresalió la Historia como el área de mayor producción frente al exilio, seguida de los estudios literarios y de los de corte sociológico; se observa poca tendencia a producir de forma cooperativa este tipo de trabajos aunque la riqueza temática es amplia.

  13. ¿Por qué la Gente Vota a la Izquierda? Clivajes, Ideología y Voto Retrospectivo en Bolivia y Uruguay en Perspectiva Comparada

    Directory of Open Access Journals (Sweden)

    Tomáš Došek

    2014-09-01

    Full Text Available El objetivo de este artículo es explicar las razones del voto de los ciudadanos hacia Evo Morales y José Mujica en las elecciones presidenciales de 2009 y evaluar en qué medida los determinantes del voto permiten distinguir las supuestas "dos izquierdas" en América Latina. Utilizando datos de encuestas de opinión pública para los dos casos representativos este trabajo muestra cómo las razones son diferentes, ya que en Uruguay pesa relativamente más la ideología y los elementos programáticos y en Bolivia más el voto retrospectivo, cruzado cada uno por distintos clivajes estructurales. Discutiendo los resultados con la literatura secundaria sobre los demás casos sudamericanos, se argumenta que la clásica clasificación en dos izquierdas no se sostiene a partir del análisis de los determinantes del voto. Metodológicamente, se recurre al análisis de regresión logística binomial y a la comparación de una serie de modelos estadísticos.

  14. Correlação entre etiologia e a localização das estenoses de uretra - estudo retrospectivo em pacientes atendidos no CHS/PUC-SP

    Directory of Open Access Journals (Sweden)

    Marcelo Cabral Lamy de Miranda

    2008-07-01

    Full Text Available RESUMO Objetivo: análise retrospectiva dos pacientes que estão no programa de dilatação de uretra do Conjunto Hospitalar de Sorocaba, levando em consideração as principais localizações de estenose de uretra relacionada com suas causas específicas e prevalências, no período de fevereiro de 2002 a abril de 2005. Sujeitos e métodos: este trabalho foi realizado mediante estudo retrospectivo dos prontuários médicos e fichas de cadastramento do programa de dilatação de uretra de 115 pacientes registrados no período de fevereiro de 2002 a abril de 2005. Resultados: neste estudo, os pacientes com estenose de uretra tiveram como média de idade 57,5 anos e 3,33% eram do sexo feminino. Nos pacientes do sexo masculino foram encontrados 49,17% das lesões na uretra anterior, enquanto que 47,5% na uretra posterior. As principais localidades de estenose notificadas foram: meato, com 31 casos (25,8%; uretra prostática, com 23 casos (19,1%; colo, com 22 casos (18,33%; fossa navicular, com 21 casos (17,5%; uretra bulbar, com 13 casos (10,8%; uretra peniana, com 6 casos (5%; uretra feminina, com 4 casos (3,33%.

  15. Direct observations of magnetic flux rope formation during a solar coronal mass ejection

    OpenAIRE

    Song, Hongqiang; Zhang, Jie; Chen, Yao; Cheng, Xin

    2014-01-01

    Coronal mass ejections (CMEs) are the most spectacular eruptive phenomena in the solar atmosphere. It is generally accepted that CMEs are results of eruptions of magnetic flux ropes (MFRs). However, a heated debate is on whether MFRs pre-exist before the eruptions or they are formed during the eruptions. Several coronal signatures, \\textit{e.g.}, filaments, coronal cavities, sigmoid structures and hot channels (or hot blobs), are proposed as MFRs and observed before the eruption, which suppor...

  16. First use of synoptic vector magnetograms for global nonlinear force free coronal magnetic field models

    OpenAIRE

    Tadesse, Tilaye; Wiegelmann, T.; Gosain, S.; Macneice, P.; Pevtsov, Alexei A.

    2013-01-01

    The magnetic field permeating the solar atmosphere is generally thought to provide the energy for much of the activity seen in the solar corona, such as flares, coronal mass ejections (CMEs), etc. To overcome the unavailability of coronal magnetic field measurements, photospheric magnetic field vector data can be used to reconstruct the coronal field. Currently there are several modelling techniques being used to calculate three-dimension of the field lines into the solar atmosphere. For the ...

  17. Estudio de la incidencia de listeriosis en España

    Directory of Open Access Journals (Sweden)

    Fernando Parrilla Valero

    2014-01-01

    Full Text Available Estudio descriptivo retrospectivo, basado en la información documental disponible, sobre los casos de listeriosis ocurridos en España en 2001-2007, con el objetivo de conocer la carga y la evolución de esta enfermedad en nuestro país. Partiendo de diversas fuentes informativas, en total se recogió la información epidemiológica de 1242 casos de listeriosis, lo que supone una tasa de incidencia media de 0,56 casos por 100.000 habitantes y año, que consideramos el valor estimado global para España. La incidencia ha mostrado una tendencia anual ascendente estadísticamente significativa (p <0,001, y ha sido muy superior a la notificada en España (0,16 mediante el Sistema de Información Microbiológica, de carácter voluntario, lo que evidencia la infradeclaración existente. La inclusión de la listeriosis en el Sistema de Enfermedades de Declaración Obligatoria permitiría dimensionar su presencia, así como conocer las características de la afectación humana y mejorar su prevención y control.

  18. Estudio de las características clínicas y de mortalidad de una serie de pacientes con síndrome de distrés respiratorio agudo que precisaron ventilación mecánica invasiva

    OpenAIRE

    Lázaro del Campo, Paula; Ortega Lobete, Olga

    2016-01-01

    Presentamos un estudio retrospectivo y observacional que incluye una cohorte de pacientes con SDRA ingresados a lo largo de dos años en el Servicio de Medicina Intensiva del Hospital Clínico Universitario de Valladolid. Todos ellos fueron diagnosticados de SDRA según los criterios de la definición de Berlín y necesitaron intubación orotraqueal y/o traqueotomía con asistencia respiratoria a presión positiva mediante ventilación mecánica con conexión a respirador volumétrico. ...

  19. Charge States of Solar Cosmic Rays and Constraints on Acceleration Times and Coronal Transport

    CERN Document Server

    Ruffolo, D

    1997-01-01

    We examine effects on the charge states of energetic ions associated with gradual solar flares due to shock heating and stripping at high ion velocities. Recent measurements of the mean charges of various elements after the flares of 1992 Oct 30 and 1992 Nov 2 allow one to place limits on the product of the electron density times the acceleration or coronal residence time. In particular, any residence in coronal loops must be for < 0.03 s, which rules out models of coronal transport in loops, such as the bird cage model. The results do not contradict models of shock acceleration of energetic ions from coronal plasma at various solar longitudes.

