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Sample records for al abordaje coronal

  1. 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

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    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

  2. Descripción de nuevo abordaje quirúrgico anterior al codo

    OpenAIRE

    Ramírez Gallego, Alejandro

    2015-01-01

    Los accesos medial, lateral y posterior al codo permiten la visualización y manejo de la mayor parte de las patologías traumáticas de esta articulación. Sin embargo cuando se trata de fracturas de la coronoides o de la porción articular anterior de la tróclea y el capitelum, estas vías clásicas tienen limitaciones ya que se requieren abordajes amplios con desinserciones ligamentarias, dobles abordajes u osteotomías para lograr una exposición adecuada. Se realizó disección anató...

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

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    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.

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

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    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.

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

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    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.

  6. ABORDAJE RELACIONAL AL CONCEPTO BIOLÓGICO DE VIDA Y SUS IMPLICACIONES ÉTICAS Y JURÍDICAS

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    Francisco Coutinho

    2011-11-01

    Full Text Available En el contexto sociocultural actual los avances científicos en la biología,especialmente en la Genética, afectan de muchas formas los interesespúblicos y privados. Por ello, se torna necesario explicitar el conceptobiológico de vida, dado que esa explicitación podrá guiar el establecimentode límites éticos de determinadas inversiones de instituciones estatales,privadas y de legisladores que comúnmente recurren al apoyo de la cienciapara fundamentar sus opiniones. Bajo esta perspectiva articulamosargumentos para fundamentar la concepción relacional de la vida encontraposición al abordaje esencialista o de simple listado de atributos. Estees muy utilizado para definir al ser vivo, mas necesariamente es pocoabarcador y esclarecedor. Tal abordaje ha producido un amplio número dedefiniciones para el concepto sobre lo que es la vida, lo que resulta más enconfusiones que en esclarecimientos. Al contrario, la concepción relacionalde vida parte de la definición de que la vida es  adaptación flexible. Taldefinición emerge a partir de investigaciones realizadas sobre la vidaartificial y privilegia una metafísica de procesos al revés de una metafísicade sustancias. Entretanto, aunque el concepto relacional de la vida tengaventaja sobre la mayoria de los demás, tal vez no sea útil para ayudar adefinir mejor los límites y prerrogativas éticas y legales de intervencionesque amenacen vidas individuales, tales como el aborto y la eutanasia y noacarrear prejuicios o estabelecer privilegios de alcances sociales escasos.Concluimos con una apreciación jurídica del concepto relacional de la vida,especialmente la vida humana y su tutela en Brasil, informando lanaturaleza, los límites y la extensión de esa protección.

  7. Apendicectomía laparoscópica frente al abordaje abierto para el tratamiento de la apendicitis aguda

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    C. Fortea-Sanchis

    2012-04-01

    Conclusiones: El abordaje laparoscópico presenta menos alteraciones en la herida quirúrgica y de hernias incisionales, pero mayor coste económico, mayor tiempo quirúrgico y mayor curva de aprendizaje. Según nuestros resultados, no puede establecerse una indicación clara para uno u otro abordaje, debiéndose individualizar la elección en cada caso.

  8. Cercamientos y derechos comunales en la Inglaterra del siglo XIII: Un abordaje historiográfico en torno al Estatuto de Merton [1236

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    Lucio Mir

    2011-04-01

    Full Text Available El siguiente trabajo intenta un abordaje general de las diversas interpretaciones relativas a un documento del siglo XIII, el Estatuto de Merton [1236]. El contexto que preside este abordaje fueron las transformaciones del sistema económico feudal y, en sus aspectos específicos, apunta a reconsiderar el proceso de cercamiento en la Inglaterra de aquel siglo. A pesar de que muchas investigaciones planteen el origen de las enclosures en los siglos XV y XVI, el Estatuto estaría atestiguando su presencia anterior. El presente trabajo procura reflexionar sobre las producciones historiográficas que se han realizado en relación al tema. El estudio de este notable documento adquiere importancia para analizar los antecedentes de la transición del feudalismo al capitalismo

  9. La adherencia al autocuidado en personas con enfermedad cardiovascular: abordaje desde el Modelo de Orem

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    Madeleine Cecilia Olivella-Fernández

    2012-01-01

    Full Text Available Objetivo: el presente artículo constituye una actualización del papel fundamental de los profesionales de enfermería en el cuidado de las personas con enfermedad crónica de origen cardiovascular. Método: se abordan dos aspectos importantes: la adherencia y el autocuidado. Esta revisión pretende trascender la visión biomédica con que se originó la concepción de adherencia terapéutica por una mirada integradora del autocuidado. Resultados: se aclara el significado del autocuidado al presentar una desviación de la salud como un sistema integrador que permite al enfermo ser competente en su autocuidado -desde el diagnóstico y durante toda la trayectoria de la enfermedad-, permitiéndole aplicar el conocimiento relevante o significativo brindado por los prestadores de salud, y que es necesario para mantenerse estable. Conclusiones: se presenta la complejidad del autocuidado desde el quehacer de enfermería, abordando el Modelo de Orem que constituye un aporte disciplinar importante y una opción de vida para la persona que padece enfermedad cardiovascular.

  10. Evidencia científica en torno al abordaje terapéutico de la fascitis plantar en corredores: Revisión sistemática

    OpenAIRE

    Vicente Liras, Maider

    2014-01-01

    RESUMEN: La fascitis plantar afecta aproximadamente al 10% de los corredores durante su carrera deportiva. Objetivos: Investigar acerca de la fascitis plantar, la evidencia científica en torno al abordaje terapéutico de esta lesión en corredores. Métodos: Se consultó los principales buscadores y bases de datos biomédicas: PubMed, PEDro (Physiotherapy Evidence Database), The Cochane Library y Lilacs IBECS, con restricción de fecha, en castellano, inglés y francés. Se seleccionaron ensayo...

