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Sample records for abordaje coronal estudio

  1. Algunas reflexiones en torno al estudio de las controversias y su abordaje

    Stefoni, Andrés

    2015-01-01

    Al momento de diseñar mi investigación allá por el año 2010 estaba en curso de presentarme a una beca de investigación para el CONICET y justifiqué mi aproximación al campo de estudio del periodismo político bajo la idea de las prácticas periodísticas y “la construcción de las noticias”. Sometido a las exigencias de formalización y de diseño de ese organismo, me propuse un abordaje de los periodistas como un mundo social al cuál ingresaría por medio de un trabajo de campo de tipo etnográfico ...

  2. Estudios sobre periodismo digital: ejes principales que guiaron el abordaje de la digitalización de las noticias

    Juan Pablo Hamada

    2013-04-01

    Full Text Available Los trabajos enfocados en estudiar los procesos de digitalización de las noticias ya no constituyen un tema incipiente en el campo de la comunicación. Pasaron más de 15 años de la aparición de los primeros formatos online de los periódicos y ya es posible encontrar diversos tipos de abordajes académicos que dan cuenta de preocupaciones teóricas y metodológicas sobre los modos de abordar los procesos de digitalización de las noticias. En el siguiente trabajo presentaremos una síntesis de los principales aportes realizados en Iberoamérica y Estados Unidos con el objeto agrupar 3 matrices que en general han guiado a los intereses de estos trabajos: a relevar las primeras experiencias de digitalización de periódicos ya reconocidos, b analizar las nuevas características que asume la práctica periodística y los componentes discursivos de los nuevos formatos periodísticos y c reconocer la emergencia de nuevos actores que comienzan a disputar el campo periodístico.

  3. Artefactos de molienda y materias primas : Propuesta para su abordaje y estudio de casos en valles del noroeste argentino

    Babot, María del Pilar; Larrahona, Pedro Orlando

    2010-01-01

    En este trabajo se efectúa una propuesta metodológica para el estudio de la selección y abastecimiento de materiales líticos para la manufactura de artefactos de molienda en sus fases de campo y laboratorio. Se plantea un esquema para establecer bases de recursos líticos específicas para estos artefactos y se proporciona una discusión crítica acerca de atributos litológicos pertinentes para el trabajo de molienda. Se expone un caso actual del Noroeste argentino (NOA) que muestra esta situació...

  4. Estudio sobre el abordaje de la obesidad a sobrepeso tras una aproximación terapeútica basada en el premio-castigo

    Hermosín Peña, Marta

    2014-01-01

    En el presente trabajo realizamos una revisión sobre el sobrepeso y obesidad y su abordaje dentro de una consulta nutricional. Hemos querido realizarlo desde un enfoque psicoterapéutico, dando protagonismo al coaching nutricional y al modelo conceptual del premio-castigo. Tras una introducción general sobre la obesidad, el sobrepeso y sus problemas asociados, pasamos a revisar su prevención, su tratamiento psicológico y las bases para estas terapias. Aclaramos la problemátic...

  5. Abordaje de la tuberculosis en Atención Primaria. Estudio de contactos Dealing with tuberculosis in primary care. Contact tracing procedures

    F. Teruel

    2007-01-01

    Full Text Available Aunque el número de casos de tuberculosis en Navarra ha descendido en los últimos años, resulta necesario adaptar los programas de control a la nueva situación. Las claves para avanzar en su prevención y control son: conseguir un diagnóstico precoz y un tratamiento efectivo de los enfermos y detectar y tratar a las personas con infección latente. En ambas actividades la atención primaria juega un importante papel. La mitad de los casos de tuberculosis activa que se diagnostican han sido contactos de enfermos bacilíferos o bien tenían una elevada predisposición personal de desarrollar la enfermedad. Por ello la detección y tratamiento de la infección latente en nuestro medio se debe realizar: 1. Mediante cribado en personas con alto riesgo de infectarse y desarrollar enfermedad, y 2. Fundamentalmente en el estudio sistemático de contactos de los casos con enfermedad. En el tratamiento, tanto de la tuberculosis activa como de la infección latente, es imprescindible conseguir un buen cumplimiento del paciente.Although the number of cases of tuberculosis in Navarre has fallen in recent years, it is necessary to adapt the control programs to the new situation. The keys to advancing in its prevention and control are: obtaining an early diagnosis and an effective treatment of patients and detecting and treating people with a latent infection. Primary care plays an important role in both activities. Half of the cases of active tuberculosis that are diagnosed have been contacts by bacilliferous TB patients or else have had a high personal predisposition to developing the disease. That is why detection and treatment of the latent infection in our setting must be carried out: 1 through screening persons at high risk of becoming infected and developing the disease, and 2 trough a systematic study of contacts of persons with the disease. In the treatment of both active tuberculosis and latent infection it is essential to obtain good patient

  6. El Proyecto MADAI: Un estudio epidemiológico sobre el abordaje y manejo del dolor agudo periquirúrgico MADAI project: an epidemiologic study about the perioperative pain management and treatment

    J. L. Balibrea

    2008-05-01

    Full Text Available Objetivo. Obtener información descriptiva sobre el abordaje y el manejo del paciente con dolor agudo periquirúrgico tratado con analgésicos parenterales en el ámbito hospitalario. Metodología. Estudio epidemiológico, descriptivo, multicéntrico. Pacientes ingresados en los servicios de cirugía general, torácica, cardiovascular, angiología y cirugía vascular, ginecología, traumatología y urología. Resultados. Participaron 76 hospitales distribuidos por las diferentes comunidades autónomas y un total de 439 investigadores. Se evaluaron 1972 pacientes de los que el 43.9% y 25.5%, respectivamente pertenecieron a los servicios de cirugía general y traumatología. El 52.8% de los pacientes tenían más de 60 años, un 31.2 % no presentaron ninguna enfermedad concomitante, el 36.7% padecían hipertensión y un 16.5% diabetes. En el 5.8% de los pacientes se utilizaron escalas para valorar la intensidad del dolor al ingreso. En las sucesivas visitas, este porcentaje oscila entre el 10 % y el 15%. En el postoperatorio, los principales analgésicos administrados son los AINE (sobre todo el metamizol, que utilizan del 63.6% al 40.5% del total de pacientes del estudio y el paracetamol, que utilizan el 41.3% a las 0-12horas y el 27% el día 4. El porcentaje que recibe medicación de rescate va disminuyendo, desde el primer control (25.7%, al del cuarto día (6%, siendo la medicación más utilizada el paracetamol. Conclusiones. A pesar de que en el ámbito de la cirugía se considera importante el tratamiento del dolor, la utilización de protocolos no es habitual. La elaboración y utilización de guías terapéuticas para el tratamiento del dolor peri quirúrgico podría mejorar el confort del paciente y su recuperación.Objective. To obtain descriptive information about patient treatment with acute perioperative pain receiving parenteral analgesics in hospital environments. Methodology. Epidetniologic descriptive multicentre study. Patients

  7. Pobreza y desarrollo cognitivo infantil : Posibles modalidades de abordaje

    Mazzoni, Cecilia Clara; Stelzer, Florencia; Cervigni, Mauricio

    2011-01-01

    El efecto de la pobreza sobre el desarrollo cognitivo infantil, ha sido documentado por numerosos estudios científicos durante más de ocho décadas. Ambos fenómenos son complejos y multidimensionales y, por consiguiente, su relación ha sido investigada desde múltiples enfoques. En el presente trabajo se distinguen dos modalidades principales de abordaje de la relación entre pobreza y desarrollo cognitivo.

  8. Estudio descriptivo sobre las características de las funciones cognitivas de un paciente que ha sufrido un traumatismo encefalocraneano luego de un abordaje fonoaudiológico.

    Angoneli, Julieta Soledad

    2015-01-01

    La rehabilitación cognitiva es una herramienta terapéutica útil en el tratamiento del paciente con lesión cerebral, que tiene por finalidad mejorar y/o compensar aquellas capaci- dades funcionales disminuidas o perdidas después de un traumatismo encefalocraneano. Objetivo: Analizar las características de las funciones cognitivas, lenguaje, D.B.A., funciones ejecutivas, gnosias y praxias, de un paciente que ha sufrido un TEC luego de un abordaje fonoaudiológico en un inst...

  9. Analizando la invisibilización del ambiente. La danza y el movimiento como abordaje metodológico en estudios de sensibilidad y percepción ambiental

    Victoria D'hers

    2012-10-01

    Full Text Available Partiendo de lo observado en un estudio previo, referido como procesos de "invisibilización/silenciamiento" de las condiciones ambientales en las cuales los sujetos construyen cotidianamente sus vidas, se propone un estudio exploratorio de las posibilidades de aplicación de metodología cualitativa ligada a expresiones creativas y el movimiento.En primer término, se recorren las conclusiones previas, argumentando que en la población habitante de asentamientos precarios se da una superposición de sufrimientos fuertemente marcados por la necesidad, donde se ocluyen las referidas condiciones ambientales adversas presentes en barrios asentados sobre lo que fueran basurales a cielo abierto.Luego, se propone la aplicación de metodologías basadas en la expresividad y la creatividad en el movimiento, tanto en la generación de datos como en la apertura para ex-presar aquello invisibilizado −poniendo en juego el sentido práctico de los sujetos−, como en su posterior análisis e interpretación hacia la comprensión de las sensibilidades sociales. En esta línea se presentan las primeras indagaciones a nivel de las preguntas básicas planteadas por estos objetivos, un breve estado del arte en estudios de este tipo y los desafíos que se plantean

  10. Cine y estudios de género: Imagen, representación e ideología. Notas para un abordaje crítico Cinema and gender studies: Image, representation and ideology. Notes for a critical approach

    Paula Laguarda

    2006-01-01

    El cine, en tanto productor de imágenes, representaciones, significados e ideologías, aparece como un terreno óptimo para el rastreo del modo en que se han construido las subjetividades, desde la popularización de esta técnica en las primeras décadas del siglo XX hasta la actualidad. En este sentido ofrece a los estudios de género una fuente de primer orden para el análisis de las representaciones socialmente dominantes acerca de lo femenino y lo masculino y las características asignadas a ca...

  11. Cine y estudios de género: Imagen, representación e ideología. Notas para un abordaje crítico Cinema and gender studies: Image, representation and ideology. Notes for a critical approach

    Paula Laguarda

    2006-12-01

    Full Text Available El cine, en tanto productor de imágenes, representaciones, significados e ideologías, aparece como un terreno óptimo para el rastreo del modo en que se han construido las subjetividades, desde la popularización de esta técnica en las primeras décadas del siglo XX hasta la actualidad. En este sentido ofrece a los estudios de género una fuente de primer orden para el análisis de las representaciones socialmente dominantes acerca de lo femenino y lo masculino y las características asignadas a cada uno; así como la interacción de la categoría de género con otras como clase, etnicidad, nación, domesticidad, educación, ejercicio de la sexualidad y edad. En el artículo se abordan críticamente las principales líneas teóricas que han vinculado cine y feminismo y las posibilidades que éste ofrece a los estudios de género, al permitir la indagación simultánea sobre aspectos textuales (discursivos, narrativos y recursos propios del lenguaje cinematográfico y contextuales (al considerar al cine a la vez como industria cultural y manifestación de la cultura popular.Cinema, as a producer of images, representations, meanings and ideologies, seems to be an optimum territory for tracing the way in which subjectivities had been constructed, sinces the popularization of this technique on the early decades of XX century to the present day. In this sense, cinema provides gender studies with a source of prime order to analyse socially dominant representations about female and male, and the characteristics assigned to each other; such as the interaction between gender category and other like class, ethnicity, nation, domesticity, education, sexuality and age. This article approaches critically to the main theoretical lines that had conected cinema and feminism, and to the possibilities it offers to gender studies, by allowing simultaneous research on textual aspects (discoursive, narrative elements and resources of cinematographic language and

  12. A mulher japonesa vivenciando o câncer cérvico-uterino: um estudo de caso com abordagem da fenomenologia social La mujer japonesa vivenciando el cáncer cervico-uterino: un estudio del caso con abordaje fenomenológía social A japanese woman going through cervical uterine cancer: a case study with the social phenomenology approach

    Rosa Yuka Sato Chubaci

    2005-06-01

    Full Text Available Trata-se de estudo sobre a experiência de uma mulher japonesa, com câncer cérvico-uterino, realizado em um hospital da cidade de Osaka-Japão, no qual se utilizou o "estudo de caso" com abordagem da Fenomenologia Social de Alfred Schütz. Objetivou-se conhecer o significado da doença e da hospitalização para essa mulher, buscando compreender os motivos que envolvem a sua ação. Por meio da análise dos dados, foi possível compreender que o processo da hospitalização deve ser visto respeitando, além da característica individual, o mundo cultural que nos remete às ações humanas e que exerce influência importante no comportamento e atitude em relação à doença e hospitalização.Se trata de un estudio sobre la experiencia de una mujer japonesa, con cáncer cérvico-uterino, realizado en un hospital de la ciudad de Osaka-Japón, en el cual se utilizó el "estudio de caso" con abordaje de la Fenomenología Social de Alfred Schütz. El objetivo fue conocer el significado de la enfermedad y de la hospitalización para esa mujer, buscando comprender los motivos que involucran su acción. Por medio del análisis de los datos, fue posible comprender que el proceso de la hospitalización debe ser visto respetan-do, además de la característica individual, el mundo cultural que nos remite a las acciones humanas y que ejerce influencia importante en el comportamiento y actitud en relación a la enfermedad y hospitalización.This is the study of the experience of a Japanese woman with cervical uterine cancer carried out in a hospital in the city of Osaka, Japan, using Alfred Schütz's "case study" with the Social Phenomenology approach. The aim was to grasp the meaning of the disease and of hospitalization for this woman, and to try to understand the reasoning around her action. Through the analysis of the data, it was possible to understand that the hospitalization process has to be seen respecting, in addition to individual

  13. El Desguante craneorbitofacial como abordaje craneofacial y sus aplicaciones clínicas

    Rubén Muñoz

    2012-09-01

    Full Text Available El propósito de este estudio es describir la técnica quirúrgica para el abordaje del tercio superior y medio facial para cirugía craneofacial. Es un método de disección del macizo craneofacial que utiliza incisiones palpebrales tipo blefaroplastia, incisión bicoronal, incisión endonasal supracartilaginosa bilateral y dependiendo de las necesidades el Cirujano, abordajes preauriculares tipo Ritidectomía. La técnica está indicada en pacientes con múltiples fracturas cráneo-faciales y sus secuelas, tumores craneofaciales benignos, malignos y corrección de deformidades craneofaciales. En el presente estudio se reporta dos casos de pacientes que asistieron al Servicio de Cirugia Bucal y Maxilofacial del Hospital Universitario "Dr Angel Larralde", presentado secuela de fractura frontal y Naso-órbito-etmoidal Tipo III, ambos con una evolución de 6 meses. Se decide su resolución mediante abordaje craneorbitofacial (The Dismasking Flap, reconstrucción del tercio superior y medio facial mediante material de  osteosíntesis, así como desfuncionalización del seno frontal y reconstrucción de la pared anterior. Como resultado, no se evidencio compromiso de la mímica facial ni de la sensibilidad. En conclusión el abordaje craniorbitofacial es una herramienta para el abordaje de fracturas craneofaciales, recontrucciones craneofaciales, resección de tumores de la fosa craneal anterior, cirugía microvascular y trasplante facial.

  14. Interpretación musical, abordaje semiológico : La actividad de la interpretación

    Sergio, Daniel Agustín

    2005-01-01

    El objeto de estudio se circunscribe a la música escrita; el método utilizado para el abordaje del objeto fue preparado y aplicado en autores de la línea estética compositiva pertenecientes a los austrohúngaros J. Haydn, W. A. Mozart y L. V. Beethoven. Al situar la problemática alrededor del signo musical se desprende la relación de significado en un doble camino hacia su forma sonora en relación al significante y su forma espacial como materia ocupante de un lugar. El método de abordaj...

  15. Tecnología de gráficos en computadora, enfoques subyacentes a su abordaje en carreras universitarias proyectuales

    Balmaceda, María Isabel

    2015-01-01

    Existen múltiples teorías desde donde se puede entender y definir la tecnología. Cada una de ellas supone diferentes posicionamientos frente a la realidad, condiciona la definición de objetos de estudio y también las metodologías para su abordaje desde la educación. En este trabajo se analizan los posicionamientos que subyacen a tres modalidades diferentes en relación con el abordaje de la “tecnología de gráficos en computadora” (como parte del universo de la tecnología computacional), en car...

  16. Assistência à criança com disfunção neuromotora na abordagem da rede social: um estudo de caso Asistencia al niño con disfunción neuromotora en el abordaje de la red social: un estudio de caso Assistance to the child with neuromotor disorder using a social networkapproach: a case study

    Renata Dourado da Silveira

    2009-03-01

    Full Text Available O estudo de caso teve como propósito descrever a situação de saúde de uma criança com disfunção neuromotora e sua rede social, com aprofundamento no contexto socioeconômico. Os objetivos foram: identificar o cuidador da criança; construir o mapa da rede social da criança; discutir a importância do cuidador e contexto familiar no desenvolvimento da criança com disfunção neuromotora. Os dados foram coletados no prontuário na consulta de enfermagem; na abordagem da mãe durante a fisioterapia; na visita à casa da avó materna; na observação sistemática da criança, e mantiveram-se contatos pelo telefone. Os resultados mostraram que a menina está envolvida com diferentes pessoas e tem variados vínculos. Conclui-se que, apesar de a rede social ser ampla e densa, seus vínculos são fragilizados, o que torna a relação íntima e direta da menina restrita a poucas pessoas, como mãe, irmão e avó materna.El estudio de caso tuvo como propósito describir la situación de la salud de una niña con disfunción neuromotora y su red social, con profundización en el contexto socio-económico. Los objetivos fueron: identificar el cuidador de la niña; construir el mapa de la red social de la niña; discutir la importancia del cuidador y del contexto familiar en el desarrollo de la niña con disfunción neuromotora. Los datos fueron colectados en el registro médico; consulta de enfermería; abordaje de la madre durante la fisioterapia; visita a la casa de la abuela materna; observación sistemática de la niña y contactos por teléfono. Los resultados mostraron que la niña está enredada con diversas personas y variados enlaces. Se concluye aunque la red social sea amplia y densa, sus enlaces son fragilizados, lo que torna la relación íntima y directa a la niña restricta a pocas personas, como madre, hermano, abuela materna.The case study's intention was to describe the situation regarding the health of a child with neuromotor

  17. Coronal Holes

    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.

  18. Abordaje transeptal para el reemplazo valvular mitral

    Juan C. Medrano; Carlos A. Ingino; Carlos A. Rapallo; Carlos Barrero; Félix Ramírez; Arnaldo Milani; Miguel Rubio; Raúl A. Borracci

    2010-01-01

    IntroducciónA pesar de que es técnicamente más demandante, el acceso a la válvula mitral por vía transeptal permite una exposición mayor de sus valvas y del aparato subvalvular, en especial en aurículas pequeñas, en reoperaciones o cuando se combina con el tratamiento de la válvula tricuspídea.ObjetivosEvaluar las dificultades técnicas y las complicaciones asociadas con el abordaje transeptal para el reemplazo valvular mitral.Material y métodosEntre 2006 y 2009 se incluyeron 62 pacientes cons...

  19. Los Modelos Operantes Internos y sus Abordajes en Psicoterapia

    Susana Morales Silva; María Pía Santelices Álvarez

    2007-01-01

    Este artículo presenta una discusión sobre las aproximaciones teóricas acerca de los estilos de apego adulto y su abordaje en Psicoterapia. Para ello se aborda la medición del apego en el adulto; se revisan las investigaciones actuales en el tema y se discuten alternativas psicoterapéuticas más utilizadas en este campo. Para el abordaje de los Modelos Operantes Internos, se revisa un método basado en la mentalización y que sugiere el reconocimiento de los factores involucrados en ...

  20. Modelo de estudio de dos informativas familias colombianas con síndrome de usher

    Tamayo ML.; González C; Gelvez N.

    2011-01-01

    Establecer y evaluar un modelo de abordaje para el estudio del Síndrome de Usher, que abarca el diagnóstico clínico de los pacientes, establecimiento y confirmación del subtipo mediante estudios moleculares y posterior correlación genotipo-fenotipo.

  1. Modelo de estudio de dos informativas familias colombianas con Síndrome de Usher

    Tamayo ML.

    2001-06-01

    Full Text Available Establecer y evaluar un modelo de abordaje para el estudio del Síndrome de Usher, que abarca el diagnóstico clínico de los pacientes, establecimiento y confirmación del subtipo mediante estudios moleculares y posterior correlación genotipo-fenotipo.

  2. Influencia del género en el conocimiento, percepción y abordaje de las prácticas tradicionales perjudiciales: Mutilación Genital Femenina

    León Larios, Fátima; Casado Mejía, Rosa María

    2012-01-01

    Justificación: Los procesos migratorios existentes en las sociedades contemporáneas visualizan pautas culturales diferentes y para las que los profesionales sanitarios pueden no tener competencia cultural para su abordaje. La Mutilación Genital Femenina es un problema emergente, minoritario, pero que no debería ser obviado. Objetivo: Explorar la influencia del género en el conocimiento, percepción y abordaje de la Mutilación Genital Femenina. Diseño: Estudio cualitativo. Se han realiza...

  3. Approach-related morbidity in transthoracic anterior spine surgery: a clinical study and review of literature Morbilidad relacionada con el abordaje torácico anterior de la columna: estudio clínico y revisión de la literatura Morbidade relacionada à abordagem transtorácica anterior da coluna: estudo clínico e revisão da literatura

    Juliane Zenner

    2010-03-01

    presente estudio fue observar los resultados relacionados con la morbilidad de la toracotomía abierta para la corrección de la deformidad de la columna vertebral y toracotomía para la colocación de tubo de drenaje torácica, utilizando ese grupo como Control. MÉTODOS: con base en un cuestionario respondido por los pacientes; y relacionado con la evaluación de la morbilidad del abordaje anterior de la columna torácica y utilizando criterios estrictos de inclusión de los pacientes, fueron evaluados 43 pacientes sometidos a toracotomía abierta para tratamiento de la escoliosis; y 30 pacientes portadores de otras enfermedades de menor gravedad, que fueron sometidos a la toracotomía para la colocación de dreno de tórax después del procedimiento. RESULTADOS: el promedio de edad de los pacientes sometidos al procedimiento en el tórax y a la toracotomía para la colocación de dreno o toracotomía abierta para tratamiento de escoliosis fue, respectivamente: 50.2 años y 16.5 años; el seguimiento clínico fue de 32.2 meses y 54.8 meses; y la extensión de la incisión de la piel 2.5 cm y 25 cm. El promedio del número de vértebras artrosadas fue 5.8 en el grupo sometido a la toracotomía abierta para la corrección de deformidad. La morbilidad promedio (variando de 0% - ninguna morbilidad a 100% - alta morbilidad en el grupo de pacientes sometidos a la toracotomía para colocación de dreno de tórax fue de 10.8±15.4 (0-59.5%, y un 42% de los pacientes no presentaron morbilidad. En el grupo sometido a la toracotomía abierta para la colocación del dreno de tórax fue observada neuralgia intercostal en 16.7%, y 35% de los pacientes presentaron morbilidad mayor que 10% (pormedio de un 27.5%. La morbilidad fue definida como la presencia de dolor crónico después de la toracotomía. En el grupo sometido a la toracotomía abierta para tratamiento de escoliosis el promedio de la morbilidad fue 7.0±12.7% (0-52.1%, y 44% no presentaron morbilidad. Señales de neuralgia

  4. Estudo sobre os elementos de uma interpretação invasiva na abordagem psicanalítica winnicottiana Estudio sobre los elementos de una interpretación invasiva en el abordaje psicoanalítico winnicottiano Study on the elements of an invasive interpretation in the Winnicott psychoanalytical approach

    Conceição Aparecida Serralha

    2012-04-01

    Full Text Available Partindo dos textos freudianos, este estudo reapresenta brevemente a técnica da interpretação em psicanálise e, baseando-se na obra de Winnicott, discute os elementos de uma interpretação sentida de forma invasiva pelo analisando. São identificados, nomeados e discutidos os elementos apontados por este autor: tempo, modo, graus de confiabilidade, objetividade e conhecimento, sendo ilustrados por alguns fragmentos de sessão de casos de Winnicott e de um caso da autora. O estudo evidencia a importância da capacidade de o analista se identificar com o analisando para interpretar, recebendo e entendendo a comunicação deste sobre a adequação de todos esses elementos ao seu caso.Partiendo de los textos freudianos, este estudio reapresenta brevemente la técnica de la interpretación en psicoanálisis y, basándose en la obra de Winnicott, discute los elementos de una interpretación sentida de forma invasiva por el analizando. Son identificados, nombrados y discutidos los elementos apuntados por este autor: tiempo, modo, grados de confiabilidad, objetividad y conocimiento, siendo ilustrados por algunos fragmentos de sesión de casos de Winnicott y de un caso de lo autor. El estudio evidencia la importancia de la capacidad de el analista identificarse con el analizando para interpretar, recibiendo y entendiendo la comunicación de este sobre la adecuación de todos esos elementos a su caso.From the Freudian texts, this study reintroduces briefly the technique of interpretation in psychoanalysis and, based on the Winnicott's works, discusses the elements of an interpretation felt invasive by the patient. The elements pointed out by this author and identified, named and discussed include: time, manner, degrees of trustworthiness, objectiveness and knowledge. They are illustrated with fragments of session of Winnicott's cases and one case of the author. The study highlights the importance of the analyst's capacity of identifying him

  5. The Coron System

    Kaytoue, Mehdi; Marcuola, Florent; Napoli, Amedeo; Szathmary, Laszlo; Villerd, Jean

    2011-01-01

    Coron is a domain and platform independent, multi-purposed data mining toolkit, which incorporates not only a rich collection of data mining algorithms, but also allows a number of auxiliary operations. To the best of our knowledge, a data mining toolkit designed specifically for itemset extraction and association rule generation like Coron does not exist elsewhere. Coron also provides support for preparing and filtering data, and for interpreting the extracted units of knowledge.

  6. Abordaje transumbilical en pacientes pediátricos con sospecha de apendicitis aguda. Un serie de 424 pacientes

    Luis Augusto Zárate Suárez

    2013-05-01

    Full Text Available Antecedentes: El tratamiento de la apendicitis aguda implica su extirpación; es frecuente la solicitud de cicatrices postquirúrgicas del mejor tamaño posible. Una de las estrategias disponibles es el abordaje transumbilical. Objetivos: Descubrir las características clínicas y los desenlaces operatorios de los pacientes pediátricos en quienes se realiza apendicectomía vía transumbilical. Metodología: Estudio prospectivo de 424 pacientes sucesivos en cuanto a los desenlaces operatorios a corto plazo. Resultados: El tiempo promedio de intervención quirúrgica fue de 22 minutos; 95,8% de los pacientes presentó evolución satisfactoria del postquirúrgico; 1,4% de los pacientes se reintervino para drenar un absceso intracavitario residual y 0,2% presentó infencción de sitio operatorio sin mas complicaciones. Conclusión: El abordaje transumbilical de la apendicitis es una alternativa minimamente invasiva para todos los estados de apendicitis aguda e implica disminución del tiempo de realización, menor estancia del postquirúrgico, menor incidencia de complicaciones y mayor conformidad con los resultados estéticos.

  7. Can coronal hole spicules reach coronal temperatures?

    Madjarska, M. S.; Vanninathan, K.; Doyle, J. G.

    2011-01-01

    We aim with the present study to provide observational evidences on whether coronal hole spicules reach coronal temperatures. We combine multi-instrument co-observations obtained with the SUMER/SoHO and with the EIS/SOT/XRT/Hinode. The analysed three large spicules were found to be comprised of numerous thin spicules which rise, rotate and descend simultaneously forming a bush-like feature. Their rotation resembles the untwisting of a large flux rope. They show velocities ranging from 50 to 2...

  8. El sesgo de "deseabilidad social" en el abordaje del fenómeno de la discriminación en las relaciones interculturales: algunas reflexiones sobre las guías de pautas como "teorías en acto"

    Plotnik, Gabriela; González, Anahí P.

    2012-01-01

    El estudio de la conflictividad existente en las relaciones interculturales asume algunas características, consideraciones y dificultades metodológicas particulares. En este sentido, el presente trabajo se plantea como objetivo principal la problematización de aquellos modos de abordaje metodológicos que conllevan la posibilidad de rastrear las representaciones sociales discriminatorias presentes en la relación nativos-migrantes externos en la institución educativa y judicial argentina.

  9. Propuesta de abordaje sobre determinantes sociales de la salud y cambio climático en comunidades dependientes de los desechos sólidos en Managua, Nicaragua

    Paredes Gaitán, Yolanda

    2014-01-01

    OBJETIVOS: Esta investigación elabora una propuesta de abordaje sobre los determinantes sociales de la salud y el cambio climático en una comunidad dependiente de los desechos sólidos en la ciudad de Managua, Nicaragua. Partiendo del análisis social y económico, tanto del país como de la comunidad en estudio, se plantean acciones sociales y económicas basadas en los determinantes sociales que inciden en la salud. DESCRIPCIÓN: Con base en el análisis social y económico hecho ...

  10. Propuesta de abordaje sobre determinantes sociales de la salud y cambio climático en comunidades dependientes de los desechos sólidos en Managua, Nicaragua

    Paredes Gaitán, Yolanda; Martín, Miguel

    2014-01-01

    OBJETIVOS: Esta investigación elabora una propuesta de abordaje sobre los determinantes sociales de la salud y el cambio climático en una comunidad dependiente de los desechos sólidos en la ciudad de Managua, Nicaragua. Partiendo del análisis social y económico, tanto del país como de la comunidad en estudio, se plantean acciones sociales y económicas basadas en los determinantes sociales que inciden en la salud. DESCRIPCIÓN: Con base en el análisis social y económico hecho a la población dep...

  11. Can coronal hole spicules reach coronal temperatures?

    Madjarska, M. S.; Vanninathan, K.; Doyle, J. G.

    2011-08-01

    Aims: The present study aims to provide observational evidence of whether coronal hole spicules reach coronal temperatures. Methods: We combine multi-instrument co-observations obtained with the SUMER/SoHO and with the EIS/SOT/XRT/Hinode. Results: The analysed three large spicules were found to be comprised of numerous thin spicules that rise, rotate, and descend simultaneously forming a bush-like feature. Their rotation resembles the untwisting of a large flux rope. They show velocities ranging from 50 to 250 kms-1. We clearly associated the red- and blue-shifted emissions in transition region lines not only with rotating but also with rising and descending plasmas. Our main result is that these spicules although very large and dynamic, are not present in the spectral lines formed at temperatures above 300 000 K. Conclusions: In this paper we present the analysis of three Ca ii H large spicules that are composed of numerous dynamic thin spicules but appear as macrospicules in lower resolution EUV images. We found no coronal counterpart of these and smaller spicules. We believe that the identification of phenomena that have very different origins as macrospicules is due to the interpretation of the transition region emission, and especially the He ii emission, wherein both chromospheric large spicules and coronal X-ray jets are present. We suggest that the recent observation of spicules in the coronal AIA/SDO 171 Å and 211 Å channels probably comes from the existence of transition region emission there. Movie is available in electronic form at http://www.aanda.org

  12. Stellar Flares and Coronal Structure

    Guedel, M.

    2003-01-01

    Coronal structure and coronal heating are intimately related in magnetically active stars. Coronal structure is commonly inferred from radio interferometry and from eclipse and rotational modulation studies. We discuss to what extent flares may be responsible for coronal structure and global observable properties in magnetically active stars.

  13. Coronal Waves and Oscillations

    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.

  14. Mechanisms of Coronal Heating

    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.

  15. Can coronal hole spicules reach coronal temperatures?

    Madjarska, M S; Doyle, J G

    2011-01-01

    We aim with the present study to provide observational evidences on whether coronal hole spicules reach coronal temperatures. We combine multi-instrument co-observations obtained with the SUMER/SoHO and with the EIS/SOT/XRT/Hinode. The analysed three large spicules were found to be comprised of numerous thin spicules which rise, rotate and descend simultaneously forming a bush-like feature. Their rotation resembles the untwisting of a large flux rope. They show velocities ranging from 50 to 250 km/s. We clearly associated the red- and blue-shifted emissions in transition region lines with rotating but also with rising and descending plasmas, respectively. Our main result is that these spicules although very large and dynamic, show no presence in spectral lines formed at temperatures above 300 000 K. The present paper brings out the analysis of three Ca II H large spicules which are composed of numerous dynamic thin spicules but appear as macrospicules in EUV lower resolution images. We found no coronal counte...

  16. Los estudios organizacionales en el abordaje de los determinantes de la salud

    Alvarez Pérez, A. G.; Fariñas, A. G.; Rodriguez Salvá, A.; Bonet Gorbea, M.; de Vos, P.; Van der Stuyft, P.

    2009-01-01

    There is a lack of national and international publications on organizational studies as a alternative to assess the role of health services in the process of health social production y, specially as a health determinant. In present paper are exposed features related to this matter, are proposed the conceptual bases of organizational studies in health services to explain at local level how is produced the mentioned contribution for population health, which are its success factor...

  17. Global Coronal Waves

    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...

  18. Entrevista não-diretiva: uma possibilidade de abordagem em grupo Entrevista no directiva: una posibilidad de abordaje en grupo Non-directive interview: a possibility of group approach

    Maria Vitória Hoffmann

    2009-12-01

    Full Text Available Relato de experiência que descreve a abordagem metodológica entrevista não-diretiva, explicitando a possibilidade da abordagem em grupo. Apresenta os estudos que utilizaram este tipo de entrevista em grupo e a dinâmica de coleta de dados. Conclui-se que a abordagem possibilita ao pesquisador articular teoria e prática em torno de uma proposta de estudo.Relato de experiencia que describe el abordaje metodológico - entrevista no directiva; explicita la posibilidad del abordaje en grupo. Presenta los estudios que utilizaron la entrevista no directiva en grupo y la dinámica de la recollección de datos. Se concluye que el abordaje posibilita al investigador articular teoría y práctica en torno de una propuesta de estudio.Experience report that describes the methodological approach - non-directive interview, highlighting the possibility of group approach. It presents the studies that used this type of group and the dynamics of data collection. It was concluded that the approach enables the researcher to combine theory and practice around a study proposition.

  19. Episodic coronal heating

    Sturrock, P. A.; Dixon, W. W.; Klimchuk, J. A.; Antiochos, S. K.

    1990-01-01

    A study is made of the observational consequences of the hypothesis that there is no steady coronal heating, the solar corona instead being heated episodically, such that each short burst of heating is followed by a long period of radiative cooling. The form of the resulting contribution to the differential emission measure (DEM), and to a convenient related function (the differential energy flux, DEF) is calculated. Observational data for the quiet solar atmosphere indicate that the upper branch of the DEM, corresponding to temperatures above 100,000 K, can be interpreted in terms of episodic energy injection at coronal temperatures.

  20. Episodic coronal heating

    A study is made of the observational consequences of the hypothesis that there is no steady coronal heating, the solar corona instead being heated episodically, such that each short burst of heating is followed by a long period of radiative cooling. The form of the resulting contribution to the differential emission measure (DEM), and to a convenient related function (the differential energy flux, DEF) is calculated. Observational data for the quiet solar atmosphere indicate that the upper branch of the DEM, corresponding to temperatures above 100,000 K, can be interpreted in terms of episodic energy injection at coronal temperatures. 22 refs

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

    Omar Marcelo Vargas Fuentes; Omar Manuel Mustafá Millán; Jorge Alberto Fuentes Soliz

    2011-01-01

    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 ...

  2. La experiencia de la delincuencia en dos abordajes etnográficos alternativos

    Joaquín Santiago Gomez

    2011-10-01

    Full Text Available En este artículo reseñaré críticamente tres etnografías que han abordado la experiencia de la delincuencia en las sociedades contemporáneas. Lo haré señalando el modo en que han definido su objeto y realizado su trabajo, como es de rigor, pero sobre todo conduciendo la discusión a lo que entiendo dos formas radicalmente otras de construir el campo. Precisamente, atender al lugar diferencial que ocupa el "hecho delictivo" en estos trabajos antropológicos llevará a situar en líneas de indagación alternativas, por un lado, el reciente trabajo realizado en Argentina por Daniel Míguez y, por otro, dos etnografías brasileñas ancladas en la ciudad de Rio de Janeiro - entre las que encontramos una clara continuidad -, los trabajos de Alba Zaluar y Marcos Alvito. En un último apartado, me detendré a señalar la fructífera relación, no reconocida explícitamente en las etnografías que reseñamos, que esta línea de trabajo desarrollada en Brasil puede tener con los trabajos de Michel Foucault (esa relación es más patente en otros autores, como Michel Misse, cuya producción también podría ser incluida en esta perspectiva. De este modo, pretendo llamar la atención sobre aquellos abordajes que si bien pueden ofrecer aportes valiosos sobre tal o cual cuestión puntual, permanecen ciegos a los mismos fenómenos que la criminología convencional ignora dado que comparten con ésta la construcción de un campo de estudio centrado en la "delincuencia".

  3. Abordaje transconjuntival más transcaruncular: amplia exposición de la pared medial orbitaria. Una alternativa al abordaje coronal Transconjunctival, transcaruncular approach: enlarged orbital medial wall exposure. An alternative to the coronal approach

    J. Rodríguez

    2008-06-01

    Full Text Available Los pliegues nasolabiales prominentes son uno de los aspectos que más preocupan a los pacientes candidatos a un lifting facial, y han sido descritas muchas técnicas que intentan atenuar este signo distintivo del envejecimiento. Las sustancias de relleno tienen limitaciones inherentes. Las disecciones amplias del SMAS y su posterior suspensión no tienen efecto después de transcurridas 24 horas. La suspensión de la almohadilla grasa malar tiene un efecto que se extiende como máximo a los dos años de duración. La extirpación directa de la grasa lateralmente al surco nasolabial, aunque debe hacerse con mucha cautela, es la única técnica que proporciona resultados permanentes. Técnicamente, esta resección grasa se ha descrito realizada valiéndose de pinzas y tijeras, con cánulas de liposucción o con curetas. Este procedimiento requiere un control muy preciso, táctil y visual, de la localización y profundidad de la extirpación, control que puede mejorarse usando una gubia ósea con una mano para extirpar la grasa a eliminar de la dermis, mientras la otra mano maneja el colgajo cutáneo de la mejilla, para un control alternativo interno y externo del efecto escultural de la extirpación y para permitir una guía táctil externa.Prominent nasolabial folds are of concern to many face lift candidates. Many techniques have been described which tackle this distinct sign of ageing. Crease fillers have inherent limitations. Extended SMAS dissection and suspension has no effect after 24 hours. Malar fat pad suspension has an effect which extends maximally to 2 years. Direct fat excision lateral to the crease must be done cautiously. However, it is the only technique providing permanent results. Fat removal can be done with tweezers and scissors, with liposuction canules, and with curettes. Tactile and visual control over location and depth of the resection is required. Such is possible when using a bone rongeur in one hand to reduce the fat mount which has been dissected off the dermis. The other hand turns over the cheek flap for alternating internal and external control of the sculpturing effect, and for external tactile guidance.

  4. The coronal fricative problem

    Dinnsen, Daniel A.; Dow, Michael C.; GIERUT, JUDITH A.; Morrisette, Michele L.; Christopher R. Green

    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 evidenc...

  5. Coronal Waves and Oscillations

    Nakariakov Valery M.; Verwichte Erwin

    2005-01-01

    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 interactio...

  6. Coronal hole dynamics

    The dynamics of high speed streams of solar plasma emanating from a coronal hole is investigated by use of a two-fluid model with polytropic equations of state. Steady outflow is considered along a flow tube which has a radial orientation with respect to the Sun, and a cross-sectional area proportional to r sup(s) where r is the heliocentric radius and s is a divergence parameter (>=2). The equations of continuity, momentum and state may be used to obtain a single, nonlinear, ordinary differential equation for the outflow velocity, and the problem reduces to the numerical solution of three pairs of simultaneous algebraic equations. It is found that the velocity profiles are generally highly dependent on the divergence parameter s, as well as the polytropic indices. Numerical results are given for a variety of cases most relevant to the solar corona. As s increases from 2, the value appropriate to the purely spherically symmetric expansion, the outflow velocity increases throughout the range from the coronal base out to infinity, over a certain parameter range. Although the terminal outflow speed for s > 2 may be far in excess of the purely spherically symmetric value, it is found that high speed streams emanating from coronal holes cannot be accounted for by geometrical effects alone. The results may have important applications in the general theory of stellar winds

  7. Estudio de usabilidad del Portal de Periódicos de CAPES

    Luciana Ferreira da Costa; Francisca Arruda Ramalho

    2011-01-01

    Objetivo. El estudio analiza la usabilidad del Portal de Periódicos de la Coordinación de Perfeccionamiento de Personal de Nivel Superior (CAPES) en base a los parámetros de usabilidad desarrollados por el estudioso Jakob Nielsen y bajo la perspectiva de un estudio de usuario, haciendo una vinculación inevitable de la información con los ámbitos de la tecnología y la Ciencia de la Información. Método. Este es un estudio de naturaleza descriptiva, usa un abordaje cualitativo con aporte cuantit...

  8. Estudio antropológico de redes sociales de madres adolescentes durante el embarazo

    Lorena Pasarin

    2009-01-01

    La atención de la salud incluye a diversos actores sociales, por ello en su estudio debe contemplarse el papel que adquieren los contextos socioculturales. El estudio de las redes sociales resulta conveniente para abordarlos. Este trabajo presenta una aplicación del análisis de redes sociales como complemento de abordaje metodológico al estudio de las prácticas y comportamientos relacionados con la salud de madres adolescentes durante el período prenatal. Utilizando la herramienta EgoNet, se ...

  9. Observational features of equatorial coronal hole jets

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

  10. Factores emocionales en el abordaje de las enfermedades cardiovasculares. Valoración actualizada desde la Psicocardiología

    Teresa Rodríguez Rodríguez

    2012-09-01

    Full Text Available El tratamiento de las enfermedades cardiovasculares exige un abordaje desde la multidisciplinariedad, por la presencia de diversos factores en su origen y evolución. La Psicocardiología se encarga de estudiar los factores de orden psicológico vinculados a estas enfermedades. En el presente trabajo se abordan los factores emocionales que repercuten en diferentes padecimientos coronarios, así como el vínculo de estos, con los diferentes tipos de personalidad. Se exponen resultados obtenidos sobre el estudio de diversas emociones en pacientes portadores de infarto agudo del miocardio en fase aguda, y se ilustra cómo realizar la intervención psicológica para lograr el control emocional de estos pacientes porque puede ser útil para los enfermos y en el mejoramiento del cuadro clínico en general. Finalmente se apela a la necesidad de crear una concientización en la comunidad médica, para que no se desestime el papel de factores de índole subjetiva a la hora de prevenir, diagnosticar y tratar cualquier enfermedad cardiaca.

  11. The Coronal Solar Magnetism Observatory

    Tomczyk, S.; Landi, E.; Zhang, J.; Lin, H.; DeLuca, E. E.

    2015-12-01

    Measurements of coronal and chromospheric magnetic fields are arguably the most important observables required for advances in our understanding of the processes responsible for coronal heating, coronal dynamics and the generation of space weather that affects communications, GPS systems, space flight, and power transmission. The Coronal Solar Magnetism Observatory (COSMO) is a proposed ground-based suite of instruments designed for routine study of coronal and chromospheric magnetic fields and their environment, and to understand the formation of coronal mass ejections (CME) and their relation to other forms of solar activity. This new facility will be operated by the High Altitude Observatory of the National Center for Atmospheric Research (HAO/NCAR) with partners at the University of Michigan, the University of Hawaii and George Mason University in support of the solar and heliospheric community. It will replace the current NCAR Mauna Loa Solar Observatory (http://mlso.hao.ucar.edu). COSMO will enhance the value of existing and new observatories on the ground and in space by providing unique and crucial observations of the global coronal and chromospheric magnetic field and its evolution. The design and current status of the COSMO will be reviewed.

  12. The coronal fricative problem

    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

  13. The coronal fricative problem.

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

    2013-07-01

    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

  14. Coronal heating via nanoflares

    It has been recently proposed that the coronae of single late-type main sequence stars represent the radiative output from a large number of tiny energy release events, the so-called nanoflares. Although this suggestion is attractive and order of magnitude estimates of the physical parameters involved in the process are consistent with available data, nanoflares have not yet been observed and theoretical descriptions of these phenomena are still very crude. In this paper we examine the temporal behavior of a magnetic flux tube subject to the repeated occurrence of energy release events, randomly distributed in time, and we show that an originally empty cool loop may, in fact, reach typical coronal density and temperature values via nanoflare heating. By choosing physical parameters appropriate to solar conditions we also explore the possibilities for observationally detecting nanoflares. Although the Sun is the only star where nanoflares might be observed, present instrumentation appears to be inadequate for this purpose

  15. Dynamical behaviour in coronal loops

    Haisch, Bernhard M.

    1986-01-01

    Rapid variability has been found in two active region coronal loops observed by the X-ray Polychromator (XRP) and the Hard X-ray Imaging Spectrometer (HXIS) onboard the Solar Maximum Mission (SMM). There appear to be surprisingly few observations of the short-time scale behavior of hot loops, and the evidence presented herein lends support to the hypothesis that coronal heating may be impulsive and driven by flaring.

  16. Solar Coronal Plumes

    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.

  17. Guerra y paz al sur del Sahara. Nuevos abordajes conceptuales, frente a un escenario cambiante

    Diego Buffa

    2014-05-01

    Full Text Available En este artículo nos proponemos presentar nuevas corrientes y abordajes conceptuales, que nos permitan comprender problemáticas capitales del África subsahariana, como lo son los conflictos intra-estatales, las emergencias políticas complejas, el intervencionismo humanitario y los procesos de paz, gestados durantela Posguerra Fría; portadores de inéditas lógicas y parámetros rectores.

  18. Guerra y paz al sur del Sahara. Nuevos abordajes conceptuales, frente a un escenario cambiante

    Diego Buffa

    2014-01-01

    Full Text Available En este artículo nos proponemos presentar nuevas corrientes y abordajes concep - tuales, que nos permitan comprender problemáticas capitales del África subsaha - riana, como lo son los conflictos intra-estatales, las emergencias políticas comple - jas, el intervencionismo humanitario y los procesos de paz, gestados durante la Posguerra Fría; portadores de inéditas lógicas y parámetros rectores.

  19. Coronal Mass Ejections An Introduction

    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...

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

    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 ...

  1. Qualidade de vida: abordagens, conceitos e avaliação Calidad de vida: abordajes, conceptos y evaluaciíon Quality of life: approaches, concepts and assessment

    Érico Felden Pereira

    2012-06-01

    Full Text Available Apesar da grande relevância social, o tema qualidade de vida apresenta imprecisões teórico/metodológicas o que dificulta a investigação, o diálogo entre as diferentes áreas que trabalham com o tema e, principalmente, a aplicação do conhecimento produzido na melhoria da qualidade de vida da população. Buscando contribuir para a clarificação do conceito este estudo teve como objetivo, a partir da leitura, discussão e análise da literatura especializada, apresentar as principais abordagens, conceitos e propostas de classificação e avaliação da qualidade de vida. Verificou-se que as abordagens e conceitualizações sobre a qualidade de vida se apresentam na literatura de forma diversificada, e, por vezes, divergentes. A falta de consenso teórico leva muitas pesquisas a utilizarem conceitos como saúde, bem estar e estilo de vida como sinônimos de qualidade de vida. Novas abordagens epistemológicas no estudo do tema são necessárias bem como estudos que analisem a qualidade de vida em situações de intervenção.A pesar de la gran relevancia social, el tema calidad de vida presenta imprecisiones teórico/metodológicas, rasgo que dificulta la investigación, el diálogo entre las diferentes áreas que trabajan con el tema, principalmente, en la aplicación del conocimiento producido para mejorar la calidad de vida de la población. En la búsqueda para contribuir para aclarar el concepto, este estudio tuvo como objetivo, a partir de la lectura, discusión y análisis de la literatura especializada, presentar los principales abordajes, conceptos y propuestas de clasificación y evaluación de la calidad de vida. Se observó que los abordajes y conceptos sobre la calidad de vida se presentan en la literatura de forma diversificada y, por veces, divergentes. La falta de consenso teórico lleva muchas pesquisas a utilizaren conceptos como salud, bienestar y estilo de vida como sinónimos para calidad de vida. Nuevos abordajes

  2. Effects of Coronal Mass Ejections on Distant Coronal Streamers

    Filippov, B; Srivastava, A K; Martsenyuk, O

    2014-01-01

    The effects of a large coronal mass ejection (CME) on a solar coronal streamer located roughly 90 degrees from the main direction of the CME propagation observed on January 2, 2012 by the SOHO/LASCO coronagraph are analyzed. Radial coronal streamers undergo some bending when CMEs pass through the corona, even at large angular distances from the streamers. The phenomenon resembles a bending wave traveling along the streamer. Some researchers interpret these phenomena as the effects of traveling shocks generated by rapid CMEs, while others suggest they are waves excited inside the streamers by external impacts. The analysis presented here did not find convincing arguments in favor of either of these interpretations. It is concluded that the streamer behavior results from the effect of the magnetic field of a moving magnetic rope associated with the coronal ejection. The motion of the large-scale magnetic rope away from the Sun changes the surrounding magnetic field lines in the corona, and these changes resembl...

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

    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. ...

  4. The dynamics of coronal magnetic structures

    An analysis is made of the evolution of coronal magnetic fields due to the interaction with the solar wind. An analysis of the formation of coronal streamers, arising as a result of the stretching of bipolar fields, is given. Numerical simulations of the formation of coronal streamers are presented. Fast-mode shocks as triggers of microturbulence in the solar corona are discussed

  5. Exploring Coronal Structures with SOHO

    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.

  6. An equatorial coronal hole at solar minimum

    Bromage, B. J. I.; DelZanna, G.; DeForest, C.; Thompson, B.; Clegg, J. R.