  20. Estudios sobre Plantas Andinas, X

    Directory of Open Access Journals (Sweden)

    Cuatrecasas José

    1967-09-01

    Full Text Available Durante la preparación del género Baccharis para Prima Flora Colombiana tuve que estudiar gran número de especies andinas, tropicales y extratropicales de fuera de Colombia; el objeto principal de tales estudios fue el de tipificar las especies íntimamente relacionadas con las colombianas y establecer su diferenciación taxonómica. La consulta de los tipos específicos y la identificación de gran número de colecciones procedentes de las regiones andinas hasta el sur del continente americano permitió precisar el concepto de bastantes especies y de su área geográfica, al mismo tiempo que el establecimiento de numerosas sinonimias.  La mayor parte de las novedades taxonómicas y de los comentarios derivados de tal estudio va incluída en el texto de las Astereae de Colombia a publicar en breve. El objeto de este artículo es dar a conocer otra parte de las novedades relativas a especies andinas de los países vecinos y describir varias entidades taxonómicas deficientemente conocidas, incorporando a su conocimiento los resultados de muchas disecciones llevadas a cabo en los mencionados estudios.  El trabajo basico para estas notas fue hecho en la Smithsonian Institution; se consultaron también las colecciones de los herbarios europeos de Londres, París, Florencia, Ginebra y Madrid en viaje hecho en otoño de 1963. National Science Foundation de Washington D.C. subvencionó los trabajos.

  1. LOS ESTUDIOS DE POBREZA URBANA

    Directory of Open Access Journals (Sweden)

    Rina De León Herrera

    2007-08-01

    Full Text Available En este artículo se intenta mostrar en forma sucinta la evolución de los estudios de pobreza urbana; se retoma para ello la producción escritural de investigadores que han hecho aportes valiosos sobre la temática en diferentes épocas y espacios geográficos. La información se ha organizado en dos unidades de análisis: la producción escritural en los países desarrollados y en los países en desarrollo.

  2. Estudios de ingresos municipales: Bolivia

    OpenAIRE

    José Antonio Teran C.

    2007-01-01

    El estudio abarca tres ámbitos de evaluación y recomendaciones: i) el marco normativo que establece las políticas para las administraciones tributarias municipales; ii) las capacidades de estas administraciones y las condiciones de oferta y demanda de servicios de asistencia para su fortalecimiento; y iii) la evaluación cuantitativa de los ingresos propios municipales, el establecimiento de categorías y las políticas que podrían implementarse a partir de esta información.

  3. Estudio sobre el criseano 1

    Directory of Open Access Journals (Sweden)

    Hernando Arias P.

    2009-05-01

    Full Text Available El presente trabajo fué iniciado originalmente como una curiosidad de laboratorio. La síntesis y propiedades investigadas posteriormente surgieron a medida que avanzaba el trabajo. Una búsqueda completaen el Chemical Abstracts desde el año 1907 hasta el presente, nos ha llevado a encontrar solo unas 8 citas bibliográficas, algunas de ellas no dirigidas específicamente a nuestro compuesto, sino en forma muygeneral al estudio de los tiazoles. (Véase revisión bibliográfica.

  4. Staphylococcus aureus en quemaduras: estudio de incidencia, tendencia y pronóstico

    Directory of Open Access Journals (Sweden)

    A. García-Urquijo

    2015-06-01

    Full Text Available Realizamos un estudio descriptivo, longitudinal, retrospectivo de los últimos 10 años, en la Unidad de quemados del Hospital Universitario "Arnaldo Milián Castro" de Santa Clara, en Villa Clara, Cuba, con el objetivo de caracterizar el comportamiento del aislamiento de Staphylococcus aureus en heridas por quemaduras de pacientes ingresados. Se realizó con 1065 muestras tomadas por método cualitativo de hisopado, entre enero del 2002 y diciembre del 2011. Las variables utilizadas fueron: mes y año de realización, resultado del aislamiento, grupo de microorganismos y especies aisladas, series temporales y tasa pronóstico. Staphylococcus aureus resultó ser el microorganismos Gram positivo mas frecuentemente aislado (68,3%, representando entre el 7 y el 31,8% de las muestras realizadas cada año, con tasas de incidencias oscilando entre el 6,3 y 37,2 por cada 100 pacientes ingresados. Las tasas de incidencia mensuales se mantuvieron predominantemente en zonas de alerta y de seguridad durante los años 2011 y también en el seguimiento en 2012, sin que se produjeran picos epidémicos, mostrando una ligera tendencia al decremento con respecto al comportamiento de los 3 últimos años. Comprobamos después que la tasa de aislamiento para el siguiente año, 2012 fue de 9,5 por cada 100 ingresos, dentro de los límites del intervalo pronosticado según los estudios recogidos hasta 2011 (0 y 46,7 por cada 100 ingresos.

  5. Interpretation of the coronal magnetic field configuration of the Sun

    Institute of Scientific and Technical Information of China (English)

    Bo Li; Xing Li; Hui Yu

    2012-01-01

    The origin of the heliospheric magnetic flux on the Sun,and hence the origin of the solar wind,is a topic of hot debate.While the prevailing view is that the solar wind originates from outside the coronal streamer helmets,there also exists the suggestion that the open magnetic field spans a far wider region.Without the definitive measurement of the coronal magnetic field,it is difficult to unambiguously resolve the conflict between the two scenarios.We present two 2-dimensional,Alfvénic-turbulence-based models of the solar corona and solar wind,one with and the other without a closed magnetic field region in the inner corona.The purpose of the latter model is to test whether it is possible to realize a picture suggested by polarimetric measurements of the corona using the Fe ⅩⅢ 10747(A) line,where open magnetic field lines seem to penetrate the streamer base.The boundary conditions at the coronal base are able to account for important observational constraints,especially those on the magnetic flux distribution.Interestingly,the two models provide similar polarized brightness (pB) distributions in the field of view (FOV) of SOHO/LASCO C2 and C3 coronagraphs.In particular,a dome-shaped feature is present in the C2 FOV even for the model without a closed magnetic field.Moreover,both models fit the Ulysses data scaled to 1 AU equally well.We suggest that:1) The pB observations cannot be safely taken as a proxy for the magnetic field topology,as is often implicitly assumed.2) The Ulysses measurements,especially the one showing a nearly uniform distribution with heliocentric latitude of the radial magnetic field,do not rule out the ubiquity of open magnetic fields on the Sun.

  6. The Evolution and Space Weather Effects of Solar Coronal Holes

    Science.gov (United States)

    Krista, Larisza; Gallagher, P.

    2011-05-01

    As solar activity is the foremost important aspect of space weather, the forecasting of flare and CME related transient geomagnetic storms has become a primary initiative. Minor magnetic storms caused by coronal holes (CHs) have also proven to be important due to their long-lasting and recurrent geomagnetic effects. In order to forecast CH related geomagnetic storms, the author developed the Coronal Hole Automated Recognition and Monitoring (CHARM) algorithm to replace the user-dependent CH detection methods commonly used. CHARM uses an intensity thresholding method to identify low intensity regions in EUV or X-ray images. Since CHs are regions of "open” magnetic field and predominant polarity, magnetograms were used to differentiate CHs from other low intensity regions. The Coronal Hole Evolution (CHEVOL) algorithm was developed and used in conjunction with CHARM to study the boundary evolution of CHs. It is widely accepted that the short-term changes in CH boundaries are due to the interchange reconnection between the CH open field lines and small loops. We determined the magnetic reconnection rate and the diffusion coefficient at CH boundaries in order to test the interchange reconnection model. The author also developed the Minor Storm (MIST) package to link CHs to high-speed solar wind (HSSW) periods detected at Earth. Using the algorithm the relationship between CHs, the corresponding HSSW properties, and geomagnetic indices were studied between 2000-2009. The results showed a strong correlation between the velocity and HSSW proton plasma temperature, which indicates that the heating and acceleration of the solar wind plasma in CHs are closely related, and perhaps caused by the same mechanism. The research presented here includes analysis of CHs on small and large spatial/temporal scales, allowing us to further our understanding of CHs as a whole.