  11. Abordaje a la Cisterna Ambiens

    Science.gov (United States)

    Ajler, Pablo; Bravo, Michael Cruz; Garategui, Lucas; Goldschmidt, Ezequiel; Isolan, Gustavo; Campero, Álvaro

    2016-01-01

    Resumen Objetivo: Describir paso a paso el abordaje a la cisterna ambiens por la vía suboccipital retrosigmoidea supracerebelosa infratentorial (SRSI). Descripción: El abordaje SRSI se realiza de la misma manera que el abordaje suboccipital retrosigmoideo (SR), utilizado habitualmente para acceder a la patología del ángulo pontocerebeloso, con las siguientes modificaciones: (1) utilizamos siempre la posición semisentado, (2) la craneotomia-craniectomia debe exponer el seno transverso y extenderse 5 cm medialmente hacia el inion, (3) al realizar la apertura dural es necesario rebatir la duramadre junto con el seno transverso hacia cefálico con puntos de tracción, (4) bajo magnificación con microscopio quirúrgico se debe realizar la apertura de la cisterna cerebelobulbar para drenar líquido cefalorraquídeo, (5) en el plano supracerebeloso es fundamental cortar las bridas aracnoidales y de ser necesario debemos coagular y cortar las venas puente, todas estas maniobras sumadas al efecto de la gravedad brindan mayor apertura del corredor supracerebeloso. Conclusión: El abordaje a la cisterna ambiens por la vía SRSI es una opción segura para el acceso de patologías tumorales que se alojan en esta zona con un componente predominantemente infratentorial. PMID:27999709

  12. SINDROME KID: ABORDAJE INTERDISCIPLINARIO

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    Carla De Negri

    Full Text Available Se presenta el caso clínico, de una niña de 2 años de edad, nacida en el Centro Hospitalario Pereira Rossell, portadora del Síndrome KID. Se trata de una displasia congénita ectodérmica caracterizada por la asociación de queratitis, ictiosis y sordera. Es producida por un desorden autosómico dominante, esporádico. Algunos autores lo refieren asociado a la presencia de alteraciones estructurales de órganos dentarios, del tipo hipoplasia e hipomineralización del esmalte y también a gingivitis y candidiasis a nivel de la mucosa bucal. La intervención oportuna del odontopediatra, integrando el equipo de salud, brinda un aporte importante, en la búsqueda de estrategias terapéuticas adecuadas al paciente y al contexto asistencial. El abordaje de tratamiento en pacientes portadores del Síndrome KID debe ser multidisciplinario, requiriendo en niños, la integración de un equipo de salud con pediatra, dermatólogo, oftalmólogo, otorrinolaringólogo y odontopediatra

  13. Plan de Cuidados al Paciente Pluripatológico Crónico: abordaje Integral: caso clínico

    OpenAIRE

    Bustamante Ramos, Laura

    2015-01-01

    Introducción: El progresivo envejecimiento de la población supone un problema mundial emergente; la elevada prevalencia de pacientes pluripatológicos con enfermedades crónicas conlleva la aparición de reagudizaciones y patologías interrelacionadas que condicionan una especial fragilidad clínica que grava al paciente con un deterioro progresivo y una disminución gradual de su autonomía y capacidad funcional. Estos pacientes demandan una elevada utilización de recursos sanitarios y sociales, si...

  14. Conocimiento y Prácticas del personal docente con relación al abordaje del proceso de duelo en adolescentes.

    OpenAIRE

    Viriam Leiva Díaz; María Elena López Bermúdez; Aurora Torres Madrigal

    2012-01-01

    En el siguiente artículo se presentan los resultados parciales sobre el conocimiento y prácticas del personal docente en el abordaje del proceso de duelo en adolescentes del Instituto Superior Julio Acosta García en San Ramón. Dicha investigación se realizó con un enfoque cuantitativo, descriptivo. Para la recolección de la información se aplicó un cuestionario, el cual permitió caracterizar y conocer los aspectos mencionados entorno a la temática del proceso de duelo en adolescentes. La info...

  15. Cuestionamientos a la total obsolencia de los enfoques del realismo clásico al abordaje del conflicto de Medio Oriente

    OpenAIRE

    Delaney, Cecilia Carolina

    2000-01-01

    El presente trabajo está orientado por un afán de elucidación de los conceptos que implica el abordaje analítico del conflicto árabe – israelí desde una doble perspectiva que no redunde sólo en una posición discursiva respecto “de” Medio Oriente sino también que de cuenta de las singularidades y regularidades susceptibles de observar tanto en la génesis y desarrollo del conflicto así como las características de la estructura que sirve de marco a esta dinámica, es decir, el análisis de Medio O...

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

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    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. Nueva variante de abordaje al surco ciliar en la fijación transescleral de lentes de cámara posterior New variant of approach to the ciliary sulcus in the transcleral fixation of posterior chamber lens

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    Ileana Vila Dópico

    2002-06-01

    Full Text Available Se expone una variante de abordaje al surco ciliar para la fijación del lente intraocular de cámara posterior, que está a nuestro alcance, en pacientes en que no existe soporte capsular o este es insuficiente. Se describe la técnica. Se realizó en 17 pacientes de los que se obtuvo mejoría visual en todos los casos (20/50-20/20 con un seguimiento promedio de 12 meses. Esta variante tiene la ventaja de evitar el paso de la aguja por el surco ciliar a ciegas, pues se utiliza el abordaje a través de la esclera y con ello evitamos dañar estructuras oculares aledañas evitando el riesgo de complicaciones por lo que se logra la recuperación anatómica y funcional en todos los casos.A variant to approach the ciliary sulcus for fixating the posterior chamber intraocular lens, which is within our reach, in patients with insufficient or no capsular support, is explained. The technique is described here and it was applied to 17 patients. Visual improvement was obtained in all cases (20/50-20/20 with an average follow-up of 12 months. This variant allows to prevent the blind passage of the needle through the ciliary sulcus, since it is approached via the sclera, avoiding to damage adjoining ocular structures and to have complications, and making possible the anatomic and functional recovery of all patients.

  18. Abordajes sobre la negociación colectiva durante la convertibilidad: Aportes para interrogar al presente Approaches concerning collective bargaining on convertibility: Contributions to ask at the present time

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    Cecilia Anigstein

    2011-12-01

    Full Text Available En la actualidad, ¿se ha reestablecido la "pauta tradicional" de negociación colectiva luego de un paréntesis demarcado por el régimen de convertibilidad? ¿O mantiene vigencia la pauta de negociación instaurada con la flexibilización laboral?. Estos interrogantes reclaman una revisión de las argumentaciones que se articularon en torno a los cambios en los patrones de la negociación colectiva durante la década de los noventa y de sus premisas conceptuales. El propósito es construir un punto de partida conceptual que nos habilite un abordaje del presente, sino exento, al menos advertido de algunas perspectivas normativas.At present, the guideline was re-established the " traditional guideline " of collective bargaining after a parenthesis limited by the regime of convertibility? Or, does it follow in force the guideline of collective bargaining installed in the decade of the nineties?. These questions claim a review of the argumentations that were articulated concerning the changes in the bosses of the collective bargaining during the decade of the nineties and of his conceptual premises. The intention is to construct a point of conceptual item that a boarding of the present enables us, but exempt, at least warned of some normative perspectives.