    1997-01-01

    The large transequatorial coronal hole that was observed in the solar corona at the end of August 1996 is presented. It consists of a north polar coronal hole called the 'elephant's trunk or tusk'. The observations of this coronal hole were carried out with the coronal diagnostic spectrometer onboard the Solar and Heliospheric Observatory (SOHO). The magnetic field associated with the equatorial coronal hole is strongly connected to that of the active region at its base, resulting in the two features rotating at almost the same rate.

  7. Aplicación de la teoria de formacion de ingroups y outgroups al estudio del clima organizacional : Caso personal universitario de la Facultad de Ciencias Económicas y Sociales de la Universidad Nacional de Mar del Plata

    Pujol Cols, Lucas Joan; Mussano, Florencia Paula

    2014-01-01

    El estudio del Clima Organizacional a menudo se ha focalizado desde abordajes cuantitativos, destinados a medir la percepción de los participantes frente a distintas variables que componen el constructo teórico. Si bien algunos de ellos han propuesto complementar el análisis mediante un abordaje cualitativo, el análisis de los datos obtenidos se ha limitado casi exclusivamente al contenido del discurso. Lo que aquí se propone es la aplicación de una óptica complementaria, integrando el anális...

  8. El abordaje de la dimensión social en el diseño industrial

    Caló, Julieta

    2012-01-01

    El presente trabajo propone dar cuenta de la importancia de la dimensión social en el campo del Diseño Industrial. El propósito es establecer qué factores sociales e intelectuales influyeron en el abordaje de la disciplina. El encuadre epistemológico del Diseño Industrial como disciplina proyectual, se establece en el cruce de tres dimensiones: i) Dimensión Social; ii) Dimensión Artístico-Proyectual; y la iii) Dimensión Tecnológica-Productiva. La dimensión social tomó protagonismo en la...

  9. Protocolo para el Abordaje Integral de la Violencia Sexual desde el Sector Salud

    Cuevas Garavito, Aura; Pinilla Moya, Fernando; Barrios Acosta, Miguel; Gómez Sánchez, Pio Iván; Vásquez Rojas, Rafael; Cárdenas Rivera, Miguel Eduardo; Pardo Sierra, Fideligno; Urrego Mendoza, Zulma Consuelo; Ángel Muller, Edith; Cuervo Maldonado, Sonia; Macana Tuta, Neidy; Espitia Cruz, Martha Isabel; Torres, Petty Janeth; Botia, Luis; Hernández Molina, Luz Mery

    2008-01-01

    La Secretaría Distrital de Salud, como institución responsable de ejecutar políticas de salud pública, está comprometida con la promoción del buen trato y la prevención y atención de la violencia sexual. Cumpliendo con sus funciones dentro del actual Sistema General de Seguridad Social en Salud, la Secretaría Distrital de Salud ha creado el presente documento, Protocolo para el abordaje integral de la violencia sexual desde el Sector Salud, para brindar herramientas a las instituciones públic...

  10. Reconstrucción del ligamento cruzado anterior por un abordaje trastendón rotuliano

    Alejandro Corral, I. F.; Cortés, J. María; Bureo, F. J.; Quiles, Manuel

    1998-01-01

    Describimos la técnica de la plastia del ligamento cruzado anterior (LCA) usando el hueso-tendón-hueso a través de un abordaje transtendón rotuliano. Esto facilita la condiloplastia, la visión de los puntos de inserción del ligamento cruzado anterior y la realización de intervenciones asociadas con meniscectomía o suturas meniscales. Los resultados clínicos son semejantes a los de otras técnicas a cielo abierto o por atroscopia.

  11. Abordaje de la artrosis desde la atención primaria

    Lafuente Navarro, Ana; Lafuente Navarro, Cándida

    2006-01-01

    La artrosis es una enfermedad crónica prevalente asociada a dolor, discapacidad y empeoramiento de la calidad de vida. Las herramientas de apoyo que utilizamos a menudo en atención primaria para el abordaje de esta patología son las guías de la práctica clínica. En estas guías hay recomendaciones basadas en la evidencia,que ayudan al profesional en su práctica habitual a tomar la decisión más adecuada para cada paciente. A su vez permiten actuar de una forma conjunta y sincronizada a los dife...

  12. Intrinsic Instability of Coronal Streamers

    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...

  13. Ponderomotive Acceleration in Coronal Loops

    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...

  14. PARATIROIDECTOMIA ENDOSCOPICA. ESTUDIO EXPERIMENTAL EN EL PERRO

    Jorge Ramón Lucena Olavarrieta

    2008-01-01

    Full Text Available La primera paratiroidectomía exitosa fue realizada en Viena, Austria, en 1925. Los procedimientos laparoscópicos estuvieron inicialmente limitadas a las zonas corporales con cavidades preexistentes, recientemente, el acceso a espacios anatómicos potenciales ha extendido las indicaciones de la cirugía endoscópica minimamnete invasiva.Desde el primer reporte sobre la paratiroidectomía endoscópica en 1996, las técnicas video-asistidas han comenzado a utilizarse en la cirugía del cuello, y en varias series se han documentado la factibilidad y seguridad de este tipo de abordaje. La finalidad de esta investigación fue el determinar la factibilidad, seguridad y eficacia de la paratiroidectomía endoscopia en el modelo canino.Entre el 25 de noviembre del 2005 y 15 de octubre del 2007, se intervinieron en el Instituto de Cirugía Experimental de la Universidad Central de Venezuela 31 perros, mestizos sanos desparasitados,asignándose a dos grupos: homogéneos "A" 16, a cirugía convencional, "B" 15 a cirugía video-asistida. Se midieron las siguientes variables; sexo, peso, exámenes de laboratorio, laringoscopia pre y postoperatoria, posición, dirección de la incisión, longitud, localización, valores pre y postoperatorios de calcio, fósforo, proteína C reactiva, hemoglobina, hematocrito, tipo de disección, número y posición de las paratiroides, identificación de los nervios recurrentes y rama externa del nervio laríngeo superior, sangramiento, dificultades intraoperatorias, tiempo, resultado del estudio histopatológico.Las deducciones de este estudio experimental proporcionan evidencias de que la paratiroidectomía endoscópica es factible y segura. El abordaje mínimo tiene mejores resultados cosméticos y el potencial de disminuir la morbi-mortalidad.

  15. Abordaje areolar en mamoplastia de aumento Areolar approach in augmentation mammaplasty

    P Castillo Delgado

    2007-06-01

    Full Text Available La mamoplastia de aumento se ha consolidado como una cirugía segura, de rápida recuperación y con resultados predecibles e inmediatos. Las expectativas de las pacientes son cada vez mayores, exigiendo resultados naturales y sin estigmas quirúrgicos. Todas las vías de abordaje clásicas, para la colocación de implantes mamarios, dejan cicatrices visibles. En mujeres con areolas de diámetro grande, es posible emplear un abordaje dentro de la areola, que deja una cicatriz oculta en su unión con el pezón. Se describe la técnica y posteriormente se discuten sus indicaciones, ventajas y desventajas.Augmentation mammoplasty has gained acceptance as a safe surgical procedure with fast recovery and a readily predictable outcome. Increasing patient expectations impose demands on natural appearance without signs of surgery. All standard incision areas for insertion of implant leave visible scars. For women with large areolar diameter, it is possible to leave a hidden scar at the aerola-nipple junction by conducting an intra- areolar approach. The technique is described and its intended application and advantages and disadvantages are discussed.

  16. Abordaje médico forense de los cuerpos mutilados criminalmente

    José Vicente Pachar Lucio

    2015-12-01

    Full Text Available La mutilación post-mórtem de un cadáver es una forma criminal de separación de las partes corporales que responde a diversas motivaciones. El abordaje adecuado, desde el lugar del hallazgo hasta el examen en la morgue, es fundamental para la recolección de los indicios que permitan la reconstrucción del hecho investigado. Los métodos e instrumentos utilizados para la mutilación han sido descritos por investigadores de distintos países; sin embargo, las motivaciones mencionadas en la literatura sobre la mutilación deben ser ampliadas ante la complejidad de los casos encontrados en la región (Centroamérica y México. Se realiza una revisión descriptiva de lo publicado sobre el tema, con el propósito de actualizar conceptos útiles en la práctica médico forense, elementos que deben estar disponibles para el abordaje e interpretación de los hallazgos. Además se presenta un modelo de protocolo de actuación médico forense, específico para estos casos.

  17. Low-latitude coronal holes, decaying active regions and global coronal magnetic structure

    Petrie, Gordon

    2013-01-01

    We study the relationship between decaying active region magnetic fields, coronal holes and the global coronal magnetic structure using Global Oscillations Network Group (GONG) synoptic magnetograms, Solar Terrestrial RElations Observatory (STEREO) extreme ultra-violet (EUV) synoptic maps and coronal potential-field source-surface (PFSS) models. We analyze 14 decaying regions and associated coronal holes occurring between early 2007 and late 2010, four from cycle 23 and 10 from cycle 24. We investigate the relationship between asymmetries in active regions' positive and negative magnetic intensities, asymmetric magnetic decay rates, flux imbalances, global field structure and coronal hole formation. Whereas new emerging active regions caused changes in the large-scale coronal field, the coronal fields of the 14 decaying active regions only opened under the condition that the global coronal structure remained almost unchanged. This was because the dominant slowly-varying, low-order multipoles prevented opposin...

  18. EUV Coronal Dimming and its Relationship to Coronal Mass Ejections

    Mason, James

    2016-05-01

    As a coronal mass ejection (CME) departs from the inner solar atmosphere, it leaves behind a void. This region of depleted plasma results in a corresponding decrease in coronal emissions that can be observed by instruments tuned to measure the extreme ultraviolet (EUV) part of the electromagnetic spectrum. These coronal dimmings can be observed with EUV imagers and EUV spectral irradiance instruments. Onboard the Solar Dynamics Observatory (SDO), the EUV Variability Experiment (EVE) and Atmospheric Imaging Assembly (AIA) provide complementary observations; together they can be used to obtain high spatial and spectral resolution. AIA provides information about the location, extent, and spatial evolution of the dimming while EVE data are important to understand plasma temperature evolution. Concurrent processes with similar timescales to mass-loss dimming also impact the observations, which makes a deconvolution method necessary for the irradiance time series in order to have a “clean” mass-loss dimming light curve that can be parameterized and compared with CME kinematics. This presentation will first provide background on these various physical processes and the deconvolution method developed. Two case studies will then be presented, followed by a semi-statistical study (~30 events) to establish a correlation between dimming and CME parameters. In particular, the slope of the deconvolved irradiance dimming light curve is representative of the CME speed, and the irradiance dimming depth can serve as a proxy for CME mass. Finally, plans and early results from a more complete statistical study of all dimmings in the SDO era, based on an automated detection routine using EVE data, will be described and compared with independently derived dimmings automatically detected with AIA data.

  19. Incompletitud corporal en la persona posamputada portadora de dolor de miembro fantasma: estudio cualitativo

    Ma. Cristina Ochoa Estrada; Sebastián Bustamante Edquen; Carlos Hernández Peraza

    2015-01-01

    Introducción: En el cuerpo se vivencía el mundo, la alegría, el encuentro, la seguridad, el dolor las reacciones anatomofisiológicas inherentemente al cuerpo; se experimenta la afección por el dolor físico y psíquico, con sensaciones corporales de ansiedad, temor y angustia. Materiales y Métodos: Estudio de abordaje cualitativo-descriptivo, exploratorio; como técnica se empleó la entrevista semiestructurada, de los informantes seleccionados se trataba de personas que fueron atendidas en el Ho...

  20. Anomalous transmission of a coronal "EIT wave" through a nearby coronal hole

    Long, David; Perez-Suarez, David; Valori, Gherardo

    2016-05-01

    Observations of reflection at coronal hole boundaries and transmission through the coronal hole suggest that "EIT waves" may be interpreted as freely--propagating wave--pulses initially driven by the rapid expansion of a coronal mass ejection (CME) in the low corona. An "EIT wave" observed on 2012 July 07 is seen to impact an adjacent coronal hole. However, rather than reappearing at the far edge of the coronal hole as with previous observations, the "EIT wave" was subsequently observed to reappear ~360 Mm away in the quiet Sun. The non-typical evolution of the "EIT wave" is examined using a combination of observations of the eruption from SDO/AIA and STEREO-A/EUVI as well as extrapolations of the global magnetic field. The observed "jump" in position of the "EIT wave" is shown to be due to the wave pulse traveling along hot coronal loops connecting the edge of the coronal hole with the quiet Sun.

  1. Estudio seguridad bobinadora IHT

    Odériz Santos, Carlos

    2011-01-01

    Este proyecto fin de carrera tiene como objetivo el estudio de seguridad y salud de una bobinadora de la empresa ValcoMelton. Con dicho estudio nos aseguraremos que la citada máquina cumpla el marcado CE.

  2. Blind Stereoscopy of the Coronal Magnetic Field

    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...

  3. EIT waves and coronal magnetic field diagnostics

    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.

  4. The Inconvenient Truth About Coronal Dimmings

    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?

  5. Diversidad juvenil en el contexto educativo: reflexiones para un abordaje intercultural

    Morales-Trejos, Carol Graciela

    2015-01-01

    Full Text Available Este ensayo enmarca la relevancia teórico-práctica de la educación intercultural, como herramienta para generar nuevas lecturas de la complejidad educativa, donde la diversidad sea comprendida como una oportunidad de aprendizaje y de riqueza, promoviendo el desarrollo de contextos educativos más heterogéneos y equitativos. Se aborda el tema de la diversidad juvenil en este contexto desde la perspectiva intercultural. Finalmente se realiza una propuesta de abordaje de esta temática desde los aportes de este enfoque educativo, reconociendo la multiplicidad de factores que configuran los mundos juveniles, las nuevas formas de interacción y la construcción de identidades individuales y colectivas.

  6. Tiroides lingual: un nuevo abordaje quirúrgico Lingual thyroid: a new surgical approach

    I. Zubillaga Rodríguez

    2004-10-01

    Full Text Available El tiroides lingual es una rara anomalía congénita del desarrollo tiroideo resultante de la ausencia de descenso del mismo desde el foramen caecum hasta la localización prelaríngea habitual. Presentamos el caso de una paciente en edad postmenopáusica con diagnóstico anatomopatológico de tiroides lingual de gran tamaño y localización profunda en la base de la lengua que producía disfagia y dificultad respiratoria crecientes. Asimismo, planteamos un nuevo abordaje quirúrgico para la resección combinando cervicotomía media, pull-through lingual y glosotomía media. Se discuten las distintas pruebas complementarias para llegar a su diagnóstico y se revisan las diferentes técnicas quirúrgicas habitualmente empleadas en su tratamiento concluyendo con las ventajas del abordaje empleado en este caso.Lingual thyroid is an uncommon congenital disorder of thyroid gland development, resulting in a lack of descend of the gland from the foramen caecum to his normal prelaringeal location. In this paper we present a case of a postmenopausic patient presenting with a big size lingual thyroid deeply located in the base of the tongue, suffering increasing disphagia and respiratory impairment. For tumor resection, we chose a surgical approach combining a cervical submental incision, lingual pull- through and midline glossotomy. We discuss the different image studies recommended for proper diagnosis also reviewing the most common surgical techniques used for treatment, as compared with the approach we have described in this case.

  7. Reflexiones metodológicas sobre algunas contribuciones de la terapia familiar sistémica a un estudio antropológico de la familia

    Maffia, Marta Mercedes

    2013-01-01

    El fenómeno migratorio ha sido tratado a partir de diferentes estudios históricos, sociológicos, demográficos y antropológicos. Muchas veces estos abordajes solo ofrecen respuestas parciales a las problemáticas que conforman la migración. Nuestras investigaciones se centraron en el estudio de grupos de inmigrantes caboverdeanos en Argentina, aportando modelos sobre la organización e interacción de esos grupos, con el fin de explorar temas críticos, como inmigración y familia, identidad y etni...

  8. Observational features of equatorial coronal hole jets

    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.

  9. Recent advances in coronal heating

    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.

  10. Coronal Diagnostics from Cometary Emission

    Bryans, Paul; Pesnell, William D; Seaton, Daniel B; West, Matthew J

    2014-06-01

    The extreme ultraviolet (EUV) emission observed from sungrazing comets as they pass through the solar atmosphere can be used to infer the properties of the corona. In this paper we will discuss several of these properties that can be estimated from the EUV observations of Comet Lovejoy from AIA/SDO and SWAP/PROBA2. The longevity of the emission allows us to constrain the coronal electron density through which the comet passes. We will also discuss how dispersion of the emitting cometary material we can be used to estimate the local Alfven speed in the corona. Finally, measuring the deformation of the magnetic field as it is impacted by the comet can be used to estimate the magnetic field strength in this location. In the absence of the comet, none of these parameters are directly measurable in the corona. Sungrazing comets are thus unique probes of the solar atmosphere.

  11. Space weather and coronal mass ejections

    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

  12. Tipología de propuestas de abordaje de contenidos de Lengua y Literatura con inclusión de TIC

    Alejo Ezequiel González López Ledesma

    2014-10-01

    Full Text Available En un estudio previo (Álvarez y González, en prensa, recurrimos a los principios básicos de la teoría fundamentada para analizar las modalidades de inclusión de las tecnologías de la información y la comunicación (TIC en propuestas didácticas de abordaje de contenidos de Lengua y Literatura. Caracterizamos las propuestas analizadas en función de diferentes categorías: contenido disciplinar, destinatarios, propuesta de trabajo, enfoque disciplinar del contenido, recursos tecnológicos y tipos de inclusión tecnológica. En el trabajo que presentamos ahora, partimos de esa categorización con el objeto de verificarla, ampliarla y ajustarla a partir de un corpus de propuestas más amplio. Para ello, hemos optado por articular las dimensiones didáctica, tecnológica y disciplinar. De esta manera, establecimos una tipología –por el momento provisoria– que da cuenta de las diferentes modalidades de inclusión de las TIC en propuestas que abordan contenidos propios del área de Lengua y Literatura: inclusión de tecnología como soporte del desarrollo de contenidos y actividades; inclusión de tecnología para ejemplificar su uso a partir de un contenido; e inclusión de tecnología para crear e innovar.

  13. GANGLIO CENTINELA EN MELANOMA DE CARA: ABORDAJE INICIAL Sentinel ganglion in melanoma of the face: an initial approach

    Enrique Cadena-Piñeros

    2012-09-01

    Full Text Available A pesar de las campañas preventivas no se ha logrado disminuir la incidencia de las neoplasias cutáneas, probablemente por las alteraciones de la capa de ozono, con el consecuente aumento de la radiación ultravioleta, por eso en países del trópico se presentan lesiones como el melanoma de piel, que es considerado como una de las lesiones tumorales más agresivas. La cara y el cuello son zonas del cuerpo con una alta exposición solar, reflejándose en un mayor número de casos de este sombrío tumor. El mayor factor pronóstico en contra de los pacientes que padecen esta enfermedad es la presencia de metástasis ganglionares, por eso el grupo tratante debe esclarecer si están presentes, debido a esto hace varias décadas se realizan disecciones de cuello profilácticas, pero en la mayoría de los casos los ganglios extirpados son negativos. Una posible solución para evitar esto, es la extracción del o de los primeros ganglios que drenan el sitio del tumor primario (Ganglio Centinela. En el área de cabeza y cuello usualmente están presentes varios a la vez, lo que dificulta tomar la decisión de cuál extirpar. En nuestro grupo hemos iniciado la estandarización de esta técnica, y como abordaje inicial se realizó el primer caso de una paciente con melanoma de la cara a quien se practicó resección local amplia del tumor y extracción de los centinelas marcados por linfogammagrafía y a la vez disección de los relevos ganglionares positivos para drenaje demostrados por este estudio de medicina nuclear.In spite of preventative campaigns having been mounted, it still has not been possible to reduce cutaneous neoplasia incidence, probably due to alterations in the ozone layer. This has led to a consequent increase in ultraviolet radiation and thus lesions occurring in tropical countries such as skin cancer (melanoma, considered as being one of the most aggressive tumour lesions. The face and neck are the body areas having the highest

  14. Apuntes antropológicos para el estudio del control social

    Pablo Quintero

    2005-01-01

    Full Text Available La cuestión del “control social” ha sido abordada ampliamente por las ciencias sociales desde principios del siglo XX; comúnmente estos abordajes se han realizado desde una perspectiva sociológica que trata esta cuestión sólo a lo interno de una sociedad determinada. Partiendo del concepto de sociabilidad este articulo pretende generar una aproximación teórica al estudio del “control social” desde una perspectiva antropológica que dé cuenta de la amplia gama de posibilidades que genera su estudio, no sólo a lo interno de una sociedad o grupo social, sino al modo global del sistema mundial moderno a la luz del dominio hegemónico de la modernidad.

  15. Microwave Enhancement in Coronal Holes: Statistical Properties

    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.

  16. MHD Waves in the coronal holes

    Banerjee, D

    2015-01-01

    Coronal holes are the dark patches in the solar corona associated with relatively cool, less dense plasma and unipolar fields. The fast component of the solar wind emanates from these regions. Several observations reveal the presence of magnetohydrodynamic (MHD) waves in coronal holes which are believed to play a key role in the acceleration of fast solar wind. The recent advent of high-resolution instruments had brought us many new insights on the properties of MHD waves in coronal holes which are reviewed in this article. The advances made in the identification of compressive slow MHD waves in both polar and equatorial coronal holes, their possible connection with the recently discovered high- speed quasi-periodic upflows, their dissipation, and the detection of damping in Alfven waves from the spectral line width variation are discussed in particular.

  17. Multidimensional modeling of coronal rain dynamics

    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...

  18. Observational features of equatorial coronal hole jets

    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...

  19. MULTIDIMENSIONAL MODELING OF CORONAL RAIN DYNAMICS

    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.

  20. MULTIDIMENSIONAL MODELING OF CORONAL RAIN DYNAMICS

    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.

  1. Los Estudios Culturales, la Historiografía y los sectores subalternos Cultural studies, Historiography and the subaltern sectors

    María Mercedes Tenti

    2012-01-01

    El propósito de este trabajo es indagar la relación entre los Estudios Culturales y la Historiografía, en particular los modos en que esta última aborda la problemática de los sectores subalternos. Una amplia franja de actores sociales no se visibilizan en la mayoría de los trabajos historiográficos, contribuyendo a ratificar imágenes preconcebidas por posturas tradicionales. Corrientes emergentes en las últimas décadas ponen énfasis en estas nuevas formas de abordaje. El planteo de una 'nuev...

  2. The Global Coronal Structure Investigation

    Golub, Leon

    1998-02-01

    During the past year we have completed the changeover from the NIXT program to the new TXI sounding rocket program. The NIXT effort, aimed at evaluating the viability of the remaining portions of the NIXT hardware and design, has been finished and the portions of the NIXT which are viable and flightworthy, such as filters, mirror mounting hardware, electronics and telemetry interface systems, are now part of the new rocket payload. The backup NIXT multilayer-coated x-ray telescope and its mounting hardware have been completely fabricated and are being stored for possible future use in the TXI rocket. The H-alpha camera design is being utilized in the TXI program for real-time pointing verification and control via telemetry. A new H-alpha camera has been built, with a high-resolution RS170 CCD camera output. Two papers, summarizing scientific results from the NIXT rocket program, have been written and published this year: 1. "The Solar X-ray Corona," by L. Golub, Astrophysics and Space Science, 237, 33 (1996). 2. "Difficulties in Observing Coronal Structure," Keynote Paper, Proceedings STEPWG1 Workshop on Measurements and Analyses of the Solar 3D Magnetic Field, Solar Physics, 174, 99 (1997).

  3. Crecer en movimiento. Abordaje etnográfico del desarrollo infantil en comunidades Mbya (Argentina

    Carolina Remorini

    2010-10-01

    Full Text Available Me propongo analizar y discutir algunos resultados de una investigación etnográfica desarrollada en comunidades Mbya Guaraníes (Misiones, Argentina acerca de las representaciones y prácticas relacionadas con la crianza y el desarrollo infantil.En este trabajo caracterizo las categorías, representaciones y valores Mbya, en torno a los procesos de crecimiento y desarrollo, focalizando la mirada en el “movimiento” —en tanto indicador de “crecimiento” y salud—, en las prácticas cotidianas de crianza que lo promueven, y en las creencias y saberes que las justifican. A partir de ello, planteo la estrecha relación entre movimiento, salud e identidad.Discuto los resultados a la luz de conceptos y enfoques de la antropología, sociología y psicología, a fin de avanzar hacia la integración de diferentes aportes disciplinares en el abordaje del impacto del movimiento y otros modos de educación del cuerpo en el desarrollo infantil y sus variaciones según diversos contextos eco-culturales e históricos.

  4. Abordaje integral comunitario de los consumos problemáticos de drogas: construyendo un modelo

    Ana Clara Camarotti

    2015-01-01

    Full Text Available Se presentan los lineamientos del modelo integral comunitario del abordaje del consumo problemático de drogas. Estos comprenden las dimensiones de integralidad, vulnerabilidad y cuidados en sentido amplio. La caracterización de estas dimensiones lleva a lo que las autoras denominan modelo integral comunitario, en oposición al denominado modelo moralista normativo. Las diferencias entre ambos modelos se centran en las concepciones de salud, los objetivos de las actividades propuestas, las concepciones sobre los sujetos y los marcos operativos en los que se basan cada uno de ellos. Se proponen también los pasos que deberían seguirse en la aplicación del modelo comunitario, cuyo objetivo último es lograr un sistema de respuestas comunitarias para debilitar al sistema que genera el consumo problemático de drogas. Dichos pasos comprenden la identificación del problema por parte de la comunidad, la reunión de datos y experiencias previas, la organización comunitaria incluyendo la capacitación de sus agentes, el fortalecimiento y la articulación de los recursos existentes en la comunidad y el diseño consensuado de respuestas al problema.

  5. Estudio de cohortes comparando los resultados obtenidos tras la estadificación y el tratamiento quirúrgico por laparotomía frente al realizado por laparoscopia en el cáncer primario de endometrio estadio I clínico

    Gil Moreno, Antonio

    2004-01-01

    El cáncer de endometrio es actualmente la neoplasia más frecuente del tracto genital inferior en los países desarrollados. La estadificación es quirúrgico-patológica y se basa en el estudio de la pieza operatoria. El tratamiento estándar se realiza mediante laparotomía, si bien hay estudios que sugieren puede ser llevado a cabo mediante abordaje laparoscópico-vaginal, con igual radicalidad oncológica y sin mayor número de complicaciones. El propósito de este estudio fue describir la factibili...

  6. Estrategia probesci: un abordaje terapéutico de menor coste para el paciente obeso Probesci strategy: a cheaper therapeutic approach for obese patients

    C. Vázquez

    2006-12-01

    Full Text Available Desde la experiencia clínica todas las evidencias hacen suponer que la obesidad, epidemia que amenaza la Salud Pública de los países más ricos de la Tierra, se presenta como un síndrome que abarca distintas enfermedades, todas ellas con un rasgo común, el exceso de grasa corporal, pero con respuestas clínicas claramente diferenciadas ante la misma estrategia terapéutica. Si las respuestas son tan heterogéneas es que la etiopatogenia también lo es, por lo que un estudio fenotípico exhaustivo ayudaría a establecer grupos clínicos que presumiblemente tendrían una respuesta más homogénea ante el mismo tratamiento. En este caso el abordaje y manejo terapéutico de los distintos grupos clínicos permitiría diversificar el tratamiento y posiblemente, mejorar su efectividad. El gran inconveniente para llevar a la práctica un estudio fenotípico exhaustivo es el elevado coste, por el consumo de tiempos recursos humanos que exige, lo que es con frecuencia inviable. En este estudio se describe la "estrategia PROBESCI" como un sistema organizativo de estudio y recogida de datos que sistematiza, estandariza y caracteriza la información constituyendo la base para la consiguiente clasificación y establecimiento de perfiles fenotípicos dentro de la obesidad. Es una nueva modalidad de consulta inicial en grupo, de valoración del paciente obeso, que ha demostrado su viabilidad. Se estudian los costes de esta nueva modalidad, comparándolos con los de la consulta clásica y se demuestra que supone un gran ahorro, ya que disminuye un 58% los costes de la consulta inicial y un 21% los costes totales del tratamiento.Obesity has become epidemic in Western countries. From clinical practice, obestity may be considered as a disease characterized by an excess of body fat mass, but patients usually demonstrate different responses to the same therapeutic strategy. It could be possible that the latter may be a consecuence of different pathophysiological

  7. The redshifted footpoints of coronal loops

    I. E. Dammasch

    2008-10-01

    Full Text Available The physics of coronal loops holds the key to understanding coronal heating and the flow of mass and energy in the region. However, the energy source, structure maintenance and mass balance in coronal loops are not yet fully understood. Observations of blue- and redshifted emissions have repeatedly been used in the construction of loop models. But observations and interpretations of line shifts have been widely debated. Here we present detailed SUMER observations, which clearly show a steady downflow in both footpoints of coronal loops observed at transition region (TR and lower corona temperatures. We also show and quantify a correlation existing between this Doppler shift and the spectral radiance. Our results indicate a strong correlation which holds from the chromosphere to the lower corona. We suggest that the downflow in the footpoints may be a common phenomenon on all scales, which could explain, why on a statistical basis bright pixels tend to be more redshifted. We conclude by presenting interpretation of such results and their implications in the light of a viable coronal loop model. The observation of steady downflow in redshifted footpoints seems to be in conflict with impulsive heating.

  8. Los grupos de interés en la política exterior norteamericana : Estudio de caso: las estrategias y gestiones de lobby de la American Task Force Argentina (2006-2008)

    Fernández Alonso, José

    2008-01-01

    Destacado desarrollo ha tenido el abordaje de la incidencia gubernamental de los grupos de interés en el contexto de Estados Unidos, donde las acciones de lobby reportan histórica institucionalización y acabada regulación. Con un estudio de caso referido al accionar de un grupo de interés harto relevante para la reinserción financiera de Argentina post-default, el trabajo se constituye como un aporte a tal trayectoria de investigación. Es propósito del estudio indagar acerca de las estrategia...

  9. Tendencias del régimen de precipitación y el manejo sustentable de los agroecosistemas: estudio de un caso en el noroeste de la provincia de Buenos Aires, Argentina.

    Silvia P. Pérez; Eduardo M. Sierra

    2006-01-01

    Durante las últimas décadas se ha tomado una creciente conciencia de la importancia del cambio climático sobre el manejo sustentable de los agroecosistemas. El abordaje de esta problemática requiere un enfoque interdisciplinario que puede hacerse a través de la metodología de estudio del caso. Un caso de estudio de notable interés se presenta en el noroeste de la Provincia de Buenos Aires, Argentina, donde el aumento en las precipitaciones permitió un incremento de la superficie dedicada a l...

  10. Abordaje del niño con hipercalcemia: reporte de 3 casos

    Nancy Chavarría-Arana

    2013-09-01

    Full Text Available La hipercalcemia en niños es un trastorno electrolítico raro. Su presentación clínica es variable, al igual que su etiología. En esta publicación se abordan los casos de tres niños con hipercalcemia. Primeramente, un neonato de 24 días con irritabilidad, pobre succión y nefrocalcinosis. El segundo caso es de un niño de 1 año de edad con estenosis pulmonar, falla para progresar, retraso en el desarrollo psicomotor, fascies de duende y nefrocalcinosis. Por último, se presenta una niña de 11 años, con cuadro de dolor abdominal, polidipsia, náuseas, vómitos, lesiones líticas en huesos largos y anemia. Las causas determinadas para cada caso fueron, respectivamente: acidosis tubular distal, síndrome de Williams y leucemia linfocítica aguda. Para el abordaje del niño con hipercalcemia se muestran dos esquemas de diagnóstico realizados con fundamento en los hallazgos clínicos, laboratorio y gabinete. Laterapeúticaenestosniñosdebebasarseenelaumentode la excreción renal de calcio (hidratación, diuréticos, reducción de la absorción a nivel intestinal (restricción nutricional de calcio y vitamina D, glucocorticoides, inhibición de la resorción ósea (bifosfonatos, glucocorticoides, redistribución del calcio y, sobre todo, la prontitud con la que se instaure una terapia eficaz, ya que esta tendrá un impacto a largo plazo sobre su salud y calidad de vida.

  11. Propuesta de protocolo de abordaje de mujeres víctimas de delitos sexuales que son atendidas en la sección clínica médico forense y en las unidades médico legales del departamento de medicina legal del Organismo de Investigación Judicial Poder Judicial - Costa Rica

    Micxy Trejos Romanini

    2014-12-01

    Full Text Available Los delitos sexuales constituyen uno de los motivos de consulta más comunes en la Sección Clínica Médico Forense y en las Unidades Médico Legales del Departamento de Medicina Legal del Organismo de Investigación Judicial del Poder Judicial de Costa Rica y a la fecha no se cuenta con un protocolo formal de abordaje para la valoración de éstos. La elaboración de un protocolo forense de abordaje de víctimas de delitos sexuales en sí mismo tiene algunos beneficios nada despreciables entre ellos: fomentar la minimización de errores en el proceso de recolección de datos y evidencia, recolectar adecuadamente la información permitiendo la realización de estudios prospectivos, promoviendo con todo lo anteriormente señalado la elaboración de un Dictamen Médico Legal de calidad.

  12. Free Magnetic Energy and Coronal Heating

    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

  13. SUMER Observations of Coronal-Hole Temperatures

    Wilhelm, Klaus

    2012-11-01

    Observations of emission lines in the vacuum-ultraviolet spectral range with calibrated instrumentation provide crucial information on the prevailing plasma temperatures in the solar atmosphere. Coronal-hole temperatures measured by the SUMER spectrometer on SOHO will be presented in this contribution. Electron temperatures can be estimated from the formation temperatures of the observed emission lines. Line-ratio and emission-measure analyses, however, offer higher accuracies. Typical electron temperatures at altitudes of H<200 Mm in coronal holes are below 1 MK in bright structures—the coronal plumes—with higher values in darker areas—the inter-plume regions. Line-width measurements yield effective ion temperatures, which are much higher than the electron temperatures. Observations of line profiles emitted from species with different masses allow a separation of the effective temperatures into ion temperatures and unresolved non-thermal motions along the line of sight.

  14. The structure and evolution of coronal holes

    Timothy, A. F.; Krieger, A. S.; Vaiana, G. S.

    1975-01-01

    Soft X-ray observations of coronal holes are analyzed to determine the structure, temporal evolution, and rotational properties of those features as well as possible mechanisms which may account for their almost rigid rotational characteristics. It is shown that coronal holes are open features with a divergent magnetic-field configuration resulting from a particular large-scale magnetic-field topology. They are apparently formed when the successive emergence and dispersion of active-region fields produce a swath of unipolar field founded by fields of opposite polarity, and they die when large-scale field patterns emerge which significantly distort the original field configuration. Two types of holes are described (compact and elongated), and three possible rotation mechanisms are considered: a rigidly rotating subphotospheric phenomenon, a linking of high and low latitudes by closed field lines, and an interaction between moving coronal material and open field lines.

  15. Sunquake Generation by Coronal Magnetic Restructuring

    Russell, Alexander J B; Leake, James E; Hudson, Hugh S

    2016-01-01

    Sunquakes are the surface signatures of acoustic waves in the Sun's interior that are produced by some but not all flares and coronal mass ejections (CMEs). This letter explores a mechanism for sunquake generation by the magnetic field changes that occur during flares and CMEs, using MHD simulations with a semiempirical FAL-C atmosphere to demonstrate the generation of acoustic waves in the interior in response to changing magnetic tilt in the corona. We find that Alfv\\'en-sound resonance combined with the ponderomotive force produces acoustic waves in the interior with sufficient energy to match sunquake observations when the magnetic field angle changes by the order of 10 degrees in a region where the coronal field strength is a few hundred gauss or more. The most energetic sunquakes are produced when the coronal field is strong, while the variation of magnetic field strength with height and the timescale of the tilt change are of secondary importance.

  16. Simulating coronal condensation dynamics in 3D

    Moschou, S P; Xia, C; Fang, X

    2015-01-01

    We present numerical simulations in 3D settings where coronal rain phenomena take place in a magnetic configuration of a quadrupolar arcade system. Our simulation is a magnetohydrodynamic simulation including anisotropic thermal conduction, optically thin radiative losses, and parametrised heating as main thermodynamical features to construct a realistic arcade configuration from chromospheric to coronal heights. The plasma evaporation from chromospheric and transition region heights eventually causes localised runaway condensation events and we witness the formation of plasma blobs due to thermal instability, that evolve dynamically in the heated arcade part and move gradually downwards due to interchange type dynamics. Unlike earlier 2.5D simulations, in this case there is no large scale prominence formation observed, but a continuous coronal rain develops which shows clear indications of Rayleigh-Taylor or interchange instability, that causes the denser plasma located above the transition region to fall do...

  17. Interchange Reconnection and Coronal Hole Dynamics

    Edmondson, J. K.; Antiochos, S. K.; DeVore, C. R.; Lynch, B. J.; Zurbuchen, T. H.

    2011-01-01

    We investigate the effect of magnetic reconnection between open and closed field, (often referred to as "interchange" reconnection), on the dynamics and topology of coronal hole boundaries. The most important and most prevalent 3D topology of the interchange process is that of a small-scale bipolar magnetic field interacting with a large-scale background field. We determine the evolution of such a magnetic topology by numerical solution of the fully 3D MHD equations in spherical coordinates. First, we calculate the evolution of a small-scale bipole that initially is completely inside an open field region and then is driven across a coronal hole boundary by photospheric motions. Next the reverse situation is calculated in which the bipole is initially inside the closed region and driven toward the coronal hole boundary. In both cases we find that the stress imparted by the photospheric motions results in deformation of the separatrix surface between the closed field of the bipole and the background field, leading to rapid current sheet formation and to efficient reconnection. When the bipole is inside the open field region, the reconnection is of the interchange type in that it exchanges open and closed field. We examine, in detail, the topology of the field as the bipole moves across the coronal hole boundary, and find that the field remains well-connected throughout this process. Our results imply that open flux cannot penetrate deeply into the closed field region below a helmet streamer and, hence, support the quasi-steady models in which open and closed flux remain topologically distinct. Our results also support the uniqueness hypothesis for open field regions as postulated by Antiochos et al. We discuss the implications of this work for coronal observations. Subject Headings: Sun: corona Sun: magnetic fields Sun: reconnection Sun: coronal hole

  18. Coronal Fractures of the Scaphoid: A Review.

    Slutsky, David J; Herzberg, Guillaume; Shin, Alexander Y; Buijze, Geert A; Ring, David C; Mudgal, Chaitanya S; Leung, Yuen-Fai; Dumontier, Christian

    2016-08-01

    Coronal (or frontal plane) fractures of the scaphoid are distinctly uncommon. There are few published reports of coronal fractures of the scaphoid. This fracture is often missed on the initial X-ray films. A high index of suspicion should exist when there is a double contour of the proximal scaphoid pole on the anteroposterior X-ray view. A computed tomography scan is integral in making the diagnosis. Early recognition is key in salvaging the scaphoid fracture and in preventing articular damage. Level of Evidence IV. Retrospective case series. PMID:27574573

  19. Magnetohydrodynamic Simulation of a Streamer Beside a Realistic Coronal Hole

    Suess, S. T.; Wu, S. T.; Wang, A. H.; Poletto, G.

    1994-01-01

    Existing models of coronal streamers establish their credibility and act as the initial state for transients. The models have produced satisfactory streamer simulations, but unsatisfactory coronal hole simulations. This is a consequence of the character of the models and the boundary conditions. The models all have higher densities in the magnetically open regions than occur in coronal holes (Noci, et al., 1993).

  20. Estudio del horizonte local

    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).

  1. Factores emocionales en el abordaje de las enfermedades cardiovasculares. Valoración actualizada desde la Psicocardiología

    2012-01-01

    El tratamiento de las enfermedades cardiovasculares exige un abordaje desde la multidisciplinariedad, por la presencia de diversos factores en su origen y evolución. La Psicocardiología se encarga de estudiar los factores de orden psicológico vinculados a estas enfermedades. En el presente trabajo se abordan los factores emocionales que repercuten en diferentes padecimientos coronarios, así como el vínculo de estos, con los diferentes tipos de personalidad. Se exponen resultados obtenidos so...

  2. Cavernomas de la región temporal mesial: Anatomía microquirúrgica y abordajes

    Alvaro Campero

    2015-01-01

    Objetivo: Describir la anatomía microquirúrgica y los abordajes a la región temporal mesial (RTM), en relación a cavernomas de dicho sector. Materiales y Método: Cinco cabezas de cadáveres adultos, fijadas en formol e inyectadas con silicona coloreada, fueron estudiadas. Además, desde enero de 2007 a junio de 2014, 7 pacientes con cavernomas localizados en la RTM fueron operados por el autor. Resultados: Anatomia: La RTM fue dividida en 3 sectores: Anterior, medio y posterior. Pacientes: 7 en...

  3. ANÁLISIS DE FACTORES PROTECTORES EN EL ABORDAJE DEL MALTRATO INFANTIL DESDE LA MIRADA CLÍNICA

    Gabriela Morelato; Silvina Giménez; José María Vitaliti; Leandro Casari; Georgina Soria

    2015-01-01

    El objetivo de este trabajo fue explorar desde una mirada clínica la presencia de los factoresprotectores necesarios para otorgar el alta en un proceso terapéutico de casos de maltrato in-fantil confirmados, según la opinión de los profesionales especialistas en su abordaje. Desdela perspectiva cualitativa, se utilizó una muestra no probabilística ocasional constituida por 51médicos, psicólogos, trabajadores sociales y otras disciplinas afines, especialistas en el abordajede casos de maltrato...

  4. Detección, derivación y abordaje de las necesidades educativas especiales en infantil: caso real

    Aranda-Mora, Edurne

    2015-01-01

    El trabajo ha partido de la necesidad de estudiar e investigar un campo muy relevante dentro de la educación infantil: la detección, derivación y abordaje de las necesidades educativas especiales. Los objetivos marcados se han centrado en conocer todo el proceso que se da desde que se detecta un niño con necesidades en el ciclo de infantil y el cómo se detecta, siguiendo con el protocolo de actuación a seguir, los profesionales implicados en todo el proceso, los documentos donde queda regi...

  5. Abordaje supracerebeloso transtentorial suprameatal a la totalidad de la región mediobasal del lóbulo temporal

    Quilis Quesada, Vicent

    2015-01-01

    La región mediobasal del lóbulo temporal (RMT), por su compleja anatomía y su localización, constituye a día de hoy un reto neuroquirúrgico de primer orden. El desarrollo de la cirugía microquirúrgica de base craneal y los nuevos horizontes de la cirugía endoscópica siguen sin ofrecer un abordaje óptimo para aquellas lesiones asentadas en la totalidad de la RMT (principalmente oncológicas y vasculares). La exposición parcial de la RMT y el compromiso de estructuras neurovasculares no implica...

  6. Consumo problemático de sustancias : Concepción interdisciplinaria para su abordaje

    Cabrera, Gonzalo; Vera, Ruth

    2013-01-01

    Este trabajo está enmarcado en el proyecto de investigación “Adicciones y suicidio. Representaciones de los jóvenes entre 15 y 25 años de la ciudad de Río Gallegos. Un estudio para la elaboración de un proyecto de prevención y promoción en salud socio comunitaria” que hemos iniciado a principios de este año y que tiene como antecedente la investigación “Los jóvenes en el fin del mundo. ¿Quiénes son?, ¿qué quieren?, ¿qué hacen? Un estudio sobre los intereses necesidades y obstáculos de los jóv...

  7. Role of Magnetic Carpet in Coronal Heating

    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.

  8. OBSERVING CORONAL NANOFLARES IN ACTIVE REGION MOSS

    The High-resolution Coronal Imager (Hi-C) has provided Fe XII 193Å images of the upper transition region moss at an unprecedented spatial (∼0.''3-0.''4) and temporal (5.5 s) resolution. The Hi-C observations show in some moss regions variability on timescales down to ∼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 Å 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 1023 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).

  9. Coronal Behavior Before the Large Flare Onset

    Imada, Shinsuke; Kusano, Kanya

    2014-01-01

    Flares are a major explosive event in our solar system. They are often followed by coronal mass ejection that has a potential to trigger the geomagnetic storms. There are various studies aiming to predict when and where the flares are likely to occur. Most of these studies mainly discuss the photospheric and chromospheric activity before the flare onset. In this paper we study the coronal features before the famous large flare occurrence on December 13th, 2006. Using the data from Hinode/EUV Imaging Spectrometer (EIS), X-Ray Telescope (XRT), and Solar and Heliospheric Observatory (SOHO) /Extreme ultraviolet Imaging Telescope (EIT), we discuss the coronal features in the large scale (~ a few 100 arcsec) before the flare onset. Our findings are as follows: 1) The upflows in and around active region start growing from ~10 to 30 km /s a day before the flare. 2) The expanding coronal loops are clearly observed a few hours before the flare. 3) Soft X-ray and EUV intensity are gradually reduced. 4) The upflows are f...

  10. Coronal bright points associated with minifilament eruptions

    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 109 cm–3. These new observational results indicate that CBPs are more complex in dynamical evolution and magnetic structure than previously thought.

  11. Observing coronal nanoflares in active region moss

    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...

  12. MAGNETIC TOPOLOGY OF CORONAL HOLE LINKAGES

    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 new important 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 nulls. Finally, the coronal holes are not connected by an open-field 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 the 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.

  13. Radio signatures of interplanetary coronal mass ejections

    Krupař, Vratislav; Santolík, Ondřej; Maksimovic, M.; Souček, Jan; Krupařová, Oksana

    Weihai: Shandong University, 2015. s. 114. [Solar Wind 14. 22.06.2015-26.06.2015, Weihai] Institutional support: RVO:68378289 Keywords : magnetosphere * coronal mass ejection Subject RIV: BL - Plasma and Gas Discharge Physics http://sw14.csp.escience.cn/dct/page/65580

  14. The Inconvenient Truth About Coronal Dimmings

    McIntosh, Scott W.

    2009-03-01

    We investigate the occurrence of a coronal mass ejection (CME)-driven coronal dimming using unique high-resolution spectral images of the corona from the Hinode spacecraft. Over the course of the dimming event, we observe the dynamic increase of nonthermal line broadening in the 195.12 Å emission line of Fe XII as the corona opens. As the corona begins to close, refill and brighten, we see a reduction of the nonthermal broadening toward the pre-eruption level. We propose that the dynamic evolution of the nonthermal broadening is the result of the growth of Alfvén wave amplitudes in the magnetically open rarefied dimming region, compared to the dense closed corona prior to the CME. We suggest, based on this proposition, that, as open magnetic regions, coronal dimmings must act just as coronal holes and be sources of the fast solar wind, but only temporarily. Further, we propose that such a rapid transition in the thermodynamics of the corona to a solar wind state may have an impulsive effect on the CME that initiates the observed dimming. This last point, if correct, poses a significant physical challenge to the sophistication of CME modeling and capturing the essence of the source region thermodynamics necessary to correctly ascertain CME propagation speeds, etc.

  15. THE INCONVENIENT TRUTH ABOUT CORONAL DIMMINGS

    We investigate the occurrence of a coronal mass ejection (CME)-driven coronal dimming using unique high-resolution spectral images of the corona from the Hinode spacecraft. Over the course of the dimming event, we observe the dynamic increase of nonthermal line broadening in the 195.12 A emission line of Fe XII as the corona opens. As the corona begins to close, refill and brighten, we see a reduction of the nonthermal broadening toward the pre-eruption level. We propose that the dynamic evolution of the nonthermal broadening is the result of the growth of Alfven wave amplitudes in the magnetically open rarefied dimming region, compared to the dense closed corona prior to the CME. We suggest, based on this proposition, that, as open magnetic regions, coronal dimmings must act just as coronal holes and be sources of the fast solar wind, but only temporarily. Further, we propose that such a rapid transition in the thermodynamics of the corona to a solar wind state may have an impulsive effect on the CME that initiates the observed dimming. This last point, if correct, poses a significant physical challenge to the sophistication of CME modeling and capturing the essence of the source region thermodynamics necessary to correctly ascertain CME propagation speeds, etc.

  16. Minilaparoscopic-assisted transvaginal approach in benign liver lesions Abordaje transvaginal asistido por minilaparoscopia en lesiones benignas del hígado

    R. Castro-Pérez

    2010-06-01

    complejidad y situadas en subsegmentos periféricos, de forma segura y con un mejor resultado estético que en la cirugía laparoscópica. No obstante, serán necesarios estudios futuros que demuestren las ventajas de esta vía de abordaje en las lesiones hepáticas.

  17. Abordajes clínicos de las problemáticas actuales en la infancia.

    Alicia Muniz Martoy

    2013-11-01

    Full Text Available El presente artículo ofrece algunas reflexiones en torno a la experiencia clínica con niños y sus familias en el Uruguay actual tomando algunos autores de diversas disciplinas. Se plantea la importancia de considerar las condiciones de producción de subjetividad que inciden en los modos de presentación de los niños y sus dificultades en diversas áreas. Asimismo se plantean cuestiones en torno a las instituciones involucradas en estos procesos de subjetivación como lo son la Familia, la Escuela y la Salud, con sus discursos, padecimientos y prácticas actuales. Se observan las estrategias de abordaje en psicología clínica enmarcadas en las prestaciones de salud mental, advirtiendo efectos reduccionistas sobre la compleja situación de los niños cuyas conductas se patologizan a la luz de las exigencias epocales. Se propone para la psicología clínica una concepción del diagnóstico como acto promotor de sentido nuevo y preventivo de estigmatización y exclusión. This paper provides some reflections on the clinical experience with children and their families today in Uruguay, taking some authors from various disciplines. The importance of considering the conditions involving the production of subjectivity that affects the way children express their difficulties in various areas, is raised. This paper also raises questions about the institutions involved in these processes of subjectification such as the Family, the School and the Health, with their current speeches, sufferings and practices. Clinical psychology approach strategies that are framed in mental health benefits are observed and the reductive effects on the complex situation of children whose behavior is pathologized in the light of current demands is taken into consideration. A conception of diagnosis as a promoter act of new meaning and as having a preventive effect on the stigmatization and exclusion is proposed for clinical psychology.