  7. Coronal Loops: Observations and Modeling of Confined Plasma

    Directory of Open Access Journals (Sweden)

    Fabio Reale

    2014-07-01

    Full Text Available Coronal loops are the building blocks of the X-ray bright solar corona. They owe their brightness to the dense confined plasma, and this review focuses on loops mostly as structures confining plasma. After a brief historical overview, the review is divided into two separate but not independent parts: the first illustrates the observational framework, the second reviews the theoretical knowledge. Quiescent loops and their confined plasma are considered and, therefore, topics such as loop oscillations and flaring loops (except for non-solar ones, which provide information on stellar loops are not specifically addressed here. The observational section discusses the classification, populations, and the morphology of coronal loops, its relationship with the magnetic field, and the loop stranded structure. The section continues with the thermal properties and diagnostics of the loop plasma, according to the classification into hot, warm, and cool loops. Then, temporal analyses of loops and the observations of plasma dynamics, hot and cool flows, and waves are illustrated. In the modeling section, some basics of loop physics are provided, supplying fundamental scaling laws and timescales, a useful tool for consultation. The concept of loop modeling is introduced and models are divided into those treating loops as monolithic and static, and those resolving loops into thin and dynamic strands. More specific discussions address modeling the loop fine structure and the plasma flowing along the loops. Special attention is devoted to the question of loop heating, with separate discussion of wave (AC and impulsive (DC heating. Large-scale models including atmosphere boxes and the magnetic field are also discussed. Finally, a brief discussion about stellar coronal loops is followed by highlights and open questions.

  8. Geoeffectiveness of Coronal Mass Ejections in the SOHO Era

    DEFF Research Database (Denmark)

    Dumbovic, M.; Devos, A.; Vrsnak, B.;

    2014-01-01

    The main objective of the study is to determine the probability distributions of the geomagnetic Dst index as a function of the coronal mass ejection (CME) and solar flare parameters for the purpose of establishing a probabilistic forecast tool for the geomagnetic storm intensity. Several CME...... and flare parameters as well as the effect of successive-CME occurrence in changing the probability for a certain range of Dst index values, were examined. The results confirm some of already known relationships between remotely-observed properties of solar eruptive events and geomagnetic storms, namely...

  9. 3D reconstruction methods of coronal structures by radio observations

    Science.gov (United States)

    Aschwanden, Markus J.; Bastian, T. S.; White, Stephen M.

    1992-01-01

    The ability to carry out the three dimensional (3D) reconstruction of structures in the solar corona would represent a major advance in the study of the physical properties in active regions and in flares. Methods which allow a geometric reconstruction of quasistationary coronal structures (for example active region loops) or dynamic structures (for example flaring loops) are described: stereoscopy of multi-day imaging observations by the VLA (Very Large Array); tomography of optically thin emission (in radio or soft x-rays); multifrequency band imaging by the VLA; and tracing of magnetic field lines by propagating electron beams.

  10. Magnetic fields, plasmas, and coronal holes - The inner solar system

    Science.gov (United States)

    Burlaga, L. F.

    1979-01-01

    Recent results concerning streams and magnetic fields in the inner solar system are reviewed. Observations have shown that MHD streams are bounded by thin shear layers within 1 AU, probably because they originate in coronal holes which have sharp boundaries. The properties of Alfvenic fluctuations in streams cannot be fully explained on the basis of the hypothesis that they are plane, transverse Alfven waves. A more complete and accurate description might be that they represent nonplanar general Alfven waves weakly coupled to a compressive mode and moving through a medium containing tangential discontinuities and other convected inhomogeneities.

  11. Huge Coronal Structure and Heating Constraints Determined from Serts Observations

    Science.gov (United States)

    Falconer, D. A.; Davila, J. M.

    2001-01-01

    Intensities of the extreme-ultraviolet (EUV) spectral lines were measured as a function of radius off the solar limb by two flights of the Goddard's Solar Extreme-Ultraviolet Rocket Telescope and Spectrograph (SERTS) for three quiet-Sun regions. Density scale heights were determined for the different spectral lines. Limits on the filling factor were determined. In the one case where an upper limit was determined it was much less than unity. coronal heating above 1.15 solar radii is required for all three regions studied. For reasonable filling factors, local heating is needed.

  12. Fraturas vertebrais em grandes animais: estudo retrospectivo de 39 casos (1987-2002 Vertebral fractures in large animals: retrospective study of 39 cases (1987-2002

    Directory of Open Access Journals (Sweden)

    A.S. Borges

    2003-04-01

    Full Text Available Realizou-se estudo retrospectivo (1987-2002 dos aspectos clínicos das fraturas vertebrais em eqüinos, bovinos, ovinos, caprinos e suínos atendidos no hospital veterinário da FMVZ-Unesp de Botucatu. Todos os casos tiveram confirmação radiográfica ou post-mortem. Segundo a espécie, a ordem de acometimento foi: bovina, eqüina, ovina, caprina e suína. As lesões ocorreram desde os 12 dias de idade até os 10 anos, com maior freqüência até os 12 meses. O segmento torácico foi o mais comprometido seguido dos segmentos lombar, cervical e sacral. As fraturas vertebrais devem fazer parte da lista de diagnósticos diferenciais de animais em decúbito, independente da espécie, sexo ou idade.It was performed a retrospective study (1987-2002 of clinical features of spinal fractures in the equine, bovine, ovine, caprine and swine referred to the Veterinary Hospital - FMVZ-Unesp in Botucatu, SP, Brazil. All the cases were confirmed by necropsy or radiographic evaluation. Bovines were the most affected species, followed by horses, sheep, goats and swines, and lesions occurred from 12 days to 10 years of age, being more frequent up to 12 months of age. Thoracic vertebrae were the most affected, followed by lumbar, cervical and sacral segments. Vertebral fractures should be included for differential diagnosis of recumbent animals, independently on species, sex or age.