  19. Democracia deliberativa y ética del discurso: un abordaje crítico al problema de la posible complementación

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    Santiago N. Prono

    2009-06-01

    Full Text Available La teoría de la democracia deliberativa constituye una de las propuestas filosófico-políticas más importantes de los últimos años para la reconstrucción normativa del Estado democrático de derecho, y que, al igual que la ética del discurso, constituye una derivación teórica del enfoque de la racionalidad discursiva. Ahora bien, una cuestión que es necesario analizar es qué tipo de relación se plantea entre ambas teorías. Esta es una tarea pendiente, porque para algunos de los exponentes de tal teoría ética, ella parece asumir el rol de conducir y guiar de un modo exclusivo las decisiones políticas, lo cual implica una reducción de la Filosofía política al campo de la ética olvidando que dicha Filosofía, si bien presupone la ética, tiene sus propios principios. El presente artículo analiza entonces esta teoría política desde un punto de vista interno, señalando los problemas que podrían seguirse a partir de abordar filosóficamente el cuestión de la política democrática exclusivamente desde la perspectiva de la ética del discurso.The theory of deliberative democracy is one of the most important philosophical-political proposals in the last years for the Normative reconstruction of the democratic State of Law, and, as the Discourse Ethics, constitutes a theoretical derivation of the perspective of discursive rationality. In this respect, is necessary to analyze what kind of relation there is between both theories. This one is a hanging task, because for some of its exponents the ethical theory seems to assume the role of driving and guiding, in an exclusive way, the political decisions, which implies a reduction of the political Philosophy to the field of the ethics. But, even when presupposes ethics, politics has his own rules. The present article analyzes this political theory from an internal point of view, indicating the problems that might follow from one philosophical approaching to the issue of the

  20. El diseño de material didáctico como aporte al abordaje de los problemas ambientales en entornos educativos y comunitarios

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    Julián David Becerra-Barón

    2014-01-01

    Full Text Available La necesidad de diseñar materiales que promuevan reflexiones alrededor de los problemas ambientales, hace que las instituciones educativas asuman escenarios promotores en la generación de estrategias didácticas en relación al tema. En este trabajo, se presenta el proceso de diseño de un módulo didáctico denominado: “Reflexionemos sobre los Problemas Ambientales del Municipio de Tunja”, que tiene como finalidad el reconocimiento de los problemas ambientales más relevantes que afectan a esta ciudad. El diseño fue abordado en tres etapas: a Exploración del contexto y documentación, para verificar la relevancia del tema en la comunidad; b. Selección del modelo didáctico y c. Construcción del módulo. Finalmente, se presenta a modo de ejemplo una actividad de juego de roles, diseñada bajo el enfoque de enseñanza-aprendizaje de educación para la sostenibilidad y cuestiones socio-científicas (CSC que permite reflexionar cada uno de los problemas ambientales tratados.

  1. Coronal dynamics

    Science.gov (United States)

    Nakariakov, V. M.

    2007-07-01

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

  2. Coronal Partings

    CERN Document Server

    Nikulin, Igor F

    2015-01-01

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

  3. Evaluación nasal en el abordaje quirúrgico de la patología selar

    OpenAIRE

    Sariego R,Homero; Bogado C,Mariana

    2008-01-01

    Introducción: El abordaje quirúrgico de la hipófisis ha experimentado un importante desarrollo desde sus inicios; desde el abordaje transcraneal al transesfenoidal, siendo éste último el más utilizado para el tratamiento de la patología selar. Objetivo: Comunicar la experiencia quirúrgica del manejo del septum y fosas nasales, en el abordaje selar en el Instituto de Neurocirugía Dr. Alfonso Asenjo (INCA). Material y Método: Se realizó un estudio descriptivo-transversal de pacientes operados p...

  4. Coronal magnetometry

    CERN Document Server

    Zhang, Jie; Bastian, Timothy

    2014-01-01

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

  5. Coronal Holes

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    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.

  6. Coronal Holes

    CERN Document Server

    Cranmer, Steven R

    2009-01-01

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

  7. Abordaje subfrontal para el tratamiento de un estesioneuroblastoma

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    Alfonso Mogedas-Vegara

    2014-10-01

    La resección craneofacial, empleando un abordaje subfrontal, es uno de los abordajes de elección para el tratamiento de esta compleja entidad. Describimos un caso tratado en nuestra institución que fue resuelto favorablemente con este procedimiento, así como una revisión exhaustiva de la bibliografía con respecto a este tipo de tumor y a las ventajas de este abordaje.

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

    Directory of Open Access Journals (Sweden)

    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.

  9. Bootstrapping the Coronal Magnetic Field with STEREO

    Science.gov (United States)

    Aschwanden, Markus J.

    2010-05-01

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

  10. EL ABORDAJE DEL CONOCIMIENTO COTIDIANO DESDE LA TEORÍA DE LAS REPRESENTACIONES SOCIALES

    Directory of Open Access Journals (Sweden)

    Claudia Alejandra Mazzitelli

    2010-01-01

    Full Text Available En este trabajo proponemos un abordaje conceptual del estudio del conocimiento cotidiano acerca de los fenómenos naturales, asociados al aprendizaje de las Ciencias, desde una perspectiva psicosocial. Entendemos que el conocimiento cotidiano que poseen los alumnos podría considerarse próximo a las representaciones sociales en su definición tradicional. En esta línea, lograr un aprendizaje, y la consecuente reelaboración conceptual, implicaría un cambio en las representaciones socialmente compartidas. Pensamos que este abordaje nos permitirá analizar y reinterpretar de manera más holística las dificultades de aprendizaje de las Ciencias de la Naturaleza.