  18. CORONAL SEISMOLOGY USING EIT WAVES: ESTIMATION OF THE CORONAL MAGNETIC FIELD STRENGTH IN THE QUIET SUN

    Coronal EIT waves have been observed for many years. The nature of EIT waves is still contentious, however, there is strong evidence that some of them might be fast magnetosonic waves, or at least have a fast magnetosonic wave component. The fast magnetosonic wave speed is formed from two components; the Alfven speed (magnetic) and the sound speed (thermal). By making measurements of the wave speed, coronal density and temperature it is possible to calculate the quiet-Sun coronal magnetic field strength through coronal seismology. In this paper, we investigate an EIT wave observed on 2009 February 13 by the SECCHI/EUVI instruments on board the STEREO satellites. The wave epicenter was observed at disk center in the STEREO B (Behind) satellite. At this time, the STEREO satellites were separated by approximately 90 deg., and as a consequence the STEREO A (Ahead) satellite observed the wave on the solar limb. These observations allowed us to make accurate speed measurements of the wave. The background coronal density was derived through Hinode/Extreme-ultraviolet Imaging Spectrometer observations of the quiet Sun and the temperature was estimated through the narrow temperature response in the EUVI bandpasses. The density, temperature, and speed measurements allowed us to estimate the quiet-Sun coronal magnetic field strength to be approximately 0.7 ± 0.7 G.

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

    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...

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

    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.

  1. Identificación de causales de abandono de estudios universitarios : Uso de procesos de explotación de información

    Kuna, Horacio; García Martínez, Ramón; Villatoro, Francisco

    2009-01-01

    El abandono de los estudios universitarios en el nivel de pregrado, es un fenómeno global en el Sistema Universitario Argentino, que conlleva la necesidad de desarrollar políticas de retención de estudiantes. Estas políticas requieren la identificación de las posibles causas de deserción. En este articulo se presenta el uso de algoritmos TDIDT para descubrir reglas que caractericen el abandono a partir de la información disponible en el Sistema SIU-Guarani. El abordaje empleado ha permitido i...

  2. Factores que inciden en las decisiones de diversificación productiva. Un abordaje cualitativo

    Baldino Burelli, Carla

    2014-01-01

    Esta investigación tiene como objetivo principal analizar los factores que inciden en la decisión de diversificar en una PyME metalmecánica marplatense. El enfoque metodológico que se utiliza es cualitativo a través de un estudio de caso único, con información proveniente de entrevistas en profundidad. Los resultados sugieren que tanto la diversidad inicial, la estructura de mercado (clientes, competidores, precio), la capacidad ociosa, las habilidades acumuladas, la existencia de un departam...

  3. El cuerpo del niño como trastorno : aproximaciones discursivas al abordaje del TDAH

    Ceardi Marambio, Andrea; Améstica Abarca, José Manuel; Núñez Muñoz, Carmen Gloria; López Leiva, Verónica; López Guerrero, Valeska; Gajardo Molina, Julio

    2016-01-01

    El Trastorno de Déficit Atencional con Hiperactividad (TDAH) es el diagnóstico neurológico más frecuente en niños en edad escolar atendidos en el servicio de atención primaria en Chile. Se han implementado nuevas regulaciones que definen cuáles profesionales pueden diagnosticar y tratar el trastorno. En este estudio nos aproximamos a la construcción del TDAH desde una perspectiva discursiva, a través del análisis de entrevistas a padres, profesionales de las áreas de la salud y educación enca...

  4. Leptospirosis humana:un abordaje de su epidemiología en Cuba

    Verdasquera Corcho, Denis

    2011-01-01

    La leptospirosis humana constituye la zoonosis de mayor impacto en salud pública. En Cuba, durante los últimos diez años se notifican brotes en varias provincias. Este trabajo abarcó un ciclo de investigaciones operacionales insertadas en el funcionamiento del Programa Nacional de Prevención y Control de la Leptospirosis.. El universo temporal de los estudios transcurrió entre 1998 y 2009. Se analizó la variación, la tendencia y el pronóstico de la morbilidad y la mortalidad por leptospirosis...

  5. SALUD MENTAL: UN ABORDAJE DESDE LA PERSPECTIVA ACTUAL DE LA PSICOLOGÍA DE LA SALUD

    Moisés Mebarak; Alberto De Castro; María del Pilar Salamanca; María Fernanda Quintero

    2009-01-01

    Este artículo está basado en un estudio estado del arte acerca del entendimiento actual que se tiene sobre el concepto de salud mental, especialmente desde la perspectiva de la psicología de la salud. Con el fin de ilustrar este campo, se presentan algunos aportes y/o investigaciones tanto a nivel general como de la región costa Caribe colombiana. Se ha encontrado que el concepto de salud mental implica el desarrollo de estilos de vida y de características personales, interpersonales, sociale...

  6. Grupo de Estudios Peirceanos

    Jaime Nubiola; Sara F. Barena

    2001-01-01

    El Grupo de Estudios Peirceanos (http://www.unav.es/gep/index.htm) de la Universidad de Navarra se creó en 1994. Tiene coo objetivo promover el estudio de la obra de Charles S. Peirce (1839-1914), especialmente en España y en los países de lengua castellana, con la convicción deque en su pensamiento pueden encontrarse algunas claves decisivas para la cultura, la ciencia y la filosofía del siglo XXI. El Grupo proporciona un ámbito para el inter...

  7. El abordaje estatal de la pobreza en Programas de Transferencias Monetarias Condicionadas

    Rebeca Cena

    2015-02-01

    Full Text Available El presente texto tiene por objetivo contribuir al estudio, análisis y comprensión de los mecanismos de estructuración social del capitalismo actual mediante los Programas de Transferencias Monetarias Condicionadas (PTMC dirigidos a niños, niñas y adolescentes “pobres”, con base en la experiencia de cuatro países del Cono Sur: Argentina, Bolivia, Brasil y Chile. Nos centramos en el estudio del diseño de los PTMC de alcance nacional vigentes en el período 2009-2013, para considerar algunos indicios sobre cómo se concibe y construye la “niñez” en los sectores más pobres desde la mirada estatal, y analizar críticamente qué formas toma la gestión de estas poblaciones. Así, es posible visibilizar los marcos institucionales en los que se reconoce un colectivo y se direccionan las demandas asociadas al vivir en condiciones de carencias, en un régimen responsable de tal estado de cosas.

  8. ACCIONES Y PRÁCTICAS DE MERCADO VERDE EN EMPRESAS COLOMBIANAS (CASOS DE ESTUDIO)

    Juán Ramón Samper; Lina María Echeverri Cañas

    2011-01-01

    El abordaje del mercadeo verde o ecológico inicia en la década de los sesenta a raíz de los cambios climatológicos y la preocupación constante por el cuidado del medio ambiente.Escritores como Ottman, Hailes y Polonsky han dado interesantes aportes sobre la conceptualización del mercadeo verde en la teoría y en la práctica. En Colombia existen estudios específicos sobre la aplicación del mercadeo ecológico en grandes empresas y también investigaciones sobre el análisis del consumidor verde de...

  9. Observation of coronal loop torsional oscillation

    Zaqarashvili, T V

    2003-01-01

    We suggest that the global torsional oscillation of solar coronal loop may be observed by the periodical variation of a spectral line width. The amplitude of the variation must be maximal at the velocity antinodes and minimal at the nodes of the torsional oscillation. Then the spectroscopic observation as a time series at different heights above the active region at the solar limb may allow to determine the period and wavelength of global torsional oscillation and consequently the Alfv{\\'e}n speed in corona. From the analysis of early observation (Egan & Schneeberger \\cite{egan}) we suggest the value of coronal Alfv{\\'e}n speed as $\\sim 500 {\\rm km}{\\cdot}{\\rm s}^{-1}$.

  10. Sinonasal polyposis: investigation by direct coronal CT

    To demonstrate the typical clinical and CT features of sinonasal polyposis, we reviewed the clinical records and preoperative direct coronal CT scans of 35 patients with surgically proven disease. Symptoms included progressive nasal stuffiness (100 %), rhinorrhea (69 %), facial pain (60 %), headache (43 %) and anosmia (17 %). We found associations with rhinitis (46 %), asthma (29 %) and aspirin sensitivity (9 %). Coronal CT features included polypoid masses in the nasal cavity (91 %), partial or complete pansinus opacification (90 %), enlargement of infundibula (89 %), bony attenuation of the ethmoid trabeculae (63 %) and nasal septum (37 %), opacified ethmoid sinuses with convex lateral walls (51 %) and air-fluid levels (43 %). The latter feature correlated with symptoms and signs of acute sinusitis in only 40 % of patients. Recognition of sinonasal polyposis is important to the endoscopic surgeon since it can be the most troubling sinonasal inflammatory disease to manage due to its aggressive nature and tendency to recur despite appropriate treatment. (orig.)

  11. Microflares as Possible Sources for Coronal Heating

    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.

  12. On Tripolar Magnetic Reconnection and Coronal Heating

    Pandey, K; Lohani, N K; Pandey, Kumud; Narain, Udit

    2003-01-01

    Using recent data for the photosphere-chromosphere region of the solar atmosphere the magnetic reconnection in tripolar geometry has been investigated through the procedure of Sturrock (1999). Particular attention has been given to the width of the reconnecting region, wave number of the rapidly growing tearing mode, island length scales, frequency of MHD fluctuations, tearing mode growth rate, energy dissipation rate and minimum magnetic field strength required to heat chromospheric plasma to coronal temperatures. It is found that small length scales are formed in the upper chromosphere. The maximum growth rate of tearing mode instability coincides with the peak in the energy dissipation rate both of which occur in the upper chromosphere at the same height. It is realized that the distribution of magnetic field with height is essential for a better understanding of the coronal heating problem.

  13. Geometrical Properties of Coronal Mass Ejections

    Cremades, Hebe; Bothmer, Volker

    Based on the SOHO/LASCO dataset, a collection of "structured" coronal mass ejections (CMEs) has been compiled within the period 1996-2002, in order to analyze their three-dimensional configuration. These CME events exhibit white-light fine structures, likely indicative of their possible 3D topology. From a detailed investigation of the associated low coronal and photospheric source regions, a generic scheme has been deduced, which considers the white-light topology of a CME projected in the plane of the sky as being primarily dependent on the orientation and position of the source region's neutral line on the solar disk. The obtained results imply that structured CMEs are essentially organized along a symmetry axis, in a cylindrical manner. The measured dimensions of the cylinder's base and length yield a ratio of 1.6. These CMEs seem to be better approximated by elliptic cones, rather than by the classical ice cream cone, characterized by a circular cross section.

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

    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.

  15. Sunquake Generation by Coronal Magnetic Restructuring

    Russell, A. J. B.; Mooney, M.; Leake, J. E.; Hudson, H. S.

    2015-12-01

    Solar flares and coronal mass ejections are powered by major restructurings of the coronal magnetic field, which appear to strongly perturb the magnetic field in the photosphere as well. Could the associated Lorentz forces generate sunquakes, as suggested by Hudson et al. 2008? Here, we present the first MHD simulations of sunquake generation by magnetic field perturbations, and explore the details of this mechanism. The downgoing magnetic field change is modelled as an Alfven wave, which propagates into the lower atmosphere. When it reaches the vicinity of the beta=1 layer (where the Alfven and sound speeds are equal), non-linear coupling excites a downgoing acoustic wave, which we interpret as a sunquake. The amplitude of the acoustic wave increases nonlinearly with the amplitude of the magnetic perturbation, reaching a limit where around 35% of the injected Poynting flux is transferred to the seismic wave - enough energy to match sunquake observations.

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

    Raouafi, N. E.; Patsourakos, S.; 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.

    2016-07-01

    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.

  17. Solar Energetic Particles: Sampling Coronal Abundances

    Reames, Donald V.

    1998-05-01

    In the large solar energetic particle (SEP) events, coronal mass ejections (CMEs) drive shock waves out through the corona that accelerate elements of the ambient material to MeV energies in a fairly democratic, temperature-independent manner. These events provide the most complete source of information on element abundances in the corona. Relative abundances of 22 elements from H through Zn display the well-known dependence on the first ionization potential (FIP) that distinguishes coronal and photospheric material. For most elements, the main abundance variations depend upon the gyrofrequency, and hence on the charge-to-mass ratio, Q/A, of the ion. Abundance variations in the dominant species, H and He, are not Q/A dependent, presumably because of non-linear wave-particle interactions of H and He during acceleration. Impulsive flares provide a different sample of material that confirms the Ne:Mg:Si and He/C abundances in the corona.

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

    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...

  19. A SURVEY OF CORONAL CAVITY DENSITY PROFILES

    Coronal cavities are common features of the solar corona that appear as darkened regions at the base of coronal helmet streamers in coronagraph images. Their darkened appearance indicates that they are regions of lowered density embedded within the comparatively higher density helmet streamer. Despite interfering projection effects of the surrounding helmet streamer (which we refer to as the cavity rim), Fuller et al. have shown that under certain conditions it is possible to use a Van de Hulst inversion of white-light polarized brightness (pB) data to calculate the electron density of both the cavity and cavity rim plasma. In this article, we apply minor modifications to the methods of Fuller et al. in order to improve the accuracy and versatility of the inversion process, and use the new methods to calculate density profiles for both the cavity and cavity rim in 24 cavity systems. We also examine trends in cavity morphology and how departures from the model geometry affect our density calculations. The density calculations reveal that in all 24 cases the cavity plasma has a flatter density profile than the plasma of the cavity rim, meaning that the cavity has a larger density depletion at low altitudes than it does at high altitudes. We find that the mean cavity density is over four times greater than that of a coronal hole at an altitude of 1.2 Rsun and that every cavity in the sample is over twice as dense as a coronal hole at this altitude. Furthermore, we find that different cavity systems near solar maximum span a greater range in density at 1.2 Rsun than do cavity systems near solar minimum, with a slight trend toward higher densities for systems nearer to solar maximum. Finally, we found no significant correlation of cavity density properties with cavity height-indeed, cavities show remarkably similar density depletions-except for the two smallest cavities that show significantly greater depletion.

  20. TV Review: Coronation Street - Surrogacy in Weatherfield

    Blyth, Eric

    2013-01-01

    The British TV soap opera, Coronation Street, has become an established national institution since the first episode was screened in December 1960. It is on several nights each week and is set in 'Weatherfield', a fictional working class neighbourhood in Manchester. One of the programme's many plots this year has focused on a surrogacy arrangement made between intending parents Isabelle (Izzy) and Gary and their friend, Tina. This being 'soapland', there are various sub-plots. As a result...

  1. Coronal Plumes in the Fast Solar Wind

    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.

  2. Spectroscopic Diagnostics of Polar Coronal Plumes

    Wilhelm, K; Dwivedi, B N

    2009-01-01

    Polar coronal plumes seen during solar eclipses can now be studied with space-borne telescopes and spectrometers. We briefly discuss such observations from space with a view to understanding their plasma characteristics. Using these observations, especially from SUMER/SOHO, but also from EUVI/STEREO, we deduce densities, temperatures, and abundance anomalies in plumes and inter-plume regions, and discuss their implications for better understanding of these structures in the Sun's atmosphere.

  3. Coronal Mass Ejections of Solar Cycle 23

    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.

  4. Acción COST Femicide Across Europe, un espacio de cooperación trasnacional para el estudio y el abordaje del feminicidio en Europa

    Belén Sanz-Barbero

    2016-09-01

    Full Text Available El feminicidio o asesinato de mujeres por razones de género es ya un reconocido problema de salud pública, además de una grave vulneración de los derechos humanos. Todavía se desconoce con exactitud su magnitud en el mundo, dadas las dificultades metodológicas para diferenciar estos asesinatos de otros homicidios de mujeres. El Programa de la Unión Europea «Redes de Cooperación Europea en Ciencia y Tecnología» puso en marcha en 2013 la Acción COST Femicide across Europe, abriendo un marco europeo óptimo para la cooperación transnacional entre personas expertas que aborden grandes retos sociales y de salud pública como el feminicidio. En esta nota de campo se describen sus principales objetivos, los grupos de expertos y expertas que lo conforman, y los resultados obtenidos a medio plazo con dicha experiencia.

  5. A Mechanism for Coronal Hole Jets

    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...

  6. EIT Observations of Coronal Mass Ejections

    Gurman, J. B.; Fisher, Richard B. (Technical Monitor)

    2000-01-01

    Before the Solar and Heliospheric Observatory (SOHO), we had only the sketchiest of clues as to the nature and topology of coronal mass ejections (CMEs) below 1.1 - 1.2 solar radii. Occasionally, dimmings (or 'transient coronal holes') were observed in time series of soft X-ray images, but they were far less frequent than CME's. Simply by imaging the Sun frequently and continually at temperatures of 0.9 - 2.5 MK we have stumbled upon a zoo of CME phenomena in this previously obscured volume of the corona: (1) waves, (2) dimmings, and (3) a great variety of ejecta. In the three and a half years since our first observations of coronal waves associated with CME's, combined Large Angle Spectroscopic Coronagraph (LASCO) and extreme ultra-violet imaging telescope (EIT) synoptic observations have become a standard prediction tool for space weather forecasters, but our progress in actually understanding the CME phenomenon in the low corona has been somewhat slower. I will summarize the observations of waves, hot (> 0.9 MK) and cool ejecta, and some of the interpretations advanced to date. I will try to identify those phenomena, analysis of which could most benefit from the spectroscopic information available from ultraviolet coronograph spectrometer (UVCS) observations.

  7. Frequency of coronal transients and solar activity

    The High Altitude Observatory's white light coronagraph aboard Skylab observed some 110 coronal transients - rapid changes in appearance of the corona - during its 227 days of operation. The longitudes of the origins of these transients were not distributed uniformly around the solar surface (51 of the 100 events observed in seven solar rotations arose from a single quadrant of longitude). Further, the frequency of transient production from each segment of the solar surface was well correlated with the sunspot number and Ca II plage (area x brightness) index in the segment, rotation by rotation. This correlation implies that transients occur more often above strong photospheric and chromospheric magnetic fields, that is, in regions where the coronal magnetic field is stronger and, perhaps, more variable. This pattern of occurrence is consistent with the belief that the forces propelling transient material outward are, primarily, magnetic. A quantitative relation between transient production from an area and the Zuerich sunspot number appropriate to that area is derived, and it is speculated that the relation is independent of phase in the solar activity cycle. If true, the Sun may give rise to as many as 100 white light coronal transients per month at solar cycle maximum. (Auth.)

  8. Optical coronal polarization and solar dust ring

    Observations of the outer solar corona on the Java island were carried out on June 11, 1983, at a 30-km altitude using a B-15 balloon. At 5325, 5965, 7200, and 8015 A, data on polarizations in a field of 5 deg x 5 deg centered nearly on the sun were obtained. Our contour maps of polarization are the first of the two-dimensional polarization distribution covering wide area. An excess of polarization at the four wavelengths was found in the ecliptic plane and at the location of a coronal streamer. High polarization at the coronal streamer is caused mainly by coronal electrons, but dust grains in the region out of the ecliptic plane contribute also in a few percent to the high polarization degree in this streamer. It is confirmed by additional data that there is a peak in the polarization excess in the ecliptic between 4(R solar) and 5(R solar) as already reported by Isobe et al. (1985; AAA 40.074.053). This excess is considered to be due to an enhanced distribution of dust in a ring or a thick wide band around the sun. (author)

  9. Coronal heating in coupled photosphere-chromosphere-coronal systems: turbulence and leakage

    Verdini, Andrea; Velli, Marco

    2011-01-01

    Coronal loops act as resonant cavities for low frequency fluctuations that are transmitted from the deeper layers of the solar atmosphere and are amplified in the corona, triggering nonlinear interactions. However trapping is not perfect, some energy leaks down to the chromosphere, thus limiting the turbulence development and the associated heating. We consider the combined effects of turbulence and leakage in determining the energy level and associated heating rate in models of coronal loops which include the chromosphere and transition region. We use a piece-wise constant model for the Alfven speed and a Reduced MHD - Shell model to describe the interplay between turbulent dynamics in the direction perpendicular to the mean field and propagation along the field. Turbulence is sustained by incoming fluctuations which are equivalent, in the line-tied case, to forcing by the photospheric shear flows. While varying the turbulence strength, we compare systematically the average coronal energy level (E) and dissi...

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

    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 ...

  11. Recent VLA Observations of Coronal Faraday Rotation

    Kooi, Jason E.; Fischer, P. D.; Buffo, J. J.; Spangler, S. R.

    2014-01-01

    Proposed mechanisms for coronal heating and acceleration of the fast solar wind, such as Joule heating by coronal currents or dissipation of Alfvén waves, depend on the magnetic field structure and plasma characteristics of the corona within heliocentric distances of 5 solar radii. Faraday rotation observations can provide unique information on the magnetic field in this region of the corona. We report on sensitive full-polarization observations of the radio galaxy 3C228 through the solar corona at heliocentric distances of 4.6 - 5.0 solar radii. The observations were made with the VLA in August of 2011. We performed these observations at 5.0 and 6.1 GHz (each with a bandwidth of 128 MHz), permitting measurements deeper in the corona than previous VLA observations at 1.4 and 1.7 GHz. While the measured Faraday rotation was lower than our a priori expectations, we can understand the magnitude of the observed Faraday rotation in terms of observed properties of the corona on the day of observation. For coronal remote sensing, an advantage of using extended extragalactic radio sources such as 3C228 is that such observations provide multiple lines of sight through the corona. Our data provide two lines of sight (separated by 46″, 33,000 km in the corona), one to a northern hotspot and the other to a southern hotspot with fractional polarizations of 14% and 8% respectively. We detected three periods over the eight-hour observing session during which there appeared to be a difference in the Faraday rotation between these two closely spaced lines of sight. These measurements yield an estimate of 2 - 4 GA for coronal currents. We did not directly detect rotation measure fluctuations. Our data impose upper limits on rotation measure fluctuations caused by coronal waves. The observed upper limits were 3.3 and 6.4 rad/m2 and are comparable to and not inconsistent with some models for Alfvén wave heating. This research was supported at the University of Iowa by grants ATM09

  12. SALUD MENTAL: UN ABORDAJE DESDE LA PERSPECTIVA ACTUAL DE LA PSICOLOGÍA DE LA SALUD

    Moisés Mebarak

    2009-01-01

    Full Text Available Este artículo está basado en un estudio estado del arte acerca del entendimiento actual que se tiene sobre el concepto de salud mental, especialmente desde la perspectiva de la psicología de la salud. Con el fin de ilustrar este campo, se presentan algunos aportes y/o investigaciones tanto a nivel general como de la región costa Caribe colombiana. Se ha encontrado que el concepto de salud mental implica el desarrollo de estilos de vida y de características personales, interpersonales, sociales y laborales que apuntan a una idea integrada de bienestar biopsicosocial. De esta forma, la salud mental se entiende que sobrepasa y no es reducida a la simple ausencia de síntomas.

  13. Repensando la libertad de expresión desde el abordaje al art. 213 del Código Penal argentino

    Matalone, Noelia

    2013-12-01

    Full Text Available Este ensayo intenta presentar abordajes críticos sobre el delito tipificado en el art. 213 del Código Penal. En tal temperamento, se contrapone el tipo penal de apología del delito con los derechos individuales de las personas, en particular, la libertad de expresión. En este sentido, la autora formula una propuesta de derogación de la norma, como consecuencia de los fundamentos y efectos de esta norma, todo ello en orden a preservar, por sobre los intereses que puedan sostener este tipo de prohibición, la pluralidad de voces en la sociedad. Para ello, apela al sentido de la tolerancia social y a los principios de razonalibidad y de necesidad del sistema penal al momento de investigar y perseguir este tipo de casos.

  14. Abordaje del Trauma Cráneo Encefálico en Patología Forense

    Maikel Vargas Sanabria

    2014-01-01

    En el presente artículo se describen los mecanismos de trauma y las principales lesiones que se encuentran en una muerte violenta ocasionada por traumatismo cráneo encefálico con el fin de contribuir a un abordaje práctico de estos casos en Patología Forense, tanto para los médicos de planta como para los que están en formación, con el propósito de homogenizar y unificar criterios y siempre con el objetivo final de contribuir con una adecuada administración de justicia y así cumplir con el ob...

  15. The role of active region coronal magnetic field in determining coronal mass ejection propagation direction

    Wang, Rui; Liu, Ying D.; Dai, Xinghua; Yang, Zhongwei; Huang, Chong; Hu, Huidong

    2015-01-01

    We study the role of the coronal magnetic field configuration of an active region in determining the propagation direction of a coronal mass ejection (CME). The CME occurred in the active region 11944 (S09W01) near the disk center on 2014 January 7 and was associated with an X1.2 flare. A new CME reconstruction procedure based on a polarimetric technique is adopted, which shows that the CME changed its propagation direction by around 28$^\\circ$ in latitude within 2.5 R$_\\odot$ and 43$^\\circ$ ...

  16. 3D Coronal Slow Modes: Towards 3D Seismology

    Marsh, M. S.; Walsh, R. W.; Plunkett, S.

    2009-01-01

    On 2008 January 10, the twin Solar Terrestrial Relations Observatory (STEREO) A and B spacecraft conducted a high time cadence study of the solar corona with the Extreme UltraViolet Imager (EUVI) instruments with the aim of investigating coronal dynamics. Observations of the three-dimensional propagation of waves within active region coronal loops and a measurement of the true coronal slow mode speed are obtained. Intensity oscillations with a period of approximately 12 minutes are observed t...

  17. Computed tomography myelography with coronal and oblique coronal views for diagnosis of nerve root avulsion in brachial plexus injury

    We describe a new computed tomography (CT) myelography technique with coronal and oblique coronal views to demonstrate the status of the cervical nerve rootlets that are involved in brachial plexus injury. We discuss the usefulness of this technique for the diagnosis of nerve root avulsion compared with that of CT myelography with axial view. CT myelography was performed with enhancement of the cervical subarachnoid space by using a contrast medium. Subsequently, coronal and oblique coronal reconstructions were created. The results of CT myelography were evaluated and classified in the presence of pseudomeningocele, intradural ventral nerve rootlets, and intradural dorsal nerve rootlets. The diagnosis was based on the findings of extraspinal surgical exploration with or without spinal evoked potential measurements and choline acetyltransferase activity measurement in 25 patients and recovery by a natural course in 3 patients. The diagnostic accuracies of CT myelography with coronal and oblique coronal views and that with axial view were compared and correlated with the surgical findings or natural course in 57 cervical roots in 28 patients. Coronal and oblique coronal views were superior to axial views in the visualization of the rootlets and orientation of the exact level of the root. They showed 100% sensitivity, 96% specificity, and 98% diagnostic accuracy (26 true-positive findings, 27 true-negative findings, none false-positive findings, and one false-negative findings) for diagnosing root avulsion. No statistically significant difference was observed between the coronal and oblique coronal views and the axial views. The information obtained using coronal and oblique coronal slice CT myelography enabled the assessment of the rootlets of the brachial plexus and provided valuable data for deciding the appropriate treatment strategy, namely, exploration, nerve repair, or primary reconstruction. (author)

  18. Evidence linking coronal transients to the evolution of coronal holes. [solar X-ray observations on Skylab

    Webb, D. F.; Nolte, J. T.; Solodyna, C. V.; Mcintosh, P. S.

    1978-01-01

    The positions of X-ray coronal transients outside of active regions observed during Skylab were superposed on H-alpha synoptic charts and coronal hole boundaries for seven solar rotations. A detailed spatial association between the transients and neutral lines was confirmed. It was found that most of the transients were related to large-scale changes in coronal hole area and tended to occur on the borders of evolving equatorial holes.

  19. The role of active region coronal magnetic field in determining coronal mass ejection propagation direction

    Wang, Rui; Dai, Xinghua; Yang, Zhongwei; Huang, Chong; Hu, Huidong

    2015-01-01

    We study the role of the coronal magnetic field configuration of an active region in determining the propagation direction of a coronal mass ejection (CME). The CME occurred in the active region 11944 (S09W01) near the disk center on 2014 January 7 and was associated with an X1.2 flare. A new CME reconstruction procedure based on a polarimetric technique is adopted, which shows that the CME changed its propagation direction by around 28$^\\circ$ in latitude within 2.5 R$_\\odot$ and 43$^\\circ$ in longitude within 6.5 R$_\\odot$ with respect to the CME source region. This significant non-radial motion is consistent with the finding of M$\\ddot{o}$stl et al. (2015). We use nonlinear force-free field (NLFFF) and potential field source surface (PFSS) extrapolation methods to determine the configurations of the coronal magnetic field. We also calculate the magnetic energy density distributions at different heights based on the extrapolations. Our results show that the active region coronal magnetic field has a strong ...

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

    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...

  1. Solar Jet-Coronal Hole Collision and a Closely Related Coronal Mass Ejection

    Zheng, Ruisheng; Chen, Yao; Du, Guohui; Li, Chuanyang

    2016-03-01

    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 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.

  2. Coronal Loops: Evolving Beyond the Isothermal Approximation

    Schmelz, J. T.; Cirtain, J. W.; Allen, J. D.

    2002-05-01

    Are coronal loops isothermal? A controversy over this question has arisen recently because different investigators using different techniques have obtained very different answers. Analysis of SOHO-EIT and TRACE data using narrowband filter ratios to obtain temperature maps has produced several key publications that suggest that coronal loops may be isothermal. We have constructed a multi-thermal distribution for several pixels along a relatively isolated coronal loop on the southwest limb of the solar disk using spectral line data from SOHO-CDS taken on 1998 Apr 20. These distributions are clearly inconsistent with isothermal plasma along either the line of sight or the length of the loop, and suggested rather that the temperature increases from the footpoints to the loop top. We speculated originally that these differences could be attributed to pixel size -- CDS pixels are larger, and more `contaminating' material would be expected along the line of sight. To test this idea, we used CDS iron line ratios from our data set to mimic the isothermal results from the narrowband filter instruments. These ratios indicated that the temperature gradient along the loop was flat, despite the fact that a more complete analysis of the same data showed this result to be false! The CDS pixel size was not the cause of the discrepancy; rather, the problem lies with the isothermal approximation used in EIT and TRACE analysis. These results should serve as a strong warning to anyone using this simplistic method to obtain temperature. This warning is echoed on the EIT web page: ``Danger! Enter at your own risk!'' In other words, values for temperature may be found, but they may have nothing to do with physical reality. Solar physics research at the University of Memphis is supported by NASA grant NAG5-9783. This research was funded in part by the NASA/TRACE MODA grant for Montana State University.

  3. Coronal Heating, Spicules, and Solar-B

    Moore, Ron; Falconer, David; Porter, Jason; Hathaway, David; Yamauchi, Yohei

    2003-01-01

    Falconer et al. investigated the heating of the quiet corona by measuring the increase of coronal luminosity with the amount of the magnetic flux in the underlying network at solar minimum when there were no active regions on the face of the Sun. The coronal luminosity was measured from Fe IX/X - Fe XII pairs of coronal images from SOHO/EIT, under the assumption that practically all of the coronal luminosity in these very quiet regions came from plasma in the temperature range 0.9 x 10(exp 6) K is less than or equal to T is less than or equal to 1.3 x 10(exp 6) K. The network magnetic flux content was measured from SOHO/MDI magnetograms. It was found that luminosity of the corona in these quiet regions increased roughly in proportion to the square root of the magnetic flux content of the network and roughly in proportion to the length of the perimeter of the network flux clumps. From 1) this result; 2) the observed occurrence of many fine-scale explosive events (e.g., spicules) at the edges of network flux clumps; and 3) a demonstration that it is energetically feasible for the heating of the corona in quiet regions to be driven by explosions of granule-sized sheared-core magnetic bipoles embedded in the edges of the network flux clumps, Falconer et al. infer that in quiet regions that are not influenced by active regions the corona is mainly heated by such magnetic activity in the edges of the network flux clumps. From their observational results together with their feasibility analysis, Falconer et al. predict that 1) At the edges of the network flux clumps there are many transient sheared core bipoles of the size and lifetime of granules and having transverse field strengths greater than approx. 100 G; 2) Approx. 30 of these bipoles are present per supergranule; and 3) Most spicules are produced by explosions of these bipoles. The photospheric vector magnetograms, chromospheric filtergrams, and EUV spectra from Solar-B are expected to have sufficient sensitivity

  4. Coronal Heating versus Solar Wind Acceleration

    Cranmer, Steven R.

    2004-01-01

    Parker's initial insights from 1958 provided a key causal link between the heating of the solar corona and the acceleration of the solar wind. However, we still do not know what fraction of the solar wind's mass, momentum, and energy flux is driven by Parker-type gas pressure gradients, and what fraction is driven by, e.g., wave-particle interactions or turbulence. SOHO has been pivotal in bringing these ideas back to the forefront of coronal and solar wind research. This paper reviews our cu...

  5. The Inconvenient Truth About Coronal Dimmings

    McIntosh, Scott W.

    2008-01-01

    We investigate the occurrence of a CME-driven coronal dimming using unique high resolution spectral images of the corona from the Hinode spacecraft. Over the course of the dimming event we observe the dynamic increase of non-thermal line broadening in the 195.12Angstrom emission line of Fe XII as the corona opens. As the corona begins to close, refill and brighten, we see a reduction of the non-thermal broadening towards the pre-eruption level. We propose that the dynamic evolution of non-the...

  6. Discurso, performatividad y emergencia del sujeto: Un abordaje desde el post-estructuralismo

    María Virginia Morales

    2014-02-01

    Full Text Available El estudio de las estructuras de significación y la conformación de hegemonías desempeñan un papel protagónico para las teorías post-estructuralistas de la política. En el presente escrito abordo una serie de aspectos ontológicos de dichas teorías a partir de la reflexión de las condiciones de emergencia de los sistemas de significación, el modo en que estos sistemas son construidos y la manera en que los mismos constituyen al campo de lo social y a los sujetos que se posicionan en él. De este modo, me motiva el objetivo de analizar unos de los principales presupuestos epistemológicos de categorías que considero centrales para cualquier investigación post-estructuralista, a saber: discurso, performatividad y sujeto. En pocas palabras, el presente escrito tiene la doble finalidad de indagar en aspectos ontológicos que fundan a las teorías en cuestión, a la vez que comenzar a desarrollar un marco conceptual desde el cual abordar las condiciones de emergencia de las estructuras discursivas que conforman y dan sentido a los sujetos y a lo social.

  7. Low-Coronal Sources of Stealth CMEs

    Alzate, Nathalia; Morgan, Huw

    2016-05-01

    Coronal mass ejections (CMEs) are eruptions in the solar atmosphere, which expand and propagate into space. They are generally associated with eruptive phenomena in the lower corona such as solar flares, filament eruptions, EUV waves or jets, known as low-coronal signatures (LCS). Recent studies have observed CMEs without a LCS and these have been referred to as stealth CMEs. Through new image processing applied to EUV images we find clear evidence of LCS leading to stealth CMEs. In this work, the new processing methods are applied to some of the data identified to contain stealth CMEs in previous studies to investigate the possible existence of observable LCS. The LCS of stealth CMEs are fairly sizeable yet faint eruptions with structure consistent with a rising flux tube, possibly formed higher in the corona in regions of weaker magnetic field. We believe these flux tubes are formed mostly in polar regions due to the larger shear resulting from the more slowly rotating lower atmosphere below the more rapidly rotating corona. This would allow the formation of large flux tubes in weaker field regions, leading to low-energy and low-density flux tube eruptions

  8. Ultraviolet spectroscopy of narrow coronal mass ejections

    Dobrzycka, D; Biesecker, D A; Li, J; Ciaravella, A

    2003-01-01

    We present Ultraviolet Coronagraph Spectrometer (UVCS) observations of 5 narrow coronal mass ejections (CMEs) that were among 15 narrow CMEs originally selected by Gilbert et al. (2001). Two events (1999 March 27, April 15) were "structured", i.e. in white light data they exhibited well defined interior features, and three (1999 May 9, May 21, June 3) were "unstructured", i.e. appeared featureless. In UVCS data the events were seen as 4-13 deg wide enhancements of the strongest coronal lines HI Ly-alpha and OVI (1032,1037 A). We derived electron densities for several of the events from the Large Angle Spectrometric Coronagraph (LASCO) C2 white light observations. They are comparable to or smaller than densities inferred for other CMEs. We modeled the observable properties of examples of the structured (1999 April 15) and unstructured (1999 May 9) narrow CMEs at different heights in the corona between 1.5 and 2 R(Sun). The derived electron temperatures, densities and outflow speeds are similar for those two ty...

  9. Interplanetary Propagation of Coronal Mass Ejections

    Gopalswamy, Nat

    2011-01-01

    Although more than ten thousand coronal mass ejections (CMEs) are produced during each solar cycle at the Sun, only a small fraction hits the Earth. Only a small fraction of the Earth-directed CMEs ultimately arrive at Earth depending on their interaction with the solar wind and other large-scale structures such as coronal holes and CMEs. The interplanetary propagation is essentially controlled by the drag force because the propelling force and the solar gravity are significant only near the Sun. Combined remote-sensing and in situ observations have helped us estimate the influence of the solar wind on the propagation of CMEs. However, these measurements have severe limitations because the remote-sensed and in-situ observations correspond to different portions of the CME. Attempts to overcome this problem are made in two ways: the first is to model the CME and get the space speed of the CME, which can be compared with the in situ speed. The second method is to use stereoscopic observation so that the remote-sensed and in-situ observations make measurements on the Earth-arriving part of CMEs. The Solar Terrestrial Relations Observatory (STEREO) mission observed several such CMEs, which helped understand the interplanetary evolution of these CMEs and to test earlier model results. This paper discusses some of these issues and updates the CME/shock travel time estimates for a number of CMEs.

  10. Coronal Heating versus Solar Wind Acceleration

    Cranmer, S R

    2004-01-01

    Parker's initial insights from 1958 provided a key causal link between the heating of the solar corona and the acceleration of the solar wind. However, we still do not know what fraction of the solar wind's mass, momentum, and energy flux is driven by Parker-type gas pressure gradients, and what fraction is driven by, e.g., wave-particle interactions or turbulence. SOHO has been pivotal in bringing these ideas back to the forefront of coronal and solar wind research. This paper reviews our current understanding of coronal heating in the context of the acceleration of the fast and slow solar wind. For the fast solar wind, a recent model of Alfven wave generation, propagation, and non-WKB reflection is presented and compared with UVCS, SUMER, radio, and in-situ observations at the last solar minimum. The derived fractions of energy and momentum addition from thermal and nonthermal processes are found to be consistent with various sets of observational data. For the more chaotic slow solar wind, the relative rol...

  11. Particle Heating Resulting from Coronal Mass Ejection

    Paul, Suman; Sundar De, Syam; Guha, Gautam

    2016-07-01

    Coronal Mass Ejection (CME) is a continuous phenomena occurring from the entire solar coronal zone responsible for the outflow of solar masses, viz., protons, electrons, neutrons and solar wind in the form of plasma. These perturb the Earth's atmosphere via magnetopause. Very high temperature plasma generator in the solar atmosphere produces huge magnetic dipoles with intense magnetic field. It traps the energetic charged particles released from the solar corona. These particles gyrate along the magnetic field lines and are gradually elongated outwards from the Sun. Due to this, the field lines get detached at some critical limit thereby enhancing the magnetic reconnection with the interplanetary magnetic field releasing huge energy in the form of X-rays and γ-rays. This perturbs the Earth's atmosphere. In this work, the situation has been investigated by momentum balance equation, energy balance equation along with the equations of continuity and states. From the analyses, the dispersive nature of the thermospheric medium is studied. Variation of normalized electron temperature with dimensionless time has been critically contemplated. The altitude dependent electric field in the medium is also investigated.

  12. Stellar Coronal Response to Differential Rotation and Flux Emergence

    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...

  13. Solar Wind Associated with Near Equatorial Coronal Hole

    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.

  14. Solar Wind Associated with Near Equatorial Coronal Hole

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

    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 wavelengths 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.

  15. Grupo de Estudios Peirceanos

    Jaime Nubiola

    2001-01-01

    Full Text Available El Grupo de Estudios Peirceanos (http://www.unav.es/gep/index.htm de la Universidad de Navarra se creó en 1994. Tiene coo objetivo promover el estudio de la obra de Charles S. Peirce (1839-1914, especialmente en España y en los países de lengua castellana, con la convicción deque en su pensamiento pueden encontrarse algunas claves decisivas para la cultura, la ciencia y la filosofía del siglo XXI. El Grupo proporciona un ámbito para el intercambio de ideas acerca de la obra de Peirce, el pragmatismo americano, su recepción en Europa y en el mundo hispánico, y otros temas afines y desde sus comienzos ha contado con la participación de distintos campos como historia, lingüística, literatura, filosofía de la ciencia, derecho, teoría de la comunicación y teología.

  16. un estudio comparativo

    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.

  17. Nicasio Salvador Miguel y Santiago López-Ríos (eds.), El Quijote desde el siglo XXI : Alcalá de Henares (Madrid): Centro de Estudios Cervantinos, 2005, 250 pp.

    Aguilar, Dietris

    2008-01-01

    El Quijote desde el siglo XXI se divide en diez secciones, cada una de ellas referida a las múltiples lecturas que, desde los diversos ámbitos, lenguajes y/o medios (cine, teatro, artes plásticas, ediciones, comunicación, grabado y dibujo, la heroicidad del personaje, entre otros), la genial obra de Cervantes ha dado lugar. No obstante, su autor no queda fuera de estos estudios, ya que –en muchos casos– es considerado como el sujeto más importante de abordaje, ya sea en cuanto a su hábil mane...

  18. Los estudios políticos en Perú: ausencias, desconexión de la realidad y la necesidad de la ciencia política como disciplina

    Martín Tanaka

    2005-01-01

    Resumen El siguiente trabajo presenta una crítica de los estudios políticos en Perú en las últimas décadas, y sostiene que el panorama está signado por la ausencia de trabajos serios sobre temas fundamentales, o por un abordaje basado en marcos conceptuales y teóricos inapropiados; esto es consecuencia de una excesiva politización, dentro de diversas corrientes de izquierda. Un hecho llamativo, porque si algo caracteriza la realidad política del Perú es precisamente su carácter poco previsibl...

  19. RECONSTRUYENDO EL OBJETO DE LA CRÍTICA: SOBRE LAS POSIBLES CONFLUENCIAS ENTRE PSICOLOGÍA CRÍTICA Y ESTUDIOS SOCIALES DE LA CIENCIA Y LA TECNOLOGÍA

    Bruno Jaraba-Barrios; Fredy Mora-Gámez

    2010-01-01

    En su calidad de recursos metodológicos y conceptuales quepueden apoyar el propósito de la psicología crítica, se presentanalgunos aspectos generales de los estudios sociales dela ciencia y la tecnología (esct), los cuales han abierto promisoriassendas para el abordaje de la recíproca constituciónentre ciencia y sociedad. Las directrices del llamado programafuerte de sociología del conocimiento científico, los métodosy líneas de acción de las etnografías del laboratorio, y el abordajede análi...

  20. Abordaje multidisciplinario de la enfermedad humana por infiltración de sustancias modelantes

    J. Gordillo-Hernández

    2013-09-01

    Full Text Available En la búsqueda por mejorar la apariencia del cuerpo y de la cara con fines estéticos o reconstructivos por alguna deformidad, han aparecido técnicas no quirúrgicas que consisten en inyectar diversas sustancias modelantes bajo la premisa de que son métodos sencillos, poco dolorosos, económicos y aparentemente seguros. La sociedad actual exige una mayor preocupación por los patrones estéticos, lo que ha motivado la práctica cada vez más frecuente de la aplicación de sustancias ilícitas con el fin de aumentar el volumen y modelar ciertas partes del cuerpo sin someterse a procedimientos quirúrgicos. La ignorancia que existe en algunos países como México y otros de Latinoamerica, ha propiciado que el número de pacientes que se somete a este tipo de tratamientos por personal no capacitado y en lugares no autorizados sea cada vez mayor, sin considerar el daño irreversible que causarán a su salud física, a su autoestima y finalmente a su calidad de vida futura. Los Servicios de Cirugía Plástica y Reumatología del Hospital General de México, han sido pioneros en el estudio integral y multidisciplinario de la enfermedad humana por modelantes, han ampliado el conocimiento de la historia natural de la enfermedad, de su tratamiento médico y quirúrgico, asi como de su pronóstico. El objetivo principal de este trabajo es concentrar toda esta información en un protocolo de manejo sistematizado, mediante búsqueda en el archivo del Servicio de Cirugia Plástica "Dr. Fernando Ortiz Monasterio" del Hospital General de Mexico. Esta búsqueda abarcó 35 pacientes de los cuales se obtuvieron resultados con datos durante el periodo 2006 a 2010, demostrando la importancia de diagnosticar a los pacientes, llevar un control estrecho, explicar paso a paso el proceso de su enfermedad, el tratamiento multidiciplinario, así como el pronóstico en cuanto a si es candidato a una reconstrucción o continuará con tratamiento médico.

  1. Reconstruyendo el objeto de la crítica: sobre las posibles confluencias entre psicología crítica y estudios sociales de la ciencia y la tecnología/ reconstructing the object of the critic: on intersections between critical psychology and...

    Jaraba Barrios, Bruno; Mora Gámez, Fredy

    2010-01-01

    En su calidad de recursos metodológicos y conceptuales que pueden apoyar el propósito de la psicología crítica, se presentan algunos aspectos generales de los estudios sociales de la ciencia y la tecnología (esct), los cuales han abierto promisorias sendas para el abordaje de la recíproca constitución entre ciencia y sociedad. Las directrices del llamado programa fuerte de sociología del conocimiento científico, los métodos y líneas de acción de las etnografías del laboratorio, y el abordaje ...

  2. COMBINING PARTICLE ACCELERATION AND CORONAL HEATING VIA DATA-CONSTRAINED CALCULATIONS OF NANOFLARES IN CORONAL LOOPS

    We model nanoflare heating of extrapolated active-region coronal loops via the acceleration of electrons and protons in Harris-type current sheets. The kinetic energy of the accelerated particles is estimated using semi-analytical and test-particle-tracing approaches. Vector magnetograms and photospheric Doppler velocity maps of NOAA active region 09114, recorded by the Imaging Vector Magnetograph, were used for this analysis. A current-free field extrapolation of the active-region corona was first constructed. The corresponding Poynting fluxes at the footpoints of 5000 extrapolated coronal loops were then calculated. Assuming that reconnecting current sheets develop along these loops, we utilized previous results to estimate the kinetic energy gain of the accelerated particles. We related this energy to nanoflare heating and macroscopic loop characteristics. Kinetic energies of 0.1-8 keV (for electrons) and 0.3-470 keV (for protons) were found to cause heating rates ranging from 10–6 to 1 erg s–1 cm–3. Hydrodynamic simulations show that such heating rates can sustain plasma in coronal conditions inside the loops and generate plasma thermal distributions that are consistent with active-region observations. We concluded the analysis by computing the form of X-ray spectra generated by the accelerated electrons using the thick-target approach. These spectra were found to be in agreement with observed X-ray spectra, thus supporting the plausibility of our nanoflare-heating scenario.

  3. ANÁLISIS DE FACTORES PROTECTORES EN EL ABORDAJE DEL MALTRATO INFANTIL DESDE LA MIRADA CLÍNICA

    Gabriela Morelato

    2015-01-01

    Full Text Available El objetivo de este trabajo fue explorar desde una mirada clínica la presencia de los factoresprotectores necesarios para otorgar el alta en un proceso terapéutico de casos de maltrato in-fantil confirmados, según la opinión de los profesionales especialistas en su abordaje. Desdela perspectiva cualitativa, se utilizó una muestra no probabilística ocasional constituida por 51médicos, psicólogos, trabajadores sociales y otras disciplinas afines, especialistas en el abordajede casos de maltrato infantil. Como instrumentos, se implementaron entrevistas y grupos deenfoque. Los resultados señalan la necesidad de la evaluación y fortalecimiento de las funcionesparentales. Además, se rescataron notablemente los recursos y potencialidades propios del niñoy de la familia, los recursos institucionales y los del equipo de salud. Esta propuesta se orienta aintegrar la investigación con la reflexión acerca de las prácticas en el ámbito del maltrato infan-til, con el fin de mejorar las intervenciones clínicas.

  4. A magnetohydrodynamic theory of coronal loop transients

    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.

  5. Bayesian Magnetohydrodynamic Seismology of Coronal Loops

    Arregui, Inigo

    2011-01-01

    We perform a Bayesian parameter inference in the context of resonantly damped transverse coronal loop oscillations. The forward problem is solved in terms of parametric results for kink waves in one-dimensional flux tubes in the thin tube and thin boundary approximations. For the inverse problem, we adopt a Bayesian approach to infer the most probable values of the relevant parameters, for given observed periods and damping times, and to extract their confidence levels. The posterior probability distribution functions are obtained by means of Markov Chain Monte Carlo simulations, incorporating observed uncertainties in a consistent manner. We find well localized solutions in the posterior probability distribution functions for two of the three parameters of interest, namely the Alfven travel time and the transverse inhomogeneity length-scale. The obtained estimates for the Alfven travel time are consistent with previous inversion results, but the method enables us to additionally constrain the transverse inho...

  6. Kinematical properties of coronal mass ejections

    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...

  7. Waiting Time Distribution of Coronal Mass Ejections

    Chin-Teh Yeh; Ming-De Ding; Peng-Fei Chen

    2005-01-01

    Inspired by the finding that the large waiting time of solar flares presents a power-law distribution, we investigate the waiting time distribution (WTD) of coronal mass ejections (CMEs). SOHO/LASCO CME observations from 1996 to 2003 are used in this study. It is shown that the observed CMEs have a similar power-law behavior to the flares, with an almost identical power-law index. This strongly supports the viewpoint that solar flares and CMEs are different manifestations of the same physical process. We have also investigated separately the WTDs of fast-type and slow-type CMEs and found that their indices are identical, which imply that both types of CME-5-originate from the same physical mechanism.