  13. Hemorragia intracerebral espontânea: estudo retrospectivo de 72 casos operados Primary intracerebral hemorrhage: retrospective study of 72 operated cases

    Directory of Open Access Journals (Sweden)

    JOSÉ CORREIA DE FARIAS BRITO

    2000-06-01

    Full Text Available Realizamos estudo retrospectivo de 72 casos de hemorragia intracerebral espontânea (HICE operados no período de 1970 a 1999. Foram excluídos do grupo os casos de hemorragias cerebrais decorrentes de traumatismos cranianos, tumores, malformações vasculares e doenças hematológicas. A idade variou de 20 a 81 anos com média de 58,2 anos. A maioria dos pacientes era do gênero masculino e de cor branca. Em um terço deles, a pressão arterial estava elevada, e os hematomas lobares ocorreram em maior número de vezes que os ganglionares. A sintomatologia dominante resultou do aumento da pressão intracraniana e das lesões cerebrais focais. Em 52 (72,7% casos, foi possível realizar tomografia computadorizada de crânio. A avaliação dos resultados cirúrgicos foi dirigida para cada década, em separado, mostrando taxas de mortalidade com significativas diferenças.We analysed 72 cases of primary intracranial hemorrhage surgically treated from 1970 to 1999. The hemorrhages were diagnosed by computerized axial tomography in 52 pacients. Most hematomas were situated in the cerebral hemispheres (30 percent in thalamus-basal ganglia region and 50 percent in the subcortical matter. There were 10 patients with cerebellar hemorrhage. Hypertension (based in blood pressure recordings in the hospital and history was found in 24 patients (33 percent. The most frequent findings were coma, intracranial hypertension and hemimotor deficit. The death rate registred was 27.7 percent; however, it was found a significant difference in the mortality index when considering the 70-79 decade (62.7 percent and the 90-99 decade (20.7 percent. A critical analysis was made about depth hematomas, consciousness state and intracranial hypertension with herniation related to surgical procedure.

  14. Estudo retrospectivo das complicações intra-operatórias na cirurgia de revascularização do miocárdio

    Directory of Open Access Journals (Sweden)

    Ariana Rodrigues Silva Carvalho

    2008-12-01

    Full Text Available As complicações intra-operatórias na cirurgia de revascularização miocárdica (CRM quando reconhecidas previamente podem guiar os cuidados prestados na sala operatória, dando continuidade na Unidade de Terapia Intensiva e durante toda internação. Quando a equipe conhece essas complicações sofridas pelo indivíduo poderá prever e prover cuidados mais específicos na seqüência de sua evolução cirúrgica. O objetivo desse estudo foi investigar a freqüência e tipos de complicações observadas no intra-operatório da CRM. Trata-se de um estudo retrospectivo, descritivo, transversal, baseado em dados secundários, com amostra intencional de 123 sujeitos. A coleta de dados realizou-se por meio do acesso ao banco de dados do Instituto de Moléstias Cardiovasculares do Oeste do Paraná, em Cascavel. Os dados foram analisados no programa computadorizado Statistic, versão 6,0. Os tipos de complicações observadas nesse período foram: cardiovasculares, pulmonares, alteração nos vasos do enxerto e sangramento. Dentre essas, a que obteve maior freqüência foi “alteração nos vasos do enxerto”, em 33 (26,8% casos. As complicações no intra-operatório podem não ser passíveis de prevenção quando consideradas as características individuais de cada sujeito, entretanto, todos os esforços precisam ser direcionados para que o evento, quando ocorrer, seja bem atendido, evitando dessa forma, complicações adicionais maiores.

  15. Chromospheric and Coronal Activity in the 500 Myr old Open Cluster M37: Evidence for Coronal Stripping?

    Science.gov (United States)

    Núñez, Alejandro; Agüeros, Marcel A.; Covey, Kevin R.; López-Morales, Mercedes

    2017-01-01

    We present the results of a spectroscopic survey to characterize chromospheric activity, as measured by {{H}}α emission, in low-mass members of the 500 Myr old open cluster M37. Combining our new measurements of {{H}}α luminosities ({L}{{H}α }) with previously cataloged stellar properties, we identify saturated and unsaturated regimes in the dependence of the {L}{{H}α }-to-bolometric luminosity ratio, {L}{{H}α }/{L}{bol}, on the Rossby number R o . All rotators with R o smaller than 0.03 ± 0.01 converge to an activity level of {L}{{H}α }/{L}{bol}=(1.27+/- 0.02)× {10}-4. This saturation threshold ({R}o,{sat}=0.03+/- 0.01) is statistically smaller than that found in most studies of the rotation–activity relation. In the unsaturated regime, slower rotators have lower levels of chromospheric activity, with {L}{{H}α }/{L}{bol}(R o ) following a power-law of index β =-0.51+/- 0.02, slightly shallower than that found for a combined ≈650 Myr old sample of Hyades and Praesepe stars. By comparing this unsaturated behavior to that previously found for coronal activity in M37 (as measured via the X-ray luminosity, {L}{{X}}), we confirm that chromospheric activity decays at a much slower rate than coronal activity with increasing R o . While a comparison of {L}{{H}α } and {L}{{X}} for M37 members with measurements of both reveals a nearly 1:1 relation, removing the mass-dependencies by comparing instead {L}{{H}α }/{L}{bol} and {L}{{X}}/{L}{bol} does not provide clear evidence for such a relation. Finally, we find that {R}o,{sat} is smaller for our chromospheric than for our coronal indicator of activity ({R}o,{sat}=0.03+/- 0.01 versus 0.09 ± 0.01). We interpret this as possible evidence for coronal stripping.

  16. Converging Supergranular Flows and the Formation of Coronal Plumes

    Science.gov (United States)

    Wang, Y.-M.; Warren, H. P.; Muglach, K.

    2016-01-01

    Earlier studies have suggested that coronal plumes are energized by magnetic reconnection between unipolar flux concentrations and nearby bipoles, even though magnetograms sometimes show very little minority-polarity flux near the footpoints of plumes. Here we use high-resolution extreme-ultraviolet (EUV) images and magnetograms from the Solar Dynamics Observatory (SDO) to clarify the relationship between plume emission and the underlying photospheric field. We find that plumes form where unipolar network elements inside coronal holes converge to form dense clumps, and fade as the clumps disperse again. The converging flows also carry internetwork fields of both polarities. Although the minority-polarity flux is sometimes barely visible in the magnetograms, the corresponding EUV images almost invariably show loop-like features in the core of the plumes, with the fine structure changing on timescales of minutes or less. We conclude that the SDO observations are consistent with a model in which plume emission originates from interchange reconnection in converging flows, with the plume lifetime being determined by the approximately 1-day evolutionary timescale of the supergranular network. Furthermore, the presence of large EUV bright points and/or ephemeral regions is not a necessary precondition for the formation of plumes, which can be energized even by the weak, mixed-polarity internetwork fields swept up by converging flows.

  17. Impulsively Driven Waves And Flows In Coronal Active Regions

    Science.gov (United States)

    Ofman, Leon; Wang, T.; Davila, J. M.; Liu, W.

    2012-05-01

    Recent SDO/AIA and Hinode EIS observations indicate that both (super) fast and slow magnetosonic waves are present in active region (AR) magnetic structures. Evidence for fast (100-300 km/s) impulsive flows is found in spectroscopic and imaging observations of AR loops. The super-fast waves were observed in magnetic funnels of ARs. The observations suggest that waves and flow are produced by impulsive events, such as (micro) flares. We have performed three-dimensional magnetohydrodynamic (3D MHD) simulations of impulsively generated flows and waves in coronal loops of a model bi-polar active region (AR). The model AR is initiated with a dipole magnetic field and gravitationally stratified density, with impulsively driven flow at the coronal base of the AR in localized magnetic field structures. We model the excitation of the flows in hot (6MK) and cold (1MK) active region plasma, and find slow and fast magnetosonic waves produced by these events. We also find that high-density (compared to surrounding corona) loops are produced as a result of the upflows. We investigate the parametric dependence between the properties of the impulsive flows and the waves. The results of the 3D MHD modeling study supports the conjecture that slow magnetosonic waves are often produced by impulsive upflows along the magnetic field, and fast magnetosonic waves can result from impulsive transverse field line perturbations associated with reconnection events. The waves and flows can be used for diagnostic of AR structure and dynamics.