  11. Assistência de enfermagem ao portador de Hanseníase: abordagem transcultural Asistencia de enfermería al portador de Lepra: abordaje transcultural Nursing assistance to a Leprosy-infected patient: transcultural approach

    Directory of Open Access Journals (Sweden)

    Fernando José Guedes da Silva Júnior

    2008-11-01

    Full Text Available Trata-se de um estudo de caso, desenvolvido em um Centro de Saúde em Teresina - PI, que abordou a problemática da assistência de enfermagem prestada a uma paciente com Hanseníase Multibacilar, enfocando o cuidado de Enfermagem Transcultural, Diagnósticos e Intervenções de Enfermagem segundo a Taxonomia II da NANDA. Realizou-se a entrevista semi-estruturada e observação participante, que possibilitaram a coleta dos dados, os quais foram tratados baseados nos padrões normativos, valores e prática diárias, modos de cuidado popular e cuidados requeridos no sistema profissional. Neste estudo, constatou-se que o planejamento da assistência de enfermagem visou, principalmente, contribuir para a adesão ao tratamento da doença, diminuindo os riscos potenciais e utilizando a preservação, negociação e re-padronização do sistema profissional. Observou-se também a adesão ao tratamento e a realização de autocuidado voltado para a hanseníase de forma culturalmente satisfatória.Es un estudio de caso, desarrollado en un centro de salud en Teresina-PI, que abordó la problemática de la asistencia de enfermería dada a una paciente con lepra multibacilar, enfocando el cuidado de Enfermería Transcultural, Diagnósticos, e Intervenciones de Enfermería segundo la Taxonomía II de NANDA. Se realizó una entrevista semi-estructurada y observación participante, que posibilitaron la colecta de los datos, los cuales fueron tratados basados em los padrones normativos, valores y prácticas diárias, modos de cuidado popular y cuidados requeridos en el sistema profesional. En este estudio, se constató que el planeamiento de la asistencia de enfermería objetivó, principalmente, contribuir para la adhesión al tratamiento de la enfermidad, disminuyendo los riscos potenciales y utilizando la preservación, negociación y repradonización del sistema profesional. Se observó también la adhesión al tratamiento y la realización del auto cuidado

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

    CERN Document Server

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

    2015-01-01

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

  13. Abordaje de la artrosis desde la atención primaria

    OpenAIRE

    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...

  14. Coronal influence on dynamos

    CERN Document Server

    Warnecke, Jörn

    2013-01-01

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

  15. Influencia de los abordajes craneomandibular y cervical sobre los desórdenes temporomandibulares en el latigazo cervical: estudio de caso

    OpenAIRE

    Sánchez Robledo, Alejandra

    2016-01-01

    Introducción: Muchos autores evidencian la relación entre desórdenes temporomandibulares (DTM) y latigazo cervical. Concluyen que su fisiopatología es más compleja que en DTM sin antecedente traumático, perpetuando los síntomas y dificultando la respuesta al tratamiento. Son pocos los protocolos que incluyen un abordaje de ATM tras whiplash o estudian los efectos de diversos abordajes ante esta patología. Objetivos: Identificar la efectividad de diferentes estrategias terapéuticas ante pat...

  16. The attitudes of nurses from an intensive care unit in the face of errors: an approach in light of bioethics Postura de los enfermeros de una unidad de terapia intensiva frente al error: un abordaje utilizando referenciales bioéticos Postura dos enfermeiros de uma unidade de terapia intensiva frente ao erro: uma abordagem à luz dos referenciais bioéticos

    Directory of Open Access Journals (Sweden)

    Rita de Cássia Pires Coli

    2010-06-01

    Full Text Available This study analyzed the attitudes of nurses concerning the occurrence of errors in nursing procedures carried out in an Intensive Care Unit (ICU based on the bioethics framework. This descriptive study with qualitative approach was carried out with 14 nurses from a private hospital in the city of São Paulo, Brazil. Results were analyzed according to Bardin’s proposal of content analysis. The resulting themes were: acknowledging one’s fallibility; acknowledging and reporting errors; hiding errors. The nurses’ reports are based on considerations through the lens of bioethics: taking responsibility for an error implies acknowledging one’s own vulnerabilities; acknowledging an error with responsibility implies ethical conditions in the relationships among those involved; and errors are in the context of a particular environment. This study enables re-thinking nursing practice based on bioethics, resorting to the analysis of errors focusing on the relationships between those involved.El objetivo de este trabajo es analizar, a partir de referenciales de la bioética, la postura de los enfermeros delante de la ocurrencia de errores en procedimientos de enfermería, en una unidad de terapia intensiva (UTI. Se trata de investigación descriptiva, bajo abordaje cualitativo, realizado con 14 enfermeros de una UTI, en un hospital privado de Sao Paulo. El análisis de los resultados fue realizado según la propuesta de análisis de contenido de Bardin. Los resultados evidenciados fueron: reconociendo ser falible, reconociendo y comunicando el error, y omitiendo el error. Los relatos de los enfermeros formaron la base para las consideraciones apuntadas a la luz de los referenciales bioéticos; la responsabilidad delante del error supone el reconocimiento de las propias vulnerabilidades, asumir el error con responsabilidad supone condiciones éticas en las relaciones entre las personas envueltas y el error tiene un ambiente. Este estudio propicia

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

    Science.gov (United States)

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

    1995-01-01

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

  18. Bootstrapping the Coronal Magnetic Field with STEREO/EUVI

    Science.gov (United States)

    Aschwanden, Markus; Sandman, Anne

    2010-05-01

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

  19. Coronal Mass Ejections

    Science.gov (United States)

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

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

  20. Coronal Waves and Oscillations

    Directory of Open Access Journals (Sweden)

    Nakariakov Valery M.

    2005-07-01

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

  1. Mechanisms of Coronal Heating

    Indian Academy of Sciences (India)

    S. R. Verma

    2006-06-01

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

  2. Free Magnetic Energy and Coronal Heating

    Science.gov (United States)

    Winebarger, Amy; Moore, Ron; Falconer, David

    2012-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-11-10

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

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

    Science.gov (United States)

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

    2017-01-01

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

  5. Comment on "Sizes and relative geoeffectiveness of interplanetary coronal mass ejections and the preceding shock sheaths during intense storms in 1996-2005" by J. Zhang et al

    CERN Document Server

    Yermolaev, Yu I

    2008-01-01

    Recently Zhang et al. [2008] presented a statistical study of sizes and relative geoeffectiveness of ICMEs (bodies of magnetic clouds) and preceding sheaths for 46 events responsible for intense (Dst < -100 nT) geomagnetic storms in 1996-2005 in which only a single ICME was responsible for generating the storm. Here we would like to comment several results and conclusions of this paper.