  8. The coronal structure of active regions

    A four-parameter model which assumes a Gaussian dependence of both temperature and pressure on distance from center is used to fit the compact part of coronal active regions as observed in X-ray photographs from a rocket experiment. The four parameters are the maximum temperature Tsub(M), the maximum pressure Psub(M)=2Nsub(M)kTsub(M), the width of the pressure distribution sigmasub(P), and the width of the temperature distribution sigmasub(T)=αsup(1/2)sigmasub(P). The maximum temperature Tsub(M) ranges from 2.2 to 2.8x106K, and the maximum density Nsub(M) from 2 to 9x109cm-3. The range of sigmasub(P) is from 2 to 4x109 cm and that of α from 2 to 7. (Auth.)

  9. Magnetic structure of Coronal Mass Ejections

    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.

  10. Numerical Simulation of DC Coronal Heating

    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.

  11. A Model for Stealth Coronal Mass Ejections

    Lynch, Benjamin J.; Masson, Sophie; Li, Yan; DeVore, C. Richard; Luhmann, Janet; Antiochos, Spiro K.; Fisher, George H.

    2016-05-01

    Stealth coronal mass ejections (CMEs) are events in which there are almost no observable signatures of the CME eruption in the low corona but often a well-resolved slow flux rope CME observed in the coronagraph data. We present results from a three-dimensional numerical magnetohydrodynamics (MHD) simulation of the 2008 June 1-2 slow streamer blowout CME that Robbrecht et al. [2009] called “the CME from nowhere.” We model the global coronal structure using a 1.4 MK isothermal solar wind and a low-order potential field source surface representation of the Carrington Rotation 2070 magnetogram synoptic map. The bipolar streamer belt arcade is energized by simple shearing flows applied in the vicinity of the helmet streamer’s polarity inversion line. The slow expansion of the energized helmet-streamer arcade results in the formation of a radial current sheet. The subsequent onset of expansion-driven flare reconnection initiates the stealth CME while gradually releasing ~1.5E+30 erg of stored magnetic energy over the 20+ hour eruption duration. We show the energy flux available for flare heating and flare emission during the eruption is approximately two orders of magnitude below the energy flux required to heat the ambient background corona, thus confirming the “stealth” character of the 2008 June 1-2 CME’s lack of observable on disk signatures. We also present favorable comparisons between our simulation results and the multi-viewpoint SOHO-LASCO and STEREO-SECCHI coronagraph observations of the pre-eruption streamer structure and the initiation and evolution of the stealth streamer blowout CME.

  12. SAUSAGE OSCILLATIONS OF CORONAL PLASMA STRUCTURES

    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-β 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 Alfvén speed correspond to more efficient trapping of sausage modes: the cutoff value of the wavelength increases with the steepness and the density (or Alfvén 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 Alfvén speed.

  13. Estudio de competencias del teleformador

    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.

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

    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.

  15. Estudio con imágenes de la cefalea

    Claudia Jimena Ortiz Liévano

    2012-08-01

    Full Text Available El objetivo de este artículo es brindar al clínico pautas para el uso racional y adecuado de los avances tecnológicos en imaginología, para de esta manera lograr un criterio multidisciplinario en el momento de tomar una decisión buscando el beneficio del paciente sin someterlo a exámenes de poca utilidad. Se realizó una búsqueda sistemática de la literatura médica acerca de la cefalea abarcando su fisiopatología, clasificación y, específicamente, el uso de imágenes diagnósticas. Para ello se hizo búsqueda en diferentes bases de datos según las palabras claves indicadas. El abordaje clínico y la diferenciación entre el tipo de cefalea es primordial para decidir el beneficio y la necesidad del uso de imágenes diagnósticas. Las neuroimágenes no son comúnmente solicitadas en pacientes con cefalea primaria, se comienza la sospecha clínica ante la presencia de señales de alarma. Las cefaleas secundarias requieren un estudio más extenso en los cuales se incluye la toma de imágenes radiológicas. Teniendo en cuenta los beneficios de la TC y la RM que se exponen en esta revisión, la TC es preferida en situaciones de urgencia, y para aquellas que no lo son, la RM es más adecuada.

  16. MODELO DIDÁCTICO BASADO EN LA CREATIVIDAD Y ORIENTADO AL ABORDAJE DE LA EDUCACIÓN ALIMENTARIA Y NUTRICIONAL, EN EL NIVEL DE EDUCACION INICIAL

    Ernesto Elías De La Cruz Sánchez

    2013-08-01

    investigación permitió generar un aporte didáctico orientado al abordaje de la educación alimentaria y nutricional basado en la creatividad para el nivel de Educación Inicial. El modelo se sustentó en las diferentes dimensiones emergentes que permiten interpretar el comportamiento alimentario del ser humano, en las teorías interaccionistas de la creatividad relacionadas con la enseñanza y el aprendizaje en la Educación Inicial. El estudio se ubicó en una investigación cualitativa, de naturaleza fenomenológica interpretativa y de enfoque etnometodológico, centrado en la comprensión de la realidad expresada por los sujetos, el investigador, la praxis educativa en el aula de preescolar y en la comprensión del acto alimentario. Los sujetos %u2013informantes clave- de la investigación se seleccionaron de modo intencional y en total fueron 3 especialistas en nutrición-medicina (INN, Fundación Bengoa y CANIA, 3 docentes universitarios en Educación Preescolar y 6 maestras del Centro Nacional Bolivariano de Educación Inicial, ubicado en Petare, Estado Miranda, y contexto del estudio. Se utilizó como técnicas de recolección de información: la entrevista cualitativa, la observación participante y las conversaciones grupales. Se emplearon como instrumentos: el cuaderno de anotaciones y la guía de entrevista. Para el procesamiento de la información se asumió la teoría fundamentada y el método comparativo continuo propuesto por Strauss y Corbin (2002 y el apoyo en la herramienta de Atlas-ti, versión 5.0. La investigación arrojó: un modelo didáctico basado en la creatividad orientado a sustentar un enfoque creativo para la enseñanza de la educación alimentaria y nutricional en el Nivel de Educación Inicial, el cual incluye recomendaciones para el docente, los padres, la escuela y una sintesis de doce (12 estrategias didácticas para ser incorporadas en la rutina escolar. La validez se determinó por juicio de experto, en base a 10 criterios: integral

  17. Turbulent Coronal Heating Mechanisms: Coupling of Dynamics and Thermodynamics

    Dahlburg, R B; Rappazzo, A F; Velli, M

    2012-01-01

    Context. Photospheric motions shuffle the footpoints of the strong axial magnetic field that threads coronal loops giving rise to turbulent nonlinear dynamics characterized by the continuous formation and dissipation of field-aligned current sheets where energy is deposited at small-scales and the heating occurs. Previous studies show that current sheets thickness is orders of magnitude smaller than current state of the art observational resolution (~700 km). Aim. In order to understand coronal heating and interpret correctly observations it is crucial to study the thermodynamics of such a system where energy is deposited at unresolved small-scales. Methods. Fully compressible three-dimensional magnetohydrodynamic simulations are carried out to understand the thermodynamics of coronal heating in the magnetically confined solar corona. Results. We show that temperature is highly structured at scales below observational resolution and nonhomogeneously distributed so that only a fraction of the coronal mass and ...

  18. Nonlinear Processes in Coronal Heating and Slow Solar Wind Acceleration

    Rappazzo, A F

    2010-01-01

    This work consists of two parts: the first devoted to the study of the heating of the magnetically confined Solar Corona, and the second to the acceleration of the Slow Solar Wind. Direct 3D reduced MHD simulations are presented. They model the heating of coronal loops in the solar atmosphere via the tangling of coronal field lines by photospheric footpoints motions within the framework of the "Parker scenario". We have derived scalings of physical quantities with loop length, and the ratio of photospheric to coronal Alfven velocities. The development of a turbulent dynamics makes the dissipation rate independent of the Reynolds number. The dynamics in physical space are desribed by weak turbulence, which develops when an MHD system is embedded in a strong axial magnetic field. The slow wind originates in and around the coronal streamer belt. The LASCO instrument onboard the SOHO spacecraft has observed plasma density enhancements forming beyond the cusp of a helmet streamer. Previous theoretical models for t...

  19. Standing sausage modes in coronal loops with plasma flow

    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...

  20. Anticipating the Geoeffectiveness of Coronal Mass Ejections Project

    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...

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

    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.

  2. Cyclical Variation of the Quiet Corona and Coronal Holes

    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.

  3. Coronal Activity and Extended Solar Cycles

    Altrock, R. C.

    2012-12-01

    Wilson et al. (1988, Nature 333, 748) discussed a number of solar parameters, which appear at high latitudes and gradually migrate towards the equator, merging with the sunspot "butterfly diagram". They found that this concept had been identified by earlier investigators extending back to 1957. They named this process the "Extended Solar Cycle" (ESC). Altrock (1997, Solar Phys. 170, 411) found that this process continued in Fe XIV 530.3 nm emission features. In cycles 21 - 23 solar maximum occurred when the number of Fe XIV emission regions per day > 0.19 (averaged over 365 days and both hemispheres) first reached latitudes 18°, 21° and 21°, for an average of 20° ± 1.7°. Other recent studies have shown that Torsional Oscillation (TO) negative-shear zones are co-located with the ESC from at least 50° down to the equator and also in the zones where the Rush to the Poles occur. These phenomena indicate that coronal activity occurring up to 50° and higher latitudes is related to TO shear zones, another indicator that the ESC is an important solar process. Another high-latitude process, which appears to be connected with the ESC, is the "Rush to the Poles" ("Rush") of polar crown prominences and their associated coronal emission, including Fe XIV. The Rush is is a harbinger of solar maximum (cf. Altrock, 2003, Solar Phys. 216, 343). Solar maximum in cycles 21 - 23 occurred when the center line of the Rush reached a critical latitude. These latitudes were 76°, 74° and 78°, respectively, for an average of 76° ± 2°. Applying the above conclusions to Cycle 24 is difficult due to the unusual nature of this cycle. Cycle 24 displays an intermittent "Rush" that is only well-defined in the northern hemisphere. In 2009 an initial slope of 4.6°/yr was found in the north, compared to an average of 9.4 ± 1.7 °/yr in the previous three cycles. This early fit to the Rush would have reached 76° at 2014.6. However, in 2010 the slope increased to 7.5°/yr (an increase

  4. The Multithermal and Multi-stranded Nature of Coronal Rain

    Antolin, P.; Vissers, G.; Pereira, T. M. D.; Rouppe van der Voort, L.; Scullion, E.

    2015-06-01

    We analyze coordinated observations of coronal rain in loops, spanning chromospheric, transition region (TR), and coronal temperatures with sub-arcsecond spatial resolution. Coronal rain is found to be a highly multithermal phenomenon with a high degree of co-spatiality in the multi-wavelength emission. EUV darkening and quasi-periodic intensity variations are found to be strongly correlated with coronal rain showers. Progressive cooling of coronal rain is observed, leading to a height dependence of the emission. A fast-slow two-step catastrophic cooling progression is found, which may reflect the transition to optically thick plasma states. The intermittent and clumpy appearance of coronal rain at coronal heights becomes more continuous and persistent at chromospheric heights just before impact, mainly due to a funnel effect from the observed expansion of the magnetic field. Strong density inhomogeneities of 0\\buildrel{\\prime\\prime}\\over{.} 2-0\\buildrel{\\prime\\prime}\\over{.} 5 are found, in which a transition from temperatures of 105 to 104 K occurs. The 0\\buildrel{\\prime\\prime}\\over{.} 2-0\\buildrel{\\prime\\prime}\\over{.} 8 width of the distribution of coronal rain is found to be independent of temperature. The sharp increase in the number of clumps at the coolest temperatures, especially at higher resolution, suggests that the bulk distribution of the rain remains undetected. Rain clumps appear organized in strands in both chromospheric and TR temperatures. We further find structure reminiscent of the magnetohydrodynamic (MHD) thermal mode (also known as entropy mode), thereby suggesting an important role of thermal instability in shaping the basic loop substructure. Rain core densities are estimated to vary between 2 × 1010 and 2.5× {{10}11} cm-3, leading to significant downward mass fluxes per loop of 1-5 × 109 g s-1, thus suggesting a major role in the chromosphere-corona mass cycle.

  5. Exploración del modelo coronal MHD de Uchida

    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

  6. El componente educativo en el abordaje integral del asma bronquial The educational component in an integrated approach to bronchial asthma

    María Paola Fasciglione

    2010-04-01

    Full Text Available El asma bronquial es una enfermedad inflamatoria crónica de las vías respiratorias cuya prevalencia está aumentando en el mundo. Actualmente no se dispone de un tratamiento curativo, y el objetivo principal de todo abordaje es el control de la enfermedad y la optimización de la calidad de vida de los pacientes. En este sentido, durante las últimas décadas se han estado implementando y evaluando programas de intervención complementarios a los tratamientos médicos convencionales. Gran parte de éstos consisten en intervenciones educativas o incluyen algún tipo de componente educativo. El objetivo del presente trabajo fue analizar las características y el impacto de las intervenciones educativas en el asma, a través de: a revisión actualizada sobre los diferentes tipos de intervenciones educativas desarrolladas e implementadas para el asma; b identificación de aspectos comunes a todas estas intervenciones; c análisis de los hallazgos de la investigación referidos a su impacto sobre la salud y la calidad de vida de los pacientes. Se concluye que las intervenciones educativas son efectivas para mejorar la salud y la calidad de vida de los pacientes con asma, y para reducir el uso y el costo de recursos sanitarios. Estos hallazgos señalan la importancia de incluir el componente educativo como parte esencial del abordaje integral de esta población clínica. Asimismo, la complejidad inherente al proceso educativo pone de manifiesto la necesidad del trabajo conjunto y complementario entre diferentes profesionales de la salud.Bronchial asthma is an inflammatory chronic disease of the respiratory tract whose prevalence is increasing worldwide. Since there is no curative treatment available, the principal objective of every approach is to control the disease and to improve the quality of life of patients. Over the last few decades, intervention programs supplementing conventional medical treatments have been tested and implemented. The

  7. Coronal Dynamics at Recent Total Solar Eclipses

    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

  8. Evolving Coronal Holes and Interplanetary Erupting Stream Disturbances

    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. Coronal seismology of flare-excited longitudinal slow magnetoacoustic waves in hot coronal loops

    Wang, T.; Ofman, L.; Sun, X.; Provornikova, E. A.; Davila, J. M.

    2015-12-01

    The flare-excited longitudinal intensity oscillations in hot flaring loops have been recently detected by SDO/AIA in 94 and 131 bandpasses. These oscillations show similar physical properties (such as period, decay time, and trigger) as those slow-mode standing waves previously detected by the SOHO/SUMER spectrometer in Doppler shift of flare lines formed above 6 MK. The multi-wavelength AIA observations with high spatio-temporal resolution and wide temperature coverage enable us to measure both thermal and wave properties of the oscillating hot plasma with unprecedented accuracy. These new measurements can be used to diagnose the complicated energy transport processes in flare plasma by a technique called coronal seismology based on the combination of observations and MHD wave theory. From a detailed case study we have found evidence for thermal conduction suppression in hot loops by measuring the polytropic index and analyzing the phase relationship between the temperature and density wave signals. This result is not only crucial for better understanding the wave dissipation mechanism but also provides an alternative mechanism to explain the puzzles of long-duration events and X-ray loop-top sources which show much slower cooling than expected by the classical Spitzer conductive cooling. This finding may also shed a light on the coronal heating problem because weak thermal conductivity implies slower cooling of hot plasma in nanoflares, so increasing the average coronal temperature for the same heating rate. We will discuss the effects of thermal conduction suppression on the wave damping and loop cooling based on MHD simulations.

  10. Why are halo coronal mass ejections faster?

    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.

  11. Multiscale Modeling of Solar Coronal Magnetic Reconnection

    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.

  12. A coronal wave as CME footprint

    Delannée, Cécile

    2013-01-01

    I report a coronal wave observed in Fexii, soft X-ray, and Halpha on November 6, 2006, jointly with a CME and a flare to show the spatial and temporal relation of the wave and the CME. I also take advantage of the spectral resolution of the wave to obtain an approximation of its temperature. Finally, I compare the magnetic field topology to the wave location. The observations in two band passes show bright fronts that are co-spatial when observed at the same time, therefore I believe that the same wave is observed in different band passes. The wave front is not observable in Halpha, but just in Fexii and in soft X-ray, indicating that the temperature of the wave front is slightly higher than the chromospheric temperature. The ratio of emission through two SXI filters gives a temperature of 7 10^6 K for the wave front. The northern-most edge of the CME footprint related to this wave corresponds to the last location of the wave on the limb. The image processing reveals stationary brightenings produced on the pa...

  13. Magnetic flux supplement to coronal bright points

    Mou, Chaozhou; Xia, Lidong; Madjarska, Maria S; Li, Bo; Fu, Hui; Jiao, Fangran; Hou, Zhenyong

    2015-01-01

    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 analyse longitudinal magnetograms from the Helioseismic and Magnetic Imager to investigate the photospheric magnetic flux evolution of 70 BPs. From images taken in the 193 A passband of the Atmospheric Imaging Assembly (AIA) we dermine that the BPs' lifetimes vary from 2.7 to 58.8 hours. 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 a MBF can involve more than one of these processes. Out of the 70 cases, flux emergence is the main process of a 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 \\AA\\ passband varie...

  14. Surface Flux Emergence and Coronal Eruption

    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.

  15. Trata: Esclavitud invisibilizada en Costa Rica. Estudio de cinco casos

    Marianela Méndez-Marenco

    2013-12-01

    Full Text Available La trata de personas con fines de explotación sexual comercial es una problemática solapada en Costa Rica. Resulta necesario conocer este fenómeno, puesto que cada día más ciudadanos son atrapados y sometidos a una forma de esclavitud, que denigra su integridad física, psicológica, social y espiritual. A partir de las experiencias vividas como profesional en una organización sin fines de lucro (ONG con un programa para esta población, hizo evidente el desconocimiento y los excesivos prejuicios sobre las víctimas en la sociedad. Se explora el hecho de que la información sobre este fenómeno en Costa Rica es escasa y el abordaje psicológico lo es aún más. La investigación tiene sus bases en la metodología cualitativa descriptiva; se propone un diseño fenomenológico que parte de la teoría humanista del Análisis Transaccional de Berne (1976 para efectuar estudio múltiple de casos. La muestra estuvo constituida por un grupo de cinco mujeres, que se encontraron en proceso de restauración en la ONG bajo las categorías de análisis “Trata de personas con fines de explotación sexual comercial nacional” (dentro de Costa Rica, “Avasallamientos” y “Desarrollo personal”. Los resultados identificaron avasallamientos, a los que fueron sometidas las mujeres de esta muestra, antes, durante y después de ser captadas en la trata. Asimismo, se analiza cómo el desarrollo de las mujeres víctimas de trata en este estudio se ve obstaculizado por dichos avasallamientos y cómo algunas lograron obtener el crecimiento personal a pesar de lo sucedido.

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

    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.

  17. Coronal Heating and the Magnetic Flux Content of the Network

    Falconer, D. A.; Moore, R. L.; Porter, J. G.; Hathaway, D. H.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    Previously, from analysis of SOHO/EIT coronal images in combination with Kitt Peak magnetograms (Falconer et al 1998, ApJ, 501, 386-396), we found that the quiet corona is the sum of two components: the e-scale corona and the coronal network. The large-scale corona consists of all coronal-temperature (T approx. 10(exp 6) K) structures larger than supergranules (>approx.30,000 km). The coronal network (1) consists of all coronal-temperature structures smaller than supergranules, (2) is rooted in and loosely traces the photospheric magnetic network, (3) has its brightest features seated on polarity dividing fines (neutral lines) in the network magnetic flux, and (4) produces only about 5% of the total coronal emission in quiet regions. The heating of the coronal network is apparently magnetic in origin. Here, from analysis of EIT coronal images of quiet regions in combination with magnetograms of the same quiet regions from SOHO/MDI and from Kitt Peak, we examine the other 95% of the quiet corona and its relation to the underlying magnetic network. We find: (1) Dividing the large-scale corona into its bright and dim halves divides the area into bright "continents" and dark "oceans" having spans of 2-4 supergranules. (2) These patterns are also present in the photospheric magnetograms: the network is stronger under the bright half and weaker under the dim half. (3) The radiation from the large-scale corona increases roughly as the cube root of the magnetic flux content of the underlying magnetic network. In contrast, Fisher et A (1998, ApJ, 508, 985-998) found that the coronal radiation from an active region increases roughly linearly with the magnetic flux content of the active region. We assume, as is widely held, that nearly all of the large-scale corona is magnetically rooted in the network. Our results, together with the result of Fisher et al (1999), suggest that either the coronal heating in quiet regions has a large non-magnetic component, or, if the heating

  18. Estudio antropológico de redes sociales de madres adolescentes durante el embarazo

    Lorena Pasarin

    2009-07-01

    Full Text Available La atención de la salud incluye a diversos actores sociales, por ello en su estudio debe contemplarse el papel que adquieren los contextos socioculturales. El estudio de las redes sociales resulta conveniente para abordarlos. Este trabajo presenta una aplicación del análisis de redes sociales como complemento de abordaje metodológico al estudio de las prácticas y comportamientos relacionados con la salud de madres adolescentes durante el período prenatal. Utilizando la herramienta EgoNet, se analiza la estructura de las redes personales identificando redes integradas principalmente por familiares que brindan consejos y prestan ayuda instrumental, actuando como facilitadoras respecto a la realización de los controles de salud. La perspectiva de análisis de redes sociales permitió destacar el papel decisivo que cobran ciertas relaciones personales, funcionando como lazos eficaces que afectan significativamente el accionar de las adolescentes respecto a su salud durante el embarazo.The health care includes several social actors, this implies that its study should consider the role of the sociocultural contexts. The study of social networks is appropriate to address them. This paper presents an application of social network analysis as a complement of the methodological approach for the study of practices and health-related behaviors in adolescents mothers. This structure of personal networks is analyzed by EgoNet sofware. That structure is disscussed by identifying family networks that offer advices and provide instrumental assistance, acting as facilitators for the prenatal health controls. The social networks analysis perspective allows to emphasize the critical role acquired by certain personal relationships, which operate affecting significantly the health actions of the teenagers mothers during pregnancy.

  19. y casos de estudios

    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.

  20. MEXCODE* CASO DE ESTUDIO

    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.

  1. CME Interaction with Coronal Holes and Their Interplanetary Consequences

    Gopalswamy, N.; Makela, P.; Xie, H.; Akiyama, S.; Yashiro, S.

    2008-01-01

    A significant number of interplanetary (IP) shocks (-17%) during cycle 23 were not followed by drivers. The number of such "driverless" shocks steadily increased with the solar cycle with 15%, 33%, and 52% occurring in the rise, maximum, and declining phase of the solar cycle. The solar sources of 15% of the driverless shocks were very close the central meridian of the Sun (within approx.15deg), which is quite unexpected. More interestingly, all the driverless shocks with their solar sources near the solar disk center occurred during the declining phase of solar cycle 23. When we investigated the coronal environment of the source regions of driverless shocks, we found that in each case there was at least one coronal hole nearby suggesting that the coronal holes might have deflected the associated coronal mass ejections (CMEs) away from the Sun-Earth line. The presence of abundant low-latitude coronal holes during the declining phase further explains why CMEs originating close to the disk center mimic the limb CMEs, which normally lead to driverless shocks due to purely geometrical reasons. We also examined the solar source regions of shocks with drivers. For these, the coronal holes were located such that they either had no influence on the CME trajectories. or they deflected the CMEs towards the Sun-Earth line. We also obtained the open magnetic field distribution on the Sun by performing a potential field source surface extrapolation to the corona. It was found that the CMEs generally move away from the open magnetic field regions. The CME-coronal hole interaction must be widespread in the declining phase, and may have a significant impact on the geoeffectiveness of CMEs.

  2. Muerte, donación de órganos y eutanasia. Abordaje jurídico, ético y religioso.

    Hierro Vázquez, María Eugenia

    2013-01-01

    En la sanidad vemos a las personas desde una perspectiva holística, en la cual incluimos la espiritualidad. Los valores y creencias de las personas son de gran importancia en la hora de la muerte y definen sus posturas frente a algunas prácticas como la eutanasia o la donación de órganos. Por ello es vital conocer los aspectos jurídicos y religiosos sobre estas prácticas para poder hacer un abordaje ético y ayudar a alcanzar una muerte lo más digna posible.

  3. Conformación de un espacio de aprendizaje para el abordaje computacional de problemas de la Física y otras disciplinas

    Lara, Luis; Navone, Hugo D.; Turner, Pablo A.

    1996-01-01

    El rol de los recursos informáticos en el de$arrollo de las diversas disciplinas científicas ha originado nuevos enfoques en el tratamiento y en la resolución de los problemas derivados de las mismas. Más aún, la complejidad de los distintos. sistemas que hoy se estudian exige una formulación, en muchos casos, estrictamente algorítmica. Pero este ,desarrollo en el campo profesional no ha modificado el abordaje de la enseñanza de las ciencias en general y de la físicos en particular. En est...

  4. Endomarketing- Un abordaje a la motivación de las pequeñas y medianas empresas

    Simões Machado, José António

    2015-01-01

    Tesis Doctoral leída en la Universidad Rey Juan Carlos de Madrid en 2015. Directores de la Tesis: Rocío Samino García y Mafalda Ferreira Este estudio intenta contribuir a la literatura existente sobre la motivación (intrínseca y extrínseca), a través del estudio de la relación entre los factores de satisfacción y los factores de motivación en las PYMES, así como del análisis del impacto de las variables "Tener un puesto di Dirección", "Género", "Educación Superior", "Experiencia en cargos ...

  5. Probing Coronal Mass Ejections with Faraday Rotation

    Spangler, Steven R.; Fischer, P. D.; Kooi, J. E.; Buffo, J. J.

    2013-07-01

    Coronal Mass Ejections (CMEs) are one of the most important solar phenomena in affecting conditions on Earth. There is not a consensus as to the physical mechanisms responsible for ejecting CME material from the solar atmosphere. Measurements that specify basic physical properties close to the Sun, when the CME is still evolving, should be useful in determining the correct theoretical model. One of the best observational techniques is that of Faraday rotation, a rotation in the plane of polarization of radio waves when propagating through a magnetized medium like the corona. The importance of Faraday rotation in determining the structure and evolutionary history of CMEs was discussed in Liu et al (ApJ 665, 1439, 2007). In this paper, we report Faraday rotation observations of ``constellations'' of background extragalactic radio sources near the Sun on three days in August, 2012, with the intention of observing a source occulted by a CME. Observations were made with the Jansky Very Large Array (VLA) of the National Radio Astronomy Observatory. We made polarization measurements at 6 frequencies between 1.31 and 1.94 GHz. On August 2, 2012, a CME clearly visible on the LASCO C3 coronagraph occulted a radio source from our sample, 0843+1547. Preliminary data analysis shows a Faraday rotation transient for 0843+1547 which appears to be associated with the CME. The Faraday rotation measure changes from nearly 0 before CME passage, to a value of about -12 radians/square-meter before declining after CME passage. We will discuss the interpretation of these data in terms of models for CME structure, as well as the status of our observations of other sources on August 2, and on other days. This work was supported at the University of Iowa by grant ATM09-56901.

  6. Magnetic Reconnection in Interplanetary Coronal Mass Ejections

    Fermo, R. L.; Opher, M.; Drake, J. F.

    2014-12-01

    Magnetic reconnection is a ubiquitous phenomenon in many varied space and astrophysical plasmas, and as such plays an important role in the dynamics of interplanetary coronal mass ejections (ICMEs). It is widely regarded that reconnection is instrumental in the formation and ejection of the initial CME flux rope, but reconnection also continues to affect the dynamics as it propagates through the interplanetary medium. For example, reconnection on the leading edge of the ICME, by which it interacts with the interplanetary medium, leads to flux erosion. However, recent in situ observations by Gosling et al. found signatures of reconnection exhausts in the interior. In light of this data, we consider the stability properties of systems with this flux rope geometry with regard to their minimum energy Taylor state. Variations from this state will result in the magnetic field relaxing back towards the minimum energy state, subject to the constraints that the toroidal flux and magnetic helicity remain invariant. In reversed field pinches, this relaxation is mediated by reconnection in the interior of the system, as has been shown theoretically and experimentally. By treating the ICME flux rope in a similar fashion, we show analytically that the the elongation of the flux tube cross section in the latitudinal direction will result in a departure from the Taylor state. The resulting relaxation of the magnetic field causes reconnection to commence in the interior of the ICME, in agreement with the observations of Gosling et al. We present MHD simulations in which reconnection initiates at a number of rational surfaces, and ultimately produces a stochastic magnetic field. If the time scales for this process are shorter than the propagation time to 1 AU, this result explains why many ICME flux ropes no longer exhibit the smooth, helical flux structure characteristic of a magnetic cloud.

  7. Coronal Seismology: Inferring Magnetic Fields and Exploring Damping Mechanisms

    McAteer, R. T. James; Ireland, Jack

    2015-08-01

    Recent observations in extreme ultra-violet wavelengths have shown that the solar corona oscillates at many different spatial sizes and temporal size scales. However, much remains unknown about many of these oscillations; they are intermittent for unknown reasons, appear on some coronal features and not on other, similar, neighboring features, and may (or may not) be magnetohydrodynamic (MHD) wave modes. Definitive causes of the structure and origins of these oscillations are still largely lacking. Here, we use automated oscillation detection routines to study a large sample of oscillations, inferring physical mechanisms as to how and why the corona varies.First, we measure the oscillation content of different physical regions on the Sun in SDO AIA data, using two different automated oscillation detection algorithms. This shows a power-law distribution in oscillatory frequency, disagreeing with strong historical assumptions about the nature of coronal heating and coronal seismology. We show how such disagreements can be reconciled by using a power-law background for oscillatory signals.Second we use coronal seismology to provide a means to infer coronal plasma parameters and to differentiate between potential damping mechanisms. Recent sets of kink-mode observations (usually 5-8 loops) have come insights into how the coronal is structured and how it evolves. We present a complex set of flare-induced, off-limb, coronal kink-mode oscillations of almost 100 loops. These display a spread of periods, amplitudes, and damping times, allowing us to probe the spatial distribution of these parameters for the first time. Both Fourier and Wavelet routines are used to automatically extract and characterize these oscillations. An initial period of P~500s, results in an inferred coronal magnetic field of B~20G. The decrease in the oscillation period of the loop position corresponds to a drop in number density inside the coronal loop, as predicted by MHD. As the the period drops

  8. Deriving Coronal Magnetic Fields Using Parametric Transformation Analysis

    Gary, G. A.

    2001-05-01

    When plasma β >1 then the gas pressure dominates over the magnetic pressure. This ratio as a function along the coronal magnetic field lines varies from β > 1 in the photosphere at the base of the field lines, to β 1 in the upper corona. Almost all magnetic field extrapolations do not or cannot take into account the full range of β . They essentially assume β 1 regions. We use a basic parametric representation of the magnetic field lines such that the field lines can be manipulated to match linear features in the EUV and SXR coronal images in a least squares sense. This research employs free-form deformation mathematics to generate the associated coronal magnetic field. In our research program, the complex magnetic field topology uses Parametric Transformation Analysis (PTA) which is a new and innovative method to describe the coronal fields that we are developing. In this technique the field lines can be viewed as being embedded in a plastic medium, the frozen-in-field-line concept. As the medium is deformed the field lines are similarly deformed. However the advantage of the PTA method is that the field line movement represents a transformation of one magnetic field solution into another magnetic field solution. When fully implemented, this method will allow the resulting magnetic field solution to fully match the magnetic field lines with EUV/SXR coronal loops by minimizing the differences in direction and dispersion of a collection of PTA magnetic field lines and observed field lines. The derived magnetic field will then allow β > 1 regions to be included, the electric currents to be calculated, and the Lorentz force to be determined. The advantage of this technique is that the solution is (i) independent of the upper and side boundary conditions, (ii) allows non-vanishing magnetic forces, and (iii) provides a global magnetic field solution, which contains high- and low- β regimes and maximizes the similarity between the field lines structure and all the

  9. Standing Slow MHD Waves in Radiatively Cooling Coronal Loops

    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.

  10. Magnetic Evolution and Temperature Variation in a Coronal Hole

    Zhang, Jun; Wang, Jingxiu; Wang, Haimin

    2007-01-01

    We have explored the magnetic flux evolution and temperature variation in a coronal-hole region, using Big Bear Solar Observatory (BBSO) deep magnetograms and {\\it SOHO}/EIT images observed from 2005 October 10 to 14. For comparison, we also investigated a neighboring quiet region of the Sun. The coronal hole evolved from its mature stage to its disappearance during the observing period. We have obtained the following results: (1) When the coronal hole was well developed on October 10, about 60 % of the magnetic flux was positive. The EUV brightness was 420 counts pixel$^{-1}$, and the coronal temperature, estimated from the line ratio of the EIT 195 {\\AA} and 171 {\\AA} images, was 1.07 MK. (2) On October 14, when the coronal hole had almost disappeared, 51 % of the magnetic flux was positive, the EUV radiance was 530 counts pixel$^{-1}$, and the temperature was 1.10 MK. (3) In the neighboring quiet region, the fraction of positive flux varied between 0.49 and 0.47. The EUV brightness displayed an irregular v...

  11. Education for Democratic Citizenship in Educational Institutions: The Socio-educational Approach La educación para una ciudadanía democrática en las instituciones educativas: Su abordaje sociopedagógico

    Arturo Torres Bugdud

    2013-08-01

    Full Text Available Citizenship education is one of the most relevant topics in education. It comprises key aspects of the student’s personal and social behavior, and has significant points of convergence with other areas of the educational practice. Democracy is emphasized in this paper as an important feature of citizenship education, which requires special attention in terms of its socio-educational approach. Citizenship education may be studied from different scientific disciplines; in this case, the pedagogical approach is studied from the social perspective. The main objective of this paper is to discuss the theoretical basis on the subject matter of this project, through studies conducted in different contexts of the social sciences, underlining the importance of citizenship education today, regardless of the educational level in which it is taught. Analysis-synthesis and historical-logical methods were used to assess the background on the subject, obtaining results that could be developed in the educational institutions, in the future.Recibido 20 de mayo de 2012 • Corregido 17 de junio de 2013 • Aceptado 19 de junio de 2013La educación ciudadana es uno de los temas educativos de mayor actualidad, además de abordar aspectos esenciales de la dimensión personal y social del estudiante, posee puntos de contacto importantes con otras direcciones de la práctica educativa. En este artículo se enfatiza la democracia como cualidad importante de la educación ciudadana que requiere especial atención en su abordaje sociopedagógico. El tema de la educación ciudadana se afronta por diferentes disciplinas científicas, en este caso se acentúa el enfoque pedagógico desde una perspectiva social. El objetivo fundamental de este artículo de reflexión es argumentar los sustentos teóricos sobre esta temática, a través de estudios realizados en diferentes contextos desde el campo de las ciencias sociales, destacando la importancia que adquiere la educaci

  12. Factores emocionales en el abordaje de las enfermedades cardiovasculares. Valoración actualizada desde la Psicocardiología Emotional Factors in the present a topic of Cardiovascular Diseases. Updated Assessment from Psychocardiology

    Teresa Rodríguez Rodríguez

    2012-11-01

    Full Text Available El tratamiento de las enfermedades cardiovasculares exige un abordaje desde la multidisciplinariedad, por la presencia de diversos factores en su origen y evolución. La Psicocardiología se encarga de estudiar los factores de orden psicológico vinculados a estas enfermedades. En el presente trabajo se abordan los factores emocionales que repercuten en diferentes padecimientos coronarios, así como el vínculo de estos, con los diferentes tipos de personalidad. Se exponen resultados obtenidos sobre el estudio de diversas emociones en pacientes portadores de infarto agudo del miocardio en fase aguda, y se ilustra cómo realizar la intervención psicológica para lograr el control emocional de estos pacientes porque puede ser útil para los enfermos y en el mejoramiento del cuadro clínico en general. Finalmente se apela a la necesidad de crear una concientización en la comunidad médica, para que no se desestime el papel de factores de índole subjetiva a la hora de prevenir, diagnosticar y tratar cualquier enfermedad cardiaca.The treatment of cardiovascular diseases requires an approach from a variety of disciplines due to the presence of several factors in its origins and evolution. Psychocardiology is responsible for studying the factors related to psychology associated with these diseases. This paper addresses the emotional factors affecting different coronary heart diseases, as well as the link among them, with different types of personalities. Results on the study of various emotions in patients with acute myocardial infarction in the acute phase are presented and it is illustrates how to achieve psychological intervention for emotional control in these patients because it can be useful for them in the improvement of the overall clinical condition. Finally, it is appealed to the need of creating an awareness in the medical community not to discard the role of subjectivity when it comes to preventing, diagnosing and treating any cardiac

  13. La implementación del abordaje colaborativo en Costa Rica: hacia una integración entre la psiquiatría y la atención primaria

    Ricardo Millán-González

    2014-12-01

    Full Text Available Introducción: la Organización Mundial de la Salud ha postulado que para reducir la brecha de tratamiento, la inversión en salud mental debe centrarse en la atención primaria. El abordaje colaborativo es una metodología estandarizada que cuenta con evidencia científica de efectividad y costo -efectividad en estas poblaciones. Objetivo: discutir la implementación del abordaje colaborativo en Costa Rica, a partir de una revisión bibliográfica dirigida, y realizar una valoración crítica del modelo actual costarricense. Diseño: revisión bibliográfica, análisis del modelo nacional y propuesta de aplicación. Resultados: en Costa Rica existe un modelo de atención de referencia, el cual tiene menor sustento científico que el abordaje colaborativo, y posiblemente tiende a aumentar la brecha de tratamiento. Discusión y recomendaciones: el abordaje colaborativo permitiría un mayor reconocimiento de la comorbilidad psiquiátrica, mejoraría las técnicas de abordaje y tratamiento, incrementaría el balance costo - beneficio y, probablemente, disminuiría la brecha de tratamiento. Conclusiones: la mayor parte de los recursos en psiquiatría deben emplearse en el primer nivel de atención. El abordaje colaborativo ha demostrado ser la mejor estrategia de tratamiento de la comorbilidad psiquiátrica en esa población. Su instauración en Costa Rica es viable, debido a la amplia cobertura existente en la atención primaria, y su aplicación debería gestarse desde el Ministerio de Salud, la Caja Costarricense de Seguro Social, y las escuelas de medicina.

  14. Estudio diferencial del nivel de estrés percibido, liderazgo, cohesión y autoconfianza en Unidades de Élite de la Armada Española, en la Operación Active Endeavour de la OTAN

    Ángel J. Galindo

    2014-09-01

    Full Text Available Antecedentes y objetivos: Fruto de los atentados terroristas del 11 de septiembre de 2001 en Estados Unidos, surge la operación antiterrorista Active Endeavour con la participación de la Armada Española con la función de control marítimo y el abordaje de buques con actividad sospechosa terrorista. Este estudio trata de analizar las características diferenciales de los grupos especiales de abordaje de buques (boarding teams, en relación a sus niveles de estrés percibido, liderazgo, cohesión y autoconfianza. Material y métodos: Para ello se emplea una muestra de 120 militares españoles integrados en el segundo grupo marítimo de la OTAN, de los que 17 pertenecen al equipo de abordaje y el resto actuaría como grupo de comparación y control. Rellenaron el cuestionario de estrés percibido de Cohen adaptado a población española, y el Cuestionario de Perfil de Moral de Unidad que evalúa aspectos implicados en la adaptación a zona de operaciones, destacando el liderazgo, la cohesión y la autoconfianza. Resultados: Los resultados muestran que no hay diferencias estadísticamente significativas en los niveles de estrés percibido en ambos grupos, pero sí existen diferencias en el nivel de cohesión siendo mayor en el equipo de abordaje. Conclusiones: La cohesión ha sido un factor clásicamente relacionado con una mayor adaptación a entornos operativos, debido a la percepción de apoyo social que reciben los miembros del grupo, y la posibilidad de aumentar los recursos de afrontamiento frente al estrés. Los grupos de abordaje poseen un mayor nivel de exposición al riesgo debido a su función al interceptar buques sospechosos, sin embargo no presentan mayores niveles de estrés percibido, debido a la presencia de unos mejores recursos de afrontamiento. Se detecta la presencia de mayores niveles de cohesión grupal, factor clásicamente asociado a un mejor afrontamiento de situaciones estresantes. Se concluye que de todas las

  15. La implementación del abordaje colaborativo en Costa Rica: hacia una integración entre la psiquiatría y la atención primaria

    Ricardo Millán-González

    2014-01-01

    Introducción: la Organización Mundial de la Salud ha postulado que para reducir la brecha de tratamiento, la inversión en salud mental debe centrarse en la atención primaria. El abordaje colaborativo es una metodología estandarizada que cuenta con evidencia científica de efectividad y costo -efectividad en estas poblaciones. Objetivo: discutir la implementación del abordaje colaborativo en Costa Rica, a partir de una revisión bibliográfica dirigida, y realizar una valoración crítica del model...

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

    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.

  17. Features of calcaneonavicular coalition on coronal computed tomography

    Objective. To determine the findings of calcaneonavicular coalition on coronal CT.Design. We retrospectively reviewed the CT scans of 14 calcaneonavicular coalitions in eight patients. All coalitions were visible on the axial scans, and the diagnosis was confirmed by surgery in five patients. These CT scans were compared with scans of ten normal feet.Results. We identified two features of calcaneonavicular coalition on coronal CT: lateral bridging (an abnormal bony mass lateral to the head of the talus) and rounding of the talus. All eight patients demonstrated at least one of these two findings.Conclusion. Although calcaneonavicular coalition is best seen on axial CT scans of the feet, there are two abnormalities, lateral bridging and rounding of the head of the talus, which should suggest the diagnosis on coronal CT scans. (orig.)

  18. Flux Rope Formation Preceding Coronal Mass Ejection Onset

    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.

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

    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.

  20. Study of impurity behaviour in non-coronal equilibrium state

    Cheng Fa-Yin; Shi Bing-Ren

    2007-01-01

    A physical model of analysing the behaviour of impurities out of coronal equilibrium in tokamak plasmas has been proposed. Through solving the time-dependent rate equations including the effects of atomic processes and the particle transport losses, the ionization state distribution is obtained for a range of low Z impurities such as helium, carbon,oxygen and argon. By using the ionization state distribution of these impurities, the radiation rate coefficients and the mean charge state changing with plasma temperature are calculated. The results show that the mean charge stateis sensitively dependent on the parameter neτ, and this is the reason why the radiation power of impurities under non-coronal equilibrium conditions is several orders of magnitude higher than that under coronal equilibrium condition.

  1. A data driven kinetic approach to coronal heating

    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...

  2. The Nature of CME-Flare Associated Coronal Dimming

    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,...

  3. Magnetic reconnection between a solar filament and nearby coronal loops

    Li, Leping; Peter, Hardi; Priest, Eric; Chen, Huadong; Guo, Lijia; Chen, Feng; Mackay, Duncan

    2016-01-01

    Magnetic reconnection, the rearrangement of magnetic field topology, is a fundamental physical process in magnetized plasma systems all over the universe1,2. Its process is difficult to be directly observed. Coronal structures, such as coronal loops and filament spines, often sketch the magnetic field geometry and its changes in the solar corona3. Here we show a highly suggestive observation of magnetic reconnection between an erupting solar filament and its nearby coronal loops, resulting in changes in connection of the filament. X-type structures form when the erupting filament encounters the loops. The filament becomes straight, and bright current sheets form at the interfaces with the loops. Many plasmoids appear in these current sheets and propagate bi-directionally. The filament disconnects from the current sheets, which gradually disperse and disappear, reconnects to the loops, and becomes redirected to the loop footpoints. This evolution of the filament and the loops suggests successive magnetic recon...

  4. Transverse, Propagating Velocity Perturbations in Solar Coronal Loops

    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)...

  5. FLUX ROPE FORMATION PRECEDING CORONAL MASS EJECTION ONSET

    We analyze 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.

  6. Shock Formation of Slow Magnetosonic Waves in Coronal Plumes

    Cuntz, Manfred; Suess, Steven T.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    We investigate the height of shock formation in coroner plumes for slow magnetosonic waves. The models take into account plume geometric spreading, heat conduction and radiative damping. The wave parameters as well as the spreading functions of the plumes and the base magnetic field strengths are given by empirical constraints mostly from Solar and Heliospheric Observatory/Ultraviolet Coronagraph Spectrometer (SOHO/UVCS). Our models show that shock formation occurs at low coronal heights, i.e., within 1.3 solar radius, depending on the model parameters. The shock formation is calculated using the well-established wave breaking condition given by the intersection of C+ characteristics in the space-time plane. Our models show that shock heating by slow magnetosonic waves is expected to be relevant at most heights in solar coronal plumes, although slow magnetosonic waves are most likely not a solely operating energy supply mechanism.

  7. Coronal Seismology and the Propagation of Acoustic Waves Along Coronal Loops

    Klimchuk, J A; De Moortel, I

    2004-01-01

    We use a combination of analytical theory, numerical simulation, and data analysis to study the propagation of acoustic waves along coronal loops. We show that the intensity perturbation of a wave depends on a number of factors, including dissipation of the wave energy, pressure and temperature gradients in the loop atmosphere, work action between the wave and a flow, and the sensitivity properties of the observing instrument. In particular, the scale length of the intensity perturbation varies directly with the dissipation scale length (i.e., damping length) and the scale lengths of pressure, temperature, and velocity. We simulate wave propagation in three different equilibrium loop models and find that dissipation and pressure and temperature stratification are the most important effects in the low corona where the waves are most easily detected. Velocity effects are small, and cross-sectional area variations play no direct role for lines-of-sight that are normal to the loop axis. The intensity perturbation...

  8. Los diagramas de fuerzas como elemento fundamental en la enseñanza-aprendizaje de las leyes de newton bajo un enfoque constructivista: estudio de caso en X grado de la institución educativa San José Obrero del municipio de Medellín

    Muñoz Guzmán, Edwin Alberto

    2011-01-01

    Los diagramas de fuerzas son una herramienta fundamental para el estudio de la física básica y concretamente, para el abordaje de las leyes de Newton, en la medida en que permiten al estudiante visualizar lo que ocurre en un sistema físico a nivel representacional -enmarcado en la teoría del aprendizaje significativo (AS)- permitiendo identificar las variables que determinan el comportamiento de un sistema físico y plantear estrategias para su solución, logrando la argumentación de la situaci...

  9. un objeto de estudio emergente

    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.

  10. DICHOTOMY OF SOLAR CORONAL JETS: STANDARD JETS AND BLOWOUT JETS

    By examining many X-ray jets in Hinode/X-Ray Telescope 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 Hα macrospicules, jets in which the jet-base magnetic arch undergoes a miniature version of the blowout eruptions that produce major coronal mass ejections. 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 A 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 ∼ 104 - 105 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.

  11. Eruptions that Drive Coronal Jets in a Solar Active Region

    Sterling, Alphonse C.; Moore, Ronald L.; Falconer, David A.; Panesar, Navdeep K.; Akiyama, Sachiko; Yashiro, Seiji; Gopalswamy, Nat

    2016-01-01

    Solar coronal jets are common in both coronal holes and in active regions (e.g., Shibata et al. 1992, Shimojo et al. 1996, Cirtain et al. 2007. Savcheva et al. 2007). Recently, Sterling et al. (2015), using data from Hinode/XRT and SDO/AIA, found that coronal jets originating in polar coronal holes result from the eruption of small-scale filaments (minifilaments). The jet bright point (JBP) seen in X-rays and hotter EUV channels off to one side of the base of the jet's spire develops at the location where the minifilament erupts, consistent with the JBPs being miniature versions of typical solar flares that occur in the wake of large-scale filament eruptions. Here we consider whether active region coronal jets also result from the same minifilament-eruption mechanism, or whether they instead result from a different mechanism (e.g. Yokoyama & Shibata 1995). We present observations of an on-disk active region (NOAA AR 11513) that produced numerous jets on 2012 June 30, using data from SDO/AIA and HMI, and from GOES/SXI. We find that several of these active region jets also originate with eruptions of miniature filaments (size scale 20'') emanating from small-scale magnetic neutral lines of the region. This demonstrates that active region coronal jets are indeed frequently driven by minifilament eruptions. Other jets from the active region were also consistent with their drivers being minifilament eruptions, but we could not confirm this because the onsets of those jets were hidden from our view. This work was supported by funding from NASA/LWS, NASA/HGI, and Hinode. A full report of this study appears in Sterling et al. (2016).

  12. Estudio de funciones con geogebra

    Benedicto Baldonado, Clara

    2012-01-01

    Nuestra investigación, “Estudio de funciones con GeoGebra”, se ha desarrollado en el “Máster Universitario en Profesor de Educación Secundaria” de la Universitat de València. El estudio se centra en cómo alcanzar una correcta comprensión de los conceptos referidos a funciones haciendo uso del GeoGebra. El problema que motiva esta investigación radica en que, en los cursos tradicionales de 2º de Bachillerato, cantidades significativas de estudiantes no logran comprender los conceptos básico...

  13. Self-organized braiding in solar coronal loops

    Berger, M. A.; Asgari-Targhi, M.; Deluca, E. E.

    2015-08-01

    In this paper, we investigate the evolution of braided solar coronal loops. We assume that coronal loops consist of several internal strands which twist and braid about each other. Reconnection between the strands leads to small flares and heating of the loop to x-ray temperatures. Using a method of generating and releasing braid structure similar to a forest fire model, we show that the reconnected field lines evolve to a self-organised critical state. In this state, the frequency distributions of coherent braid sequences as well as flare energies follow power law distributions. We demonstrate how the presence of net helicity in the loop alters the distribution laws.

  14. Coronal seismology waves and oscillations in stellar coronae

    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

  15. More of the Inconvenient Truth About Coronal Dimmings

    McIntosh, Scott W.; Burkepile, Joan; 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 towar...