  18. The 3D structure of Coronal Mass Ejections

    Science.gov (United States)

    Patsourakos, Spiros

    2016-07-01

    Coronal Mass Ejections (CMEs) represent one of the most powerful energy release phenomena in the entire solar system and are a major driver of space weather. Prior to 2006, our observational access to CMEs was limited to single viewpoint remote sensing observations in the inner/outer corona, and in-situ observations further away, e.g. at 1 AU. Taking all these factors together, turned out to be a major obstacle in our understanding and characterizing of the 3D structure and evolution of CMEs. The situation improved dramatically with the availability of multi-viewpoint imaging observations of CMEs, all way through from the Sun to 1 AU, from the STEREO mission since 2006, combined with observations from other missions (SOHO, Hinode, SDO, IRIS). With this talk we will discuss several key recent results in CME science resulting from the analysis of multi-viewpoint observations. This includes: (1) shape and structure; (2) kinematics and energetics; (3) trajectories, deflections and rotations; (4) arrival times and velocities at 1 AU; (5) magnetic field structure; (6) relationships with coronal and interplanetary shocks and solar energetic particles. The implications of these results in terms of CME theories and models will be also addressed. We will conclude with a discussion of important open issues in our understanding of CMEs and how these could be addressed with upcoming (Solar Orbiter, Solar Probe Plus) and under-study missions (e.g., L5).

  19. Swift X-ray monitoring of M dwarf coronal variability

    Science.gov (United States)

    Miller, Brendan P.; Hagen, Cedric; Gallo, Elena; Wright, Jason

    2017-01-01

    We present new Swift observations of two M dwarfs with known exoplanets: GJ 15A and GJ 674. GJ 15A b is around 5.3 Earth masses with an 11.4 day orbital period, while GJ 674 is around 11.1 Earth masses with a 4.7 day orbital period. GJ 15A was observed several times in late 2014 and then monitored at approximately weekly intervals for several months in early 2016, for a total exposure of 18 ks. GJ 674 was monitored at approximately weekly intervals for most of 2016, for a total exposure of 40 ks. We provide light curves and hardness ratios for both sources, and also compare to earlier archival X-ray data. Both sources show significant X-ray variability, including between consecutive observations. We quantify the energy distribution for coronal flaring, and compare to optical results for M dwarfs from Kepler. Finally, we discuss the implications of M dwarf coronal activity for exoplanets orbiting within the nominal habitable zone.

  20. AN MHD AVALANCHE IN A MULTI-THREADED CORONAL LOOP

    Energy Technology Data Exchange (ETDEWEB)

    Hood, A. W.; Cargill, P. J.; Tam, K. V. [School of Mathematics and Statistics, University of St Andrews, St Andrews, Fife, KY16 9SS (United Kingdom); Browning, P. K., E-mail: awh@st-andrews.ac.uk [School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester, M13 9PL (United Kingdom)

    2016-01-20

    For the first time, we demonstrate how an MHD avalanche might occur in a multithreaded coronal loop. Considering 23 non-potential magnetic threads within a loop, we use 3D MHD simulations to show that only one thread needs to be unstable in order to start an avalanche even when the others are below marginal stability. This has significant implications for coronal heating in that it provides for energy dissipation with a trigger mechanism. The instability of the unstable thread follows the evolution determined in many earlier investigations. However, once one stable thread is disrupted, it coalesces with a neighboring thread and this process disrupts other nearby threads. Coalescence with these disrupted threads then occurs leading to the disruption of yet more threads as the avalanche develops. Magnetic energy is released in discrete bursts as the surrounding stable threads are disrupted. The volume integrated heating, as a function of time, shows short spikes suggesting that the temporal form of the heating is more like that of nanoflares than of constant heating.

  1. Full Halo Coronal Mass Ejections: Arrival at the Earth

    CERN Document Server

    Shen, Chenglong; Pan, Zonghao; Miao, Bin; Ye, Pinzhong; Wang, S

    2014-01-01

    A geomagnetic storm is mainly caused by a front-side coronal mass ejection (CME) hitting the Earth and then interacting with the magnetosphere. However, not all front-side CMEs can hit the Earth. Thus, which CMEs hit the Earth and when they do so are important issues in the study and forecasting of space weather. In our previous work (Shen et al., 2013), the de-projected parameters of the full-halo coronal mass ejections (FHCMEs) that occurred from 2007 March 1 to 2012 May 31 were estimated, and there are 39 front-side events could be fitted by the GCS model. In this work, we continue to study whether and when these front-side FHCMEs (FFHCMEs) hit the Earth. It is found that 59\\% of these FFHCMEs hit the Earth, and for central events, whose deviation angles $\\epsilon$, which are the angles between the propagation direction and the Sun-Earth line, are smaller than 45 degrees, the fraction increases to 75\\%. After checking the deprojected angular widths of the CMEs, we found that all of the Earth-encountered CM...

  2. ON THE OBSERVATION AND SIMULATION OF SOLAR CORONAL TWIN JETS

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jiajia; Wang, Yuming; Zhang, Quanhao [CAS Key Laboratory of Geospace Environment, School of Earth and Space Sciences, University of Science and Technology of China, NO. 96, Jinzhai Road, Hefei, Anhui 230026 (China); Fang, Fang [Laboratory for Atmospheric and Space Physics, University of Colorado at Boulder, 1234 Innovation Drive, Boulder, CO 80303 (United States); McIntosh, Scott W.; Fan, Yuhong [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307 (United States)

    2016-02-01

    We present the first observation, analysis, and modeling of solar coronal twin jets, which occurred after a preceding jet. Detailed analysis on the kinetics of the preceding jet reveals its blowout-jet nature, which resembles the one studied in Liu et al. However, the erupting process and kinetics of the twin jets appear to be different from the preceding one. Lacking detailed information on the magnetic fields in the twin jet region, we instead use a numerical simulation using a three-dimensional (3D) MHD model as described in Fang et al., and find that in the simulation a pair of twin jets form due to reconnection between the ambient open fields and a highly twisted sigmoidal magnetic flux, which is the outcome of the further evolution of the magnetic fields following the preceding blowout jet. Based on the similarity between the synthesized and observed emission, we propose this mechanism as a possible explanation for the observed twin jets. Combining our observation and simulation, we suggest that with continuous energy transport from the subsurface convection zone into the corona, solar coronal twin jets could be generated in the same fashion addressed above.

  3. Physical properties of erupting plasma associated with coronal mass ejections

    Science.gov (United States)

    Lee, J.; Raymond, J. C.; Reeves, K. K.; Moon, Y.; Kim, K.