  6. Abordaje de la disfagia en enfermos de alzhéimer

    Directory of Open Access Journals (Sweden)

    Marta Baena González

    Full Text Available Introducción: la disfagia es un síntoma que se refiere a la dificultad para mover el bolo alimentario desde la boca al estómago. A pesar de su relevancia y de la gravedad de sus posibles complicaciones, es poco conocida y estudiada. La prevalencia de la disfagia orofaríngea en enfermos de alzhéimer es de un 84% y puede originar complicaciones de gran trascendencia clínica como consecuencia de las alteraciones en la eficacia de la deglución, y en la seguridad de la misma. Objetivo: conocer el estado actual del conocimiento en relación al abordaje de la disfagia en enfermos de alzhéimer, localizando aquellos factores que permitan un diagnóstico precoz que facilite la prevención de complicaciones y la elección de la pauta de actuación más adecuada. Metodología: revisión sistemática. Estudios publicados entre 2005 y 2014 en inglés y castellano. Bases de datos: PubMed, Cochrane, Scopus, Elsevier, Scielo y Dialnet. Términos MeSH empleados: disfagia, dysphagia, alzheimer, modified y texture food. Resultados: el diagnóstico en los pacientes de alzhéimer se realiza mediante métodos clínicos y exploraciones complementarias como la videofluoroscopia, considerada como el estándar para el estudio de la disfagia orofaríngea, ya que permite identificar entre 1/3 y 1/4 de los pacientes que presentan aspiraciones silentes no diagnosticables clínicamente. Existen estrategias terapéuticas que incluyen cambios en el volumen y viscosidad del bolo, cambios posturales, maniobras deglutorias, procedimientos de rehabilitación y técnicas de incremento sensorial que han demostrado su eficacia, pero se trata de una labor compleja que exige un abordaje multidisciplinar para un correcto diagnóstico y tratamiento. Conclusiones: existe una escasa evidencia científica en el abordaje de la disfagia y un gran desconocimiento en cuanto a la alimentación de los enfermos de alzhéimer. Esta patología necesita una intervención multidisciplinar en la

  7. Global Coronal Waves

    CERN Document Server

    Chen, P F

    2016-01-01

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

  8. A Two-Fluid, MHD Coronal Model

    Science.gov (United States)

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

    1999-01-01

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

  9. Principais conceitos da abordagem sistêmica em cuidados de enfermagem ao individuo e sua família Principales conceptos del abordaje sistemico en cuidados de enfermería al individuo y su familia Nursing care to the individual and his/her family: main concepts of the systemic approach

    Directory of Open Access Journals (Sweden)

    Sueli Aparecida Frari Galera

    2002-06-01

    Full Text Available Dada a ênfase atual na questão família surgiu o interesse de trazer para a discussão alguns conceitos que fundamentam aabordagem sistêmica em cuidados de enfermagem, que tem como principal instrumento a entrevista com a família. Osconceitos discutidossão:sistema, ser humano, família, saúde familiar, intervenção de enfermagem, hipóteses, circularidade,hipótese sistêmica e neutralidade. Procurou-se fornecer exemplos práticos que facilitassem a compreensão dos conceitos, bem como sua aplicabilidade.Considerando la enfasis actual en la cuestión familia surgió el interés en traer para la discusión algunos conceptos que fundamentan el abordaje sistémico en cuidados de enfermería, que tiene como principal instrumento la entrevista con lafamilia. Los conceptos discutidos son: sistema, ser humano, familia, salud familiar, intervención de enfermeria, hipótesis,circularidad, hipótesis sistémica, neutralidad. Se buscd fornecer ejemplos prácticos que facilitasen la comprensión de los conceptos, bién como su aplicabilidad.With the current emphasis in the family question it is important to discuss some concepts underlying the systemicapproach to the family nursing care, which has in the interview with the family its main instrument . In this paper thefollowing concepts are discussed: system, human being, family, familiar health, nursing intervention, hypotheses, circularity,systemic hypothesis and neutrality. It was aimed to supply practical examples that could facilitated the understandingof the concepts, as well as its applicability.

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

    Directory of Open Access Journals (Sweden)

    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.

  11. Coronal Mass Ejections

    CERN Document Server

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

    2006-01-01

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

  12. Hemangioma capilar de la parótida. Abordaje transoral

    Directory of Open Access Journals (Sweden)

    Luis Domingo Sarra

    2014-10-01

    Presentamos un caso en una paciente adulta que consultó por una masa en la región parotídea y parálisis facial periférica con el mayor componente tumoral que se manifestaba en la cavidad oral. La ecografía mostró una masa sólida. La punción aspiración con aguja fina fue negativa con material hemático en 2 oportunidades. No tuvimos sospecha de la presencia de un tumor de origen vascular, por lo que no fue solicitada una RMN. El caso fue resuelto a través de un abordaje quirúrgico poco utilizado, tras obtener una biopsia por congelación negativa.

  13. Standing sausage modes in coronal loops with plasma flow

    CERN Document Server

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

    2014-01-01

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

  14. Coronal radiation belts

    CERN Document Server

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

    2009-01-01

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

  15. Abordajes teóricos sobre las juventudes indígenas en Latinoamérica

    Directory of Open Access Journals (Sweden)

    Laura Kropff-Causa

    2017-01-01

    Full Text Available Una dificultad al proponer una sistematización de la información sobre juventud indígena en Latinoamérica tiene que ver con que las categorías “juventud” e “indígena” no emergen como datos directos de la realidad, sino que son construidas a partir de definiciones. Para contribuir al análisis de este entramado, esta investigación se focaliza en las definiciones con las que la academia latinoamericana ha contribuido en los últimos años. Finalmente, se propone el abordaje de edad y etnicidad como clivajes que definen la movilidad estructurada de subjetividades, identidades y agencias cuya trama debe leerse situada en cada contexto sociopolítico e histórico particular.

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

    Science.gov (United States)

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

    2016-01-01

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

  17. 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

    Directory of Open Access Journals (Sweden)

    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

  18. Coronal Magnetic Field Models

    Science.gov (United States)

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

    2017-09-01

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

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

    OpenAIRE

    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...

  20. Coronal Mass Ejections: Observations

    Directory of Open Access Journals (Sweden)

    David F. Webb

    2012-06-01

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

  1. Realidad Virtual Acústica: El Abordaje de las Redes Neuronales Artificiales

    Directory of Open Access Journals (Sweden)

    Jose Francisco Lucio

    2015-05-01

    Full Text Available En este trabajo se presenta un nuevo abordaje para obtener las respuestas impulsivas biauriculares (BIRs para un sistema de aurilización utilizando un conjunto de redes neuronales artificiales (RNAs. El método propuesto es capaz de reconstruir las respuestas impulsivas asociadas a la cabeza humana (HRIRs por medio de modificación espectral y de interpolación espacial. Para poder cubrir todo el espacio auditivo de recepción, sin aumentar la complejidad de la arquitectura de la red, una estructura con varias RNAs (conjunto fue adoptada, donde cada red opera en una región específica del espacio (gomo. El error de modelaje en el dominio de la frecuencia es investigado considerando la naturaleza logarítmica de la audición humana. A través de la metodología propuesta se obtuvo un ahorro del tiempo de procesamiento computacional de aproximadamente 62% en relación al método tradicional de procesamiento de señales utilizado para aurilización. La aplicabilidad del nuevo método en sistemas de aurilización es reforzada mediante un análisis comparativo de los resultados, que incluyen la generación de las BIRs y el cálculo de un parámetro acústico biauricular (IACF, los cuales muestran errores con magnitudes reducidas.