  16. Homicidios en relaciones de pareja: un abordaje desde la criminología positivista (1927-1930)

    Castells, Florencia Claudia

    2015-01-01

    Este artículo analiza el proceso judicial a partir de “homicidios” ocurridos por conflictos de pareja en las clases trabajadoras, durante las primeras décadas del siglo XX. A partir de un estudio centrado en dos causas criminales de mujeres que asesinaron a sus parejas masculinas, se pretende abordar desde una dimensión social del fenómeno jurídico, la consolidación de la criminología positivista en la práctica judicial. Se examina la intersección de ésta última con el dispositivo psiquiátric...

  17. A new way to convert Alfven waves into heat in solar coronal holes - Intermittent magnetic levitation

    Moore, R. L.; Hammer, R.; Musielak, Z. E.; Suess, S. T.; An, C.-H.

    1992-01-01

    In our recent analysis of Alfven wave reflection in solar coronal holes, we found evidence that coronal holes are heated by reflected Alfven waves. This result suggests that the reflection is inherent to the process that dissipates these Alfven waves into heat. We propose a novel dissipation process that is driven by the reflection, and that plausibly dominates the heating in coronal holes.

  18. La comprensión de la solidaridad. Análisis de estudios empíricos

    Yicel Nayrobis Giraldo

    2015-07-01

    Full Text Available (descriptivo: En este escrito analizamos una serie de estudios empíricos sobre la solidaridad realizados en distintos países de América Latina. Se trata de trabajos en los que convergen diversas disciplinas de las ciencias sociales, la educación y las humanidades, realizados en los últimos catorce años. La base del análisis es de carácter documental y el corpus estuvo integrado por 39 textos (artículos, libros, informes de carácter investigativo. De ese modo, identificamos tres tendencias en el abordaje investigativo de la solidaridad: 1. Como acción dirigida a quien es considerado vulnerable; 2. Como espacio de mediación experta; y 3. Como práctica social orientada a la superación de la injusticia y la desigualdad. Finalmente, el análisis de estos estudios empíricos permite derivar una serie de reflexiones sobre la solidaridad en los tiempos actuales, y una propuesta general para la formulación de un programa de investigación en este campo.

  19. La ciudad desde los imaginarios urbanos del sabor: Tunja como caso de estudio

    Carlos Mario Rodríguez

    2015-06-01

    Full Text Available El artículo presenta los resultados generales de la investigación “Sabores de la ciudad imaginada”, realizada en la ciudad de Tunja, Colombia . Este estudio, hecho desde un enfoque cualitativo y bajo la metodología de análisis de los imaginarios urbanos de la ciudad, se propuso el desarrollo de una lectura de ciudad desde la perspectiva de los habitantes, a partir de la premisa ¿Cuál es el sabor de Tunja? El abordaje al ciudadano se planteó mediante el diseño de tres instrumentos: encuesta, cuestionario e intervención artística, de esta manera, se desarrolló un análisis de las percepciones del sentido del gusto con relación a la ciudad, lo cual demostró que los imaginarios urbanos son expresados, también, por medio de la percepción del sabor y que su análisis permite reconocer relaciones establecidas entre sabores y lugares que tienen que ver con el uso que se le da a los espacios, las rutinas, formas de actuar e ideas comúnmente aceptadas con relación a las características de la ciudad.

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

    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.

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

    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. Closed Field Coronal Heating Models Inspired by Wave Turbulence

    Downs, C.; Lionello, R.; Mikic, Z.; Linker, J.; Velli, M. M.

    2013-12-01

    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 dissipation (WTD) phenomenology for the heating of closed coronal loops. To do so, we employ an implementation of non-WKB equations 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 equations in 1D for an idealized loop, and the relevance to a range of solar conditions is established by computing solutions for several 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 traditional empirical heating models, and still robustly describe a broad range of quiet-sun and active region conditions. The importance of the self-reflection term in producing realistic heating scale heights and thermal non-equilibrium cycles is discussed, and preliminary 3D thermodynamic MHD simulations using this formulation are presented. Research supported by NASA and NSF.

  3. Interplanetary type II radio bursts and coronal mass ejections

    Krupař, Vratislav; Santolík, Ondřej; Maksimovic, M.; Souček, Jan; Krupařová, Oksana

    Gent: URSI, 2015. H03.1. [URSI Atlantic Radio Science Conference (AT-RASC) /1st. 18.03.2014-22.03.2015, Gran Canaria] Institutional support: RVO:68378289 Keywords : coronal mass ejections * plasmas Subject RIV: BL - Plasma and Gas Discharge Physics

  4. Merging of coronal and heliospheric numerical two dimensional MHD models

    Odstrčil, Dušan; Linker, J. A.; Lionello, R.; Mikic, Z.; Riley, P.; Pizzo, J. V.; Luhmann, J. G.

    2002-01-01

    Roč. 107, A12 (2002), s. SSH14-1 - SSH14-11. ISSN 0148-0227 R&D Projects: GA AV ČR IAA3003003 Institutional research plan: CEZ:AV0Z1003909 Keywords : coronal mass ejection * interplanetary shock * numerical MHD simulation Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 2.245, year: 2002

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

    Matsumoto, Takuma

    2016-08-01

    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 the present 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 % 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 the present study would significantly impact on the prospects of successful MHD turbulence theory in the solar chromosphere.

  6. GRADUAL INFLATION OF ACTIVE-REGION CORONAL ARCADES BUILDING UP TO CORONAL MASS EJECTIONS

    The pre-coronal mass ejection (pre-CME) structure is of great importance to understanding the origin of CMEs, which, however, has been largely unknown for CMEs originating from active regions. In this paper, we investigate this issue using the wavelet-enhanced EUV Imaging Telescope (EIT) observations combined with the Large Angle and Spectrometric Coronagraph, Michelson Doppler Imager, and GOES soft X-ray observations. Selected for studying are 16 active-region coronal arcades whose gradual inflation lead up to CMEs. Twelve of them clearly build upon post-eruptive arcades resulting from a preceding eruption; the remaining four are located high in the corona in the first place and/or have existed for days. The observed inflation lasts for 8.7 ± 4.1 hr, with the arcade rising from 1.15 ± 0.06 Rsun to 1.36 ± 0.07 Rsun within the EIT field of view (FOV). The rising speed is less than 5 km s-1 most of the time. Only at the end of this quasi-static stage does it increase to tens of kilometers per second over tens of minutes. The arcade then erupts out of the EIT FOV as a CME with similar morphology. This pre-CME structure is apparently unaffected by the flares occurring during its quasi-static inflation phase, but is closely coupled with the flare occurring during its acceleration phase. For four events that are observed on the disk, it is found that the gradual inflation of the arcade is accompanied by significant helicity injection from the photosphere. In particular, a swirling structure, which is reminiscent of a magnetic flux rope, was observed in one of the arcades over 4 hr prior to the subsequent CME, and the growth of the arcade is associated with the injection of helicity of opposite sign into the active region via flux emergence. We propose a four-phase evolution paradigm for the observed CMEs, i.e., a quasi-static inflation phase which corresponds to the buildup of magnetic free energy in the corona, followed by the frequently observed three-phase paradigm

  7. Tratamiento del maxilar posterior atrófico mediante técnica de reconstrucción tridimensional con elevación de seno y abordaje «en tunel»

    Andrés Restoy

    2015-01-01

    Conclusiones: El tratamiento del sector posterior maxilar atrófico mediante reconstrucción tridimensional con autoinjerto óseo, elevación sinusal y abordaje por tunelización es una técnica que proporciona resultados predecibles y estables, permitiendo la rehabilitación con coronas sobre implantes dentales de dimensiones adecuadas.

  8. Magnetic Field in the Gravitationally Stratified Coronal Loops

    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.

  9. Latitudinal Dependence of Coronal Hole-Associated Fast Solar Wind

    Zhao, L.; Landi, E.

    2014-05-01

    The fast solar wind can have at least two different coronal sources: high-latitude, polar coronal holes (PCH) and low-latitude, equatorial coronal holes (ECH). The in-situ differences in the PCH and ECH winds have not been well studied, nor have the differences in their evolution over the solar cycles. Ulysses' 19 years of observations from 1990 to 2009, combined with ACE observations from 1998 to the present, provide us with measurements of solar wind properties that span two entire solar cycles, which allow us to study the in-situ properties and evolution of the coronal hole-associated solar wind at different latitudes. In this work, we focus on the PCH and ECH solar winds during the minima between solar cycles 22-23 and 23-24. We use data from SWICS, SWOOPS, and VHM/FGM on board Ulysses, and SWICS, SWEPAM, and MAG on board ACE to analyze the proton dynamics, heavy ion composition, elemental abundance, and magnetic field properties of the PCH wind and ECH wind, with a special focus on their differences during the recent two solar minima. We also include the slow and hot, streamer-associated (ST) wind as a reference in the comparison. The comparison of PCH and ECH wind shows that: 1) the in-situ properties of ECH and PCH winds are significantly different during the two solar minima, and 2) the two types of coronal hole-associated solar wind respond differently to changes in solar activity strength from cycle 23 to cycle 24.

  10. AGN coronal emission models - I. The predicted radio emission

    Raginski, I.; Laor, Ari

    2016-06-01

    Accretion discs in active galactic nucleus (AGN) may be associated with coronal gas, as suggested by their X-ray emission. Stellar coronal emission includes radio emission, and AGN corona may also be a significant source for radio emission in radio quiet (RQ) AGN. We calculate the coronal properties required to produce the observed radio emission in RQ AGN, either from synchrotron emission of power-law (PL) electrons, or from cyclosynchrotron emission of hot mildly relativistic thermal electrons. We find that a flat spectrum, as observed in about half of RQ AGN, can be produced by corona with a disc or a spherical configuration, which extends from the innermost regions out to a pc scale. A spectral break to an optically thin power-law emission is expected around 300-1000 GHz, as the innermost corona becomes optically thin. In the case of thermal electrons, a sharp spectral cut-off is expected above the break. The position of the break can be measured with very long baseline interferometry observations, which exclude the cold dust emission, and it can be used to probe the properties of the innermost corona. Assuming equipartition of the coronal thermal energy density, the PL electrons energy density, and the magnetic field, we find that the energy density in a disc corona should scale as ˜R-1.3, to get a flat spectrum. In the spherical case the energy density scales as ˜R-2, and is ˜4 × 10-4 of the AGN radiation energy density. In Paper II we derive additional constraints on the coronal parameters from the Gudel-Benz relation, Lradio/LX-ray ˜ 10- 5, which RQ AGN follow.

  11. Towards a Data-Optimized Coronal Magnetic Field Model (DOC-FM): statistical method for diagnosing the coronal magnetic field

    Dalmasse, Kevin; Nychka, Doug; Gibson, Sarah; Fan, Yuhong; Flyer, Natasha

    2016-05-01

    Knowing the 3D coronal magnetic field prior to the trigger of a CME is one of the key features for predicting their geomagnetic effect. Since the magnetic field is essentially measured at the photosphere, one must rely on reconstruction models to obtain the 3D magnetic field in the corona. Hence, obtaining an accurate model of the real 3D coronal magnetic field is one of the cornerstones for precise Space Weather Forecasting. In this work, we propose a new method for data-constrained reconstruction of the 3D coronal magnetic field. Model-data fitting is achieved by optimizing a user-specified log-likelihood, quantifying the difference between a dataset (including e.g. polarization, extreme-ultraviolet emission, X-ray emission) and its synthetic analogue. The synthetic data is produced by forward calculations applied to a 3D magnetic model that depends upon a finite set of parameters. After introducing the method, we present its validation on a synthetic test bed consisting of a coronal magnetic flux rope assumed to depend on three parameters, i.e. latitude, longitude, and tilt angle. A specific value of each parameter is used to generate a ground truth and the corresponding synthetic data. We show that our method performs well and the best-fit parameters provide a good approximation of the ground-truth parameters. We discuss future plans for validation and application of our method to solar observations.

  12. The Relation between Coronal Holes and Coronal Mass Ejections during the Rise, Maximum, and Declining Phases of Solar Cycle 23

    Mohamed, A. A.; Gopalswamy, N; Yashiro, S.; Akiyama, S.; Makela, P.; Xie, H.; Jung, H.

    2012-01-01

    We study the interaction between coronal holes (CHs) and coronal mass ejections (CMEs) using a resultant force exerted by all the coronal holes present on the disk and is defined as the coronal hole influence parameter (CHIP). The CHIP magnitude for each CH depends on the CH area, the distance between the CH centroid and the eruption region, and the average magnetic field within the CH at the photospheric level. The CHIP direction for each CH points from the CH centroid to the eruption region. We focus on Solar Cycle 23 CMEs originating from the disk center of the Sun (central meridian distance =15deg) and resulting in magnetic clouds (MCs) and non-MCs in the solar wind. The CHIP is found to be the smallest during the rise phase for MCs and non-MCs. The maximum phase has the largest CHIP value (2.9 G) for non-MCs. The CHIP is the largest (5.8 G) for driverless (DL) shocks, which are shocks at 1 AU with no discernible MC or non-MC. These results suggest that the behavior of non-MCs is similar to that of the DL shocks and different from that of MCs. In other words, the CHs may deflect the CMEs away from the Sun-Earth line and force them to behave like limb CMEs with DL shocks. This finding supports the idea that all CMEs may be flux ropes if viewed from an appropriate vantage point.

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

    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...

  14. El cómo en la investigación de familia: Reflexiones de la experiencia desde un abordaje cualitativo

    Luz María López Montaño

    2005-05-01

    Full Text Available Este artículo presenta algunas discusiones y reflexiones acerca del abordaje cualitativo en investigación, a partir de la construcción metodológica desarrollada en la investigación “Trayectoria de vida en tres generaciones de una familia urbana de la ciudad de Manizales. Entre la superación y la reproducción de la pobreza”. Como resultado académico, tiene una doble pretensión: de un lado, constituirse en un aporte significativo para quienes se ocupan de la producción de conocimiento, trabajan o investigan en las áreas cualitativa y de familia; y de otro, ser un punto de partida para nuevas y más complejas discusiones al respecto.

  15. El cuidado de la persona con cáncer: Un abordaje psicosocial The care of cancer patients: A psychosocial approach

    Sílvia Regina Secoli

    2005-03-01

    Full Text Available En las últimas décadas, los avances tecnológicos en el área del cáncer permitieron que la prevención y los nuevos tratamientos favorezcan el aumento de las tasas de sobrevivencia de los pacientes y la mejoría en la calidad de su vida. En ese sentido, las investigaciones evidencian la necesidad de trascender de un modelo biomédico de atención a la salud, hacia un abordaje psicosocial. El objetivo del presente artículo es contribuir con reflexiones respecto a la temática y presentar una propuesta con este abordaje, como un instrumento de intervención de enfermería capaz de considerar la singularidad del sujeto con cáncer y su familia, en el modo de vivenciar sus experiencias, y los impactos que el cáncer provoca en la vida psíquica y social.In the last decades, the technological improvements on cancer field allowed the increasement of the patients’ survival rates and quality of life through prevention and new treatments. In this manner, the researches have made evident the necessity of transcending the biomedical model of attention to health into a psychosocial approach. So, the goal of the present article will be to contribute with the reflections about this subject and to bring a proposal of a psychosocial approach, as an instrument of intervention in nurse assistance, capable of considering the cancer patients and their families, their uniqueness way of living their experiences, regarding the impacts caused by cancer in their psychic and social life.

  16. Los estudios latinoamericanistas en Finlandia

    Elina Vuola

    2010-07-01

    Full Text Available El artículo responde a las preguntas propuestas por la Coordinación de este número para componer una imagen de la situación y perspectivas de los estudios latinoamericanos en Finlandia.Latin American Studies in FinlandThis article answers the questions posed by the Coordination of this Number in order to paint a global picture of the current situation and perspectives of Latin American Studies in Finland.

  17. Estudio plataformas IoT

    Loureiro Garrido, Rubén

    2015-01-01

    El objetivo principal de este proyecto consiste en dar una visión global del Internet de las cosas. Se comenzará describiendo los ámbitos de aplicación más importantes hoy día, siguiendo por el estudio de las principales plataformas software/hardware y, por último, se presentará una aplicación real cuyo objetivo principal es demostrar de una forma práctica lo descrito anteriormente.

  18. Fortaleciendo experiencias en estudios cooperativos

    Revista Institucional de la Facultad de Ciencias Económicas

    2011-01-01

    Como todos los años docentes del Instituto de Estudios Cooperativos de la Facultad de Ciencias Económicas intercambian en el país y en el exterior experiencias en el campo de la investigación, la docencia y la extensión vinculados al movimiento cooperativo. (Párrafo extraído del texto a modo de resumen)

  19. Organización y acción en el sindicalismo de base en argentina: un abordaje conceptual

    Santiago Duhalde

    2013-12-01

    Full Text Available En este artículo presentamos algunas conclusiones a partir de un estudio realizado en Argentina sobre tres juntas internas de delegados sindicales. El principal objetivo de este trabajo fue analizar la importancia de la dimensión organizacional de las instituciones gremiales en el contexto de su acción sindical. Se trata de un estudio comparativo de tres entidades de base de la Asociación Trabajadores del Estado de Argentina, principalmente durante el período 2003-2010, selección realizada tomando en consideración las principales corrientes políticas presentes en este sindicato. En cuanto a las técnicas de recolección de datos, se conformaron grupos de discusión y se llevaron a cabo entrevistas en profundidad a delegados, afiliados y trabajadores en general. A su vez, se recolectó y analizó una vasta y heterogénea documentación sindical, sumada a información periodística relativa al período estudiado. También la observación participante, llevada a cabo en los distintos lugares de trabajo, resultó de gran ayuda a la hora de la interpretación global de los datos obtenidos. El examen de estas entidades de base se realizó tomando en cuenta un punto de vista procesual, que destaca la presencia de diferentes etapas de estas juntas internas. Esta perspectiva procesual nos permite dar cuenta del grado de relevancia explicativa tanto de los factores organizativos como de los factores de poder disponibles en las distintas etapas de estas juntas, sea a partir de su presencia o ausencia, o a partir del carácter particular que asumen en un período determinado. Como conclusión exponemos la relación que hemos encontrado entre el tipo de organización alcanzado por estas entidades de base y los logros obtenidos por las mismas. En este sentido, una mayor articulación política interna favorece una toma de decisiones unívocas y coherentes en lo que respecta a la relación con terceros actores, lo que repercute favorablemente en la

  20. MR imaging of the anterior cruciate ligament. Value of thin slice direct oblique coronal technique

    The value of the thin slice direct oblique coronal technique, which is parallel to the anterior cruciate ligament (ACL), was assessed in the evaluation of ACL injury in comparison with conventional oblique sagittal and coronal images. A thin slice direct oblique coronal technique was developed and applied clinically to 62 patients after conventional oblique sagittal and coronal images had been obtained. MR images of these 62 patients (24 with tears and 38 without tears) with an arthroscopic correlation were evaluated by three radiologists who were unaware of the arthroscopic results. The diagnostic accuracy of these new images was compared with that of oblique sagittal and coronal images by ROC analysis. Conventional oblique sagittal and coronal images for the diagnosis of ACL tears revealed accuracies of 82%, 84%, and 84%, sensitivities of 92%, 92%, and 96% and specificities of 76%, 79%, and 76% for the three reviewers, respectively. On thin slice direct oblique coronal images, specificities of 97%, 97%, and 97%, sensitivities of 96%, 96%, and 96%, and accuracies of 97%, 97%, and 97% were obtained, respectively. Diagnostic ability was significantly better with direct oblique coronal images (mean area under the ROC curve [Az]=0.99) than with conventional oblique sagittal and coronal images (Az=0.91) (p<0.05). The addition of thin slice direct oblique coronal images significantly improved specificity and accuracy in the diagnosis of ACL tears. (author)

  1. MR imaging of the anterior cruciate ligament. Value of thin slice direct oblique coronal technique

    Katahira, Kazuhiro; Yamashita, Yasuyuki; Takahashi, Mutsumasa [Kumamoto Univ. (Japan). School of Medicine; Otsuka, Nobuko; Koga, Yukunori; Fukumoto, Tetsuya; Nomura, Kazutoshi

    2001-02-01

    The value of the thin slice direct oblique coronal technique, which is parallel to the anterior cruciate ligament (ACL), was assessed in the evaluation of ACL injury in comparison with conventional oblique sagittal and coronal images. A thin slice direct oblique coronal technique was developed and applied clinically to 62 patients after conventional oblique sagittal and coronal images had been obtained. MR images of these 62 patients (24 with tears and 38 without tears) with an arthroscopic correlation were evaluated by three radiologists who were unaware of the arthroscopic results. The diagnostic accuracy of these new images was compared with that of oblique sagittal and coronal images by ROC analysis. Conventional oblique sagittal and coronal images for the diagnosis of ACL tears revealed accuracies of 82%, 84%, and 84%, sensitivities of 92%, 92%, and 96% and specificities of 76%, 79%, and 76% for the three reviewers, respectively. On thin slice direct oblique coronal images, specificities of 97%, 97%, and 97%, sensitivities of 96%, 96%, and 96%, and accuracies of 97%, 97%, and 97% were obtained, respectively. Diagnostic ability was significantly better with direct oblique coronal images (mean area under the ROC curve [Az]=0.99) than with conventional oblique sagittal and coronal images (Az=0.91) (p<0.05). The addition of thin slice direct oblique coronal images significantly improved specificity and accuracy in the diagnosis of ACL tears. (author)

  2. Validation Of The Coronal Thick Target Source Model

    Fleishman, Gregory D; Nita, Gelu N; Gary, Dale E

    2015-01-01

    We present detailed 3D modeling of a dense, coronal thick target X-ray flare using the GX Simulator tool, photospheric magnetic measurements, and microwave imaging and spectroscopy data. The developed model offers a remarkable agreement between the synthesized and observed spectra and images in both X-ray and microwave domains, which validates the entire model. The flaring loop parameters are chosen to reproduce the emission measure, temperature, and the nonthermal electron distribution at low energies derived from the X-ray spectral fit, while the remaining parameters, unconstrained by the X-ray data, are selected such as to match the microwave images and total power spectra. The modeling suggests that the accelerated electrons are trapped in the coronal part of the flaring loop, but away from where the magnetic field is minimal, and, thus, demonstrates that the data are clearly inconsistent with electron magnetic trapping in the weak diffusion regime mediated by the Coulomb collisions. Thus, the modeling su...

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

    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...

  4. Coronal Structures as Tracers of Sub-Surface Processes

    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.

  5. Energetic characterisation and statistics of solar coronal brightenings

    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...

  6. Quasi-Periodic Oscillation of a Coronal Bright Point

    Samanta, Tanmoy; Tian, Hui

    2015-01-01

    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 underneath magnetic flux changes. We study the dynamics of a BP seen in the coronal hole using the Atmospheric Imaging Assembly (AIA) images, the Helioseismic and Magnetic Imager (HMI) magnetogram on board the Solar Dynamics Observatory (SDO) 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 FUV images. With 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 foot point of the BP as the slit position crossed it. We noticed enhanced line prof...

  7. Inferring the Coronal Density Irregularity from EUV Spectra

    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.

  8. Role of Coronal Mass Ejections in the Heliospheric Hale Cycle

    Owens, M. J.; Schwardron, N. A.; Crooker, N. U.; Hughes, W. J.; Spence, H. E.

    2007-01-01

    The 11-year solar cycle variation in the heliospheric magnetic field strength can be explained by the temporary buildup of closed flux released by coronal mass ejections (CMEs). If this explanation is correct, and the total open magnetic flux is conserved, then the interplanetary-CME closed flux must eventually open via reconnection with open flux close to the Sun. In this case each CME will move the reconnected open flux by at least the CME footpoint separation distance. Since the polarity of CME footpoints tends to follow a pattern similar to the Hale cycle of sunspot polarity, repeated CME eruption and subsequent reconnection will naturally result in latitudinal transport of open solar flux. We demonstrate how this process can reverse the coronal and heliospheric fields, and we calculate that the amount of flux involved is sufficient to accomplish the reversal within the 11 years of the solar cycle.

  9. Spatial damping of propagating sausage waves in coronal cylinders

    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 ...

  10. Coronal Rotation at Solar Minimum from UV Observations

    Mancuso, S.

    2008-01-01

    UVCS/SOHO observations have been analyzed to reconstruct intensity time series of the O VI 1032 A and H 11216 A spectral lines at different coronal heliolatitudes from 1.5 to 3.0 solar radii from Sun center. Evidence was found for coronal differential rotation that differs significantly from that of the photospheric plasma. The study of the latitudinal variation shows that the UV corona decelerates toward the photospheric rates from the equator up to the poleward boundary 2 of the midlatitude streamers, reaching a peak of 28.16+/-0.20 days around +30 from the equator at 1.5 solar radii, while a less evident peak is observed in the northern hemisphere. This result suggests a real north-south rotational asymmetry as a consequence of different activity and weak coupling between the magnetic fields of the two hemispheres. The study of the radial rotation profiles shows that the corona is rotating almost rigidly with height.

  11. Coronal Loops: Observations and Modeling of Confined Plasma

    Reale, Fabio

    2010-01-01

    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 sections: 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 loop classification and populations, and then describes the morphology of coronal loops, its relationship with the magnetic field, and the concept of loops as multi-stranded structures. The following part of this section is devoted to the characteristics of the loop plasma, and of its thermal structure in particular, according to the classification into...

  12. The Interaction between Coronal Mass Ejections (CMEs) and Coronal Holes (CHs) during the Solar Cycle 23 and its Geomagnetic Consequences

    Mohamed, Amaal; Gopalswamy, Nat

    2016-07-01

    The interactions between the two large scale phenomena, coronal holes (CHs) and coronal mass ejections (CMEs) maybe considered as one of the most important relations that having a direct impact not only on space weather but also on the relevant plasma physics. Many observations have shown that throughout their propagation from the Sun to interplanetary space, CMEs interact with the heliospheric structures (e.g., other CMEs, Corotating interaction regions (CIRs), helmet streamers, and CHs). Such interactions could enhance the southward magnetic field component, which has important implications for geomagnetic storm generation. These interactions imply also a significant energy and momentum transfer between the interacting systems where magnetic reconnection is taking place. When CHs deflect CMEs away from or towards the Sun-Earth line, the geomagnetic response of the CME is highly affected. Gopalswamy et al. [2009] have addressed the deflection of CMEs due to the existence of CHs that are in close proximity to the eruption regions. They have shown that CHs can act as magnetic barriers that constrain CMEs propagation and can significantly affect their trajectories. Here, we study the interaction between coronal holes (CHs) and coronal mass ejections (CMEs) using a resultant force exerted by all coronal holes present on the disk and is defined as the coronal hole influence parameter (CHIP). The CHIP magnitude for each CH depends on the CH area, the distance between the CH centroid and the eruption region, and the average magnetic field within the CH at the photospheric level. The CHIP direction for each CH points from the CH centroid to the eruption region. We focus on Solar Cycle 23 CMEs originating from the disk center of the Sun (central meridian distance data sets of observations of CMEs and their interplanetary counterparts; known as interplanetary CMEs (ICMEs). There are 2 subsets of ICMEs: magnetic cloud (MC) and non-magnetic cloud (non-MC) ICMEs. MCs are

  13. Combining Models of Coronal Mass Ejections and Solar Dynamos

    Warnecke, Jörn

    2013-01-01

    Observations show that Coronal Mass Ejections (CMEs) are associated with twisted magnetic flux configurations. Conventionally, CMEs are modeled by shearing and twisting the footpoints of a certain distribution of magnetic flux at the solar surface and letting it evolve at the surface. Of course, the surface velocities and magnetic field patterns should ultimately be obtained from realistic simulations of the solar convection zone where the field is generated by dynamo action. Therefore, a uni...

  14. EUV and Coronagraphic Observations of Coronal Mass Ejections

    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. Numerical simulations of transverse oscillations in radiatively cooling coronal loops

    Magyar, Norbert; Van Doorsselaere, Tom; Marcu, Alexandru

    2016-05-01

    We aim to study the influence of radiative cooling on the standing kink oscillations of coronal loops. To solve the 3D MHD ideal problem, we use the FLASH code. Our model consists of a straight, density enhanced and gravitationally stratified magnetic flux tube. We perturbed the system initially, leading to a transverse oscillation of the structure, and followed its evolution for a number of periods. A realistic radiative cooling is implemented. Results are compared to available analytical theory. We find that in the linear regime (i.e. low amplitude perturbation and slow cooling) the obtained period and damping time are in good agreement with theory. The cooling leads to an amplification of the oscillation amplitude. However, the difference between the cooling and non-cooling cases is small (around 6% after 6 oscillations). In high amplitude runs with realistic cooling, instabilities deform the loop, leading to increased damping. In this case, the difference between cooling and non-cooling is still negligible at around 12%. A set of simulations with higher density loops are also performed, to explore what happens when the cooling takes place in a very short time (t cool ≈ 100 s). In this case, the difference in amplitude after nearly 3 oscillation periods for the low amplitude case is 21% between cooling and non-cooling cases. We strengthen the results of previous analytical studies that state that the amplification due to cooling is ineffective, and its influence on the oscillation characteristics is small, at least for the cases shown here. Furthermore, the presence of a relatively strong damping in the high amplitude runs even in the fast cooling case indicates that it is unlikely that cooling could alone account for the observed, flare-related undamped oscillations of coronal loops. These results may be significant in the field of coronal seismology, allowing its application to coronal loop oscillations with observed fading-out or cooling behaviour.

  16. CORON: A Framework for Levelwise Itemset Mining Algorithms

    Szathmary, Laszlo; Napoli, Amedeo

    2005-01-01

    CORON is a framework for levelwise algorithms that are designed to find frequent and/or frequent closed itemsets in binary contexts. Datasets can be very different in size, number of objects, number of attributes, density, etc. As there is no one best algorithm for arbitrary datasets, we want to give a possibility for users to try different algorithms and choose the one that best suits their needs.

  17. On the "Extended" Solar Cycle in Coronal Emission

    Robbrecht, E.; Wang, Y.-M.; Sheeley, N. R., Jr.; Rich, N. B.

    2010-06-01

    Butterfly diagrams (latitude-time plots) of coronal emission show a zone of enhanced brightness that appears near the poles just after solar maximum and migrates toward lower latitudes; a bifurcation seems to occur at sunspot minimum, with one branch continuing to migrate equatorward with the sunspots of the new cycle and the other branch heading back to the poles. The resulting patterns have been likened to those seen in torsional oscillations and have been taken as evidence for an extended solar cycle lasting over ~17 yr. In order to clarify the nature of the overlapping bands of coronal emission, we construct butterfly diagrams from green-line simulations covering the period 1967-2009 and from 19.5 nm and 30.4 nm observations taken with the Extreme-Ultraviolet Imaging Telescope during 1996-2009. As anticipated from earlier studies, we find that the high-latitude enhancements mark the footpoint areas of closed loops with one end rooted outside the evolving boundaries of the polar coronal holes. The strong underlying fields were built up over the declining phase of the cycle through the poleward transport of active-region flux by the surface meridional flow. Rather than being a precursor of the new-cycle sunspot activity zone, the high-latitude emission forms a physically distinct, U-shaped band that curves upward again as active-region fields emerge at midlatitudes and reconnect with the receding polar-hole boundaries. We conclude that the so-called extended cycle in coronal emission is a manifestation not of early new-cycle activity, but of the poleward concentration of old-cycle trailing-polarity flux by meridional flow.

  18. Coronal Microleakage for Readymade and Hand Mixed Temporary Filling Materials

    2011-01-01

    INTRODUCTION The purpose of this in vitro study was to evaluate the sealing ability of the readymade temporary filling and hand mixed materials by assessing coronal microleakage. MATERIALS AND METHODS Standardized access cavities were prepared in 80 intact human permanent premolar teeth. They were divided randomly into four experimental groups (n=20). The teeth were restored using one of the temporary materials including Cavisol, Litrak, Zinc phosphate cement, Zinconol (IRM). Thermocycling wa...

  19. Stellar coronal magnetic fields and star-planet interaction

    Lanza, A. F.

    2009-01-01

    Evidence of magnetic interaction between late-type stars and close-in giant planets is provided by the observations of stellar hot spots rotating synchronously with the planets and showing an enhancement of chromospheric and X-ray fluxes. We investigate star-planet interaction in the framework of a magnetic field model of a stellar corona, considering the interaction between the coronal field and that of a planetary magnetosphere moving through the corona. The energy budget of the star-planet...

  20. Extended HXR Sources - Albedo Patches or Coronal Sources

    Dennis, Brian R.

    2011-01-01

    Extended HXR sources in the presence of compact footpoints have been reported based on visibility amplitudes from different detectors. Attempts have been made to determine the location and extent of these sources through direct imaging. Results of this work will be described for simulated sources and for specific flares at different solar longitudes, with a discussion of the possible nature of the extended sources as either albedo patches or coronal sources or a combination of the two.

  1. Longitudinal magnetohydrodynamics oscillations in dissipative, cooling coronal loops

    This paper investigates the effect of cooling on standing slow magnetosonic waves in coronal magnetic loops. The damping mechanism taken into account is thermal conduction that is a viable candidate for dissipation of slow magnetosonic waves in coronal loops. In contrast to earlier studies, here we assume that the characteristic damping time due to thermal conduction is not small, but arbitrary, and can be of the order of the oscillation period, i.e., a temporally varying plasma is considered. The approximation of low-beta plasma enables us to neglect the magnetic field perturbation when studying longitudinal waves and consider, instead, a one-dimensional motion that allows a reliable first insight into the problem. The background plasma temperature is assumed to be decaying exponentially with time, with the characteristic cooling timescale much larger than the oscillation period. This assumption enables us to use the WKB method to study the evolution of the oscillation amplitude analytically. Using this method we obtain the equation governing the oscillation amplitude. The analytical expressions determining the wave properties are evaluated numerically to investigate the evolution of the oscillation frequency and amplitude with time. The results show that the oscillation period increases with time due to the effect of plasma cooling. The plasma cooling also amplifies the amplitude of oscillations in relatively cool coronal loops, whereas, for very hot coronal loop oscillations the damping rate is enhanced by the cooling. We find that the critical point for which the amplification becomes dominant over the damping is in the region of 4 MK. These theoretical results may serve as impetus for developing the tools of solar magneto-seismology in dynamic plasmas.

  2. Energetic characterisation and statistics of solar coronal brightenings

    Joulin, V.; Buchlin, E.; Solomon, J.; Guennou, C.

    2016-07-01

    Context. 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. Aims: We aim at getting a better estimate of the distributions of the energy dissipated in coronal heating events using high-resolution, multi-channel extreme ultraviolet (EUV) data. Methods: To estimate the energies corresponding to heating events and deduce their distribution, we detected brightenings in five EUV channels of the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO). We combined the results of these detections and used maps of temperature and emission measure derived from the same observations to compute the energies. Results: We obtain distributions of areas, durations, intensities, and energies (thermal, radiative, and conductive) of events. These distributions are power laws and we also find power-law correlations between event parameters. Conclusions: 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. Two movies attached to Fig. 3 are available in electronic form at

  3. Simulations of Filament Channel Formation in a Coronal Magnetic Field

    Knizhnik, Kalman; DeVore, C. Richard; Antiochos, Spiro K.

    2016-05-01

    A major unanswered problem in solar physics has been explaining the presence of sheared filament channels above photospheric polarity inversion lines (PILs) and the simultaneous lack of structure in the ‘loop’ portion of the coronal magnetic field. The shear inherent in filament channels represents not only a form of magnetic energy, but also magnetic helicity. As a result, models of filament channel formation need to explain not only why helicity is observed above PILs, but also why it is apparently not observed anywhere else in the corona. Previous results (Knizhnik, Antiochos & DeVore, 2015) have suggested that any helicity injected into the coronal field inverse-cascades in scale, a process known as magnetic helicity condensation (Antiochos, 2013). In this work, we present high resolution numerical simulations of photospheric helicity injection into a coronal magnetic field that contains both a PIL and a coronal hole (CH). We show conclusively that the inverse cascade of magnetic helicity terminates at the PIL, resulting in the formation of highly sheared filament channels and a smooth, untwisted corona. We demonstrate that even though magnetic helicity is injected throughout the flux system, it accumulates only at the PIL, where it manifests itself in the form of highly sheared filament channels, while any helicity obtained by the CH is ejected out of the system. We show that the formation of filament channels is both qualitatively and quantitatively in agreement with observations and discuss the implications of our simulations for observations.This work was supported by the NASA Earth and Space Science Fellowship, LWS TR&T and H-SR Programs.

  4. Numerical simulations of transverse oscillations in radiatively cooling coronal loops

    Magyar, N.; Van Doorsselaere, T.; Marcu, A.

    2015-01-01

    We aim to study the influence of radiative cooling on the standing kink oscillations of a coronal loop. Using the FLASH code, we solved the 3D ideal magnetohydrodynamic equations. Our model consists of a straight, density enhanced and gravitationally stratified magnetic flux tube. We perturbed the system initially, leading to a transverse oscillation of the structure, and followed its evolution for a number of periods. A realistic radiative cooling is implemented. Results are compared to avai...

  5. Validation of the Coronal Thick Target Source Model

    Fleishman, Gregory D.; Xu, Yan; Nita, Gelu N.; Gary, Dale E.

    2016-01-01

    We present detailed 3D modeling of a dense, coronal thick-target X-ray flare using the GX Simulator tool, photospheric magnetic measurements, and microwave imaging and spectroscopy data. The developed model offers a remarkable agreement between the synthesized and observed spectra and images in both X-ray and microwave domains, which validates the entire model. The flaring loop parameters are chosen to reproduce the emission measure, temperature, and the nonthermal electron distribution at low energies derived from the X-ray spectral fit, while the remaining parameters, unconstrained by the X-ray data, are selected such as to match the microwave images and total power spectra. The modeling suggests that the accelerated electrons are trapped in the coronal part of the flaring loop, but away from where the magnetic field is minimal, and, thus, demonstrates that the data are clearly inconsistent with electron magnetic trapping in the weak diffusion regime mediated by the Coulomb collisions. Thus, the modeling supports the interpretation of the coronal thick-target sources as sites of electron acceleration in flares and supplies us with a realistic 3D model with physical parameters of the acceleration region and flaring loop.

  6. Interpretation of the coronal magnetic field configuration of the Sun

    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...

  7. Intermediate Inclinations of Type 2 Coronal-Line Forest AGN

    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...

  8. Solar coronal plumes and the fast solar wind

    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...

  9. Determination of the Coronal Magnetic Field by Hot Loop Oscillations

    Wang, T; Qiu, J; Wang, Tongjiang; Innes, Davina E.; Qiu, Jiong

    2006-01-01

    We apply a new method to determine the magnetic field in coronal loops using observations of coronal loop oscillations. We analyze seven Doppler shift oscillation events detected by SUMER in the hot flare line Fe XIX to obtain oscillation periods of these events. The geometry, temperature, and electron density of the oscillating loops are measured from coordinated multi-channel soft X-ray imaging observations from SXT. All the oscillations are consistent with standing slow waves in their fundamental mode. The parameters are used to calculate the magnetic field of coronal loops based on MHD wave theory. For the seven events, the plasma $\\beta$ is in the range 0.15-0.91 with a mean of 0.33$\\pm$0.26, and the estimated magnetic field varies between 21-61 G with a mean of 34$\\pm$14 G. With background emission subtracted, the estimated magnetic field is reduced by 9%-35%. The maximum backgroud subtraction gives a mean of 22$\\pm$13 G in the range 12-51 G. We discuss measurement uncertainties and the prospect of dete...

  10. Signature of mass supply to quiet coronal loops

    Tian, H; Marsch, E; He, J -S; Zhou, G -Q; 10.1051/0004-6361:20078813

    2009-01-01

    Aims. The physical implication of large blue shift of Ne viii in the quiet Sun region is investigated in this paper. Methods. We compare the significant Ne viii blue shifts, which are visible as large blue patches on the Doppler-shift map of a middlelatitude quiet-Sun region observed by SUMER, with the coronal magnetic-field structures as reconstructed from a simultaneous photospheric magnetogram by means of a force-free-field extrapolation. Results. We show for the first time that coronal funnels also exist in the quiet Sun. The region studied contains several small funnels that originate from network lanes, expand with height and finally merge into a single wide open-field region. However, the large blue shifts of the Ne viii line are not generally associated with funnels. A comparison between the projections of coronal loops onto the solar x−y-plane and the Ne viii dopplergram indicates that there are some loops that reveal large Ne viii blue shifts in both legs, and some loops with upflow in one...

  11. Effect of coronal structure on loop oscillations: exponential profiles

    Díaz, A. J.; Donnelly, G. R.; Roberts, B.

    2007-12-01

    Aims:The role of longitudinal structuring of the surrounding corona on the modes of oscillation of a coronal magnetic flux tube was studied in Donnelly et al. (2006) for a piecewise uniform profile. Here we investigate whether a more realistic continuous exponential profile changes the conclusions drawn from that paper. Methods: A partial differential equation is derived for the total pressure perturbation of the fast modes, which is then decomposed by separation of variables. The longitudinal part is solved numerically, obtaining a dispersion relation. These results are supported by an analytical investigation in terms of Bessel functions of purely imaginary order. Results: Structure in the interior of the loop shifts the frequencies of the modes (and may trap higher harmonics), an effect which can be understood by taking an averaged profile with a suitable weight. Structure in the environment modifies only slightly the frequencies, but displaces the cutoff frequency. The shift due to the structure in the fundamental period is small, but the ratio between the periods of the fundamental mode and its harmonics can be used to probe the structure. Conclusions: The results support our previous study in a more realistic, continuously varying profile and provide limits to the conclusions drawn in coronal seismology if an unstructured loop is used. Also, the ratio between the period of the fundamental kink (even) mode and its first (odd) harmonic is proven as an extra seismological tool for coronal loops.

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

    Dissauer, Karin; Temmer, Manuela; Veronig, Astrid; Vanninathan, Kamalam; Magdalenic, Jasmina

    2016-04-01

    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. 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 Å data, whereas the 335 Å filter, sensitive to hotter plasmas (T˜ 2.5 MK), shows a continuous evolution of the wave front. 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. We identify on-disk coronal dimming regions in SDO/AIA, reminiscent of core dimmings, that have no corresponding on-disk dimming signatures in STEREO-A/EUVI. Reconstructing the SDO line-of-sight (LOS) direction in STEREO-A clearly shows that the observed SDO on-disk dimming areas are not the footprints of the erupting fluxrope but result from decreased emission from the expanding CME body integrated along the LOS. In this context, we conclude that the intermittent disappearance of the EUV wave in the AIA 171, 193, 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.

  13. Spatial damping of propagating sausage waves in coronal cylinders

    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.

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

    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 ...

  15. AGN Coronal Emission models I. The Predicted Radio Emission

    Raginski, Igor

    2016-01-01

    Accretion discs in AGN may be associated with coronal gas, as suggested by their X-ray emission. Stellar coronal emission includes radio emission, and AGN corona may also be a significant source for radio emission in radio quiet (RQ) AGN. We calculate the coronal properties required to produce the observed radio emission in RQ AGN, either from synchrotron emission of power-law (PL) electrons, or from cyclo-synchrotron emission of hot mildly-relativistic thermal electrons. We find that a flat spectrum, as observed in about half of RQ AGN, can be produced by corona with a disc or a spherical configuration, which extends from the innermost regions out to a pc scale. A spectral break to an optically thin power-law emission is expected around 300-1000 GHz, as the innermost corona becomes optically thin. In case of thermal electrons, a sharp spectral cutoff is expected above the break. The position of the break can be measured with VLBI observations, which exclude the cold dust emission, and it can be used to probe...

  16. More of the Inconvenient Truth About Coronal Dimmings

    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.

  17. More of the Inconvenient Truth About Coronal Dimmings

    McIntosh, S. W.; Burkepile, J.; Leamon, R. J.

    2009-12-01

    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 Alfvén 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.

  18. The Nature of CME-flare-Associated Coronal Dimming

    Cheng, J. X.; Qiu, J.

    2016-07-01

    Coronal mass ejections (CMEs) are often accompanied by coronal dimming that is 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 the properties of CMEs in the early phase of their eruption. In this study, we analyze the event of flare, CME, and coronal dimming on 2011 December 26. We use the data from the Atmospheric Imaging Assembly on the Solar Dynamics Observatory for disk observations of the dimming, and analyze images taken by EUVI, COR1, and COR2 on board the Solar Terrestrial Relations Observatory to obtain the height and velocity of the associated CMEs observed at the limb. We also measure the magnetic reconnection rate from flare observations. Dimming occurs in a few locations next to the flare ribbons, and it is observed in multiple EUV passbands. Rapid dimming starts after the onset of fast reconnection and CME acceleration, and its evolution tracks the CME height and flare reconnection. The spatial distribution of dimming exhibits cores of deep dimming with a rapid growth, and their light curves are approximately linearly scaled with the CME height profile. From the dimming analysis we infer the process of the CME expansion, and estimate properties of the CME.

  19. An Impulsive Heating Model for the Evolution of Coronal Loops

    Li Feng; Wei-Qun Gan

    2006-01-01

    It was suggested by Parker that the solar corona is heated by many small energy release events generally called microflares or nanoflares. More and more observations showed flows and intensity variations in nonflaring loops. Both theories and observations have indicated that the heating of coronal loops should actually be unsteady. Using SOLFTM (Solar Flux Tube Model), we investigate the hydrodynamics of coronal loops undergoing different manners of impulsive heating with the same total energy deposition. The half length of the loops is 110 Mm, a typical length of active region loops. We divide the loops into two categories: loops that experience catastrophic cooling and loops that do not. It is found that when the nanoflare heating sources are in the coronal part, the loops are in non-catastrophic-cooling state and their evolutions are similar. When the heating is localized below the transition region, the loops evolve in quite different ways. It is shown that with increasing number of heating pulses and inter-pulse time, the catastrophic cooling is weakened, delayed, or even disappears altogether.

  20. A solar type II radio burst from coronal mass ejection-coronal ray interaction: Simultaneous radio and extreme ultraviolet imaging

    Simultaneous radio and extreme ultraviolet (EUV)/white-light imaging data are examined for a solar type II radio burst occurring on 2010 March 18 to deduce its source location. Using a bow-shock model, we reconstruct the three-dimensional EUV wave front (presumably the type-II-emitting shock) based on the imaging data of the two Solar TErrestrial RElations Observatory spacecraft. It is then combined with the Nançay radio imaging data to infer the three-dimensional position of the type II source. It is found that the type II source coincides with the interface between the coronal mass ejection (CME) EUV wave front and a nearby coronal ray structure, providing evidence that the type II emission is physically related to the CME-ray interaction. This result, consistent with those of previous studies, is based on simultaneous radio and EUV imaging data for the first time.

  1. Estudios sobre plantas andinas, x

    Cuatrecasas, José

    2012-01-01

    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 per...

  2. Centauros Mensajeros - Casos de estudio

    Bolívar Ramírez, Jorge Enrique

    2012-01-01

    El estudio del caso de la empresa Centaurus Mensajeros es presentado en un documento estructurado en tres partes, donde primero se expone la historia y las características del proyecto; luego se presenta su entorno empresarial; y finalmente, se muestra un ejemplo de emprendimiento a través de la historia de vida del empresario y fundador de esta organización, así como su gestión, cualidades como empresario y lucha por mantener la empresa de Centaurus Mensajeros como una de las más reconocidas...

  3. THERMAL SIGNATURES OF TETHER-CUTTING RECONNECTIONS IN PRE-ERUPTION CORONAL FLUX ROPES: HOT CENTRAL VOIDS IN CORONAL CAVITIES

    Fan, Y. [High Altitude Observatory, National Center for Atmospheric Research, 3080 Center Green Drive, Boulder, CO 80301 (United States)

    2012-10-10

    Using a three-dimensional MHD simulation, we model the quasi-static evolution and the onset of eruption of a coronal flux rope. The simulation begins with a twisted flux rope emerging at the lower boundary and pushing into a pre-existing coronal potential arcade field. At a chosen time the emergence is stopped with the lower boundary taken to be rigid. Then the coronal flux rope settles into a quasi-static rise phase during which an underlying, central sigmoid-shaped current layer forms along the so-called hyperbolic flux tube (HFT), a generalization of the X-line configuration. Reconnections in the dissipating current layer effectively add twisted flux to the flux rope and thus allow it to rise quasi-statically, even though the magnetic energy is decreasing as the system relaxes. We examine the thermal features produced by the current layer formation and the associated 'tether-cutting' reconnections as a result of heating and field aligned thermal conduction. It is found that a central hot, low-density channel containing reconnected, twisted flux threading under the flux rope axis forms on top of the central current layer. When viewed in the line of sight roughly aligned with the hot channel (which is roughly along the neutral line), the central current layer appears as a high-density vertical column with upward extensions as a {sup U-}shaped dense shell enclosing a central hot, low-density void. Such thermal features have been observed within coronal prominence cavities. Our MHD simulation suggests that they are the signatures of the development of the HFT topology and the associated tether-cutting reconnections, and that the central void grows and rises with the reconnections, until the flux rope reaches the critical height for the onset of the torus instability and dynamic eruption ensues.

  4. THERMAL SIGNATURES OF TETHER-CUTTING RECONNECTIONS IN PRE-ERUPTION CORONAL FLUX ROPES: HOT CENTRAL VOIDS IN CORONAL CAVITIES

    Using a three-dimensional MHD simulation, we model the quasi-static evolution and the onset of eruption of a coronal flux rope. The simulation begins with a twisted flux rope emerging at the lower boundary and pushing into a pre-existing coronal potential arcade field. At a chosen time the emergence is stopped with the lower boundary taken to be rigid. Then the coronal flux rope settles into a quasi-static rise phase during which an underlying, central sigmoid-shaped current layer forms along the so-called hyperbolic flux tube (HFT), a generalization of the X-line configuration. Reconnections in the dissipating current layer effectively add twisted flux to the flux rope and thus allow it to rise quasi-statically, even though the magnetic energy is decreasing as the system relaxes. We examine the thermal features produced by the current layer formation and the associated 'tether-cutting' reconnections as a result of heating and field aligned thermal conduction. It is found that a central hot, low-density channel containing reconnected, twisted flux threading under the flux rope axis forms on top of the central current layer. When viewed in the line of sight roughly aligned with the hot channel (which is roughly along the neutral line), the central current layer appears as a high-density vertical column with upward extensions as a U-shaped dense shell enclosing a central hot, low-density void. Such thermal features have been observed within coronal prominence cavities. Our MHD simulation suggests that they are the signatures of the development of the HFT topology and the associated tether-cutting reconnections, and that the central void grows and rises with the reconnections, until the flux rope reaches the critical height for the onset of the torus instability and dynamic eruption ensues.