    2013-12-01

    We investigate the physical properties (temperature, density, and mass) of erupting plasma observed in X-rays and EUV, which are all associated with coronal mass ejections observed by SOHO/LASCO. The erupting plasmas are observed as absorption or emission features in the low corona. The absorption feature provides a lower limit to the cold mass while the emission feature provides an upper limit to the mass of observed plasma in X-ray and EUV. We compare the mass constraints for each temperature response and find that the mass estimates in EUV and XRT are smaller than the total mass in the coronagraph. Several events were observed by a few passbands in the X-rays, which allows us to determine the temperature of the eruptive plasma using a filter ratio method. The temperature of one event is estimated at about 8.6 MK near the top of the erupting plasma. This measurement is possibly an average temperature for higher temperature plasma because the XRT is more sensitive at higher temperatures. In addition, a few events show that the absorption features of a prominence or a loop change to emission features with the beginning of their eruptions in all EUV wavelengths of SDO/AIA, which indicates the heating of the plasma. By estimating the physical properties of the erupting plasmas, we discuss the heating of the plasmas associated with coronal mass ejections in the low corona.

  4. Observing the formation of flare-driven coronal rain

    CERN Document Server

    Scullion, E; Antolin, P; Wedemeyer, S; Vissers, G; Kontar, E P; Gallagher, P

    2016-01-01

    Flare-driven coronal rain can manifest from rapidly cooled plasma condensations near coronal loop-tops in thermally unstable post-flare arcades. We detect 5 phases that characterise the post-flare decay: heating, evaporation, conductive cooling dominance for ~120 s, radiative / enthalpy cooling dominance for ~4700 s and finally catastrophic cooling occurring within 35-124 s leading to rain strands with s periodicity of 55-70 s. We find an excellent agreement between the observations and model predictions of the dominant cooling timescales and the onset of catastrophic cooling. At the rain formation site we detect co-moving, multi-thermal rain clumps that undergo catastrophic cooling from ~1 MK to ~22000 K. During catastrophic cooling the plasma cools at a maximum rate of 22700 K s-1 in multiple loop-top sources. We calculated the density of the EUV plasma from the DEM of the multi-thermal source employing regularised inversion. Assuming a pressure balance, we estimate the density of the chromospheric componen...

  5. Cannabis, possible cardiac deaths and the coroner in Ireland.

    LENUS (Irish Health Repository)

    Tormey, W P

    2012-01-10

    BACKGROUND: The elevated risk of triggering a myocardial infarction by smoking cannabis is limited to the first 2 h after smoking. AIM: To examine the possible role of cannabis in cardiac deaths. CASES AND RESULTS: From 3,193 coroners\\' cases over 2 years, there were 13 cases where the clinical information was compatible with a primary cardiac cause of death. An inquest was held in three cases. Myocardial infarction was the primary cause of death in 54%. Other causes were sudden adult death syndrome, sudden death in epilepsy, and poisoning by alcohol and diazepam. Cannabis was mentioned once only on a death certificate, but not as a cause of death. Blood delta9-tetrahydrocannabinol-carboxylic acid was recorded in one case and in no case was plasma tetrahydrocannabinol (THC) measured. CONCLUSIONS: To attribute sudden cardiac death to cannabis, plasma THC should be measured in the toxicology screen in coroners\\' cases where urine cannabinoids are positive. A positive urine cannabinoids immunoassay alone is insufficient evidence in the linkage of acute cardiac death and cannabis.

  6. CONVERGING SUPERGRANULAR FLOWS AND THE FORMATION OF CORONAL PLUMES

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y.-M.; Warren, H. P. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Muglach, K., E-mail: yi.wang@nrl.navy.mil, E-mail: harry.warren@nrl.navy.mil, E-mail: karin.muglach@nasa.gov [Code 674, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2016-02-20

    Earlier studies have suggested that coronal plumes are energized by magnetic reconnection between unipolar flux concentrations and nearby bipoles, even though magnetograms sometimes show very little minority-polarity flux near the footpoints of plumes. Here we use high-resolution extreme-ultraviolet (EUV) images and magnetograms from the Solar Dynamics Observatory (SDO) to clarify the relationship between plume emission and the underlying photospheric field. We find that plumes form where unipolar network elements inside coronal holes converge to form dense clumps, and fade as the clumps disperse again. The converging flows also carry internetwork fields of both polarities. Although the minority-polarity flux is sometimes barely visible in the magnetograms, the corresponding EUV images almost invariably show loop-like features in the core of the plumes, with the fine structure changing on timescales of minutes or less. We conclude that the SDO observations are consistent with a model in which plume emission originates from interchange reconnection in converging flows, with the plume lifetime being determined by the ∼1 day evolutionary timescale of the supergranular network. Furthermore, the presence of large EUV bright points and/or ephemeral regions is not a necessary precondition for the formation of plumes, which can be energized even by the weak, mixed-polarity internetwork fields swept up by converging flows.

  7. Soft X-ray emission in flaring coronal loops

    CERN Document Server

    Pinto, R F; Brun, A S

    2014-01-01

    Solar flares are associated with intense soft X-ray emission generated by the hot flaring plasma in coronal magnetic loops. Kink unstable twisted flux-ropes provide a source of magnetic energy which can be released impulsively and account for the heating of the plasma in flares. We investigate the temporal, spectral and spatial evolution of the properties of the thermal X-ray emission produced in such kink-unstable magnetic flux-ropes using a series of MHD simulations. We deduce emission diagnostics and their temporal evolution and discuss the results of the simulations with respect to observations. The numerical setup used consists of a highly twisted loop embedded in a region of uniform and untwisted background coronal magnetic field. We let the kink instability develop, compute the evolution of the plasma properties in the loop (density, temperature) and deduce the X-ray emission properties of the plasma during the whole flaring episode. During the initial phase of the instability plasma heating is mostly ...

  8. An imaging study of a complex solar coronal radio eruption

    CERN Document Server

    Feng, S W; Song, H Q; Wang, B; Kong, X L

    2016-01-01

    Solar coronal radio bursts are enhanced radio emission excited by energetic electrons accelerated during solar eruptions, studies on which are important for investigating the origin and physical mechanism of energetic particles and further diagnosing coronal parameters. Earlier studies suffered from a lack of simultaneous high-quality imaging data of the radio burst and the eruptive structure in the inner corona. Here we present a study on a complex solar radio eruption consisting of a type II and three reversely-drifting type III bursts, using simultaneous EUV and radio imaging data. It is found that the type II burst is closely associated with a propagating and evolving CME-driven EUV shock structure, originated initially at the northern shock flank and later transferred to the top part of the shock. This source transfer is co-incident with the presence of shock decay and enhancing signatures observed at the corresponding side of the EUV front. The electron energy accelerated by the shock at the flank is es...