  2. Comparativa de Abordajes de Cursos Introductorios de Programación

    Directory of Open Access Journals (Sweden)

    Mauricio R. Dávila

    2016-08-01

    Full Text Available El pensamiento computacional se basa en resolver problemas haciendo uso de conceptos de informática, desarrollar esta habilidad es la tarea principal de las asignaturas de introducción a la programación en las carreras universitarias. En general, aunque se han creado lenguajes cada vez más cercanos al lenguaje humano, la programación no resulta ser una materia intuitiva ni de fácil comprensión y, por lo tanto, suele tratarse de una asignatura con una alta tasa de deserción. En este contexto, se presenta una revisión de los métodos de enseñanza, el formato de ejercitación y el material utilizado en las materias iniciales de programación en la educación superior, tanto en universidades de los Estados Unidos como de la Argentina. A lo largo del trabajo se buscará determinar el estado de la cuestión, comparar los casos de las distintas universidades a fin de establecer qué aspectos de los distintos abordajes favorecen el proceso de la enseñanza y poder así realizar un esbozo de solución que apunte a disminuir los índices de deserción en las materias introductorias de programación.

  3. Innovación: Tensiones teóricas en su abordaje

    Directory of Open Access Journals (Sweden)

    John Eddson Burgos Burgos

    2015-11-01

    Full Text Available El trabajo presenta una revisión de la literatura sobre el desarrollo de la innovación en los diversos escenarios donde se la aborda y practica, con el objetivo de conocer cómo afecta a las personas, empresas e instituciones, a su vez como estas generan, adquieren y aplican el conocimiento para introducir cambios en sus procesos administrativos, tecnológicos y culturales. La innovación es típicamente un esfuerzo de grupo, de un individuo o una empresa que pretende mejorar sus rendimientos financieros. El tratar a la innovación crea tensiones en su abordaje, sin embargo hay que hacerle frente, pues la adopción de la innovación es un eje fundamental para el crecimiento de las naciones, de tal forma que en todas, es una política pública que va en apoyo al desarrollo socioeconómico donde intervienen todos los actores del territorio.

  4. The coronal fricative problem

    Science.gov (United States)

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

    2013-01-01

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

  5. Abordajes sobre la tercerización laboral en América Latina: aportes y perspectivas

    OpenAIRE

    Esponda, Alejandra; Basualdo, Victoria

    2014-01-01

    Esta ponencia propone una aproximación a una problemática que, aunque de inmensa relevancia, sólo recientemente ha comenzado a adquirir mayor importancia en distintos ámbitos de investigación y producción, sean académicos o político- sindicales (gubernamentales y no gubernamentales) en América Latina. Intentaremos aquí realizar una contribución al análisis del fenómeno de la tercerización en América Latina en las últimas décadas, a partir de una aproximación sintética a los distintos abordaje...

  6. Síntomas y complicaciones posfunduplicatura: abordaje diagnóstico y tratamiento

    Directory of Open Access Journals (Sweden)

    S. Sobrino-Cossío

    2017-07-01

    Full Text Available En la actualidad la funduplicatura laparoscópica tipo Nissen se considera el tratamiento quirúrgico de elección para la enfermedad por reflujo gastroesofágico (ERGE y su efectividad a largo plazo es mayor del 90%. Dentro de los factores predictores de buena respuesta clínica están la adecuada selección del paciente y la experiencia del cirujano. Sin embargo, la prevalencia de síntomas nuevos, persistentes y recurrentes posteriores al procedimiento antirreflujo puede ser de hasta un 30%. Las causas son múltiples pero en general se deben a una o más alteraciones en la anatomía y en la función esofagogástrica. Ante la persistencia de los síntomas posterior al procedimiento quirúrgico se debería de utilizar el término «falla». En el caso de que un paciente inicialmente manifieste control de sus síntomas y posteriormente estos reaparezcan, se pudiera emplear el término «disfunción». Por otra parte, ante el empeoramiento de los síntomas o la aparición de síntomas o situaciones clínicas que no existían antes de la cirugía, debe de considerarse una «complicación». La disfagia postoperatoria y los síntomas dispépticos son muy frecuentes y requieren un abordaje integral para poder determinar el mejor tratamiento posible. En esta revisión se detallan los aspectos fisiopatológicos, de diagnóstico y tratamiento de los síntomas y las complicaciones posteriores a la funduplicatura para el manejo de la ERGE.

  7. Solar Coronal Plumes

    Directory of Open Access Journals (Sweden)

    Giannina Poletto

    2015-12-01

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

  8. Solar coronal jets

    Science.gov (United States)

    Dobrzyck, D.

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

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

    Science.gov (United States)

    Scherrer, Bryan; McKenzie, David

    2017-03-01

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

  10. Abordaje fisioterapéutico en el Síndrome del Corredor (Banda Ilitibial). Revisión bibliográfica

    OpenAIRE

    Caraballo Viña, Javier

    2016-01-01

    [ES]Introducción: El running es una práctica deportiva muy extendida. Los beneficios asociados al running son innumerables, pero pueden acarrear la aparición de una serie de patologías. El propósito de esta revisión fue recopilar los abordajes fisioterapéuticos que son atribuidos a la patología del SBIT y el estudio de su evidencia científica. Método: Se realizó una revisión bibliográfica desde 2005 en ScienceDirect, SportsDiscus with Full text (EBSCO), Scopus, Cochcrane Database of Systemati...

  11. Simbolismo e identidad en las tierras bajas del paraná: un abordaje contextual del arte mobiliar cerámico

    OpenAIRE

    Flavia V. Ottalagano

    2010-01-01

    Se intenta una aproximación al simbolismo de los grupos humanos que habitaron las Tierras Bajas del río Paraná Medio durante el Holoceno Tardío, a través de un abordaje contextual de su arte mobiliar cerámico. En base a esto, se procura abrir la discusión hacia temáticas interconectadas y escasamente investigadas, como ser la identidad, las relaciones inter-grupales e intra-grupales de las poblaciones asentadas en el área en momentos prehispánicos. El carácter probablemente cotidiano de estos...