  5. Thermal Signatures of Tether-cutting Reconnections in Pre-eruption Coronal Flux Ropes: Hot Central Voids in Coronal Cavities

    Fan, Y.

    2012-10-01

    Using a three-dimensional MHD simulation, we model the quasi-static evolution and the onset of eruption of a coronal flux rope. The simulation begins with a twisted flux rope emerging at the lower boundary and pushing into a pre-existing coronal potential arcade field. At a chosen time the emergence is stopped with the lower boundary taken to be rigid. Then the coronal flux rope settles into a quasi-static rise phase during which an underlying, central sigmoid-shaped current layer forms along the so-called hyperbolic flux tube (HFT), a generalization of the X-line configuration. Reconnections in the dissipating current layer effectively add twisted flux to the flux rope and thus allow it to rise quasi-statically, even though the magnetic energy is decreasing as the system relaxes. We examine the thermal features produced by the current layer formation and the associated "tether-cutting" reconnections as a result of heating and field aligned thermal conduction. It is found that a central hot, low-density channel containing reconnected, twisted flux threading under the flux rope axis forms on top of the central current layer. When viewed in the line of sight roughly aligned with the hot channel (which is roughly along the neutral line), the central current layer appears as a high-density vertical column with upward extensions as a "U"-shaped dense shell enclosing a central hot, low-density void. Such thermal features have been observed within coronal prominence cavities. Our MHD simulation suggests that they are the signatures of the development of the HFT topology and the associated tether-cutting reconnections, and that the central void grows and rises with the reconnections, until the flux rope reaches the critical height for the onset of the torus instability and dynamic eruption ensues.

  6. Field Topology Analysis of a Long-lasting Coronal Sigmoid

    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.

  7. FIELD TOPOLOGY ANALYSIS OF A LONG-LASTING CORONAL SIGMOID

    Savcheva, A. S. [Astronomy Department, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States); Van Ballegooijen, A. A.; DeLuca, E. E., E-mail: savcheva@bu.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    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.

  8. FIELD TOPOLOGY ANALYSIS OF A LONG-LASTING CORONAL SIGMOID

    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.

  9. The multi-thermal and multi-stranded nature of coronal rain

    Antolin, P; Pereira, T M D; van der Voort, L Rouppe; Scullion, E

    2015-01-01

    In this work, we analyse coordinated observations spanning chromospheric, TR and coronal temperatures at very high resolution which reveal essential characteristics of thermally unstable plasmas. Coronal rain is found to be a highly multi-thermal phenomenon with a high degree of co-spatiality in the multi-wavelength emission. EUV darkening and quasi-periodic intensity variations are found to be strongly correlated to coronal rain showers. Progressive cooling of coronal rain is observed, leading to a height dependence of the emission. A fast-slow two-step catastrophic cooling progression is found, which may reflect the transition to optically thick plasma states. The intermittent and clumpy appearance of coronal rain at coronal heights becomes more continuous and persistent at chromospheric heights just before impact, mainly due to a funnel effect from the observed expansion of the magnetic field. Strong density inhomogeneities on spatial scales of 0.2"-0.5" are found, in which TR to chromospheric temperature ...

  10. Repeated Structures Found After the Solar Maximum in the Butterfly Diagrams of Coronal Holes

    Hofer, M. Y.; Storini, M.

    2003-09-01

    The influence of the solar cycle evolution on the coronal hole space-time distribution is well known, for polar as well as for equatorial isolated sources of high speed solar wind. Among them the long-lived coronal holes occurrence from the sunspot cycle 21 on is investigated, using the coronal hole catalogue based on HeI (1083 nm) observations (Sanchez-Ibarra and Barraza-Paredes). In at least these two solar cycles (n. 21 and n. 22) a similar structure in the latitude-time diagram of coronal holes is found. The area occurs shortly after the solar maximum at around ~35° heliolatitude and consists of over several Carrington Rotations stable coronal holes (>5 Carr. Rot.s). The diagonal disappears 2-3 years later at the helioequator. Furthermore, the analysis results in a close relation between long-lived isolated coronal holes and the soft X-class flares.

  11. Analysis and Modeling of Coronal Holes Observed by CORONAS-1. 1; Morphology and Magnetic Field Configuration

    Obridko, Vladmir; Formichev, Valery; Kharschiladze, A. F.; Zhitnik, Igor; Slemzin, Vladmir; Hathaway, David H.; Wu, Shi T.

    1998-01-01

    Two low-latitude coronal holes observed by CORONAS-1 in April and June 1994 are analyzed together with magnetic field measurements obtained from Wilcox and Kitt Peak Solar Observatories. To estimate the comparable temperature of these two coronal holes, the YOHKOH observations are also utilized. Using this information, we have constructed three-dimensional magnetic field lines to illustrate the geometrical configuration of these coronal holes. The calculated synoptic maps are used to determine the existence of closed and open field regions of the hole. Finally, we have correlated the characteristics of two coronal holes with observed solar wind speed. We found that the brighter coronal hole has high speed solar wind, and the dimmer coronal hole has low speed solar wind.

  12. Optimizing Global Coronal Magnetic Field Models Using Image-based Constraints

    Jones, Shaela I.; Davila, Joseph M.; Uritsky, Vadim

    2016-04-01

    The coronal magnetic field directly or indirectly affects a majority of the phenomena studied in the heliosphere. It provides energy for coronal heating, controls the release of coronal mass ejections, 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 that could be derived from coronal images. Here we report promising initial tests of this approach on two theoretical problems, and discuss opportunities for application.

  13. Optimizing Global Coronal Magnetic Field Models Using Image-Based Constraints

    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.

  14. NO TRACE LEFT BEHIND: STEREO OBSERVATION OF A CORONAL MASS EJECTION WITHOUT LOW CORONAL SIGNATURES

    The availability of high-quality synoptic observations of the extreme-ultraviolet (EUV) and visible corona during the SOHO mission has advanced our understanding of the low corona manifestations of coronal mass ejections (CMEs). The EUV imager/white light coronagraph connection has been proven so powerful, it is routinely assumed that if no EUV signatures are present when a CME is observed by a coronagraph, then the event must originate behind the visible limb. This assumption carries strong implications for space weather forecasting but has not been put to the test. This paper presents the first detailed analysis of a frontside, large-scale CME that has no obvious counterparts in the low corona as observed in EUV and Hα wavelengths. The event was observed by the SECCHI instruments onboard the STEREO mission. The COR2A coronagraph observed a slow flux-rope-type CME, while an extremely faint partial halo was observed in COR2B. The event evolved very slowly and is typical of the streamer-blowout CME class. EUVI A 171 A images show a concave feature above the east limb, relatively stable for about two days before the eruption, when it rises into the coronagraphic fields and develops into the core of the CME. None of the typical low corona signatures of a CME (flaring, EUV dimming, filament eruption, waves) were observed in the EUVI B images, which we attribute to the unusually large height from which the flux rope lifted off. This interpretation is supported by the CME mass measurements and estimates of the expected EUV dimming intensity. Only thanks to the availability of the two viewpoints we were able to identify the likely source region. The event originated along a neutral line over the quiet-Sun. No active regions were present anywhere on the visible (from STEREO B) face of the disk. Leaving no trace behind on the solar disk, this observation shows unambiguously that a CME eruption does not need to have clear on-disk signatures. Also it sheds light on the

  15. Coron : Plate-forme d'extraction de connaissances dans les bases de donn\\'ees

    Ducatel, Baptiste; Marcuola, Florent; Napoli, Amedeo; Szathmary, Laszlo

    2011-01-01

    Coron is a domain and platform independent, multi-purposed data mining toolkit, which incorporates not only a rich collection of data mining algorithms, but also allows a number of auxiliary operations. To the best of our knowledge, a data mining toolkit designed specifically for itemset extraction and association rule generation like Coron does not exist elsewhere. Coron also provides support for preparing and filtering data, and for interpreting the extracted units of knowledge.

  16. Clinical evaluation of lumbosacral nerve root and lateral stenosis using coronal MR imaging

    MR imaging has been used more frequently to study the lumber spine and is becoming the modality of choice in the assessment of patient with low back pain. Using a new technique of coronal and half coronal scan with MR imaging, it was possible to visualize L4, L5 and S1 nerve roots accurately. We described the MR findings of lateral stenosis using this technique. Several characteristic MR findings were identified, and the most important one was nerve root impingement in the intervertebral foramen. We consider that coronal and half coronal scan with MR imaging is useful in diagnosis of lateral stenosis. (author)

  17. La ínterdisciplina en el abordaje académico del hábitat social "informal": Fundamentos, líneas de acción y obstáculos a partir de la carrera de arquitectura

    Miguel Ángel Barreto

    2006-01-01

    El debate sobre la pobreza ocurrido en los 90´s en América Latina, dejó como consecuencia cambios significativos en los enfoques oficiales sobre los problemas del hábitat social "informal". Dos de los conceptos centrales elaborados por las ciencias sociales para recaracterizar el problema y fundamentar este enfoque han sido el de multidimensionalidad y el de heterogeneidad de la pobreza. Estas nociones condujeron, a su vez, a una estrategia de abordaje ...

  18. Estudio de Salud Agrícola

    En 1993, científicos del Instituto Nacional del Cáncer, Instituto Nacional de Ciencias Ambientales y la Agencia de Protección Ambiental de Estados Unidos iniciaron un estudio conocido como Estudio de Salud Agrícola (AHS).

  19. Reexamination of the coronal index of solar activity

    Rybanský, M.; Rušin, V.; Minarovjech, M.; Klocok, L.; Cliver, E. W.

    2005-08-01

    The coronal index (CI) of solar activity is the irradiance of the Sun as a star in the coronal green line (Fe XIV, 530.3 nm or 5303 Å). It is derived from ground-based observations of the green corona made by the network of coronal stations (currently Kislovodsk, Lomnický Štít, Norikura, and Sacramento Peak). The CI was introduced by Rybanský (1975) to facilitate comparison of ground-based green line measurements with satellite-based extreme ultraviolet and soft X-ray observations. The CI since 1965 is based on the Lomnický Štít photometric scale; the CI was extended to earlier years by Rybanský et al. (1994) based on cross-calibrations of Lomnický Štít data with measurements made at Pic du Midi and Arosa. The resultant 1939-1992 CI had the interesting property that its value at the peak of the 11-year cycle increased more or less monotonically from cycle 18 through cycle 22 even though the peak sunspot number of cycle 20 exhibited a significant local minimum between that of cycles 19 and 21. Rušin and Rybanský (2002) recently showed that the green line intensity and photospheric magnetic field strength were highly correlated from 1976 to 1999. Since the photospheric magnetic field strength is highly correlated with sunspot number, the lack of close correspondence between the sunspot number and the CI from 1939 to 2002 is puzzling. Here we show that the CI and sunspot number are highly correlated only after 1965, calling the previously-computed coronal index for earlier years (1939-1965) into question. We can use the correlation between the CI and sunspot number (also the 2800 MHz radio flux and the cosmic ray intensity) to recompute daily values of the CI for years before 1966. In fact, this method can be used to obtain CI values as far back as we have reliable sunspot observations (˜1850). The net result of this exercise is a CI that closely tracks the sunspot number at all times. We can use the sunspot-CI relationship (for 1966-2002) to identify

  20. Effect of Thermal Conduction on Acoustic Waves in Coronal Loops

    Bogdan, T. J.

    2006-05-01

    The influence of classical (Spitzer) thermal conduction on longitudinal acoustic waves in a coronal loop is determined through an idealized but exactly solvable model. The model consists of an isothermal, stratified (constant gravity) atmosphere in which a monochromatic acoustic wave, traveling in the direction of decreasing density, is imposed throughout the lower half of the atmosphere. Based on the linearized equations of motion, the complete steady state (t-->∞) solution is obtained. In addition to the imposed driving wave, the solution also contains reflected and transmitted acoustic and thermal conduction waves. The mode transformation and mixing occurs in the vicinity of the atmospheric layer where the gas pressure passes through a critical value set by the magnitude of the thermal conduction and other model parameters. For 5 minute waves in a million degree loop, this critical pressure is on the order of 8×10-4 in cgs units. Since the apex gas pressure of many coronal loops of current interest is thought to be comfortably in excess of this value, mode mixing and transformation is not likely to be a relevant factor for understanding acoustic waves in these structures. On the other hand, enhanced thermal conductivity as a result of plasma instabilities, for example, could revive the importance of this mechanism for coronal loops. If this mixing layer is present, the calculations show that the pair of thermal conduction waves invariably gains the overwhelming majority of the energy flux of the incoming acoustic wave. This energy is rapidly dissipated in the neighborhood of the mixing layer.

  1. Role of transients in the sustainability of solar coronal plumes

    Raouafi, N.-E. [The John Hopkins University Applied Physics Laboratory, Laurel, MD 20723-6099 (United States); Stenborg, G., E-mail: NourEddine.Raouafi@jhuapl.edu [SPACS, College of Science, George Mason University, Fairfax, VA 22030 (United States)

    2014-06-01

    We report on the role of small-scale, transient magnetic activity in the formation and evolution of solar coronal plumes. Three plumes within equatorial coronal holes are analyzed over the span of several days based on the Solar Dynamic Observatory (SDO)/Atmospheric Imaging Assembly 171 Å and 193 Å images and SDO/Helioseismic and Magnetic Imager line-of-sight magnetograms. The focus is on the role of transient structures at the footpoints in sustaining coronal plumes for relatively long periods of time (i.e., several days). The appearance of plumes is a gradual and lengthy process. In some cases, the initial stages of plume formation are marked by the appearance of pillar-like structures whose footpoints are the sources of transient brightenings. In addition to nominal jets occurring prior to and during the development of plumes, the data show that a large number of small jets (i.e., {sup j}etlets{sup )} and plume transient bright points (PTBPs) occur on timescales of tens of seconds to a few minutes. These features are the result of quasi-random cancellations of fragmented and diffuse minority magnetic polarity with the dominant unipolar magnetic field concentration over an extended period of time. They unambiguously reflect a highly dynamical evolution at the footpoints and are seemingly the main energy source for plumes. This suggests a tendency for plumes to be dependent on the occurrence of transients (i.e., jetlets, and PTBPs) resulting from low-rate magnetic reconnection. The decay phase of plumes is characterized by gradual fainting and multiple rejuvenations as a result of the dispersal of the unipolar magnetic concentration and its precipitation into multiple magnetic centers.

  2. About the magnetic origin of Chromospheric Spicules and Coronal Jets

    Koutchmy, S.; Filippov, B.; Tavabi, E.

    2012-06-01

    Observations of jet- like phenomena near the solar limb are reported for a long time, first in Hα (Secchi observations of spicules in the 1870 ies), and after, from eclipse high resolution coronal images taken in white-light (1920-1973) as spiky structures. EUV jets were reported in the 70 ies from rocket and space-borne CIV filtergrams and finally X-EUV jets were reported from SXT observations of Yohkoh and from EIT and CDS SoHO observations. There is now little doubt that they are of magnetic origin although no magnetic field measurements exist for these regions and thermo-dynamical models are still work out. New observations of both spicules and jets with the SOT/SXT of Hinode were subjected to an analysis showing the influence of the null point(s) of the magnetic field. The collective behavior of the H CaII SOT(Hinode) time sequences of processed with the Madmax operator images of limb spicules show the torsional effects which were partly suggested before from the interpretation of high resolution limb spectra taken on Russian coronagraphs and the VTT at SacPeak. 100 s and shorter period waves are recorded. We propose a reconnection process occurring at the top of an emerging twisted flux tube for explaining some peculiarities of the spicular eruptions and possibly, as a viable mechanism for explaining the SXR jet eruptions. The result of a numerical 3D modeling illustrates this erupting mechanism although the behavior of the magneto-plasma structure near a null point, as shown by coronal filtergrams, does not necessary imply reconnections, especially the case of jets making a long coronal ray we observed in white-light with Lasco C2.

  3. Eastward deflection of fast coronal mass ejecta in interplanetary space

    Previous work has shown that a bidirectional solar wind electron heat flux is one of the more prominent signatures of a coronal mass ejection event in the solar wind at 1 AU. Using ISEE 3 solar wind electron measurements obtained during 1978 and 1979, we have used this signature to identify the fast coronal mass ejecta driving 19 interplanetary shocks. In 17 of the 19 shock events an eastward deflection of the ejection plasma (apparent arrival from west of the sun) was observed. The average eastward deflection for all of the events was ∼30, corresponding to a typical transverse velocity of ∼25 km/s. Usually an oppositely directed (i.e., westward) flow deflection of comparable magnitude was observed within the compressed ambient plasma ahead of the ejecta. The sense of these deflections: first westward within the compressed ambient plasma and then eastward within the ejecta: is the same as is observed near the leading edges of quasi-stationary, corotating high speed streams. However, in contrast to the case of corotating streams, the west-east flow reversal does not coincide with a local maximum in static pressure. No consistent flow deflection pattern perpendicular to the ecliptic has been observed for these events, and no similar deflections have been observed for ejecta (bidirectional electron heat flux events) traveling at the same speed as or slower than the ambient plasma ahead. We suggest that the preferred eastward deflection of these fast coronal mass ejecta is a consequence of solar rotation and the spiral geometry of the ambient solar wind. copyright American Geophysical Union 1987

  4. Coronal Heating and the Magnetic Flux Content of the Network

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

    2003-05-01

    We investigate the heating of the quiet corona by measuring the increase of coronal luminosity with the amount of magnetic flux in the underlying network at solar minimum when there were no active regions on the face of the Sun. The coronal luminosity is measured from Fe IX/X-Fe XII pairs of coronal images from SOHO/EIT. The network magnetic flux content is measured from SOHO/MDI magnetograms. We find that the luminosity of the corona in our quiet regions increases roughly in proportion to the square root of the magnetic flux content of the network and roughly in proportion to the length of the perimeter of the network magnetic flux clumps. From (1) this result, (2) other observations of many fine-scale explosive events at the edges of network flux clumps, and (3) a demonstration that it is energetically feasible for the heating of the corona in quiet regions to be driven by explosions of granule-sized sheared-core magnetic bipoles embedded in the edges of network flux clumps, we infer that in quiet regions that are not influenced by active regions the corona is mainly heated by such magnetic activity in the edges of the network flux clumps. Our observational results together with our feasibility analysis allow us to predict that (1) at the edges of the network flux clumps there are many transient sheared-core bipoles of the size and lifetime of granules and having transverse field strengths > 100 G, (2) 30 of these bipoles are present per supergranule, and (3) most spicules are produced by explosions of these bipoles. This work was supported by NASA's Office of Space Science through its Solar and Heliospheric Physics Supporting Research and Technology Program and its Sun-Earth Connection Guest Investigator Program.

  5. Interpretation of the coronal magnetic field configuration of the Sun

    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. Role of transients in the sustainability of solar coronal plumes

    We report on the role of small-scale, transient magnetic activity in the formation and evolution of solar coronal plumes. Three plumes within equatorial coronal holes are analyzed over the span of several days based on the Solar Dynamic Observatory (SDO)/Atmospheric Imaging Assembly 171 Å and 193 Å images and SDO/Helioseismic and Magnetic Imager line-of-sight magnetograms. The focus is on the role of transient structures at the footpoints in sustaining coronal plumes for relatively long periods of time (i.e., several days). The appearance of plumes is a gradual and lengthy process. In some cases, the initial stages of plume formation are marked by the appearance of pillar-like structures whose footpoints are the sources of transient brightenings. In addition to nominal jets occurring prior to and during the development of plumes, the data show that a large number of small jets (i.e., jetlets) and plume transient bright points (PTBPs) occur on timescales of tens of seconds to a few minutes. These features are the result of quasi-random cancellations of fragmented and diffuse minority magnetic polarity with the dominant unipolar magnetic field concentration over an extended period of time. They unambiguously reflect a highly dynamical evolution at the footpoints and are seemingly the main energy source for plumes. This suggests a tendency for plumes to be dependent on the occurrence of transients (i.e., jetlets, and PTBPs) resulting from low-rate magnetic reconnection. The decay phase of plumes is characterized by gradual fainting and multiple rejuvenations as a result of the dispersal of the unipolar magnetic concentration and its precipitation into multiple magnetic centers.

  7. Coronal Loops: Observations and Modeling of Confined Plasma

    Reale, Fabio

    2014-07-01

    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. Coronal Loops: Observations and Modeling of Confined Plasma

    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.

  9. Coronal Loops: Observations and Modeling of Confined Plasma

    Fabio Reale

    2010-11-01

    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 loop classification and populations, and then describes the morphology of coronal loops, its relationship with the magnetic field, and the concept of loops as multi-stranded structures. The following part of this section is devoted to the characteristics of the loop plasma and of its thermal structure in particular, according to the classification into hot, warm, and cool loops. Then, temporal analyses of loops and the observations of plasma dynamics and flows are illustrated. In the modeling section some basics of loop physics are provided, supplying some fundamental scaling laws and timescales, a useful tool for consultation. The concept of loop modeling is introduced and models are distinguished between those treating loops as monolithic and static, and those resolving loops into thin and dynamic strands. Then, 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. Finally, a brief discussion about stellar X-ray emitting structures related to coronal loops is included and followed by conclusions and open questions.

  10. Estudio comparativo de la administración de la sociedad conyugal uruguaya y la sociedad de gananciales española

    Gonzalo Trobo Cabrera

    2014-03-01

    Full Text Available Un estudio comparativo de la Administración de la sociedad conyugal de Ios bienes en el matrimonio en España y en Uruguay nos revela que existen diferencias notables entre ambos. Me he propuesto realizar un análisis de ambos regímenes en simultáneo. Si bien puede resultar engorroso este método de análisis, me apuro a indicar que de esta manera puede dársele una distinta dinámica al estudio planteado, y quizás volverlo más interesante. La mera exposición de un régimen y luego el otro, y la confrontación posterior resultaría algo más clásico y convencional en su abordaje. Trataré de abordar íntegramente el tema en las legislaciones nacíonales de ambos países. Es por ello que en este trabajo se hace un somero análisis de la legislación. Se manejará fundamentalmente la obra de un autor para el detalle de la legislación de cada uno de los regímenes nacionales. En algún punto de mayor interés se incorporarán opiniones doctrinarias o jurisprudenciales adicionales. 

  11. Abordajes Frente al Terremoto y Tsunami del 27 de Febrero del 2010: Experiencia de la Sociedad Chilena de Psicología Clínica (SCPC

    Jade Ortiz Barrera

    2010-01-01

    Full Text Available En el presente artículo se describe de forma sintética las actividades realizadas por la Sociedad Chilena de Psicología Clínica posteriormente al terremoto y tsunami del 27 de Febrero del 2010, en la zona sur y centro de Chile. Dentro de éstas se presenta la coordinación de capacitaciones a psicólogos y equipos de salud que trabajaron en terreno, preparación de material escrito que fue entregado a la población en la ciudad de Santiago y el trabajo conjunto con la Policía de Investigaciones en la difusión de información al público en la zona cero de Talcahuano. Finalmente se reflexiona acerca de la necesidad de encontrarnos preparados para actuar frente a situaciones de desastre natural, especialmente dada la constitución geográfica de nuestro país. Se hace evidente desde allí incorporar en las mallas curriculares de las diversas escuelas de psicologías, cursos o al menos unidades centradas en estrés post traumático, sus abordajes y tratamientos, así como situaciones de emergencias, catástrofes y acciones orientadas a su afrontamiento.

  12. Salud mental en la comunidad en situaciones de desastre. Una revisión de los modelos de abordaje en la comunidad

    Roberto Ariel Abeldaño

    2016-02-01

    Full Text Available Resumen Resumen Se realizó un trabajo de revisión de literatura de tipo narrativo, con el objetivo de explorar los modelos de intervención psicosocial en situaciones de desastre. Se incluyeron documentos rescatados a través de PubMed, SciELO, GoogleScholar, y Medline entre los años 1980-2014 en idioma español, inglés y francés. Además se efectuaron búsquedas en sitios web de organizaciones internacionales y gubernamentales para recopilar información relacionada a documentos que reportaban experiencias y resultados. Se identificaron 4 tipos de intervenciones psicosociales en situaciones de desastre: las basadas en el tiempo, las centradas en un tipo de desastre específico, las intervenciones por esferas o niveles de acción y las centradas en las personas. Los modelos de abordaje analizados contaron con diferencias y similitudes, a partir de la concepción teórica del desastre y de la visión integral del fenómeno. Se resalta la necesidad de generar y apoyar programas donde el empoderamiento y la participación comunitaria sean el eje de las intervenciones psicosociales.

  13. DRIVING CURRENTS FOR FLUX ROPE CORONAL MASS EJECTIONS

    We present a method for measuring electrical currents enclosed by flux rope structures that are ejected within solar coronal mass ejections (CMEs). Such currents are responsible for providing the Lorentz self-force that propels CMEs. Our estimates for the driving current are based on measurements of the propelling force obtained using data from the LASCO coronagraphs aboard the SOHO satellite. We find that upper limits on the currents enclosed by CMEs are typically around 1010 A. We estimate that the magnetic flux enclosed by the CMEs in the LASCO field of view is a few times 1021 Mx.

  14. 3D reconstruction methods of coronal structures by radio observations

    Aschwanden, Markus J.; Bastian, T. S.; White, Stephen M.

    1992-11-01

    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.

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

    Dissauer, Karin; Temmer, Manuela; 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 ...

  16. A scenario of planet erosion by coronal radiation

    Sanz-Forcada, J.; Ribas, I.; Micela, G.; Pollock, A.M.T.; Garcia-Alvarez, D.; Solano, E.; Eiroa, C.

    2010-01-01

    Context: According to theory, high-energy emission from the coronae of cool stars can severely erode the atmospheres of orbiting planets. No observational tests of the long term effects of erosion have yet been made. Aims: To analyze the current distribution of planetary mass with X-ray irradiation of the atmospheres in order to make an observational assessment of the effects of erosion by coronal radiation. Methods: We study a large sample of planet-hosting stars with XMM-Newton, Chandra and...

  17. Spatial Relationship between Solar Flares and Coronal Mass Ejections

    Yashiro, S.; G. Michalek; Akiyama, S; Gopalswamy, N.; Howard, R. A.

    2007-01-01

    We report on the spatial relationship between solar flares and coronal mass ejections (CMEs) observed during 1996-2005 inclusive. We identified 496 flare-CME pairs considering limb flares (distance from central meridian > 45 deg) with soft X-ray flare size > C3 level. The CMEs were detected by the Large Angle and Spectrometric Coronagraph (LASCO) on board the Solar and Heliospheric Observatory (SOHO). We investigated the flare positions with respect to the CME span for the events with X-class...

  18. Geoeffectiveness of Coronal Mass Ejections in the SOHO Era

    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...... for predicting the probability of the geomagnetic storm intensity based on remote solar observations of CMEs and flares....

  19. Ulysses magnetic field observations of fluctuations within polar coronal flows

    Horbury, T.; Balogh, A.; Forsyth, R. J.; Smith, E. J.

    1995-01-01

    The Ulysses spacecraft has gathered data from within flows from the Sun's southern polar coronal hole, the first in situ measurement of this region. We present a brief analysis of the heliospheric magnetic field data from this region, using a fractal method. As is the case near the ecliptic, estimated spectral exponents are near 5/3 on spacecraft scales of seconds to minutes. On longer time scales, however, there appears to be a significantly different population in polar flows, which is similar to that found by the Helios spacecraft in fast solar wind flows at 0.3 AU.

  20. Perspectiva no androcéntrica en los estudios sobre familias monoparentales. Reflexiones e implicaciones metodológicas

    Dino Di Nella

    2014-12-01

    Full Text Available En este trabajo realizamos una reflexión sobre el proceso que nos llevó a la progresiva configuración de un modelo de abordaje metodológico específico para la investigación sobre las familias monoparentales. Un proceso construido y sistematizado a partir de los aportes de las epistemologías feministas al diseño metodológico y a las formas de trabajo participativas. De ello derivo una contribución científico-técnica relevante e inédita hasta la actualidad a nivel internacional: la Encuesta sobre Monoparentalidad y diversidad familiar (EMODIF, la cual proponemos como un instrumento de medición no androcéntrico de las monoparentalidades, sus perfiles, experiencias, expectativas y realidades. Con este artículo queremos ofrecer una sistematización de las implicaciones que ha tenido nuestra aplicación y materialización de la perspectiva feminista en los estudios de las familias monoparentales.

  1. Abordaje en el área de la educación física del niño con parálisis cerebral: un estudio de casos en cinco instituciones de la ciudad de Montevideo

    Rubinstein, Sofía; Franco, Vanessa

    2014-01-01

    Este artículo tiene el propósito de analizar las propuestas implementadas por los docentes de Educación física que trabajan con niños con Parálisis Cerebral en cinco instituciones de la ciudad de Montevideo, así como objetivos que tienen los docentes en las clases, las concepciones de discapacidad y los paradigmas que subyacen en su práctica profesional. Las técnicas de recolección de datos utilizadas fueron la entrevista no estructurada por pautas a docentes que desarrollan su trabajo con...

  2. Coronal Magnetic Fields Derived from Simultaneous Microwave and EUV Observations and Comparison with the Potential Field Model

    Miyawaki, Shun; Shibasaki, Kiyoto; Shiota, Daikou; Nozawa, Satoshi

    2015-01-01

    We estimated the accuracy of coronal magnetic fields derived from radio observations by comparing them to potential field calculations and the DEM measurements using EUV observations. We derived line of sight component of the coronal magnetic field from polarization observations of the thermal bremsstrahlung in the NOAA active region 11150, observed around 3:00 UT on February 3, 2011 using the Nobeyama Radioheliograph at 17 GHz. Because the thermal bremsstrahlung intensity at 17 GHz includes both chromospheric and coronal components, we extracted only the coronal component by measuring the coronal emission measure in EUV observations. In addition, we derived only the radio polarization component of the corona by selecting the region of coronal loops and weak magnetic field strength in the chromosphere along the line of sight. The upper limit of the coronal longitudinal magnetic fields were determined as 100 - 210 G. We also calculated the coronal longitudinal magnetic fields from the potential field extrapola...

  3. The observation of possible reconnection events in the boundary changes of solar coronal holes

    Coronal holes are large scale regions of magnetically open fields which are easily observed in solar soft X-ray images. The boundaries of coronal holes are separatrices between large scale regions of open and closed magnetic fields where one might expect to observe evidence of solar magnetic reconnection. Previous studies by Nolte and colleagues using Skylab X-ray images established that large scale (greater than or equal to 9 x 10(4) km) changes in coronal hole boundaries were due to coronal processes, i.e., magnetic reconnection, rather than to photospheric motions. Those studies were limited to time scales of about one day, and no conclusion could be drawn about the size and time scales of the reconnection process at hole boundaries. Sequences of appropriate Skylab X-ray images were used with a time resolution of about 90 min during times of the central meridian passages of the coronal hole labelled Coronal Hole 1 to search for hole boundary changes which can yield the spatial and temporal scales of coronal magnetic reconnection. It was found that 29 of 32 observed boundary changes could be associated with bright points. The appearance of the bright point may be the signature of reconnection between small scale and large scale magnetic fields. The observed boundary changes contributed to the quasi-rigid rotation of Coronal Hole 1

  4. Numerical simulations of homologous coronal mass ejections in the solar wind

    Soenen, A.; Zuccarello, F. P.; Jacobs, C.; Poedts, S.; Keppens, R.; van der Holst, B.

    2009-01-01

    Context. Coronal mass ejections (CMEs) are enormous expulsions of magnetic flux and plasma from the solar corona. Most scientists agree that a coronal mass ejection is the sudden release of magnetic free energy stored in a strongly stressed field. However, the exact reason for this sudden release is

  5. La lectura como práctica cultural: conceptos para el estudio de los libros escolares

    Rockwell Elsie

    2001-01-01

    Full Text Available Este artículo presenta una perspectiva para el estudio de prácticas de lectura en aula basada en el trabajo del historiador francés Roger Chartier. Para este autor, "los actos de lectura que dan a los textos sus significados plurales y móviles se sitúan en el encuentro entre las maneras de leer y los protocolos de lectura dispuestos en el objeto leído" (Chartier, 1993. Su análisis se centra en aspectos materiales del libro y prácticas de lectura, además del texto en sí. Se ilustra este abordaje con el análisis de una clase en una escuela rural mexicana. En este caso, la maestra presentaba un cuento tomado del libro de texto, siguiendo de cerca el protocolo implícito de la lección. Sin embargo, tanto el formato del texto como las maneras de leer influyeron en su interacción con el grupo. El artículo discute las relaciones cambiantes que los niños construyen con el mundo de la escritura a partir de su experiencia escolar. La historia de la lectura muestra una inflexión significativa entre la lectura intensiva del texto único y la aparición de patrones de lectura extensiva de múltiples textos, entre ellos, los libros escolares. Sin embargo, Chartier argumenta que el proceso de apropiación siempre transforma las prácticas culturales y los significados, según cada contexto. Una mayor atención a las maneras de leer en las aulas puede revelar múltiples apropiaciones de los libros de texto que señalan diversos tipos de relación, algunas más incluyentes que otras.

  6. A new instrumentation project for the Lomnicky stit coronal station

    Rybak, J.

    1993-07-01

    A proposal of a new telescope/auxiliary instrumentation system for the solar coronal station at Lomnicky Stit (2632 m asl) is described in both the general concept and some particular technical details. The main aim of the system is to observe the near-limb photospheric and chromospheric layers of the solar atmosphere by the white-light and narrow-band imaging, as well as to perform the visible and near-infrared spectroscopy and spectropolarimetry of the parts of solar disk already mentioned. These sorts of data, measured simultaneously with the coronal emission line profiles which are regularly obtained at this time by coronagraph, could give us a great amount of physical information about the solar activity events (such as the height distribution of energy, mass, magnetic fields and their time evolution). The initial ideas and motivation of the project are explained. The parameters of the system components - refractors, narrow band filters, focal plane detectors and fibre optics positioners, telescope-spectrograph coupling via fiber optics, spectrographs, detectors and computers for the control of observations and the data acquisition - are discussed. TV CCD detectors connected with the advanced frame grabbers and the IBM PC computers are especially taken into account for the data acquisition. We also briefly mention advantages and disadvantages of the system as a whole. Finally, the future prospects of the project proposal are briefly described.

  7. Coronal inflows during the interval 1996-2014

    We extend our previous counts of coronal inflows from the 5 yr interval 1996-2001 to the 18 yr interval 1996-2014. By comparing stackplots of these counts with similar stackplots of the source-surface magnetic field and its longitudinal gradient, we find that the inflows occur in long-lived streams with counting rates in excess of 18 inflows per day at sector boundaries where the gradient exceeds 0.22 G rad–1. These streams are responsible for the high (86%) correlation between the inflow rate and the longitudinal field gradient. The overall inflow rate was several times larger in sunspot cycle 23 than it has been so far in cycle 24, reflecting the relatively weak source-surface fields during this cycle. By comparison, in cycles 21-22, the source-surface field and its gradient had bursts of great strength, as if large numbers of inflows occurred during those cycles. We find no obvious relation between inflows and coronal mass ejections (CMEs) on timescales of days to weeks, regardless of the speeds of the CMEs, and only a 60% correlation on timescales of months, provided the CMEs are fast (V > 600 km s–1). We conclude that most of the flux carried out by CMEs is returned to the Sun via field line reconnection well below the 2.0 R ☉ inner limit of the LASCO field of view, and that the remainder accumulates in the outer corona for an eventual return at sector boundaries.

  8. The Relation between EIT Waves and Coronal Mass Ejections

    Chen, P F

    2009-01-01

    More and more evidence indicates that "EIT waves" are strongly related to coronal mass ejections (CMEs). However, it is still not clear how the two phenomena are related to each other. We investigate a CME event on 1997 September 9, which was well observed by both EUV imaging telescope (EIT) and the high-cadence MK3 coronagraph at Mauna Loa Solar Observatory, and compare the spatial relation between the "EIT wave" fronts and the CME leading loops. It is found that "EIT wave" fronts are co-spatial with the CME leading loops, and the expanding EUV dimmings are co-spatial with the CME cavity. It is also found that the CME stopped near the boundary of a coronal hole, a feature common to observations of "EIT waves". It is suggested that "EIT waves"/dimmings are the EUV counterparts of the CME leading loop/cavity, based on which we propose that, as in the case of "EIT waves", CME leading loops are apparently-moving density enhancements that are generated by successive stretching (or opening-up) of magnetic loops.

  9. Automated Coronal Loop Identification Using Digital Image Processing Techniques

    Lee, Jong K.; Gary, G. Allen; Newman, Timothy S.

    2003-01-01

    The results of a master thesis project on a study of computer algorithms for automatic identification of optical-thin, 3-dimensional solar coronal loop centers from extreme ultraviolet and X-ray 2-dimensional images will be presented. These center splines are proxies of associated magnetic field lines. The project is pattern recognition problems in which there are no unique shapes or edges and in which photon and detector noise heavily influence the images. The study explores extraction techniques using: (1) linear feature recognition of local patterns (related to the inertia-tensor concept), (2) parametric space via the Hough transform, and (3) topological adaptive contours (snakes) that constrains curvature and continuity as possible candidates for digital loop detection schemes. We have developed synthesized images for the coronal loops to test the various loop identification algorithms. Since the topology of these solar features is dominated by the magnetic field structure, a first-order magnetic field approximation using multiple dipoles provides a priori information in the identification process. Results from both synthesized and solar images will be presented.

  10. A Study of Small EUV Flashes around Coronal Hole Boundaries

    Boucheron, Laura E.; Valluri, Meghala; McAteer, James

    2016-05-01

    Coronal holes (CHs) are theorized to have magnetically open magnetic flux lines and are the source of high-speed solar wind. It is hypothesized that there will be small scale reconnection events at the CH boundary due to interaction between open fields of the CH and closed fields of the quiet and active sun. These reconnection events are expected to manifest themselves as spatially small and temporally short increases in extreme ultraviolet intensity at the CH boundary. We investigate an automated detection of small flashes near the CH boundary and present statistics on the characteristics of these flashes, including lifetime, size, and brightness. We compare these characteristics to those of flashes occurring away from the CH boundary. The application of active contours without edges (ACWE) allows for the automated detection of CHs without dependence on a fixed threshold value. ACWE employs an energy-minimization in which CHs are assumed to have more homogeneous intensities than surrounding active and quiet Sun. The CHs segmented with ACWE tend to correspond to unipolar magnetic regions, are consistent with concurrent solar wind observations, and qualitatively match the coronal holes segmented by other methods. Detection of flashes around the CH boundary serve as additional evidence of correct CH segmentation and provides further evidence supporting the hypothesis of reconnection events at CH boundaries, while the ACWE now provides a tool to study these flashes further in large datasets.

  11. On the Observation and Simulation of Solar Coronal Twin Jets

    Liu, Jiajia; Fang, Fang; Wang, Yuming; McIntosh, Scott W.; Fan, Yuhong; Zhang, Quanhao

    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.

  12. Spectroscopic Observations of Propagating Disturbances in Polar Coronal Hole

    Gupta, Girjesh R.; Marsch, Eckart; Solanki, Sami K.; Banerjee, Dipankar; Teriaca, Luca

    2012-07-01

    We focus on long duration spectroscopic observations of the south polar coronal hole taken on 1997 February 25 by the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) spectrometer aboard SOHO. We analyze the data in the on-disk part of the coronal hole to find any signature of propagating waves or high speed up-flows. We find the clear presence of propagating disturbances in intensity and Doppler velocity with a projected propagation speed of about 60~km~s^{-1} and a periodicity of ≈14.5~min. During the propagation, the intensity enhancement is associated with a blue-shifted Doppler velocity. These disturbances are clearly seen in intensity at higher latitudes (i.e. closer to the limb), whereas disturbances in Doppler velocity becomes faint there. We study average spectral line profiles at the roots of these disturbances and along the propagating ridge. Based on our analysis, we interpret these disturbances in terms of propagating slow magneto-acoustic waves.

  13. A Type II Radio Burst without a Coronal Mass Ejection

    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 ...

  14. Sausage Waves in Transversely Nonuniform Monolithic Coronal Tubes

    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.

  15. Coronal fuzziness modelled with pulse-heated multistranded loop systems

    Guarrasi, Massimiliano; Peres, Giovanni

    2010-01-01

    Coronal active regions are observed to get fuzzier and fuzzier (i.e. more and more confused and uniform) in harder and harder energy bands or lines. We explain this evidence as due to the fine multi-temperature structure of coronal loops. To this end, we model bundles of loops made of thin strands, each heated by short and intense heat pulses. For simplicity, we assume that the heat pulses are all equal and triggered only once in each strand at a random time. The pulse intensity and cadence are selected so as to have steady active region loops ($\\sim 3$ MK), on the average. We compute the evolution of the confined heated plasma with a hydrodynamic loop model. We then compute the emission along each strand in several spectral lines, from cool ($\\leq 1$ MK), to warm ($2-3$ MK) lines, detectable with Hinode/EIS, to hot X-ray lines. The strands are then put side-by-side to construct an active region loop bundle. We find that in the warm lines ($2-3$ MK) the loop emission fills all the available image surface. The...

  16. An imaging study of a complex solar coronal radio eruption

    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...

  17. Cannabis, possible cardiac deaths and the coroner in Ireland.

    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.

  18. Diagnostic values of coronal section with MPR method in magnetic resonance imaging of canal stenotic change

    During a 2-year period, 300 patients were screened for canal stenotic change with surface-coil MR images, and T1-weighted coronal scan was performed on 65 patients with typical radiculopathy including 45 cases of lumbar disk herniation to evaluate the effectiveness of coronal section with MPR (multi-planar reconstruction) method in pre and post-operative assessment of canal stenotic change. Coronal section with MPR method in MRI of lumbar spine has advantages in patients with radiculopathy. Although it is as sensitive as myelography in detecting the pathological site, nerve root damage can be detected more obviously by MRI coronal section with MPR method than by myelography. As bilateral nerve roots and other contents of the foramen are figurized in the same image, the shift of the root and the decrease of the fat layer surrounding the roots can be more easily detected. Adding coronal imaging to MR examination is a viable alternative to pre-operative myelography. (author)

  19. Diagnostic values of coronal section with MPR method in magnetic resonance imaging of canal stenotic change

    Kuroda, Mana; Haruhara, Shoutaro; Soh, Katsuhiro; Yokouchi, Junichi; Matsuda, Hiromichi; Inoue, Shingo; Kakizaki, Dai; Abe, Kimihiko (Tokyo Medical Coll. (Japan))

    1990-03-01

    During a 2-year period, 300 patients were screened for canal stenotic change with surface-coil MR images, and T1-weighted coronal scan was performed on 65 patients with typical radiculopathy including 45 cases of lumbar disk herniation to evaluate the effectiveness of coronal section with MPR (multi-planar reconstruction) method in pre and post-operative assessment of canal stenotic change. Coronal section with MPR method in MRI of lumbar spine has advantages in patients with radiculopathy. Although it is as sensitive as myelography in detecting the pathological site, nerve root damage can be detected more obviously by MRI coronal section with MPR method than by myelography. As bilateral nerve roots and other contents of the foramen are figurized in the same image, the shift of the root and the decrease of the fat layer surrounding the roots can be more easily detected. Adding coronal imaging to MR examination is a viable alternative to pre-operative myelography. (author).

  20. Effect of coronal temperature on the scale of solar chromospheric jets

    Iijima, H

    2015-01-01

    We investigate the effect of coronal temperature on the formation process of solar chromospheric jets using two-dimensional magnetohydrodynamic simulations of the region from the upper convection zone to the lower corona. We develop a new radiative magnetohydrodynamic code for the dynamic modeling of the solar atmosphere, employing a LTE equation of state, optically thick radiative loss in the photosphere, optically thin radiative loss in the chromosphere and the corona, and thermal conduction along the magnetic field lines. Many chromospheric jets are produced in the simulations by shock waves passing through the transition region. We find that these jets are projected farther outward when the coronal temperature is lower (similar to that in coronal holes) and shorter when the coronal temperature is higher (similar to that in active regions). When the coronal temperature is high, the deceleration of the chromospheric jets is consistent with the model in which deceleration is determined by the periodic chromo...

  1. Spectral Characteristics of Large-Scale Radio Emission Areas in Coronal Holes

    Prosovetsky, D V; Kochanov, A A

    2013-01-01

    The spectra of the coronal hole radio emission in solar cycles 23 and 24 have been studied based on RATAN-600 data in the 4-16.5 GHz range at frequencies of 5.7 and 17 GHz and 327 MHz. It has been found that bright features of coronal hole microwave emission at 17 GHz and dark features at 5.7 GHz can exist in coronal holes when the spectral index is 1.25-1.5 in the 6.5-16.5 GHz range; the radio spectrum in this range is flat when coronal holes are indiscernible against the background of a quiet Sun. The possible vertical scale of the solar atmosphere over coronal holes is discussed.

  2. Estrategias docentes de enfermería para el abordaje de la sexualidad, la salud sexual y la salud reproductiva en adolescentes y jóvenes

    Velandia Mora, Manuel Antonio

    2011-01-01

    Estudio descriptivo transversal basado en la combinación de técnicas de investigación cuantitativas (encuesta) y cualitativas (entrevistas grupales y escritas). Sus objetivos parten del supuesto de que a los estudiantes de enfermería y de Educación se les forma sobre temas relacionados con Salud Sexual, Salud Reproductiva y Sexualidad y que previamente han recibido información básica al respecto, durante su formación en el instituto. El objetivo del estudio cuantitativo ha sido reconocer si l...

  3. TRANSVERSE OSCILLATIONS OF LOOPS WITH CORONAL RAIN OBSERVED BY HINODE/SOLAR OPTICAL TELESCOPE

    The condensations composing coronal rain, falling down along loop-like structures observed in cool chromospheric lines such as Hα and Ca II H, have long been a spectacular phenomenon of the solar corona. However, considered a peculiar sporadic phenomenon, it has not received much attention. This picture is rapidly changing due to recent high-resolution observations with instruments such as the Hinode/Solar Optical Telescope (SOT), CRISP of the Swedish 1-m Solar Telescope, and the Solar Dynamics Observatory. Furthermore, numerical simulations have shown that coronal rain is the loss of thermal equilibrium of loops linked to footpoint heating. This result has highlighted the importance that coronal rain can play in the field of coronal heating. In this work, we further stress the importance of coronal rain by showing the role it can play in the understanding of the coronal magnetic field topology. We analyze Hinode/SOT observations in the Ca II H line of a loop in which coronal rain puts in evidence in-phase transverse oscillations of multiple strand-like structures. The periods, amplitudes, transverse velocities, and phase velocities are calculated, allowing an estimation of the energy flux of the wave and the coronal magnetic field inside the loop through means of coronal seismology. We discuss the possible interpretations of the wave as either standing or propagating torsional Alfven or fast kink waves. An estimate of the plasma beta parameter of the condensations indicates a condition that may allow the often observed separation and elongation processes of the condensations. We also show that the wave pressure from the transverse wave can be responsible for the observed low downward acceleration of coronal rain.

  4. Unresolved fine-scale structure in solar coronal loop-tops

    Scullion, E.; Van der Voort, L. Rouppe; Wedemeyer, S. [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029, Blindern, NO-0315 Oslo (Norway); Antolin, P., E-mail: scullie@tcd.ie [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)

    2014-12-10

    New and advanced space-based observing facilities continue to lower the resolution limit and detect solar coronal loops in greater detail. We continue to discover even finer substructures within coronal loop cross-sections, in order to understand the nature of the solar corona. Here, we push this lower limit further to search for the finest coronal loop substructures, through taking advantage of the resolving power of the Swedish 1 m Solar Telescope/CRisp Imaging Spectro-Polarimeter (CRISP), together with co-observations from the Solar Dynamics Observatory/Atmospheric Image Assembly (AIA). High-resolution imaging of the chromospheric Hα 656.28 nm spectral line core and wings can, under certain circumstances, allow one to deduce the topology of the local magnetic environment of the solar atmosphere where its observed. Here, we study post-flare coronal loops, which become filled with evaporated chromosphere that rapidly condenses into chromospheric clumps of plasma (detectable in Hα) known as a coronal rain, to investigate their fine-scale structure. We identify, through analysis of three data sets, large-scale catastrophic cooling in coronal loop-tops and the existence of multi-thermal, multi-stranded substructures. Many cool strands even extend fully intact from loop-top to footpoint. We discover that coronal loop fine-scale strands can appear bunched with as many as eight parallel strands within an AIA coronal loop cross-section. The strand number density versus cross-sectional width distribution, as detected by CRISP within AIA-defined coronal loops, most likely peaks at well below 100 km, and currently, 69% of the substructure strands are statistically unresolved in AIA coronal loops.