  9. In What Magnetic Environment Are Coronal Loop Plasmas Located?

    Science.gov (United States)

    Lim, Daye; Choe, Gwang-Son

    2017-08-01

    As for coronal loops, there is a conventional wisdom that the plasma is confined inside magnetic flux tubes. However, a plasma pressure profile, which decreases from the center of a flux rope to its periphery, can be ideal MHD interchange unstable if field line ends are freely movable. In the solar corona, the strong line-tying condition impedes the interchange of the positions of elementary flux tubes, but ubiquitous magnetic reconnection processes can change plasma distribution in such a way that the system moves to a more stable state with a lower energy. In this study, we investigate the plasma redistribution in the merging process of many small flux ropes possibly representing loop strands, by an MHD simulation. We have found that the redistributed plasma is more concentrated between flux ropes rather than near the center of individual flux ropes. When flux ropes initially have different amounts of twists, the plasma tends to accumulate in less twisted regions. As larger and larger flux ropes are formed by successive merging processes, the ratio of poloidal flux to toroidal flux in a merged flux rope becomes smaller and smaller, i.e., field lines are less and less twisted. Our study may explain why the observed coronal loops appear very little twisted and quite well ordered in spite of continuous entangling motions in the photosphere and below.

  10. Global Energetics in Solar Flares and Coronal Mass Ejections

    Science.gov (United States)

    Aschwanden, Markus J.

    2017-08-01

    We present a statistical study of the energetics of coronal mass ejections (CME) and compare it with the magnetic, thermal, and nonthermal energy dissipated in flares. The physical parameters of CME speeds, mass, and kinetic energies are determined with two different independent methods, i.e., the traditional white-light scattering method using LASCO/SOHO data, and the EUV dimming method using AIA/SDO data. We analyze all 860 GOES M- and X-class flare events observed during the first 7 years (2010-2016) of the SDO mission. The new ingredients of our CME modeling includes: (1) CME geometry in terms of a self-similar adiabatic expansion, (2) DEM analysis of CME mass over entire coronal temperature range, (3) deceleration of CME due to gravity force which controls the kinetic and potentail CME energy as a function of time, (4) the critical speed that controls eruptive and confined CMEs, (5) the relationship between the center-of-mass motion during EUV dimming and the leading edge motion observed in white-light coronagraphs. Novel results are: (1) Physical parameters obtained from both the EUV dimming and white-light method can be reconciled; (2) the equi-partition of CME kinetic and thermal flare energy; (3) the Rosner-Tucker-Vaiana scaling law. We find that the two methods in EUV and white-light wavelengths are highly complementary and yield more complete models than each method alone.

  11. Detection of thermal radio emission from a single coronal giant

    CERN Document Server

    O'Gorman, Eamon; Vlemmings, Wouter

    2016-01-01

    We report the detection of thermal continuum radio emission from the K0 III coronal giant Pollux ($\\beta$ Gem) with the Karl G. Jansky Very Large Array (VLA). The star was detected at 21 and 9 GHz with flux density values of $150\\pm21$ and $43\\pm8\\,\\mu$Jy, respectively. We also place a $3\\sigma_{\\mathrm{rms}}$ upper limit of $23\\,\\mu$Jy for the flux density at 3 GHz. We find the stellar disk-averaged brightness temperatures to be approximately 9500, 15000, and $<71000\\,$K, at 21, 9, and 3 GHz, respectively, which are consistent with the values of the quiet Sun. The emission is most likely dominated by optically thick thermal emission from an upper chromosphere at 21 and 9 GHz. We discuss other possible additional sources of emission at all frequencies and show that there may also be a small contribution from gyroresonance emission above active regions, coronal free-free emission and free-free emission from an optically thin stellar wind, particularly at the lower frequencies. We constrain the maximum mass-...

  12. A Type II Radio Burst without a Coronal Mass Ejection

    CERN Document Server

    Su, W; Ding, M D; Chen, P F; Sun, J Q

    2015-01-01

    Type II radio bursts are thought to be a signature of coronal shocks. In this paper, we analyze a short-lived type II burst that started at 07:40 UT on 2011 February 28. By carefully checking white-light images, we find that the type II radio burst is not accompanied by a coronal mass ejection, only with a C2.4 class flare and narrow jet. However, in the extreme-ultraviolet (EUV) images provided by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO), we find a wave-like structure that propagated at a speed of $\\sim$ 600 km s$^{-1}$ during the burst. The relationship between the type II radio burst and the wave-like structure is in particular explored. For this purpose, we first derive the density distribution under the wave by the differential emission measure (DEM) method, which is used to restrict the empirical density model. We then use the restricted density model to invert the speed of the shock that produces the observed frequency drift rate in the dynamic spectrum. The ...

  13. Decay-less kink oscillations in coronal loops

    Science.gov (United States)

    Anfinogentov, S.; Nisticò, G.; Nakariakov, V. M.

    2013-12-01

    Context. Kink oscillations of coronal loops in an off-limb active region are detected with the Imaging Assembly Array (AIA) instruments of the Solar Dynamics Observatory (SDO) at 171 Å. Aims: We aim to measure periods and amplitudes of kink oscillations of different loops and to determinate the evolution of the oscillation phase along the oscillating loop. Methods: Oscillating coronal loops were visually identified in the field of view of SDO/AIA and STEREO/EUVI-A: the loop length was derived by three-dimensional analysis. Several slits were taken along the loops to assemble time-distance maps. We identified oscillatory patterns and retrieved periods and amplitudes of the oscillations. We applied the cross-correlation technique to estimate the phase shift between oscillations at different segments of oscillating loops. Results: We found that all analysed loops show low-amplitude undamped transverse oscillations. Oscillation periods of loops in the same active region range from 2.5 to 11 min, and are different for different loops. The displacement amplitude is lower than 1 Mm. The oscillation phase is constant along each analysed loop. The spatial structure of the phase of the oscillations corresponds to the fundamental standing kink mode. We conclude that the observed behaviour is consistent with the empirical model in terms of a damped harmonic resonator affected by a non-resonant continuously operating external force. A movie is available in electronic form at http://www.aanda.org

  14. Posterior coronal plating for tibial fractures: technique and advantages

    Directory of Open Access Journals (Sweden)

    Montu Jain

    2014-04-01

    Full Text Available Objective:Tibial shaft fractures are straightforward to treat but when associated with soft tissue injury particularly at the nail entry/plate insertion site or there is significant comminution proximally or a large butterfly fragment/a second split component in the posterior coronal plane, it is a challenge to the treating surgeon. The aim of the present report is to describe the technique of posterior coronal plating in such a scenario and its advantages. Methods:Between July 2008 and June 2011, 12 patients were pro spectively treated by this approach using 4.5 mm broad dynamic compression plates. Results:The time of bony consolidation and full weight bearing averaged 21.7 weeks (range, 16-26 weeks. Patients were followed up for at least 24 months (range, 24-48 months. At 1 year postoper atively, no loss in reduction or alignment was observed. Mean Hospital for Lower Extremity Measurement Functional Score was 72.8 (range, 64-78. All patients were satisfied with their treatment outcomes. Conclusion:Direct posterior approach and fixation using prone position helps to visualise the fracture fragments and provide rigid fixation. The approach is simple and extensile easily, apart from advantages of less soft tissue and hardware problems compared to standard medial or lateral plating. Key words: Tibial fractures; Bone plates; Orthopedic procedures

  15. QUASI-PERIODIC OSCILLATION OF A CORONAL BRIGHT POINT

    Energy Technology Data Exchange (ETDEWEB)

    Samanta, Tanmoy; Banerjee, Dipankar [Indian Institute of Astrophysics, Koramangala, Bangalore 560034 (India); Tian, Hui, E-mail: tsamanta@iiap.res.in, E-mail: hui.tian@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2015-06-20