  12. Abordaje de la discapacidad en facultades de Psicología de universidades privadas de Bogotá, entre 1998 y 2009

    OpenAIRE

    Mónica Lucía Castelblanco Niño

    2011-01-01

    El objetivo de esta investigación fue conocer el estado del arte sobre el abordaje de la discapacidad en los trabajos de grado para optar al título de psicólogo en universidades privadas de Bogotá. Se utilizó el método de investigación documental Resumenes Analíticos de Investigación, -RAE s- de bases de datos elaborados entre los años 1998 a 2009. Se seleccionaron aquellos que abordaban la discapacidad, discapacidad física, la discapacidad cognitiva, la discapacidad sensorial y la inclusi...

  13. “IDEAS PARA MI MUNDO”, UN ESPACIO DE REFLEXIÓN Y SOCIALIZACIÓN DE EXPERIENCIAS EN LA ENSEÑANZA DE LA BIOLOGÍA ENCAMINADO AL APRENDIZAJE SIGNIFICATIVO CRÍTICO. UN ABORDAJE DESDE LA INVESTIGACIÓN ACCIÓN

    Directory of Open Access Journals (Sweden)

    Nixon Medina Talero

    2014-05-01

    En ese contexto surge el edublog “Ideas para mi Mundo” como un espacio para reflexionar y socializar las actividades realizadas en el desarrollo de la propuesta de aula basada en el ASC. El blog es un reflejo del proceso que realizamos (y seguiremos realizando. Se ha constituido como una bitácora del proceso investigativo al mismo tiempo que fomenta la participación, estructura temáticas, propicia la evaluación formativa y genera un espacio para la autoformación docente. Adicionalmente se continúa en proceso de implementación de la propuesta reconociendo que el aprendizaje significativo es un proceso que requiere tiempo y es un proceso paulatino. Se ha evidenciado hasta el momento en los estudiantes mayor estructuración del discurso científico y la consciencia de la jerarquización conceptual dinámica del conocimiento biológico.

  14. Coronal Mass Ejections: From Sun to Earth

    Science.gov (United States)

    Patsourakos, S.

    2016-06-01

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

  15. Active Longitude and Coronal Mass Ejection Occurrences

    Science.gov (United States)

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

    2017-03-01

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

  16. Coronal Seismology -- Achievements and Perspectives

    Science.gov (United States)

    Ruderman, Michael

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

  17. Geometry of solar coronal rays

    Science.gov (United States)

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

    2016-02-01

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

  18. Ponderomotive Acceleration in Coronal Loops

    Science.gov (United States)

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

    2016-11-01

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

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

    Directory of Open Access Journals (Sweden)

    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".

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Coronal Jets from Minifilament Eruptions in Active Regions

    Science.gov (United States)

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

    2016-12-01

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

  2. El desguante craneorbitofacial como abordaje craneofacial y sus aplicaciones clínicas

    OpenAIRE

    Rubén Muñoz; Jose Golaszewski; Alvaro Díaz

    2012-01-01

    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 sec...

  3. Coronal Mass Ejections An Introduction

    CERN Document Server

    Howard, Timothy

    2011-01-01

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

  4. Motion magnification in coronal seismology

    CERN Document Server

    Anfinogentov, Sergey

    2016-01-01

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

  5. Observational Analysis of Coronal Fans

    Science.gov (United States)

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

    2017-01-01

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

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

    CERN Document Server

    Ireland, Jack; Inglis, Andrew R

    2014-01-01

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

  7. Abordagem assistencial ao neonato portador de mielomeningocele segundo o modelo de adaptação de Roy Abordaje asistencial al neonato portador de mielomeningocele según el modelo de adaptación de Roy Care delivery to newborns with myelomeningocele according to Roy's adaptation model

    Directory of Open Access Journals (Sweden)

    Eloah de Paula Pessoa Gurgel

    2010-09-01

    Full Text Available O objetivo deste estudo de caso foi identificar os diagnósticos de Enfermagem de um bebê portador de mielomeningocele, internado na Unidade de Terapia Intensiva Neonatal (UTIN, abordando os aspectos fisiológicos segundo a Teoria de Adaptação de Roy, e elaborar ações de enfermagem pertinentes a estes aspectos. O estudo foi desenvolvido na UTIN da Maternidade Escola Assis Chateaubriand, na cidade de Fortaleza, Ceará, Brasil, nos meses de dezembro de 2007 a março de 2008, quando foi utilizado um roteiro de levantamento de dados. Na análise, reconheceram-se os diagnósticos: padrão respiratório ineficaz; nutrição desequilibrada: menos do que as necessidades corporais; integridade da pele prejudicada; risco para infecção e percepção sensorial perturbada. A utilização desta teoria permitiu reconhecer que o RN pode desencadear respostas positivas ou negativas mediante estímulos, e que as metas e intervenções implementadas foram importantes para a substituição de respostas ineficazes por respostas adaptativas.El objetivo de este estudio de caso fue identificar los diagnósticos de Enfermería, abordando los aspectos fisiológicos según la Teoría de Adaptación de Roy, de un bebé portador de mielomeningocele, internado en la Unidad de Terapia Intensiva Neonatal (UTIN, y elaborar acciones de enfermería pertinentes a tales aspectos. El estudio fue desarrollado en al UTIN de la Maternidad Escuela Assis Chateubriand, en la ciudad de Fortaleza-Ceará-Brasil, en los mese de diciembre de 2007 a marzo de 2008, momento en el cual fue utilizado un cuestionario para la colecta de datos. En el análisis, se reconocieron los diagnósticos: patrón diagnóstico ineficaz, nutrición desequilibrada (inferior a las necesidades corporales, integridad de la piel afectada, riesgo de infección y percepción sensorial perturbada. La utilización de esta teoría permitió reconocer que el RN puede desencadenar respuestas positivas o negativas a

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

    Science.gov (United States)

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

    2007-02-01

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

  9. Exploring Coronal Structures with SOHO

    Indian Academy of Sciences (India)

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

    2000-09-01

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

  10. Un abordaje de Five de Abbas Kiarostami

    OpenAIRE

    Molina, Stella Maris

    2007-01-01

    Se trata de una producción cinematográfica de Abbas Kiarostami, dedicada al cineasta japonés Yasujiro Ozu. Es un ensayo cinematográfico de contemplación al borde del mar en cinco momentos que el testimonio captado por la mirada. Toda dedicatoria supone en primer lugar una transferencia en sentido psicoanalítico, es decir un lugar de Otro atribuido por Kiarostami a Ozu, sin duda por su influencia como maestro. Dicha transferencia le adjudica cierto saber y es amorosa. Además esta dedicat...