  5. Presentación del estudio "Links" de hombres que tienes sexo con hombres en Buenos Aires, Argentina.

    Carballo-Diéguez, Alex; Avila, María M; Balán, Iván C; Marone, Rubén; Pando, María A; Barreda, Victoria

    2011-03-01

    Estudios previos en Buenos Aires reportaron altas prevalencias de HIV entre HSH, con valores que oscilan entre 9 y 14% durante casi 10 años de continuo testeo. El objetivo principal de este estudio fue la evaluación de factores relacionados al comportamiento de alto riesgo para transmisión del HIV entre HSH entre los que se incluyen el conocimiento y factores emocionales, socioculturales y ambientales. Por otro lado se realizó la estimación de prevalencia e incidencia de HIV utilizando RDS (Respondent Driven Sampling), así como la presencia de otras infecciones de transmisión sexual. Por último se evaluaron los hábitos de testeo para HIV indagando que factores facilitan o impiden su realización. El estudio constó de dos fases, en primer lugar una fase cualitativa y posteriormente una fase cuantitativa con una duración total de 4 años y medio. Durante la fase cualitativa se realizaron 44 entrevistas individuales en profundidad, 8 grupos focales y 10 observaciones etnográficas (hoteles, baños públicos ("teteras"), cines pornográficos, fiestas privadas, dark rooms y discotecas). Durante la fase cuantitativa del estudio se realizó el reclutamiento de 500 participantes que provinieron de la Ciudad Autónoma de Buenos Aires, así como del Gran Buenos Aires. El reclutamiento se comenzó con 16 participantes llamados semillas. Se realizó el diagnóstico de infección por HIV, hepatitis B y C (HBV y HCV), Treponema pallidum, Virus Papiloma Humano (HPV) y Chlamidias. La colaboración establecida entre los grupos de trabajo enfocados en áreas diversas posibilitó el abordaje conjunto de nuevas estrategias de investigación antes no exploradas en nuestro país. Los resultados más relevantes de esta investigación serán progresivamente publicados en sucesivos números de Actualizaciones en SIDA. PMID:25264397

  6. Modelos para el análisis de los negocios inclusivos: construcción mediante el estudio de casos

    Oscar D. Licandro

    2013-01-01

    Full Text Available El concepto de Negocios Inclusivos (NI con la Base de la Pirámide (BDP ha sido formulado para describir y sistematizar un conjunto de experiencias surgidas en los años 2000, orientadas a generar inclusión social mediante la creación de emprendimientos asociativos de personas pobres, incorporados a la cadena de valor de empresas. El desarrollo teórico y la investigación empírica sobre esta estrategia de inclusión económica y social son todavía incipientes. No obstante ello, el análisis de un amplio abanico de experiencias ha permitido elaborar algunas herramientas conceptuales útiles para orientar la reflexión teórica, la investigación empírica y el análisis estratégico de este tipo de negocio. Este documento tiene como objetivo presentar algunas de esas herramientas que han sido diseñadas en base al estudio de casos de NI en Uruguay. El documento parte de una revisión bibliográfica sobre el tema, que recorre los principales abordajes teóricos (Prahalad y Hammond, 2005; Austin y Chu, 2006; AVINA, 2010; Casado, 2011; Simanis et al., 2008 e investigaciones empíricas basadas en el estudio de casos (PNUD, 2008; Marquez et al., 2010. Luego, fundamenta la pertinencia del enfoque de NI como nueva estrategia para abordar el problema de la pobreza, formula una breve reseña de la evolución del concepto y culmina con la descripción de cinco herramientas conceptuales elaboradas a partir del estudio de 16 casos en Uruguay. Este estudio se realizó mediante entrevistas a distintos actores que participaron en el proceso de creación de cada uno de los emprendimientos, el análisis de documentos internos de los emprendimientos y páginas web y la revisión de artículos de prensa.

  7. Presentación del estudio “Links” de hombres que tienes sexo con hombres en Buenos Aires, Argentina

    Carballo-Diéguez, Alex; Ávila, María M; Balán, Iván C.; Marone, Rubén; Pando, María A.; Barreda, Victoria

    2011-01-01

    Resumen Estudios previos en Buenos Aires reportaron altas prevalencias de HIV entre HSH, con valores que oscilan entre 9 y 14% durante casi 10 años de continuo testeo. El objetivo principal de este estudio fue la evaluación de factores relacionados al comportamiento de alto riesgo para transmisión del HIV entre HSH entre los que se incluyen el conocimiento y factores emocionales, socioculturales y ambientales. Por otro lado se realizó la estimación de prevalencia e incidencia de HIV utilizando RDS (Respondent Driven Sampling), así como la presencia de otras infecciones de transmisión sexual. Por último se evaluaron los hábitos de testeo para HIV indagando que factores facilitan o impiden su realización. El estudio constó de dos fases, en primer lugar una fase cualitativa y posteriormente una fase cuantitativa con una duración total de 4 años y medio. Durante la fase cualitativa se realizaron 44 entrevistas individuales en profundidad, 8 grupos focales y 10 observaciones etnográficas (hoteles, baños públicos (“teteras”), cines pornográficos, fiestas privadas, dark rooms y discotecas). Durante la fase cuantitativa del estudio se realizó el reclutamiento de 500 participantes que provinieron de la Ciudad Autónoma de Buenos Aires, así como del Gran Buenos Aires. El reclutamiento se comenzó con 16 participantes llamados semillas. Se realizó el diagnóstico de infección por HIV, hepatitis B y C (HBV y HCV), Treponema pallidum, Virus Papiloma Humano (HPV) y Chlamidias. La colaboración establecida entre los grupos de trabajo enfocados en áreas diversas posibilitó el abordaje conjunto de nuevas estrategias de investigación antes no exploradas en nuestro país. Los resultados más relevantes de esta investigación serán progresivamente publicados en sucesivos números de Actualizaciones en SIDA. PMID:25264397

  8. Physical Conditions of Coronal Plasma at the transit of a Shock driven by a Coronal Mass Ejection

    Bemporad, A; Mancuso, S

    2015-01-01

    We report here on the determination of plasma physical parameters across a shock driven by a Coronal Mass Ejection using White Light (WL) coronagraphic images and Radio Dynamic Spectra (RDS). The event analyzed here is the spectacular eruption that occurred on June 7th 2011, a fast CME followed by the ejection of columns of chromospheric plasma, part of them falling back to the solar surface, associated with a M2.5 flare and a type-II radio burst. Images acquired by the SOHO/LASCO coronagraphs (C2 and C3) were employed to track the CME-driven shock in the corona between 2-12 R$_\\odot$ in an angular interval of about 110$^\\circ$. In these intervals we derived 2-Dimensional (2D) maps of electron density, shock velocity and shock compression ratio, and we measured the shock inclination angle with respect to the radial direction. Under plausible assumptions, these quantities were used to infer 2D maps of shock Mach number $M_\\text{A}$ and strength of coronal magnetic fields at the shock's heights. We found that i...

  9. Relatos de los equipos de salud mental de atención primaria (aps acerca del abordaje de la violencia de género en la pareja Discourses of primary mental healthcare teams on addressing gender violence within the context of relationships

    Beatriz Salgado Diez

    2012-12-01

    Full Text Available La violencia contra las mujeres en el contexto de la relación de pareja es un problema situado en la agenda pública, asociado a la determinación de género. Incorporar la perspectiva de género es, por tanto, crucial para poder entender e intervenir en este fenómeno. Para analizar si los discursos que poseen los profesionales de los Equipos de Salud Mental de APS de la Comuna de Valparaíso (Médicos/as, Psicólogos/as, Asistentes Sociales respecto del abordaje que realizan sobre violencia doméstica presentan saberes, ideas o nociones basados en perspectiva de género, se realizó estudio con metodología cualitativa, a través de entrevistas semiestructuradas y se realizó un análisis de contenido. Hay consenso sobre la forma de abordar a las mujeres agredidas, para todos es muy relevante generar un espacio terapéutico empático, de contención. Se valora en los discursos el trabajo multidiciplinario e intersectorial. Se mencionan prácticas de riesgo de generar revictimización. No existe intencionalidad hacia un empoderamiento desde una perspectiva de género, salvo en el caso de algunos/as psicólogos/as. El presente trabajo podría aportar a la evaluación crítica de los distintos discursos de los Equipos de Salud Mental de APS en el abordaje de la violencia de género.Violence against women within relationships is a problem which is in the public eye and is mainly associated with the gender factor. It is therefore crucial to incorporate a gender perspective in order to understand and intervene in this phenomenon. A qualitative study was conducted using semi-structured interviews and applying content analysis, to analyze if the declared discourse of the Primary Mental Healthcare teams in Valparaíso (physicians, psychologists, social workers, regarding tackling violence against women within the context of a relationship includes perceptions, knowledge and ideas based on the gender perspective. There is a general consensus on how to

  10. Coronal magnetic fields from multiple type II bursts

    Honnappa, Vijayakumar; Raveesha, K. H.; Subramanian, K. R.

    Coronal magnetic fields from multiple type II bursts Vijayakumar H Doddamani1*, Raveesha K H2 and Subramanian3 1Bangalore University, Bangalore, Karnataka state, India 2CMR Institute of Technology, Bangalore, Karnataka state, India 3 Retd, Indian Institute of Astrophysics, Bangalore, Karnataka state, India Abstract Magnetic fields play an important role in the astrophysical processes occurring in solar corona. In the solar atmosphere, magnetic field interacts with the plasma, producing abundant eruptive activities. They are considered to be the main factors for coronal heating, particle acceleration and the formation of structures like prominences, flares and Coronal Mass Ejections. The magnetic field in solar atmosphere in the range of 1.1-3 Rsun is especially important as an interface between the photospheric magnetic field and the solar wind. Its structure and time dependent change affects space weather by modifying solar wind conditions, Cho (2000). Type II doublet bursts can be used for the estimation of the strength of the magnetic field at two different heights. Two type II bursts occur sometimes in sequence. By relating the speed of the type II radio burst to Alfven Mach Number, the Alfven speed of the shock wave generating type II radio burst can be calculated. Using the relation between the Alfven speed and the mean frequency of emission, the magnetic field strength can be determined at a particular height. We have used the relative bandwidth and drift rate properties of multiple type II radio bursts to derive magnetic field strengths at two different heights and also the gradient of the magnetic field in the outer corona. The magnetic field strength has been derived for different density factors. It varied from 1.2 to 2.5 gauss at a solar height of 1.4 Rsun. The empirical relation of the variation of the magnetic field with height is found to be of the form B(R) = In the present case the power law index ‘γ’ varied from -3 to -2 for variation of

  11. Estudio de impacto ambiental: procedimiento y herramientas

    Encinas Malagón, María Dolores; Gómez de Balugera López de Alda, Zuriñe

    2016-01-01

    2ª edición Este trabajo consta de un manual mejorado y ampliado, que detalla los pasos necesarios para la realización de un Estudio de Impacto Ambiental, un libro excel más completo para la evaluación cualitativa y cuantitativa de los impactos ambientales en cada una de las fases del estudio y una colección de los indicadores ambientales necesarios para dicha valoración.

  12. Suicide and the Therapeutic Coroner: Inquests, Governance and the Grieving Family

    Gordon Tait

    2013-11-01

    Full Text Available This study of English Coronial practice raises a number of questions about the role played by the Coroner within contemporary governance. Following observations at over 20 inquests into possible suicides and in-depth interviews with six Coroners, three preliminary issue emerged, all of which pointed to a broader and, in many ways, more significant issue. These preliminary issues are concerned with (1 the existence of considerable slippages between different Coroners over which deaths are likely to be classified as suicide; (2 the high standard of proof required and immense pressure faced by Coroners from family members at inquest to reach any verdict other than suicide, which significantly depresses likely suicide rates; and (3 Coroners feeling no professional obligation, either individually or collectively, to contribute to the production of consistent and useful social data regarding suicide, arguably rendering comparative suicide statistics relatively worthless. These concerns lead, ultimately, to the second more important question about the role expected of Coroners within social governance and within an effective, contemporary democracy. That is, are Coroners the principal officers in the public administration of death; or are they, first and foremost, a crucial part of the grieving process, one that provides important therapeutic interventions into the mental and emotional health of the community?

  13. Hanle Effect Diagnostics of the Coronal Magnetic Field - A Test Using Realistic Magnetic Field Configurations

    Raouafi, N -E; Wiegelmann, T

    2008-01-01

    Our understanding of coronal phenomena, such as coronal plasma thermodynamics, faces a major handicap caused by missing coronal magnetic field measurements. Several lines in the UV wavelength range present suitable sensitivity to determine the coronal magnetic field via the Hanle effect. The latter is a largely unexplored diagnostic of coronal magnetic fields with a very high potential. Here we study the magnitude of the Hanle-effect signal to be expected outside the solar limb due to the Hanle effect in polarized radiation from the H {\\sc{i}} Ly$\\alpha$ and $\\beta$ lines, which are among the brightest lines in the off-limb coronal FUV spectrum. For this purpose we use a magnetic field structure obtained by extrapolating the magnetic field starting from photospheric magnetograms. The diagnostic potential of these lines for determining the coronal magnetic field, as well as their limitations are studied. We show that these lines, in particular H {\\sc{i}} Ly$\\beta$, are useful for such measurements.

  14. VECTOR TOMOGRAPHY FOR THE CORONAL MAGNETIC FIELD. II. HANLE EFFECT MEASUREMENTS

    In this paper, we investigate the feasibility of saturated coronal Hanle effect vector tomography or the application of vector tomographic inversion techniques to reconstruct the three-dimensional magnetic field configuration of the solar corona using linear polarization measurements of coronal emission lines. We applied Hanle effect vector tomographic inversion to artificial data produced from analytical coronal magnetic field models with equatorial and meridional currents and global coronal magnetic field models constructed by extrapolation of real photospheric magnetic field measurements. We tested tomographic inversion with only Stokes Q, U, electron density, and temperature inputs to simulate observations over large limb distances where the Stokes I parameters are difficult to obtain with ground-based coronagraphs. We synthesized the coronal linear polarization maps by inputting realistic noise appropriate for ground-based observations over a period of two weeks into the inversion algorithm. We found that our Hanle effect vector tomographic inversion can partially recover the coronal field with a poloidal field configuration, but that it is insensitive to a corona with a toroidal field. This result demonstrates that Hanle effect vector tomography is an effective tool for studying the solar corona and that it is complementary to Zeeman effect vector tomography for the reconstruction of the coronal magnetic field

  15. Interplanetary Coronal Mass Ejections observed by MESSENGER and Venus Express

    Good, S W

    2015-01-01

    Interplanetary coronal mass ejections (ICMEs) observed by the MESSENGER (MES) and Venus Express (VEX) spacecraft have been catalogued and analysed. The ICMEs were identified by a relatively smooth rotation of the magnetic field direction consistent with a flux rope structure, coinciding with a relatively enhanced magnetic field strength. A total of 35 ICMEs were found in the surveyed MES data (primarily from March 2007 to April 2012), and 84 ICMEs in the surveyed VEX data (from May 2006 to December 2013). The ICME flux rope configurations have been determined. Ropes with northward leading edges were about four times more common than ropes with southward leading edges, in agreement with a previously established solar cycle dependence. Ropes with low inclinations to the solar equatorial plane were about four times more common than ropes with high inclinations, possibly an observational effect. Left and right-handed ropes were observed in almost equal numbers. In addition, data from MES, VEX, STEREO-A, STEREO-B ...

  16. Stellar winds, dead zones, and coronal mass ejections

    Keppens, R

    1999-01-01

    Axisymmetric stellar wind solutions are presented, obtained by numerically solving the ideal magnetohydrodynamic (MHD) equations. Stationary solutions are critically analysed using the knowledge of the flux functions. These flux functions enter in the general variational principle governing all axisymmetric stationary ideal MHD equilibria. The magnetized wind solutions for (differentially) rotating stars contain both a `wind' and a `dead' zone. We illustrate the influence of the magnetic field topology on the wind acceleration pattern, by varying the coronal field strength and the extent of the dead zone. This is evident from the resulting variations in the location and appearance of the critical curves where the wind speed equals the slow, Alfven, and fast speed. Larger dead zones cause effective, fairly isotropic acceleration to super-Alfvenic velocities as the polar, open field lines are forced to fan out rapidly with radial distance. A higher field strength moves the Alfven transition outwards. In the ecl...

  17. Solar radio bursts and their relation of coronal magnetic structures

    Following a general introduction, chapters II and III describe a model for coronal flux tubes. The model tube is a cylindrically symmetric localized force free current, that is embedded in a potential field. In both chapters the growth rates and sizes of the kink mode instability are calculated by solving the linearized equation of motion. In chapters IV and V, observations of solar Type-I radio bursts are presented and analysed. The observations were gathered with the 60-channel radio spectrograph in Dwingeloo. Chapters VI, VII, VIII, IX and X are concerned with observations of solar microwave bursts. The observations, with high time resolution (0.1 s) and high one-dimensional angular resolution (max. 4'') were made with the Westerbork Synthesis Radio Telescope. (Auth.)

  18. Coronal Magnetic Flux Rope Equilibria and Magnetic Helicity

    2001-01-01

    Using a 2.5-dimensional (2.5-D) ideal MHD model, this paper ana lyzes the equilibrium properties of coronal magnetic flux ropes in a bipolar ambient magnetic field. It is found that the geometrical features of the magnetic flux rope,including the height of the rope axis, the half-width of the rope, and the length of the vertical current sheet below the rope, are determined by a single magnetic parameter, the magnetic helicity, which is the sum of the self-helicity of the rope and the mutual helicity between the rope field and the ambient magnetic field. All the geometrical parameters increase monotonically with increasing magnetic helicity.The implication of this result in solar active phenomena is briefly discussed.

  19. Usefulness of direct coronal CT of the abdomen

    Direct coronal CT (DCCT), in which subjects are made to sit and tip forward at the opening of gantry, was performed in patients with diseases in the retroperitoneum or pelvic cavity. The aorta, venacava, ureter and iliopsoas muscle, which are placed along the axon, were visualized on a slice of DCCT. The diaphragm and the crura of the diaphragm were serially visualized. As for the pelvic cavity, DCCT was useful in visualizing the tip and bottom of the urinary bladder, making it easy to elucidate the anatomical position between these organs and their surrounding organs. The positional relation between lavator ani muscle and inverted region of the peritoneum was also confirmed on DCCT. Extensive visualization of the spinal cord and vertebral canal was possible. (Namekawa, K)

  20. The Evolution and Space Weather Effects of Solar Coronal Holes

    Krista, Larisza Diana

    2012-01-01

    In recent years the role of space weather forecasting has grown tremendously as our society increasingly relies on satellite dependent technologies. The forecasting of flare and CME related transient geomagnetic storms has become a primary initiative, however, minor magnetic storms caused by coronal holes (CHs) have also proven to be of high importance due to their long lasting and recurrent geomagnetic effects. In order to study CH properties, the author developed an automated CH detection method (CHARM), which uses local intensity histograms to identify CH boundaries. An additional algorithm package (CHEVOL) was developed to study individual CHs by tracking their boundary evolution. 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. In order to test the interchange reconnection model, the magnetic reconnection rate and the diffusion coefficient at CH boundaries were determined using observed CH boundary ...

  1. Chromospheric, transition layer and coronal emission of metal deficient stars

    Boehm-Vitense, E.

    1982-01-01

    It is shown that while MgII k line emission decreases for metal deficient stars, the Ly alpha emission increases. The sum of chromospheric hydrogen and metallic emission appears to be independent of metal abundances. The total chromospheric energy loss is estimated to be 0.0004 F sub bol. The chromospheric energy input does not seem to decrease for increasing age. The transition layer emission is reduced for metal deficient stars, but it is not known whether the reduction is larger than can be explained by curve of growth effects only. Coronal X-ray emission was measured for 4 metal deficient stars. Within a 12 limit it could still be consistent with the emission of solar abundance stars.

  2. The Kinematics and Morphology of Solar Coronal Mass Ejections

    Byrne, Jason P

    2012-01-01

    Solar coronal mass ejections (CMEs) are large-scale eruptions of plasma and magnetic field from the Sun into the corona and interplanetary space. They are the most significant drivers of adverse space weather at Earth and other locations in the heliosphere, so it is important to understand the physics governing their eruption and propagation. However the diffuse morphology and transient nature of CMEs makes them difficult to identify and track using traditional image processing techniques. In this thesis the implementation of multiscale image processing techniques to identify and track the CME front through coronagraph images is detailed. An ellipse characterisation of the CME front is used to determine the CME kinematics and morphology with increased precision as compared to techniques used in current CME catalogues, and efforts are underway to automate this procedure for applying to a large number of CME observations for future analysis. It was found that CMEs do not simply undergo constant acceleration, bu...

  3. Numerical simulations of transverse oscillations in radiatively cooling coronal loops

    Magyar, N; Marcu, A

    2015-01-01

    We aim to study the influence of radiative cooling on the standing kink oscillations of a coronal loop. Using the FLASH code, we solved the 3D ideal magnetohydrodynamic equations. Our model consists of a straight, density enhanced and gravitationally stratified magnetic flux tube. We perturbed the system initially, leading to a transverse oscillation of the structure, and followed its evolution for a number of periods. A realistic radiative cooling is implemented. Results are compared to available analytical theory. We find that in the linear regime (i.e. low amplitude perturbation and slow cooling) the obtained period and damping time are in good agreement with theory. The cooling leads to an amplification of the oscillation amplitude. However, the difference between the cooling and non-cooling cases is small (around 6% after 6 oscillations). In high amplitude runs with realistic cooling, instabilities deform the loop, leading to increased damping. In this case, the difference between cooling and non-cooling...

  4. Nonunion of coronal shear fracture of femoral condyle

    Ajay Pal Singh; Ish Kumar Dhammi; Raju Vaishya; Anil Kumar Jain; Arun Pal Singh; Prashant Modi

    2011-01-01

    Isolated coronal fractures of femoral condyle are rare in adults and nonunion of Hoffa fracture is reported only a few times in the literature. We analyzed six cases of nonunion of Hoffa fractures over a period of three years. Three patients were treated conservatively and three patients had fixation failures. Delay of presentation was 2 months to one year. Treatment protocol consisted of open reduction, excision of pseudoarthrosis, bone grafting and internal fixation along with knee arthrolysis. Union was achieved in all patients at mean 16 weeks. The treatment of nonunion of Hoffa fractures requires careful preoperative planning and meticulous surgical technique. The literature regarding the controversies in fracture management and surgical technique are reviewed.

  5. Einstein Observatory coronal temperatures of late-type stars

    Schmitt, J. H. M. M.; Collura, A.; Sciortino, S.; Vaiana, G. S.; Harnden, F. R., Jr.

    1990-01-01

    The results are presented of a survey of the coronal temperatures of late-type stars using the Einstein Observatory IPC. The spectral analysis shows that the frequently found one- and two-temperature descriptions are mainly influenced by the SNR of the data and that models using continuous emission measure distributions can provide equally adequate and physically more meaningful and more plausible descriptions. Intrinsic differences in differential emission measure distributions are found for four groups of stars. M dwarfs generally show evidence for high-temperature gas in conjunction with lower-temperature material, while main-sequence stars of types F and G have the high-temperature component either absent or very weak. Very hot coronae without the lower-temperature component appearing in dwarf stars are evident in most of the giant stars studied. RS CVn systems show evidence for extremely hot coronae, sometimes with no accompanying lower-temperature material.

  6. Changes in the subgingival biofilm composition after coronally positioned flap

    Jadson Almeida Lima

    2011-02-01

    Full Text Available OBJECTIVES: This study evaluated the effects of coronally positioned flap (CPF on the subgingival biofilm composition. MATERIAL AND METHODS: Twenty-two subjects with gingival recessions were treated with CPF. Clinical parameters were assessed before and at 6 months after surgery. Subgingival biofilms were analyzed by checkerboard DNA-DNA hybridization technique for 40 bacterial species. RESULTS: Recession height, clinical attachment level and bleeding on probing improved significantly (p<0.05 at 6 months post-CPF. The proportions of 10 periodontal pathogens and the proportions of red and orange complexes decreased at 6 months. CONCLUSION: In conclusion, CPF can induce beneficial effects on the composition of the subgingival microbiota after 6 months.

  7. On Sun-to-Earth Propagation of Coronal Mass Ejections

    Liu, Ying D; Lugaz, Noé; Möstl, Christian; Davies, Jackie A; Bale, Stuart D; Lin, Robert P

    2013-01-01

    We investigate how coronal mass ejections (CMEs) propagate through, and interact with, the inner heliosphere between the Sun and Earth, a key question in CME research and space weather forecasting. CME Sun-to-Earth kinematics are constrained by combining wide-angle heliospheric imaging observations, interplanetary radio type II bursts and in situ measurements from multiple vantage points. We select three events for this study, the 2012 January 19, 23, and March 7 CMEs. Different from previous event studies, this work attempts to create a general picture for CME Sun-to-Earth propagation and compare different techniques for determining CME interplanetary kinematics. Key results are obtained concerning CME Sun-to-Earth propagation. Our comparison between different techniques (and data sets) also has important implications for CME observations and their interpretations. Future CME observations and space weather forecasting are discussed based on these results. See detail in the PDF.

  8. Predicting Coronal Mass Ejections Using Machine Learning Methods

    Bobra, Monica G

    2016-01-01

    Of all the activity observed on the Sun, two of the most energetic events are flares and Coronal Mass Ejections (CMEs). Usually, solar active regions that produce large flares will also produce a CME, but this is not always true (Yashiro et al., 2005). Despite advances in numerical modeling, it is still unclear which circumstances will produce a CME (Webb & Howard, 2012). Therefore, it is worthwhile to empirically determine which features distinguish flares associated with CMEs from flares that are not. At this time, no extensive study has used physically meaningful features of active regions to distinguish between these two populations. As such, we attempt to do so by using features derived from [1] photospheric vector magnetic field data taken by the Solar Dynamics Observatory's Helioseismic and Magnetic Imager instrument and [2] X-ray flux data from the Geostationary Operational Environmental Satellite's X-ray Flux instrument. We build a catalog of active regions that either produced both a flare and a...

  9. Formation of slow shock pairs associated with coronal mass ejections

    Whang, Y. V.

    1990-01-01

    The formation of a forward-reverse slow shock pair in the solar corona is presently simulated by an MHD model that uses the Rankine-Hugoniot solution to calculate the flow-property jumps at all shock crossings. The shocks divide the solution-domain into several continuous flow regions whose respective governing characteristics are solved by the method of characteristics. The plasma impact compresses the plasma near the front of the coronal mass ejection (CME); as the CME-associated slow shock pair moves outwards in interplanetary space, it evolves into a pair of fast shocks. All three phenomena are eventually manifested in interplanetary space as a magnetic cloud accompanied by a fast shock pair, with a forward shock preceding the cloud and a reverse shock appearing either within or behind the cloud.

  10. Three-Dimensional Morphology of a Coronal Prominence Cavity

    Gibson, S. E.; Kucera, T. A.; Rastawicki, D.; Dove, J.; deToma, G.; Hao, J.; Hill, S.; Hudson, H. S.; Marque, C.; McIntosh, P. S.; Rachmeler, L.; Reeves, K. K.; Schmieder, B.; Schmit, D. J.; Seaton, D. B.; Sterling, A. C.; Tripathi, D.; Williams, D. R.; Zhang, M.

    2010-01-01

    We present a three-dimensional density model of coronal prominence cavities, and a morphological fit that has been tightly constrained by a uniquely well-observed cavity. Observations were obtained as part of an International Heliophysical Year campaign by instruments from a variety of space- and ground-based observatories, spanning wavelengths from radio to soft-X-ray to integrated white light. From these data it is clear that the prominence cavity is the limb manifestation of a longitudinally-extended polar-crown filament channel, and that the cavity is a region of low density relative to the surrounding corona. As a first step towards quantifying density and temperature from campaign spectroscopic data, we establish the three-dimensional morphology of the cavity. This is critical for taking line-of-sight projection effects into account, since cavities are not localized in the plane of the sky and the corona is optically thin. We have augmented a global coronal streamer model to include a tunnel-like cavity with elliptical cross-section and a Gaussian variation of height along the tunnel length. We have developed a semi-automated routine that fits ellipses to cross-sections of the cavity as it rotates past the solar limb, and have applied it to Extreme Ultraviolet Imager (EUVI) observations from the two Solar Terrestrial Relations Observatory (STEREO) spacecraft. This defines the morphological parameters of our model, from which we reproduce forward-modeled cavity observables. We find that cavity morphology and orientation, in combination with the viewpoints of the observing spacecraft, explains the observed variation in cavity visibility for the east vs. west limbs

  11. Volumetric measurement of the maxillary sinus by coronal CT scan

    The volume of the maxillary sinus was estimated by coronal CT scan. The purpose of this study was to compare the estimated volume of the normal maxillary sinus with that of the inflamed maxillary sinus. Patients were classified following evaluation by CT scan of the paranasal sinuses into 3 categories. Group A (n=12): Patients suffered from headache, facial pain and epistaxis, but CT scans of their nasal cavity and paranasal sinus were within normal limits without inflammatory change. Group B (n=69): Patients with bilateral chronic maxillary sinusitis, CT scans of whom showed inflammatory changes in both maxillary sinuses. All of the patients in this group underwent sinus surgery after coronal CT scans. Group C (n=14): Patients with unilateral chronic maxillary sinusitis, CT scans of whom showed inflammatory change in unilateral maxillary sinuses. CT scans of these patients were measured by Plannimeter to take the area of each image of the maxillary sinus. Consecutively imaged areas were summated by integral calculus to obtain an estimate of the sinus volume. The mean maxillary sinus volume in the affected sinuses was significantly smaller than those in the contralateral normal sinuses (p<0.05, Wilcoxon-test). The various volumes of the maxillary sinuses and the developmental cause were discussed. Comparison of groups A with B suggested three distinct patterns; the maxillary sinus volume has decreased due to inflammatory changes in the bone. The small sinuses have a tendency to develop chronic inflammatory change. The aeration in the maxillary sinus may be decreased when anatomic variations that may obstruct the ethmoid infundibulum exist. (K.H.)

  12. WHAT CAN WE LEARN ABOUT SOLAR CORONAL MASS EJECTIONS, CORONAL DIMMINGS, AND EXTREME-ULTRAVIOLET JETS THROUGH SPECTROSCOPIC OBSERVATIONS?

    Solar eruptions, particularly coronal mass ejections (CMEs) and extreme-ultraviolet (EUV) jets, have rarely been investigated with spectroscopic observations. We analyze several data sets obtained by the EUV Imaging Spectrometer on board Hinode and find various types of flows during CMEs and jet eruptions. CME-induced dimming regions are found to be characterized by significant blueshift and enhanced line width by using a single Gaussian fit, while a red-blue (RB) asymmetry analysis and an RB-guided double Gaussian fit of the coronal line profiles indicate that these are likely caused by the superposition of a strong background emission component and a relatively weak (∼10%), high-speed (∼100 km s–1) upflow component. This finding suggests that the outflow velocity in the dimming region is probably of the order of 100 km s–1, not ∼20 km s–1 as reported previously. These weak, high-speed outflows may provide a significant amount of mass to refill the corona after the eruption of CMEs, and part of them may experience further acceleration and eventually become solar wind streams that can serve as an additional momentum source of the associated CMEs. Density and temperature diagnostics of the dimming region suggest that dimming is primarily an effect of density decrease rather than temperature change. The mass losses in dimming regions as estimated from different methods are roughly consistent with each other, and they are 20%-60% of the masses of the associated CMEs. With the guide of RB asymmetry analysis, we also find several temperature-dependent outflows (speed increases with temperature) immediately outside the (deepest) dimming region. These outflows may be evaporation flows that are caused by the enhanced thermal conduction or nonthermal electron beams along reconnecting field lines, or induced by the interaction between the opened field lines in the dimming region and the closed loops in the surrounding plage region. In an erupted CME loop and an

  13. Stellar Coronae with \\textit{XMM-Newton} RGS. I. Coronal Structure

    Güdel, M; Den Boggende, A J F; Brinkman, A C; Den Herder, J W A; Kaastra, J S; Mewe, R; Raassen, A J J; De Vries, C; Behar, E; Cottam, J; Kahn, S M; Paerels, F B S; Peterson, J M; Rasmussen, A P; Sako, M; Branduardi-Raymont, G; Sakelliou, I; Erd, Christian

    2000-01-01

    First results from high-resolution coronal spectroscopy with the {\\it XMM-Newton} Reflection Grating Spectrometers (RGS) are reviewed. Five stellar systems (HR 1099, Capella, Procyon, YY Gem, AB Dor) have been observed. The emphasis of the present paper is on overall coronal structure. Elemental abundances in {\\it active stars} are found to be `anomalous' in the sense that they tend to increase with increasing First Ionization Potential (FIP - i.e., signifying an inverse FIP effect). Coronal densities are measured at levels of a few times $10^{10}$ cm$^{-3}$ for cooler plasma, although there are indications for very high densities in the hotter plasma components.

  14. TRACKING CORONAL FEATURES FROM THE LOW CORONA TO EARTH: A QUANTITATIVE ANALYSIS OF THE 2008 DECEMBER 12 CORONAL MASS EJECTION

    DeForest, C. E.; Howard, T. A. [Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302 (United States); McComas, D. J., E-mail: deforest@boulder.swri.edu [Southwest Research Institute, 6220 Culebra Rd., San Antonio, TX 78249 (United States)

    2013-05-20

    We have tracked a slow magnetic cloud associated coronal mass ejection (CME) continuously from its origin as a flux rope structure in the low solar corona over a four-day passage to impact with spacecraft located near Earth. Combining measurements from the STEREO, ACE, and Wind space missions, we are able to follow major elements with enough specificity to relate pre-CME coronal structure in the low corona to the corresponding elements seen in the near-Earth in situ data. Combining extreme ultraviolet imaging, quantitative Thomson scattering data throughout the flight of the CME, and ''ground-truth'' in situ measurements, we: (1) identify the plasma observed by ACE and Wind with specific features in the solar corona (a segment of a long flux rope); (2) determine the onset mechanism of the CME (destabilization of a filament channel following flare reconnection, coupled with the mass draining instability) and demonstrate that it is consistent with the in situ measurements; (3) identify the origin of different layers of the sheath material around the central magnetic cloud (closed field lifted from the base of the corona, closed field entrained during passage through the corona, and solar wind entrained by the front of the CME); (4) measure mass accretion of the system via snowplow effects in the solar wind as the CME crossed the solar system; and (5) quantify the kinetic energy budget of the system in interplanetary space, and determine that it is consistent with no long-term driving force on the CME.

  15. Redefinición del concepto y del abordaje de las lesiones por humedad: Una propuesta conceptual y metodológica para mejorar el cuidado de las lesiones cutáneas asociadas a la humedad (LESCAH)

    Joan-Enric Torra i Bou; Manuel Rodríguez Palma; José Javier Soldevilla Agreda; Francisco P. García Fernández; Raquel Sarabia Lavín; Jaime Zabala Blanco; José Verdú Soriano; Teresa Segovia Gómez

    2013-01-01

    Actualmente se percibe una indefinición manifiesta acerca de la conceptualización y abordaje de las llamadas lesiones por humedad en los entornos clínicos, docentes e investigadores de nuestro país, que muy frecuentemente relacionan este término solo con las lesiones producidas por la orina y las heces. Dadas las diversas repercusiones que se intuye pueden tener este tipo de lesiones, se hace necesario consensuar y unificar los distintos aspectos relacionados con el cuidado de estas heridas. ...

  16. Redefinición del concepto y del abordaje de las lesiones por humedad: una propuesta conceptual y metodológica para mejorar el cuidado de las lesiones cutáneas asociadas a la humedad (LESCAH)

    Torra i Bou, Joan Enric; Rodríguez Palma, Manuel; Soldevilla Agreda, J. Javier; García Fernández, Francisco Pedro; Sarabia Lavín, Raquel; Zabala Blanco, Jaime; Verdú Soriano, José; Segovia Gómez, Teresa

    2013-01-01

    Actualmente se percibe una indefinición manifiesta acerca de la conceptualización y abordaje de las llamadas lesiones por humedad en los entornos clínicos, docentes e investigadores de nuestro país, que muy frecuentemente relacionan este término solo con las lesiones producidas por la orina y las heces. Dadas las diversas repercusiones que se intuye pueden tener este tipo de lesiones, se hace necesario consensuar y unificar los distintos aspectos relacionados con el cuidado de estas heridas. ...

  17. ABORDAJE SELECTIVO ANTEROLATERAL PARA MANEJO DE FRACTURAS DE LA REGIÓN TORACOLUMBAR (T12, L1, L2): DESCRIPCIÓN DE UNA TÉCNICA QUIRÚRGICA POR INCISIÓN MÍNIMA

    JAVIER MATTA; VICTOR ARRIETA; MARIO GONZÁLEZ; LEONARDO JAIMES

    2013-01-01

    La unión toracolumbar es el área más frecuentemente afectada por el trauma cerrado de columna vertebral. Anatómicamente es una zona transicional entre la columna torácica rígida y la lumbar móvil. Se presentan con mayor frecuencia en fracturas por acuñamiento o por estallido, con o sin déficit neurológico. El tratamiento se realiza por abordaje anterolateral en pacientes con acuñamientos inveterados, cifosis postraumática y estallidos con déficit parcial que ameriten descompresión. Se describ...

  18. Aportes de la psicología al campo de la ética: la constitución del sujeto moral en la infancia desde un abordaje psicoanalítico freudiano

    León, Marta Cristina

    2007-01-01

    Este trabajo tiene como objetivo reunir reflexiones de la Psicología relacionadas con la constitución del infante como sujeto moral. Distintos abordajes psicoanalíticos han estudiado los tiempos y modalidades de su estructuración a partir de la idea de que es producto de las interacciones entre el individuo, la sociedad y el momento histórico que enmarca y condiciona este proceso, brindando especificidad al concepto de “intersubjetividad”. La cuestión relacionada con los avatares que circulan...

  19. Evaluación de la efectividad de la terapia de grupo multifamiliar en el abordaje de la problemática conductual y emocional del adolescente

    Pérez García, María

    2016-01-01

    Objetivos: Ante la elevada demanda asistencial que motiva la conducta problemática en la etapa adolescente en un dispositivo ambulatorio de salud mental, y contando con recursos sanitarios limitados, se plantea la terapia de grupo multifamiliar (TGM) como alternativa terapéutica de fácil implementación, rentable y potencialmente efectiva respecto a otros tratamientos habitualmente utilizados (TAU) en este medio. Puesto que existen pocos estudios documentados que demuestren la eficacia y/...

  20. Influence of a coronal envelope as a free boundary to global convective dynamo simulations

    Warnecke, Jörn; Käpylä, Maarit J; Brandenburg, Axel

    2015-01-01

    We explore the effects of an outer stably stratified coronal envelope on rotating turbulent convection, differential rotation, and large-scale dynamo action in spherical wedge models of the Sun. We solve the compressible magnetohydrodynamic equations in a two-layer model with unstable stratification below the surface, representing the convection zone, and a stably stratified outer layer, the coronal envelope. The interface emulates essentially a free surface. We compare with models that have no coronal envelope. The presence of a coronal envelope is found to modify the Reynolds stress and the $\\Lambda$-effect resulting in a weaker and non-cylindrical differential rotation. This is related to the reduced latitudinal temperature variations, which are caused by and dependent on the Coriolis force. Some simulations develop a rudimentary near-surface shear layer, which we can relate to a sign change of the meridional Reynolds stress term in the thermal wind balance equation. Furthermore, the presence of a free sur...

  1. Improvements on coronal hole detection in SDO/AIA images using supervised classification

    Reiss, Martin A; De Visscher, Ruben; Temmer, Manuela; Veronig, Astrid M; Delouille, Véronique; Mampaey, Benjamin; Ahammer, Helmut

    2015-01-01

    We demonstrate the use of machine learning algorithms in combination with segmentation techniques in order to distinguish coronal holes and filaments in SDO/AIA EUV images of the Sun. Based on two coronal hole detection techniques (intensity-based thresholding, SPoCA), we prepared data sets of manually labeled coronal hole and filament channel regions present on the Sun during the time range 2011 - 2013. By mapping the extracted regions from EUV observations onto HMI line-of-sight magnetograms we also include their magnetic characteristics. We computed shape measures from the segmented binary maps as well as first order and second order texture statistics from the segmented regions in the EUV images and magnetograms. These attributes were used for data mining investigations to identify the most performant rule to differentiate between coronal holes and filament channels. We applied several classifiers, namely Support Vector Machine, Linear Support Vector Machine, Decision Tree, and Random Forest and found tha...

  2. A Data-Driven Analytic Model for Proton Acceleration by Large-Scale Solar Coronal Shocks

    Kozarev, Kamen A

    2016-01-01

    We have recently studied the development of an eruptive filament-driven, large-scale off-limb coronal bright front (OCBF) in the low solar corona (Kozarev et al. 2015), using remote observations from Solar Dynamics Observatory's Advanced Imaging Assembly EUV telescopes. In that study, we obtained high-temporal resolution estimates of the OCBF parameters regulating the efficiency of charged particle acceleration within the theoretical framework of diffusive shock acceleration (DSA). These parameters include the time-dependent front size, speed, and strength, as well as the upstream coronal magnetic field orientations with respect to the front's surface normal direction. Here we present an analytical particle acceleration model, specifically developed to incorporate the coronal shock/compressive front properties described above, derived from remote observations. We verify the model's performance through a grid of idealized case runs using input parameters typical for large-scale coronal shocks, and demonstrate ...

  3. Coronal Pseudo-Streamer and Bipolar Streamer Observed by SOHO/UVCS in March 2008

    Abbo, Lucia; Riley, Pete; Wang, Yi-Ming

    2015-01-01

    The last solar minimum is characterized by several peculiar aspects and by the presence of a complex magnetic topology with two different kinds of coronal streamers: pseudo-streamers and bipolar streamers. Pseudo-streamers or unipolar streamer are coronal structures which separate coronal holes of the same polarity, without a current sheet in the outer corona; unlike bipolar streamer that separate coronal holes of opposite magnetic polarity. In this study, two examples of these structures have been identified in the period of Carrington rotation 2067, by applying a potential-field source-surface extrapolation of the photospheric field measurements. We present a spectroscopic analysis of a pseudo-streamer and a bipolar streamer observed in the period 12-17 March 2008 at high spectral and spatial resolution by the Ultraviolet Coronagraph Spectrometer (UVCS; Kohl et al., 1995) onboard Solar and Heliospheric Observatory (SOHO). The solar wind plasma parameters, such as kinetic temperature, electron density and ou...

  4. Fast Collisionless Reconnection Condition and Self-Organization of Solar Coronal Heating

    Uzdensky, Dmitri A

    2007-01-01

    I propose that solar coronal heating is a self-regulating process that keeps the coronal plasma roughly marginally collisionless. The self-regulating mechanism is based on the interplay of two effects. First, plasma density controls coronal energy release via the transition between the slow collisional Sweet--Parker regime and the fast collisionless reconnection regime. This transition takes place when the Sweet--Parker layer becomes thinner than the characteristic collisionless reconnection scale. I present a simple criterion for this transition in terms of the upstream plasma density and magnetic field and the global length of the reconnection layer. Second, coronal energy release by reconnection raises the ambient plasma density via chromospheric evaporation and this, in turn, temporarily inhibits subsequent reconnection involving the newly-reconnected loops. Over time, however, radiative cooling gradually lowers the density again below the critical value and fast reconnection again becomes possible. As a ...

  5. An atlas of coronal electron density at 5Rs I: Data processing and calibration

    Morgan, Huw

    2015-01-01

    Tomography of the solar corona can provide cruicial constraints for models of the low corona, unique information on changes in coronal structure and rotation rates, and a valuable boundary condition for models of the heliospheric solar wind. This is the first of a series of three papers which aim to create a set of maps of the coronal density over an extended period (1996-present). The papers will describe the data processing and calibration (this paper), the tomography method (\\paperii) and resulting atlas of coronal electron density at a height of 5\\Rs\\ between years 1996-2014 (\\paperiii). This first paper presents a detailed description of data processing and calibration for the Large-Angle and Spectrometric Coronagraph (LASCO) C2 instrument onboard the Solar and Heliospheric Observatory (SOHO) and the COR2 instruments of the Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) package aboard the Solar Terrestial Relations Observatory (STEREO) A \\& B spacecraft. The methodology includes...

  6. The Sun's Global Photospheric and Coronal Magnetic Fields: Observations and Models

    Mackay, D H

    2012-01-01

    In this review, our present day understanding of the Sun's global photospheric and coronal magnetic fields is discussed from both observational and theoretical viewpoints. Firstly, the large-scale properties of photospheric magnetic fields are described, along with recent advances in photospheric magnetic flux transport models. Following this, the wide variety of theoretical models used to simulate global coronal magnetic fields are described. From this, the combined application of both magnetic flux transport simulations and coronal modeling techniques to describe the phenomena of coronal holes, the Sun's open magnetic flux and the hemispheric pattern of solar filaments is discussed. Finally, recent advances in non-eruptive global MHD models are described. While the review focuses mainly on solar magnetic fields, recent advances in measuring and modeling stellar magnetic fields are described where appropriate. In the final section key areas of future research are identified.

  7. Thermal and non-thermal emission from reconnecting twisted coronal loops

    Pinto, R; Browning, P K; Vilmer, N

    2016-01-01

    Twisted magnetic fields should be ubiquitous in the solar corona. The magnetic energy contained in such twisted fields can be released during solar flares and other explosive phenomena. Reconnection in helical magnetic coronal loops results in plasma heating and particle acceleration distributed within a large volume, including the lower coronal and chromospheric sections of the loops, and can be a viable alternative to the standard flare model, where particles are accelerated only in a small volume located in the upper corona. The goal of this study is to investigate the observational signatures of plasma heating and particle acceleration in kink-unstable twisted coronal loops using combination of MHD simulations and test-particle methods. The simulations describe the development of kink instability and magnetic reconnection in twisted coronal loops using resistive compressible MHD, and incorporate atmospheric stratification and large-scale loop curvature. The resulting distributions of hot plasma let us est...

  8. The resonant damping of fast magnetohydrodynamic oscillations in a system of two coronal slabs

    Arregui, Inigo; Oliver, Ramon; Ballester, Jose Luis

    2007-01-01

    Observations of transversal coronal loop oscillations very often show the excitation and damping of oscillations in groups of coronal loops rather than in individual and isolated structures. We present results on the oscillatory properties (periods, damping rates, and spatial distribution of perturbations) for resonantly damped oscillations in a system of two inhomogeneous coronal slabs and compare them to the properties found in single slab loop models. A system of two identical coronal loops is modeled, in Cartesian geometry, as being composed by two density enhancements. The linear magnetohydrodynamic (MHD) wave equations for oblique propagation of waves are solved and the damping of the different solutions, due to the transversal inhomogeneity of the density profile, is computed. The physics of the obtained results is analyzed by an examination of the perturbed physical variables. We find that, due to the interaction between the loops, the normal modes of oscillation present in a single slab split into sy...

  9. 77 FR 5057 - Draft Guidelines for Coroner/Medical Examiner Media Relations

    2012-02-01

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF JUSTICE Office of Justice Programs Draft Guidelines for Coroner/Medical Examiner Media Relations AGENCY: National... general public a draft document entitled, ``Guidelines for Media Relations: Dissemination of...

  10. The Sun's Global Photospheric and Coronal Magnetic Fields: Observations and Models

    Duncan Mackay

    2012-11-01

    Full Text Available In this review, our present day understanding of the Sun’s global photospheric and coronal magnetic fields is discussed from both observational and theoretical viewpoints. Firstly, the large-scale properties of photospheric magnetic fields are described, along with recent advances in photospheric magnetic flux transport models. Following this, the wide variety of theoretical models used to simulate global coronal magnetic fields are described. From this, the combined application of both magnetic flux transport simulations and coronal modeling techniques to describe the phenomena of coronal holes, the Sun’s open magnetic flux and the hemispheric pattern of solar filaments is discussed. Finally, recent advances in non-eruptive global MHD models are described. While the review focuses mainly on solar magnetic fields, recent advances in measuring and modeling stellar magnetic fields are described where appropriate. In the final section key areas of future research are identified.

  11. Evidence for the Reversal of Magnetic Field Polarity in Coronal Streamers

    Woo, Richard

    1996-01-01

    Faraday rotation observations are unique amongst radio occultation measurements in that they respond to magnetic field in addition to electron density, making it possible to probe the coronal magnetic field.

  12. UN ESTUDIO SOBRE LA INTERACCIÓN ENTRE LA PESQUISA CIENTÍFICA Y LA PRÁCTICA PROFESIONAL CONTABLE

    Ana Paula Batista da Silva

    2012-06-01

    Full Text Available Este estudio tuvo por objetivo analizar la interacción de la pesquisa científica con la práctica de la profesión contable. Se trata de un estudio exploratorio, por dedicarse a examinar un tema poco explotado en el Brasil, con abordaje cuantitativo y utilización de survey como técnica de colecta de los datos, apoyada por un instrumento de pesquisa conteniendo cuestiones que abordaron aspectos como: interés y utilización de las pesquisas; estudio y desarrollo de temas; medios de divulgación de la pesquisa; y causas de la laguna entre la pesquisa y la práctica. Es classificado en relación a los objetivos como descriptivo, en la medida en que se describió como se da esta interacción. Los datos fueron analizados mediante la técnica estadística de análisis factorial del tipo R, resumiéndolos en factores para el posterior análisis, validados por medio de los testes Kaiser-Meyer-Olkin (KMO y Bartlett de esferacidad. Se concluyó que, en razón de las diferentes naturalezas, es natural cierto distanciamiento entre la pesquisa y la práctica contable. No obstante, ése puede ser minimizado, entre otros factores, por el gran interés de los profesionales en conocer y aplicar los resultados de pesquisas en la práctica, y, también, por la confirmación de que los temas más pesquisados en el área contable corresponden a los temas de mayor interés en la opinión de los profesionales Contables. Tales resultados sugieren que la interacción y la comunicación entre la academia y los profesionales contabilistas deban merecer mayor atención visando tornarlas más eficaces.