    Coronal bright points (BPs) are small-scale luminous features seen in the solar corona. Quasi-periodic brightenings are frequently observed in the BPs and are generally linked with underlying magnetic flux changes. We study the dynamics of a BP seen in the coronal hole using the Atmospheric Imaging Assembly images, the Helioseismic and Magnetic Imager magnetogram on board the Solar Dynamics Observatory, and spectroscopic data from the newly launched Interface Region Imaging Spectrograph (IRIS). The detailed analysis shows that the BP evolves throughout our observing period along with changes in underlying photospheric magnetic flux and shows periodic brightenings in different EUV and far-UV images. With the highest possible spectral and spatial resolution of IRIS, we attempted to identify the sources of these oscillations. IRIS sit-and-stare observation provided a unique opportunity to study the time evolution of one footpoint of the BP as the slit position crossed it. We noticed enhanced line profile asymmetry, enhanced line width, intensity enhancements, and large deviation from the average Doppler shift in the line profiles at specific instances, which indicate the presence of sudden flows along the line-of-sight direction. We propose that transition region explosive events originating from small-scale reconnections and the reconnection outflows are affecting the line profiles. The correlation between all these parameters is consistent with the repetitive reconnection scenario and could explain the quasi-periodic nature of the brightening.

  16. Sausage Waves in Transversely Nonuniform Monolithic Coronal Tubes

    Science.gov (United States)

    Lopin, I.; Nagorny, I.

    2015-09-01

    We investigate fast sausage waves in a monolithic coronal magnetic tube, modeled as a local density inhomogeneity with a continuous radial profile. This work is a natural extension of our previous results, obtained for a slab loop model for the case of cylindrical geometry. Using Kneser’s oscillating theorem, we provided the criteria for the existence of trapped and leaky wave regimes as a function of the profile features. For a number of density profiles there are only trapped modes for the entire range of longitudinal wave numbers. The phase speed of these modes tends toward the external Alfvén speed in the long wavelength limit. The generalized results were supported by the analytic solution of the wave equation for the specific density profiles. The approximate Wentzel-Kramers-Brillouin solutions allowed us to obtain the desired dispersion relations and to study their properties as a function of the profile parameters. The multicomponent quasi-periodic pulsations in flaring loops, observed on 2001 May 2 and 2002 July 3, are interpreted in terms of the transversely fundamental trapped fast sausage mode with several longitudinal harmonics in a smooth coronal waveguide.

  17. Filament Shape Versus Coronal Potential Magnetic Field Structure

    CERN Document Server

    Filippov, Boris

    2015-01-01

    Solar filament shape in projection on disc depends on the structure of the coronal magnetic field. We calculate the position of polarity inversion lines (PILs) of coronal potential magnetic field at different heights above the photosphere, which compose the magnetic neutral surface, and compare with them the distribution of the filament material in H$\\alpha$ chromospheric images. We found that the most of the filament material is enclosed between two polarity inversion lines (PILs), one at a lower height close to the chromosphere and one at a higher level, which can be considered as a height of the filament spine. Observations of the same filament on the limb by the {\\it STEREO} spacecraft confirm that the height of the spine is really very close to the value obtained from the PIL and filament border matching. Such matching can be used for filament height estimations in on-disk observations. Filament barbs are housed within protruding sections of the low-level PIL. On the base of simple model, we show that th...

  18. A Study of Fast Flareless Coronal Mass Ejections

    CERN Document Server

    Song, H Q; Ye, D D; Han, G Q; Du, G H; Li, G; Zhang, J; Hu, Q

    2013-01-01

    Two major processes have been proposed to convert the coronal magnetic energy into the kinetic energy of a coronal mass ejection (CME): resistive magnetic reconnection and ideal macroscopic magnetohydrodynamic instability of magnetic flux rope. However, it remains elusive whether both processes play a comparable role or one of them prevails during a particular eruption. To shed light on this issue, we carefully studied energetic but flareless CMEs, \\textit{i.e.}, fast CMEs not accompanied by any flares. Through searching the Coordinated Data Analysis Workshops (CDAW) database of CMEs observed in Solar Cycle 23, we found 13 such events with speeds larger than 1000 km s$^{-1}$. Other common observational features of these events are: (1) none of them originated in active regions; they were associated with eruptions of well-developed long filaments in quiet-Sun regions, (2) no apparent enhancement of flare emissions was present in soft X-ray, EUV and microwave data. Further studies of two events reveal that (1) ...

  19. Forbush decreases associated to Stealth Coronal Mass Ejections

    Science.gov (United States)

    Heber, B.; Wallmann, C.; Galsdorf, D.; Herbst K.; Kühl, P.; Dumbovic, M.; Vršnak, B.; Veronig, A.; Temmer, M.; Möstl, C.; Dalla, S.

    Interplanetary coronal mass ejections (ICMEs) are structures in the solar wind that are the counterparts of coronal mass ejections (CMEs) at the Sun. It is commonly believed that enhanced magnetic fields in interplanetary shocks and solar ejecta as well as the increased turbulence in the solar wind sheath region are the cause of Forbush decreases (FDs) representing decreases of galactic cosmic ray (GCR) intensities. Recently, stealth CMEs i.e.~CMEs with no apparent solar surface association have become a subject in recent studies of solar activity. Whether all of such stealth CMEs can drive a FD is difficult to investigate on the basis of neutron monitor NM measurements because these measurements not only reflect the GCR intensity variation in interplanetary space but also the variation of the geomagnetic field as well as the conditions in the Earth atmosphere. Single detector counter from spacecraft instrumentation, here SOHO and Chandra EPHIN, exceed counting statistic of NMs allowing to determine intensity variation of less than 1 permil in interplanetary space on the basis of 30 minute count rate averages. Here we present the ongoing analysis of eleven stealth CMEs.

  20. CONSTRAINTS ON THE UBIQUITY OF CORONAL X-RAY CYCLES

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, John [Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, IL 61801 (United States); Guenther, Hans M.; Wright, Nicholas J., E-mail: hoffma24@illinois.edu, E-mail: guenther@head.cfa.harvard.edu, E-mail: nwright@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2012-11-10

    Stellar activity cycles are known to be a widespread phenomenon amongst moderately active solar- and late-type stars from long-term periodic variations in chromospheric Ca II H and K emission lines, yet to date, only a handful of coronal X-ray cycles are known. We have surveyed serendipitously observed stellar sources in fields observed multiple times in the last decade by XMM-Newton and present our analysis of nine stars from six fields. Since our sample is flux-limited, it is strongly biased toward higher levels of X-ray activity. We fit a single temperature APEC spectrum to each source and search for significant periodicities using a Lomb-Scargle periodogram. We use a Monte Carlo (MC) algorithm to yield robust analysis of the statistical significance of cycle detections and non-detections. None of the nine stellar light curves show any convincing indications of periodicity. From MC simulations, we simulate the detection capabilities of our methodology and, assuming a uniform distribution of cycle periods and strengths over the domain searched, we conclude with 95% confidence that less than 72% of the stars represented by our sample of active stars have 5-13 year coronal X-ray cycles.