  13. Compreendendo o estar com câncer ginecológico avançado: uma abordagem heideggeriana Comprendiendo el estar con cáncer ginecológico avanzado: un abordaje heideggeriano Understanding women with advanced gynecological cancer: a heideggerian approach

    Ana Regina Borges Silva

    2006-06-01

    Full Text Available A trajetória deste estudo voltou-se para a compreensão da vivência das mulheres com câncer ginecológico avançado. Optou-se por uma pesquisa qualitativa com abordagem fenomenológica, com base na questão norteadora: "Gostaria que você me contasse a sua experiência; Como é ser mulher com câncer ginecológico?" Obtiveram-se seis depoimentos dos quais emergiram as unificações ontológicas analisadas e interpretadas, segundo o referencial filosófico de Martin Heidegger. Tais unificações permitiram vislumbrar caminhos para cuidar dessas mulheres que vão além do conhecimento técnico científico. É necessário compreender o vivido, assegurando um cuidar que contemple a subjetividade e intersubjetividade.La trayectoria de este estudio se orientó a la comprensión de la vivencia de las mujeres con cáncer ginecológico avanzado. Se optó por una investigación cualitativa con abordaje fenomenológico, con base en la pregunta norteadora: "Desaría que Ud. me contase su experiencia: ¿cómo es ser mujer con cáncer ginecológico?" Se obtuvieron seis discursos de los cuales emergieron las unificaciones ontológicas analizadas e interpretadas, según el referencial filosófico de Martin Heidegger. Tales unificaciones permitieron vislumbrar caminos para cuidar a esas mujeres que van más allá del conocimiento técnico científico. Es necesario comprender lo vivido, asegurando un cuidar que contemple la subjetividad e intersubjetividad.This qualitative phenomenological research was carried out in order to understand how women experience living with advance gynecological cancer. We chose to make a qualitative survey in a phenomenological approach, based on the following directive question: "I'd like you to tell me your experience: 'How is it to be a woman with gynecological cancer?'" Six women were interviewed. The ontological unification which emerged from the speeches were analyzed and interpreted according to Martin Heidegger

  14. Coronal explosions as a signature of current loop coalescence in solar flares

    Sakai, Jun-Ichi; de Jager, Cornelis

    1989-09-01

    The coronal explosions interpreted by De Jaeger and Boelee (1984) as masnifestations of plasma streaming out of flare kernels are presently reinterpreted as signatures of current loop coalescence in the flaring region. This interpretation can quantitatively explain the various characteristics of the observed coronal explosions. The present model is expected to be very directly addressed by the soft X-ray imaging instrument that will be carried by the Solar-A mission spacecraft due for launch during the next solar maximum.

  15. Isotope Abundances of Solar Coronal Material Derived from Solar Energetic Particle Measurements

    Mewaldt, R.A; Stone, E. C.

    1987-01-01

    Coronal isotopic abundances for the elements He, C, N, O, Ne, and Mg are derived from previously published measurements of the isotopic composition of solar energetic particles by first measuring, and then correcting for, the charge-to-mass-dependent fractionation due to solar flare acceleration and propagation processes. The resulting coronal composition generally agrees with that of other samples of solar system material, but the previously noted difference between the solar flare and solar...

  16. Thermally damped linear compressional waves in a 2D solar coronal model

    Marcu, A; I. Ballai; Orza, B.

    2007-01-01

    The high resolution observations (TRACE and SOHO) of waves in coronal structures have revealed a rapid damping of modes, sometimes their damping length being of the same order as their wavelength. The rapid damping of modes in coronal loops permits us to derive values for magnetic field and transport coefficients. In this contribution we study the damping of linear compressional waves considering a two-dimensional propagation in gravitationally stratified plasma in the presence of thermal con...

  17. Unilateral and Bilateral Expression of a Quantitative Trait: Asymmetry and Symmetry in Coronal Craniosynostosis

    Heuzé, Yann; Martínez-Abadías, Neus; STELLA, JENNIFER M.; Senders, Craig W.; Simeon A Boyadjiev; Lo, Lun-Jou; Richtsmeier, Joan T.

    2012-01-01

    Bilateral symmetry in vertebrates is imperfect and mild asymmetries are found in normal growth and development. However, abnormal development is often characterized by strong asymmetries. Coronal craniosynostosis, defined here as consisting of premature suture closure and a characteristic skull shape, is a complex trait. The premature fusion of the coronal suture can occur unilaterally associated with skull asymmetry (anterior plagiocephaly) or bilaterally associated with a symmetric but brac...

  18. Enhanced phase mixing of Alfv\\'en waves propagating in stratified and divergent coronal structures

    Smith, P. D.; Tsiklauri, D.; Ruderman, M. S.

    2007-01-01

    Corrected analytical solutions describing the enhanced phase mixing of Alfven waves propagating in divergent stratified coronal structures are presented. These show that the enhanced phase mixing mechanism can dissipate Alfven waves at heights less than half that is predicted by the previous analytical solutions. The enhanced phase mixing of 0.1 Hz harmonic Alfven waves propagating in strongly divergent, H_b=5 Mm, stratified coronal structures, H_rho=50 Mm, can fulfill 100% of an active regio...

  19. The Effect of Three Irrigants on the Coronal Leakage of the Root Canals System Irrigants

    Zare Jahromi, Maryam; Barekatain, Mehrdad; Ebrahimi, Maziar; Askari, Bahare

    2010-01-01

    INTRODUCTION The production of smear layer during canal instrumentation is thought to increase coronal microleakage even after canal obturation. Previous studies have shown that the type of irrigant does not necessarily affect the seal of the obturation. Our study aimed to evaluate the effect of three irrigation solutions (MTAD, citric acid and EDTA/NaOCl) on the coronal microleakage of root canals. MATERIALS AND METHODS Fifty five intact single rooted teeth were instrumented and randomly div...

  20. Internal fixation for coronal shear fracture of the capitellum with polylactide resorbable fixation

    Kraan, Gerald A; Krijnen, Matthijs R; Eerenberg, Jan Peter

    2013-01-01

    A 24-year-old woman with pain in the right elbow after a fall demonstrated a coronal shear fracture on radiographic studies. Perioperative a coronal shear fracture was seen and treated successfully with a polylactide Rigid fix resorbable pin. The operative correction resulted in normal function at 6 months follow-up. We state that a capitellum shear fracture can be fixated with a single resorbable pin, leading to successful fusion.

  1. Vertical distance between umbilicus to aortic bifurcation on coronal view in Korean women

    Jeong, Joo Yeon; Kim, Yeo Rang; Kim, Ju Yeong; Jee, Byung Chul; Kim, Seok Hyun

    2014-01-01

    Objective To evaluate the vertical distance between umbilicus to aortic bifurcation on coronal view in Korean women and their relation with body mass index (BMI) and woman's age. Methods This retrospective study included 257 women who visited emergency center at university-based hospital from January to December 2011. All women underwent abdomino-pelvic computerized tomography (CT) due to various symptoms in a supine position. By using the electronic coronal CT images, the vertical distance b...

  2. The urgent need to change the current medical approach on tobacco cessation in Latin America Urge cambiar el abordaje de la cesación del tabaquismo por los médicos en América Latina

    Guadalupe Ponciano-Rodríguez

    2010-01-01

    que causa alteraciones funcionales y morfológicas en el sistema nervioso central de los sujetos dependientes, el consumo de tabaco continúa siendo un grave problema de salud pública en muchos países del mundo y Latinoamérica no es la excepción. En contraste con grandes avances en el área de control del tabaco, por ejemplo la firma del Convenio Marco para el Control del Tabaco por 168 países, el papel de los profesionales de la salud en la lucha contra el tabaquismo todavía dista mucho de ser lo ideal. En las escuelas de medicina de muchos países de América Latina se ha descuidado la educación de los futuros médicos para que durante el desempeño de sus actividades cotidianas sean piezas clave en la lucha contra el tabaquismo, motivando a todos sus pacientes a dejar de fumar y en la prevención de esta adicción. Si durante cada consulta el médico general o especialista interviniera con sus pacientes fumadores hablándoles de todos los beneficios que trae la cesación del tabaquismo y los apoyara a dejarlo, se estaría ganando una gran batalla en la lucha contra el tabaquismo. Asimismo, si logramos que los futuros médicos no fumen y realmente sean un ejemplo para sus pacientes, esto también redundaría en una menor prevalencia de fumadores. En este artículo se realiza una revisión de las bases neurobiológicas de la adicción a la nicotina, aspecto faltante en el currículo de la carrera de medicina que ayudaría a los futuros médicos a entender el nuevo paradigma del tabaquismo como enfermedad y no como factor de riego, y se discuten los principales argumentos que sustentan la urgencia de un cambio en el abordaje del tabaquismo por los médicos en Latinoamérica, así como la necesidad de actualizar los planes de estudio de las escuelas de medicina para formar médicos no fumadores capaces de realizar intervenciones exitosas en sus pacientes fumadores.

  3. Spectroscopic Studies of Solar Corona VI: Trend in Line-width Variation of Coronal Emission Lines with Height Independent of the Structure of Coronal Loops

    Jagdev Singh; Takashi Sakurai; Kiyoshi Ichimoto; S. Muneer

    2006-06-01

    We have obtained spectroscopic observations in coronal emission lines by choosing two lines simultaneously, one [Fe X] 6374 Å and the other [Fe XI] 7892 Å or [Fe XIII] 10747 Å or [Fe XIV] 5303 Å. We found that in 95 per cent of the coronal loops observed in 6374 Å, the FWHM of the emission line increases with height above the limb irrespective of the size, shape and orientation of the loop and that in case of 5303 Å line decreases with height in about 89 per cent of the coronal loops. The FWHM of 7892 Å and 10747 Å emission lines show intermediate behavior. The increase in the FWHM of 6374 Å line with height is the steepest among these four lines.We have also studied the intensity ratio and ratio of FWHM of these lines with respect to those of 6374 Å as a function height above the limb. We found that the intensity ratio of 7892 Å and 10747 Å lines with respect to 6374 Å line increases with height and that of 5303 Å to 6374 Å decreases with height above the limb. This implies that temperature in coronal loops will appear to increase with height in the intensity ratio plots of 7892 Å and 6374 Å; and 10747 Å and 6374 Å whereas it will appear to decrease with height in intensity ratio of 5303 Å to 6374 Å line versus height plot. These findings are up to a height of about 200 arcsec above the limb. The varying ratios with height indicate that relatively hotter and colder plasma in coronal loops interact with each other. Therefore, the observed increase in FWHM with height above the limb of coronal emission lines associated with plasma at about 1 MK may not be due to increase in non-thermal motions caused by coronal waves but due to interaction with the relatively hotter plasma. These findings also do not support the existing coronal loop models, which predict an increase in temperature of the loop with height above the limb.

  4. Diagnostics of Coronal Magnetic Fields Through the Hanle Effect in UV and IR Lines

    Raouafi, N E; Gibson, S; Fineschi, S; Solanki, S K

    2016-01-01

    The plasma thermodynamics in the solar upper atmosphere, particularly in the corona, are dominated by the magnetic field, which controls the flow and dissipation of energy. The relative lack of knowledge of the coronal vector magnetic field is a major handicap for progress in coronal physics. This makes the development of measurement methods of coronal magnetic fields a high priority in solar physics. The Hanle effect in the UV and IR spectral lines is a largely unexplored diagnostic. We use magnetohydrodynamic (MHD) simulations to study the magnitude of the signal to be expected for typical coronal magnetic fields for selected spectral lines in the UV and IR wavelength ranges, namely the H I Ly-$\\alpha$ and the He I 10830 {\\AA} lines. We show that the selected lines are useful for reliable diagnosis of coronal magnetic fields. The results show that the combination of polarization measurements of spectral lines with different sensitivities to the Hanle effect may be most appropriate for deducing coronal magne...

  5. A unified view of coronal loop contraction and oscillation in flares

    Russell, A. J. B.; Simões, P. J. A.; Fletcher, L.

    2015-09-01

    Context. Transverse loop oscillations and loop contractions are commonly associated with solar flares, but the two types of motion have traditionally been regarded as separate phenomena. Aims: We present an observation of coronal loops that contract and oscillate following the onset of a flare. We aim to explain why both behaviours are seen together and why only some of the loops oscillate. Methods: A time sequence of SDO/AIA 171 Å images is analysed to identify the positions of coronal loops following the onset of the M6.4 flare SOL2012-03-09T03:53. We focus on five loops in particular, all of which contract during the flare, with three of them oscillating as well. A simple model is then developed for the contraction and oscillation of a coronal loop. Results: We propose that coronal loop contractions and oscillations can occur in a single response to removal of magnetic energy from the corona. Our model reproduces the various types of loop motion observed and explains why the highest loops oscillate during their contraction, while no oscillation is detected for the shortest contracting loops. The proposed framework suggests that loop motions can be used as a diagnostic for the removal of coronal magnetic energy by flares, while rapid decrease in coronal magnetic energy is a newly identified excitation mechanism for transverse loop oscillations. Appendices are available in electronic form at http://www.aanda.org Warning, no authors found for 2015A&A...581A..14.

  6. Formation and evolution of coronal rain observed by SDO/AIA on February 22, 2012

    Vashalomidze, Z; Zaqarashvili, T V; Oliver, R; Shergelashvili, B; Ramishvili, G; Poedts, S; De Causmaecker, P

    2015-01-01

    The formation and dynamics of coronal rain are currently not fully understood. Coronal rain is the fall of cool and dense blobs formed by thermal instability in the solar corona towards the solar surface with acceleration smaller than gravitational free fall. We aim to study the observational evidence of the formation of coronal rain and to trace the detailed dynamics of individual blobs. We used time series of the 171 \\AA\\, and 304 \\AA\\, spectral lines obtained by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamic Observatory (SDO) above active region AR 11420 on February 22, 2012. Observations show that a coronal loop disappeared in the 171 \\AA\\ channel and appeared in the 304 \\AA\\ line$\\text{}\\text{}$ more than one hour later, which indicates a rapid cooling of the coronal loop from 1 MK to 0.05 MK. An energy estimation shows that the radiation is higher than the heat input, which indicates so-called catastrophic cooling. The cooling was accompanied by the formation of coronal rain in the fo...

  7. The unusually strong coronal emission lines of SDSS J1055+5637

    Winkler, Hartmut

    2016-01-01

    Many Seyfert galaxies display weak 'coronal' emission features corresponding to [Fe VII], [Fe XI] and [Fe XIV] in their optical spectra, whereas elsewhere these lines seem to be entirely absent. These lines appear to highlight zones in the nucleus irradiated by high-energy photons. The presence of these zones and the conditions therein as determined by the relative line strengths and profiles impose important constraints on the physical models of active galactic nuclei, and Seyferts in particular. In 2009 the discovery was announced of the highly unusual spectrum of SDSS J0952+2143, where the coronal lines are exceptionally strong. This paper presents a second object with abnormally strong coronal features, SDSS J1055+5637. The spectrum, line ratios and related parameters are compared to those of SDSS J0952+2143, three AGN with moderate coronal lines and one where the coronal lines are missing altogether. Possible mechanisms are discussed that may account for the stronger than usual coronal features.

  8. The Transition Region Response to a Coronal Nanoflare: Forward Modeling and Observations in SDO/AIA

    Viall, Nicholeen; Klimchuk, James A.

    2016-05-01

    The corona and transition region (TR) are fundamentally coupled through the processes of thermal conduction and mass exchange. Yet the temperature-dependent emissions from the two locations behave quite differently in the aftermath of an impulsive heating event such as a coronal nanoflare. In this presentation, we use results from the EBTEL hydrodynamics code to demonstrate that after a coronal nanoflare, the TR is multithermal and the emission at all temperatures responds in unison. This is in contrast to the coronal plasma, which cools sequentially, emitting first at higher temperatures and then at lower temperatures. We apply the time lag technique of Viall & Klimchuk (2012) to the simulated Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory emission and show that coronal plasma light curves exhibit post-nanoflare cooling time lags, while TR light curves show time lags of zero, as observed. We further demonstrate that time lags of zero, regardless of physical cause, do not indicate a lack of variability. Rather, strong variability must be present, and it must occur in unison in the different channels. Lastly, we show that the 'coronal' channels in AIA can be dominated by bright TR emission. When defined in a physically meaningful way, the TR reaches a temperature of roughly 60% the peak temperature in a flux tube. The TR resulting from impulsive heating can extend to 3 MK and higher, well within the range of the 'coronal' AIA channels.

  9. Additional merit of coronal STIR imaging for MR imaging of lumbar spine

    Ranjana Gupta

    2015-01-01

    Full Text Available Introduction: Back pain is a common clinical problem and is the frequent complaint for referral of lumbar spine magnetic resonance imaging (MRI. Coronal short tau inversion recovery sequence (STIR can provide diagnostically significant information in small percentage of patients. Materials and Methods: MRI examinations of a total of 350 patients were retrospectively included in the study. MR sequences were evaluated in two settings. One radiologist evaluated sagittal and axial images only, while another radiologist evaluated all sequences, including coronal STIR sequence. After recording the diagnoses, we compared the MRI findings in two subsets of patients to evaluate additional merit of coronal STIR imaging. Results: With addition of coronal STIR imaging, significant findings were observed in 24 subjects (6.8%. Twenty-one of these subjects were considered to be normal on other sequences and in three subjects diagnosis was changed with the addition of coronal STIR. Additional diagnoses on STIR included sacroiliitis, sacroiliac joint degenerative disease, sacral stress/insufficiency fracture/Looser′s zones, muscular sprain and atypical appendicitis. Conclusion: Coronal STIR imaging can provide additional diagnoses in a small percentage of patients presenting for lumbar spine MRI for back pain. Therefore, it should be included in the routine protocol for MR imaging of lumbar spine.

  10. Coronal energy input and dissipation in a solar active region 3D MHD model

    Bourdin, Philippe-A; Peter, Hardi

    2015-01-01

    Context. We have conducted a 3D MHD simulation of the solar corona above an active region in full scale and high resolution, which shows coronal loops, and plasma flows within them, similar to observations. Aims. We want to find the connection between the photospheric energy input by field-line braiding with the coronal energy conversion by Ohmic dissipation of induced currents. Methods. To this end we compare the coronal energy input and dissipation within our simulation domain above different fields of view, e.g. for a small loops system in the active region (AR) core. We also choose an ensemble of field lines to compare, e.g., the magnetic energy input to the heating per particle along these field lines. Results. We find an enhanced Ohmic dissipation of currents in the corona above areas that also have enhanced upwards-directed Poynting flux. These regions coincide with the regions where hot coronal loops within the AR core are observed. The coronal density plays a role in estimating the coronal temperatur...

  11. 3D Global Coronal Density Structure and Associated Magnetic Field near Solar Maximum

    Kramar, Maxim; Lin, Haosheng

    2016-01-01

    Measurement of the coronal magnetic field is a crucial ingredient in understanding the nature of solar coronal dynamic phenomena at all scales. We employ STEREO/COR1 data obtained near maximum of solar activity in December 2012 (Carrington rotation, CR 2131) to retrieve and analyze the three-dimensional (3D) coronal electron density in the range of heights from $1.5$ to $4\\ \\mathrm{R}_\\odot$ using a tomography method and qualitatively deduce structures of the coronal magnetic field. The 3D electron density analysis is complemented by the 3D STEREO/EUVI emissivity in 195 \\AA \\ band obtained by tomography for the same CR period. We find that the magnetic field configuration during CR 2131 has a tendency to become radially open at heliocentric distances below $\\sim 2.5 \\ \\mathrm{R}_\\odot$. We compared the reconstructed 3D coronal structures over the CR near the solar maximum to the one at deep solar minimum. Results of our 3D density reconstruction will help to constrain solar coronal field models and test the a...

  12. Grande fístula bilateral da artéria coronária: a escolha do tratamento clínico Gran fístula bilateral de la arteria coronaria: la selección del tratamiento clínico Large bilateral coronary artery fistula: the choice of clinical treatment

    Luciana Oliveira Cascaes Dourado

    2009-09-01

    Full Text Available Relatamos o caso de um paciente do sexo feminino, assintomática, com grande fístula bilateral da artéria coronária-artéria pulmonar. O monitoramento clínico foi a opção escolhida para tratamento. Discutimos os pormenores das opções terapêuticas, enfatizando a tendência excessiva de utilizar a abordagem cirúrgica e a grande escassez de acompanhamentos clínicos de longo prazo em pacientes assintomáticos.Relatamos el caso de un paciente del sexo femenino, asintomática, con gran fístula bilateral de la arteria coronaria-arteria pulmonar. El monitoreo clínico fue la opción elegida para el tratamiento. Discutimos los pormenores de las opciones terapéuticas, enfatizando la tendencia excesiva de utilizar el abordaje quirúrgico y la gran escasez de seguimientos clínicos de largo plazo en pacientes asintomáticos.

  13. La Escuela de Estudios Hispano-Americanos

    Bernabéu Albert, Salvador

    2010-01-01

    La Escuela de Estudios Hispano-Americanos es una institución cultural, perteneciente al Consejo Superior de Investigaciones Científicas, dedicada al estudio del Americanismo desde 1942 a la actualidad. Está encuadrada en el sector de Humanidades, una de las ocho áreas científico-técnicas en que se organiza el CSIC, el mayor organismo público de investigación en España. Paralelamente a los profundos cambios que están ocurriendo en la Universidad española con el Plan de ...

  14. Embellecimiento facial con el "sistema matriz de implante mandibular": abordaje endoscópico Facial beauty "mandibular matrix implant system": endoscopic access

    O. M. Ramírez

    2007-09-01

    Full Text Available Uno de los problemas estéticos mas frecuentes y de difícil corrección que afectan el tercio inferior facial, es la disarmonía entre los tejidos blandos y las estructuras óseas subyacentes. Las limitaciones de las técnicas convencionales y los escasos resultados estéticos motivaron al autor a desarrollar un sistema de implantes y una técnica de remodelación tridimensional del maxilar inferior, denominada Sistema Matriz de Implante Mandibular. El sistema Matriz de Implante Mandibular se compone de dos unidades bien definidas: un implante genio-mandibular articulado formado por dos segmentos y un implante de ángulo gonial para cada lado. Esta constituido por material biocompatible poroso de alta densidad que permite su remodelación y adaptación a las necesidades estéticas de cada paciente, además de un ensamblaje perfecto a la superficie ósea. Está indicado especialmente para el embellecimiento del contorno facial y puede realizarse conjuntamente con un lifting o como procedimiento único. También se utiliza en pacientes edéntulos o con micrognatia. El abordaje se realiza a través de una pequeña incisión submentoniana que permite introducir los implantes previa disección subperióstica, bajo visión endoscópica del lecho receptor. La elección final del tamaño, proyección y contorno de los implantes se determina después de colocar implantes de prueba y de tallar los implantes definitivos. Una vez implantado el Sistema Matriz Mandibular, se estabiliza con tornillos de fijación en el tercio anterior de los componentes del implante geniomandibular y además por la superposición del borde posterior de éstos con el borde anterior del implante de ángulo gonial. Este último no necesita fijación, ya que queda contenido entre la cincha ptérigo-masetérica y el maxilar inferior (ángulo gonial. En publicaciones previas se estudiaron las complicaciones en 50 casos, incluyendo: un desplazamiento (corregido con reposicionamiento

  15. Propuesta de protocolo de abordaje de mujeres víctimas de delitos sexuales que son atendidas en la sección clínica médico forense y en las unidades médico legales del departamento de medicina legal del Organismo de Investigación Judicial Poder Judicial - Costa Rica

    Micxy Trejos Romanini

    2014-01-01

    Los delitos sexuales constituyen uno de los motivos de consulta más comunes en la Sección Clínica Médico Forense y en las Unidades Médico Legales del Departamento de Medicina Legal del Organismo de Investigación Judicial del Poder Judicial de Costa Rica y a la fecha no se cuenta con un protocolo formal de abordaje para la valoración de éstos. La elaboración de un protocolo forense de abordaje de víctimas de delitos sexuales en sí mismo tiene algunos beneficios nada despreciables entre ellos: ...

  16. A Wide-Field Coronal EUV Imager for the ISS

    Golub, Leon; Savage, Sabrina

    2016-05-01

    We propose a novel dual-usage EUV imager designed to observe the solar corona from the solar surface out to ~3 R_sol, with the objectives of: 1. determining the dynamics of the Transition Corona, the region in which the corona changes from low-beta and dominated by magnetically confined closed structures to high beta and having generally open regions with outflowing solar wind streams and mostly radial streamer structures; 2. providing new tools for space weather forecasting via early detection of a coronal mass ejection (CME) eruption, early acceleration and path detection, and modelling of the CME magnetic structure and configuration at launch. The latter goal will be achieved in combination with ground-based measurements. A mechanism switches the observing mode to spectroscopic imaging with the goal of understanding the dynamics of CMEs and of high-temperature plasma above and around active regions. The instrument is intended to mount to the ISS, tracking the Sun continuously during its daylight passes, and will be proposed as a Mission of Opportunity within the SMEX program.

  17. Helical coronal ejections and their role in the solar cycle

    Brandenburg, Axel; Käpylä, Petri J

    2004-01-01

    The standard theory of the solar cycle in terms of an alpha-Omega dynamo hinges on a proper understanding of the nonlinear alpha effect. Boundary conditions play a surprisingly important role in determining the magnitude of alpha. For closed boundaries, the total magnetic helicity is conserved, and since the alpha effect produces magnetic helicity of one sign in the large scale field, it must simultaneously produce magnetic helicity of the opposite sign. It is this secondary magnetic helicity that suppresses the dynamo in a potentially catastrophic fashion. Open boundaries allow magnetic helicity to be lost. Simulations are presented that allow an estimate of alpha in the presence of open or closed boundaries, either with or without solar-like differential rotation. In all cases the sign of the magnetic helicity agrees with that observed at the solar surface (negative in the north, positive in the south), where significant amounts of magnetic helicity can be ejected via coronal mass ejections. It is shown tha...

  18. 3D MHD modeling of twisted coronal loops

    Reale, F; Guarrasi, M; Mignone, A; Peres, G; Hood, A W; Priest, E R

    2016-01-01

    We perform MHD modeling of a single bright coronal loop to include the interaction with a non-uniform magnetic field. The field is stressed by random footpoint rotation in the central region and its energy is dissipated into heating by growing currents through anomalous magnetic diffusivity that switches on in the corona above a current density threshold. We model an entire single magnetic flux tube, in the solar atmosphere extending from the high-beta chromosphere to the low-beta corona through the steep transition region. The magnetic field expands from the chromosphere to the corona. The maximum resolution is ~30 km. We obtain an overall evolution typical of loop models and realistic loop emission in the EUV and X-ray bands. The plasma confined in the flux tube is heated to active region temperatures (~3 MK) after ~2/3 hr. Upflows from the chromosphere up to ~100 km/s fill the core of the flux tube to densities above 10^9 cm^-3. More heating is released in the low corona than the high corona and is finely ...

  19. Parameters of the Magnetic Flux inside Coronal Holes

    Abramenko, Valentina; Watanabe, Hiroko

    2009-01-01

    Parameters of magnetic flux distribution inside low-latitude coronal holes (CHs) were analyzed. A statistical study of 44 CHs based on Solar and Heliospheric Observatory (SOHO)/MDI full disk magnetograms and SOHO/EIT 284\\AA images showed that the density of the net magnetic flux, $B_{{\\rm net}}$, does not correlate with the associated solar wind speeds, $V_x$. Both the area and net flux of CHs correlate with the solar wind speed and the corresponding spatial Pearson correlation coefficients are 0.75 and 0.71, respectively. A possible explanation for the low correlation between $B_{{\\rm net}}$ and $V_x$ is proposed. The observed non-correlation might be rooted in the structural complexity of the magnetic field. As a measure of complexity of the magnetic field, the filling factor, $ f(r)$, was calculated as a function of spatial scales. In CHs, $f(r)$ was found to be nearly constant at scales above 2 Mm, which indicates a monofractal structural organization and smooth temporal evolution. The magnitude of the fi...

  20. UV TRANSIENT BRIGHTENINGS ASSOCIATED WITH A CORONAL MASS EJECTION

    In this paper, we analyze transient UV brightenings in spectra acquired by SOHO/UltraViolet Coronagraph Spectrometer (UVCS) on 2003 June 2 in association with a coronal mass ejection (CME) that occurred at the West limb of the Sun at 08:54 UT. Brightenings have been observed in lines from cool (C III, O VI), intermediate (Si VIII, Si XII), and high ([Fe XVIII]) temperature ions over about 7 hr from the CME. Brightenings in cool lines are interpreted in terms of mini-ejections that appear at the time of, and after, the passage of the CME front through the UVCS slit. We give here their temperature and density and we point out that, assuming a spherical shape, a few of these mini-CMEs can provide a mass comparable to that quoted for typical CMEs. Hot lines, like the [Fe XVIII] line at 974.9 A which shows up in the CME associated current sheet (CS), undergo transient brightness as well, but hot lines brightenings are more difficult to interpret. We propose here a scenario where they are signatures of the passage through the UVCS slit of plasmoids similar to those observed in the filamentary CS of the magnetotail that form as a consequence of the tearing-mode instability or of a time-dependent Petschek-type reconnection.

  1. The coronal mass ejection waiting-time distribution

    Wheatland, M S

    2003-01-01

    The distribution of times $\\Delta t$ between coronal mass ejections (CMEs) in the Large Angle and Spectrometric Coronagraph (LASCO) CME catalog for the years 1996-2001 is examined. The distribution exhibits a power-law tail $\\propto (\\Delta t)^{\\gamma}$ with an index $\\gamma\\approx -2.36\\pm 0.11$ for large waiting times ($\\Delta t>10 {\\rm hours}$). The power-law index of the waiting-time distribution varies with the solar cycle: for the years 1996-1998 (a period of low activity), the power-law index is $\\gamma\\approx-1.86\\pm 0.14$, and for the years 1999-2001 (a period of higher activity), the index is $\\gamma\\approx-2.98\\pm 0.20$. The observed CME waiting-time distribution, and its variation with the cycle, may be understood in terms of CMEs occurring as a time-dependent Poisson process. The CME waiting-time distribution is compared with that for greater than C1 class solar flares in the Geostationary Operational Environmental Satellite (GOES) catalog for the same years. The flare and CME waiting-time distri...

  2. The Breakout Model for Coronal Jets with Filaments

    Wyper, Peter; DeVore, C. Richard; Antiochos, Spiro K.

    2016-05-01

    Coronal jets are impulsive, collimated plasma outflows originating low in the solar corona. Many of these events exhibit broad, curtain-like morphologies with helical structure and motions. Recently, Sterling et al. (2015) [doi:10.1038/nature14556] reported that such jets are associated with the eruption of small filaments and, therefore, are miniature versions of corona mass ejections (CMEs). This account differs from the traditional picture of jets, in that internal flare reconnection, rather than interchange reconnection with the external ambient magnetic field, creates the bright loops observed at the jet base. We present 3D simulations, performed with the Adaptively Refined MHD Solver (ARMS), which demonstrate how the magnetic breakout mechanism generates mini-CME-type jets in a compact bipolar region energized by simple footpoint motions. Our numerical model captures the formation of the strongly sheared pre-jet filament structure, the post-jet flare-like loops and ribbons, and the curtain-like untwisting dynamics observed higher in the corona. We will discuss the significance of our new results for understanding solar EUV and X-ray jets and CMEs in general. NASA supported this research by awards to the NASA Postdoctoral Program (P.F.W.) and the LWS TR&T and H-SR programs (C.R.D. & S.K.A.).

  3. Data Constrained Coronal Mass Ejections in A Global Magnetohydrodynamics Model

    Jin, M; van der Holst, B; Sokolov, I; Toth, G; Mullinix, R E; Taktakishvili, A; Chulaki, A; Gombosi, T I

    2016-01-01

    We present a first-principles-based coronal mass ejection (CME) model suitable for both scientific and operational purposes by combining a global magnetohydrodynamics (MHD) solar wind model with a flux rope-driven CME model. Realistic CME events are simulated self-consistently with high fidelity and forecasting capability by constraining initial flux rope parameters with observational data from GONG, SOHO/LASCO, and STEREO/COR. We automate this process so that minimum manual intervention is required in specifying the CME initial state. With the newly developed data-driven Eruptive Event Generator Gibson-Low (EEGGL), we present a method to derive Gibson-Low (GL) flux rope parameters through a handful of observational quantities so that the modeled CMEs can propagate with the desired CME speeds near the Sun. A test result with CMEs launched with different Carrington rotation magnetograms are shown. Our study shows a promising result for using the first-principles-based MHD global model as a forecasting tool, wh...

  4. Automatic analysis of double coronal mass ejections from coronagraph images

    Jacobs, Matthew; Chang, Lin-Ching; Pulkkinen, Antti; Romano, Michelangelo

    2015-11-01

    Coronal mass ejections (CMEs) can have major impacts on man-made technology and humans, both in space and on Earth. These impacts have created a high interest in the study of CMEs in an effort to detect and track events and forecast the CME arrival time to provide time for proper mitigation. A robust automatic real-time CME processing pipeline is greatly desired to avoid laborious and subjective manual processing. Automatic methods have been proposed to segment CMEs from coronagraph images and estimate CME parameters such as their heliocentric location and velocity. However, existing methods suffered from several shortcomings such as the use of hard thresholding and an inability to handle two or more CMEs occurring within the same coronagraph image. Double-CME analysis is a necessity for forecasting the many CME events that occur within short time frames. Robust forecasts for all CME events are required to fully understand space weather impacts. This paper presents a new method to segment CME masses and pattern recognition approaches to differentiate two CMEs in a single coronagraph image. The proposed method is validated on a data set of 30 halo CMEs, with results showing comparable ability in transient arrival time prediction accuracy and the new ability to automatically predict the arrival time of a double-CME event. The proposed method is the first automatic method to successfully calculate CME parameters from double-CME events, making this automatic method applicable to a wider range of CME events.

  5. Kink Oscillations of a Curved, Gravitationally Stratified Coronal Loop

    Hindman, Bradley W

    2012-01-01

    Loops of magnetic field in the corona are observed to oscillate and these oscillations have been posited to be the superposition of resonant kink waves. To date, most analyses of these oscillations have concentrated on calculating the frequency shifts that result from spatial variation in the kink wave speed. Further, most have ignored gravity and treated the loop as a straight tube. Here we ignore spatial variation in the wave speed, but self-consistently include the effects of gravity and loop curvature in both the equilibrium loop model and in the wave equation. We model a coronal loop as an isolated, thin, magnetic fibril that is anchored at two points in the photosphere. The equilibrium shape of the loop is determined by a balance between magnetic buoyancy and magnetic tension, which is characterized by a Magnetic Bond Number \\epsilon, that is typically small |\\epsilon| << 1. This balance produces a loop that has a variable radius of curvature. The resonant kink waves of such a loop come in two pol...

  6. SOHO/UVCS spectroscopic observations of coronal oscillations

    Mancuso, Salvatore; Raymond, John C.; Rubinetti, Sara; Taricco, Carla

    2016-06-01

    We analyzed the temporal evolution of the intensities and Doppler shifts of two sets of high-cadence sit-and-stare observations acquired with the Ultraviolet Coronagraph Spectrometer (UVCS) on board the Solar and Heliospheric Observatory (SOHO) satellite to detect the possible signature of wave and oscillatory motions in the solar corona. The first set of data consisted of H I Lyα observations collected on 1997 December 14 at 1.43 RS above the eastern limb of the Sun. Spectral analysis of the data revealed clear Doppler-shift oscillations with period P = 14.3 min over a portion of the UVCS slit. The origin of these oscillations is attributable to the excitation of propagating fast-mode magnetoacoustic kink waves along a narrow, jet-like ejection observed higher up in the white-light corona. The second set of data consisted of O VI 1032 Å observations collected on 1996 December 19 at 1.38 RS above the north polar coronal hole. In this case, clear intensity oscillations (P = 19.5 min) and Doppler-shift oscillations (P = 7.2 min) over two different portions of the UVCS slit were detected. The origin of these oscillations is attributable to the excitation of slow-mode magnetoacoustic waves propagating along polar plumes that may partially account for heating of the plasma in the corona.

  7. Acceleration and Deceleration of Coronal Mass Ejection (CME) Propagation

    Shen, F.; Wu, S.; Feng, X. S.; Wu, C.

    2011-12-01

    A major challenge to the space weather forecasting community is accurate prediction of coronal mass ejections (CME) induced Shock Arrival Time (SAT) at Earth's environment. In order to improve the current accuracy, it is necessary to understand the physical processes of the acceleration and deceleration of the CME propagation in the heliosphere. We present a three-dimensional (3D) magnetohydrodynamic (MHD) simulation of the evolution of two interacting CMEs in a realistic ambient solar wind for the March 28-31, 2001 event. The forces which caused the acceleration and deceleration are analyzed in detail. The force which caused the acceleration are Lorenz force and pressure gradient and the forces which caused the deceleration are aerodynamic drag and the Sun's gravity. In addition the momentum exchange between the solar wind and the moving CMEs can cause acceleration and deceleration of the CME which are now analyzed. In this specific CME event (March 28-31, 2001), we also investigate the interactions of two CMEs causing the acceleration and deceleration of the CMEs.

  8. CORONAL MASS EJECTION MASS, ENERGY, AND FORCE ESTIMATES USING STEREO

    Understanding coronal mass ejection (CME) energetics and dynamics has been a long-standing problem, and although previous observational estimates have been made, such studies have been hindered by large uncertainties in CME mass. Here, the two vantage points of the Solar Terrestrial Relations Observatory (STEREO) COR1 and COR2 coronagraphs were used to accurately estimate the mass of the 2008 December 12 CME. Acceleration estimates derived from the position of the CME front in three dimensions were combined with the mass estimates to calculate the magnitude of the kinetic energy and driving force at different stages of the CME evolution. The CME asymptotically approaches a mass of 3.4 ± 1.0 × 1015 g beyond ∼10 R☉. The kinetic energy shows an initial rise toward 6.3 ± 3.7 × 1029 erg at ∼3 R☉, beyond which it rises steadily to 4.2 ± 2.5 × 1030 erg at ∼18 R☉. The dynamics are described by an early phase of strong acceleration, dominated by a force of peak magnitude of 3.4 ± 2.2 × 1014 N at ∼3 R☉, after which a force of 3.8 ± 5.4 × 1013 N takes effect between ∼7 and 18 R☉. These results are consistent with magnetic (Lorentz) forces acting at heliocentric distances of ∼☉, while solar wind drag forces dominate at larger distances (∼>7 R☉).

  9. Mars atmospheric escape constrained using MAVEN IUVS coronal observations

    Chaffin, Michael S.; Deighan, Justin; Chaufray, Jean-Yves; Jain, Sonal; Stewart, Ian; McClintock, Bill; Crismani, Matteo; Stiepen, Arnaud; Holsclaw, Greg; Clarke, John; Montmessin, Franck; Eparvier, Frank; Thiemann, Ed; Chamberlain, Phil; Schneider, Nick; Jakosky, Bruce

    2015-11-01

    Every planetary atmosphere is capped by a corona: an extended, extremely tenuous region where collisions are negligible and particles follow ballistic trajectories. At Mars, the corona is especially extended due to the low gravity of the planet, and a large number of coronal particles are on escaping trajectories. Such escape has played a critical role in the history of the Mars system, likely removing a substantial fraction of the water initially present on the planet, but the mechanism and magnitude of this escape remains poorly constrained. Currently in orbit at Mars, MAVEN's Imaging Ultraviolet Spectrograph (IUVS) is mapping the distribution of oxygen and hydrogen above 200 km at a high spatial and temporal cadence, revealing a dynamic corona in unprecedented detail. Results will be presented demonstrating that the H in the corona is not spherically symmetric in its distribution, and can potentially be used as a tracer of thermospheric general circulation; and that non-thermal "hot" O (in contrast with more spatially confined "cold" thermal O) is ionospherically sourced with a characteristic energy of 1.1 eV and responds to solar EUV forcing. These results will be interpreted in terms of their impact on our current understanding of how atmospheric escape operates today. We will also discuss how these processes may have acted in the past to deplete Mars' initial water inventory, potentially altering the redox balance of the planet and atmosphere through differential escape of H and O.

  10. Equilibrium models of coronal loops that involve curvature and buoyancy

    Hindman, Bradley W. [JILA and Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309-0440 (United States); Jain, Rekha, E-mail: hindman@solarz.colorado.edu [School of Mathematics and Statistics, University of Sheffield, Sheffield S3 7RH (United Kingdom)

    2013-12-01

    We construct magnetostatic models of coronal loops in which the thermodynamics of the loop is fully consistent with the shape and geometry of the loop. This is achieved by treating the loop as a thin, compact, magnetic fibril that is a small departure from a force-free state. The density along the loop is related to the loop's curvature by requiring that the Lorentz force arising from this deviation is balanced by buoyancy. This equilibrium, coupled with hydrostatic balance and the ideal gas law, then connects the temperature of the loop with the curvature of the loop without resorting to a detailed treatment of heating and cooling. We present two example solutions: one with a spatially invariant magnetic Bond number (the dimensionless ratio of buoyancy to Lorentz forces) and the other with a constant radius of the curvature of the loop's axis. We find that the density and temperature profiles are quite sensitive to curvature variations along the loop, even for loops with similar aspect ratios.

  11. Equilibrium Models of Coronal Loops That Involve Curvature and Buoyancy

    Hindman, Bradley W.; Jain, Rekha

    2013-12-01

    We construct magnetostatic models of coronal loops in which the thermodynamics of the loop is fully consistent with the shape and geometry of the loop. This is achieved by treating the loop as a thin, compact, magnetic fibril that is a small departure from a force-free state. The density along the loop is related to the loop's curvature by requiring that the Lorentz force arising from this deviation is balanced by buoyancy. This equilibrium, coupled with hydrostatic balance and the ideal gas law, then connects the temperature of the loop with the curvature of the loop without resorting to a detailed treatment of heating and cooling. We present two example solutions: one with a spatially invariant magnetic Bond number (the dimensionless ratio of buoyancy to Lorentz forces) and the other with a constant radius of the curvature of the loop's axis. We find that the density and temperature profiles are quite sensitive to curvature variations along the loop, even for loops with similar aspect ratios.

  12. Equilibrium models of coronal loops that involve curvature and buoyancy

    Hindman, Bradley W

    2013-01-01

    We construct magnetostatic models of coronal loops in which the thermodynamics of the loop is fully consistent with the shape and geometry of the loop. This is achieved by treating the loop as a thin, compact, magnetic fibril that is a small departure from a force-free state. The density along the loop is related to the loop's curvature by requiring that the Lorentz force arising from this deviation is balanced by buoyancy. This equilibrium, coupled with hydrostatic balance and the ideal gas law, then connects the temperature of the loop with the curvature of the loop without resorting to a detailed treatment of heating and cooling. We present two example solutions: one with a spatially invariant magnetic Bond number (the dimensionless ratio of buoyancy to Lorentz forces) and the other with a constant radius of curvature of the loop's axis. We find that the density and temperature profiles are quite sensitive to curvature variations along the loop, even for loops with similar aspect ratios.

  13. Determining the Full Halo Coronal Mass Ejection Characteristics

    Fainshtein, V. G.

    2010-11-01

    Observing halo coronal mass ejections (HCMEs) in the coronagraph field of view allows one to only determine the apparent parameters in the plane of the sky. Recently, several methods have been proposed allowing one to find some true geometrical and kinematical parameters of HCMEs. In most cases, a simple cone model was used to describe the CME shape. Observations show that various modifications of the cone model ("ice cream models") are most appropriate for describing the shapes of individual CMEs. This paper uses the method of determining full HCME parameters proposed by the author earlier, for determining the parameters of 45 full HCMEs, with various modifications of their shapes. I show that the determined CME characteristics depend significantly on the chosen CME shape. I conclude that the absence of criteria for a preliminary evaluation of the CME shape is a major source of error in determining the true parameters of a full HCME with any of the known methods. I show that, regardless of the chosen CME form, the trajectory of practically all the HCMEs in question deviate from the radial direction towards the Sun-Earth axis at the initial stage of their movement, and their angular size, on average, significantly exceeds that of all the observable CMEs.

  14. Spatial Relationship between Solar Flares and Coronal Mass Ejections

    Yashiro, S; Akiyama, S; Gopalswamy, N; Howard, R A

    2007-01-01

    We report on the spatial relationship between solar flares and coronal mass ejections (CMEs) observed during 1996-2005 inclusive. We identified 496 flare-CME pairs considering limb flares (distance from central meridian > 45 deg) with soft X-ray flare size > C3 level. The CMEs were detected by the Large Angle and Spectrometric Coronagraph (LASCO) on board the Solar and Heliospheric Observatory (SOHO). We investigated the flare positions with respect to the CME span for the events with X-class, M-class, and C-class flares separately. It is found that the most frequent flare site is at the center of the CME span for all the three classes, but that frequency is different for the different classes. Many X-class flares often lie at the center of the associated CME, while C-class flares widely spread to the outside of the CME span. The former is different from previous studies, which concluded that no preferred flare site exists. We compared our result with the previous studies and conclude that the long-term LASCO...

  15. Forecasting coronal mass ejections at 1 AU using Heliospheric Imagers

    Moestl, C.; Amla, K.; Temmer, M.; Hall, J. R.; Liewer, P. C.; De Jong, E. M.; Davies, J.; Lugaz, N.; Rollett, T.; Veronig, A.; Liu, Y.; Farrugia, C. J.; Luhmann, J. G.; Galvin, A. B.; Zhang, T.

    2012-12-01

    We study the feasibility of using a Heliospheric Imager (HI) instrument, such as STEREO/HI, for space weather forecasting of interplanetary coronal mass ejections (ICMEs) at 1 AU. We compare the predictions for speed and arrival time for ~15 ICME events, each observed remotely by one STEREO spacecraft, to the speed and arrival time observed at in situ observatories. We use three different models with varying ICME geometry, from point-like (Fixed-Phi) to a circle with a given width (Self-Similar-Expansion) to a very wide circle (Harmonic Mean). The models are fitted to density tracks on HI Jmaps with the SolarSoft SATPLOT tool. All these techniques assume constant ICME speed and direction. Partly, the configuration mimics the situation of a single HI observatory parked at the L4 or L5 point in the Sun-Earth system. We discuss problems associated with this study, such as CME-CME interactions leading to complicated Jmaps. For assessing the accuracy of these predictions we look at in situ data by Wind/ACE, STEREO-A/B, and Venus Express and MESSENGER. We also look at the ratio of prediction lead time to its accuracy, and see if there is a preferred value for the ICME width.

  16. Global Energetics of Solar Flares: IV. Coronal Mass Ejection Energetics

    Aschwanden, Markus J

    2016-01-01

    This study entails the fourth part of a global flare energetics project, in which the mass $m_{\\mathrm{cme}}$, kinetic energy $E_{\\mathrm{kin}}$, and the gravitational potential energy $E_{\\mathrm{grav}}$ of coronal mass ejections (CMEs) is measured in 399 M and X-class flare events observed during the first 3.5 yrs of the Solar Dynamics Observatory (SDO) mission, using a new method based on the EUV dimming effect. The EUV dimming is modeled in terms of a radial adiabatic expansion process, which is fitted to the observed evolution of the total emission measure of the CME source region. The model derives the evolution of the mean electron density, the emission measure, the bulk plasma expansion velocity, the mass, and the energy in the CME source region. The EUV dimming method is truly complementary to the Thomson scattering method in white light, which probes the CME evolution in the heliosphere at $r > 2 R_{\\odot}$, while the EUV dimming method tracks the CME launch in the corona. We compare the CME paramet...

  17. On the Observation and Simulation of Solar Coronal Twin Jets

    Liu, Jiajia; Wang, Yuming; McIntosh, Scott W; Fan, Yuhong; Zhang, Quanhao

    2016-01-01

    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. 2014. However the erupting process and kinetics of the twin jets appear to be different from the preceding one. In lack of the 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. 2014, 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 sugges...

  18. Solar Coronal Structures and Stray Light in TRACE

    DeForest, C E; Wills-Davey, M J

    2008-01-01

    Using the 2004 Venus transit of the Sun to constrain a semi-empirical point-spread function for the TRACE EUV solar telescope, we have measured the effect of stray light in that telescope. We find that 43% of 171A EUV light that enters TRACE is scattered, either through diffraction off the entrance filter grid or through other nonspecular effects. We carry this result forward, via known-PSF deconvolution of TRACE images, to identify its effect on analysis of TRACE data. Known-PSF deconvolution by this derived PSF greatly reduces the effect of visible haze in the TRACE 171A images, enhances bright features, and reveals that the smooth background component of the corona is considerably less bright (and hence much more rarefied) than commonly supposed. Deconvolution reveals that some prior conlclusions about the Sun appear to have been based on stray light in the images. In particular, the diffuse background "quiet corona" becomes consistent with hydrostatic support of the coronal plasma; feature contrast is gre...

  19. MAGNETIC FIELD STRUCTURES TRIGGERING SOLAR FLARES AND CORONAL MASS EJECTIONS

    Solar flares and coronal mass ejections, the most catastrophic eruptions in our solar system, have been known to affect terrestrial environments and infrastructure. However, because their triggering mechanism is still not sufficiently understood, our capacity to predict the occurrence of solar eruptions and to forecast space weather is substantially hindered. Even though various models have been proposed to determine the onset of solar eruptions, the types of magnetic structures capable of triggering these eruptions are still unclear. In this study, we solved this problem by systematically surveying the nonlinear dynamics caused by a wide variety of magnetic structures in terms of three-dimensional magnetohydrodynamic simulations. As a result, we determined that two different types of small magnetic structures favor the onset of solar eruptions. These structures, which should appear near the magnetic polarity inversion line (PIL), include magnetic fluxes reversed to the potential component or the nonpotential component of major field on the PIL. In addition, we analyzed two large flares, the X-class flare on 2006 December 13 and the M-class flare on 2011 February 13, using imaging data provided by the Hinode satellite, and we demonstrated that they conform to the simulation predictions. These results suggest that forecasting of solar eruptions is possible with sophisticated observation of a solar magnetic field, although the lead time must be limited by the timescale of changes in the small magnetic structures.

  20. KELVIN-HELMHOLTZ INSTABILITY OF A CORONAL STREAMER

    Shear-flow-driven instability can play an important role in energy transfer processes in coronal plasma. We present for the first time the observation of a kink-like oscillation of a streamer that is probably caused by the streaming kink-mode Kelvin-Helmholtz instability (KHI). The wave-like behavior of the streamer was observed by the Large Angle and Spectrometric Coronagraph Experiment C2 and C3 on board the SOlar and Heliospheric Observatory. The observed wave had a period of about 70-80 minutes, and its wavelength increased from 2 R☉ to 3 R☉ in about 1.5 hr. The phase speeds of its crests and troughs decreased from 406 ± 20 to 356 ± 31 km s–1 during the event. Within the same heliocentric range, the wave amplitude also appeared to increase with time. We attribute the phenomena to the MHD KHI, which occurs at a neutral sheet in a fluid wake. The free energy driving the instability is supplied by the sheared flow and sheared magnetic field across the streamer plane. The plasma properties of the local environment of the streamer were estimated from the phase speed and instability threshold criteria