  11. Intrinsic Instability of Coronal Streamers

    CERN Document Server

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

    2009-01-01

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

  12. Saberes y trayectorias de atención a la salud de poblaciones vulneradas en México: un abordaje interdisciplinario

    Directory of Open Access Journals (Sweden)

    Luz María Espinosa Cortés

    2013-06-01

    Full Text Available El objetivo de este artículo es evidenciar la potencialidad que tiene el abordaje interdisciplinario en la comprensión integral del proceso salud/enfermedad/atención de poblaciones vulneradas de tres comunidades, una rural ubicada en el Estado de Oaxaca (Charco Redondo y dos en la Ciudad de México (Xochimilco y Magdalena Contreras. La experiencia y los saberes (representaciones y prácticas sociales se recuperan desde la perspectiva de sus habitantes, siguiendo la estrategia basada en aproximaciones multi método. Con base en referentes teóricos y metodológicos compartidos, se revisó el material empírico producido en tres investigaciones previas. El abordaje interdisciplinario se orientó hacia la reinterpretación histórica, antropológica y psicosocial de los saberes y de las trayectorias de búsqueda de atención de la población, para lograr una comprensión más amplia e integradora del proceso salud/enfermedad que contribuya a la elaboración de políticas públicas orientadas a mejorar las condiciones de salud de poblaciones vulneradas. Al final del trabajo se plantean algunas reflexiones sobre los alcances, limitaciones y los retos para impulsar la investigación interdisciplinaria.

  13. Motion Magnification in Coronal Seismology

    Science.gov (United States)

    Anfinogentov, Sergey; Nakariakov, Valery M.

    2016-11-01

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

  14. Ponderomotive Acceleration in Coronal Loops

    CERN Document Server

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

    2016-01-01

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

  15. 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

    Directory of Open Access Journals (Sweden)

    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.

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

    CERN Document Server

    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 ...

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

    CERN Document Server

    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...

  18. Lazo social y globalización: las sociedades imaginales y un abordaje metodológico para su estudio

    Directory of Open Access Journals (Sweden)

    Esteban Marcos Dipaola

    2017-03-01

    Full Text Available El objetivo en el artículo es establecer dimensiones metodológicas para analizar las sociedades contemporáneas, vínculos y procesos de subjetivación, en sus relaciones con imágenes. Primeramente, entiendo la noción de imagen en sentido extendido a formas de apropiación social: las modas, consumos y gustos, diseños, tecnologías de comunicación y redes, etc. constituyen propiedades imaginales que intervienen sobre producciones normativas de prácticas sociales. Para concretar ese análisis general deben establecerse criterios acordes al objeto de estudio: se asume como objeto general de las ciencias sociales las relaciones (no el actor o el sistema, asumiendo las lógicas discursivas de lo social. Finalmente, se proponen especificidades metodológicas, entendiendo la interdisciplinariedad y la transdisciplinariedad como fundamentales. El trabajo sobre lo imaginal, es decir, acerca de la indiscernibilidad entre lo social y las imágenes, implica un abordaje de superposiciones de capas, cuestionando esencialismos y binarismos.

  19. Anatomy of Depleted Interplanetary Coronal Mass Ejections

    Science.gov (United States)

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

    2017-01-01

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

  20. From Forbidden Coronal Lines to Meaningful Coronal Magnetic Fields

    CERN Document Server

    Judge, Philip G; Landi, Enrico

    2013-01-01

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

  1. Cultura cabocla en el sur de Brasil un abordaje preliminar

    Directory of Open Access Journals (Sweden)

    Pedro Martins

    2003-12-01

    Full Text Available This text is a research report concerning the cabocla (mestizo population of southern Brazil, focusing on cultural aspects, seen here as a distinguishing system. This population is studied in terms of the migratory process that begins with their expulsion from the countryside, their adaptation to the small towns, passing through the periphery of the large cities and finally returning to the countryside. The article attempts to understand their musical practices, the technology that they have appropriated and their religiosity, all of which have been, symbolically and materially, reconstructed in their complexity.//Este texto es un reporte de la investigación sobre la población cabocla en el sur de Brasil, centrado en los aspectos culturales vistos como un sistema distintivo. Esta población es estudiada en los términos de un proceso migratorio que empieza con su expulsión del campo, su adaptación a pueblos pequeños, pasando por la periferia de las grandes ciudades y finalmente, retornando al campo. El artículo busca entender las prácticas musicales, la tecnología que apropiaron y sus prácticas religiosas, aspectos todos que han sido simbólica y materialmente reconstruidos en su complejidad.

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

    Directory of Open Access Journals (Sweden)

    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.

  3. Magnetic shuffling of coronal downdrafts

    Science.gov (United States)

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

    2017-02-01

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

  4. Pre-flare coronal dimmings

    CERN Document Server

    Zhang, Q M; Ji, H S

    2016-01-01

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

  5. La entrevista colectiva como dispositivo para el abordaje transdisciplinar de la identidad socioterritorial. Un acercamiento desde la mirada decolonial

    Directory of Open Access Journals (Sweden)

    Martín Segovia Stanoss

    2015-04-01

    Full Text Available Hacia finales del siglo XX, se produce el reingreso del testimonio oral como fuente para la producción de conocimiento histórico, y de la Memoria al universo de la Historia como vía de acceso al imaginario de los sujetos; ello significó la posibilidad de dar cuenta de la multiplicidad de filiaciones identitarias mantenidas “al margen”, antes silenciadas, que pueden activarse en los sujetos en atención al “otro” en confrontación al cual se construye.La recuperación de las escalas de abordaje microsociales -lo local, lo barrial-, indispensable para el propósito de comprensión de los fenómenos culturales/simbólicos, permitió la organización de nuevos campos cuya adscripción disciplinar resulta dificultosamente definida.En este marco se involucran los estudios que abordan los mecanismos que contribuyen a la construcción de identidades socioterritoriales -a escala intraurbana- utilizando relatos biográficos y observando el espacio que los acontecimientos recordados ocupan en el establecimiento de relaciones simbólicas con el territorio habitado.Con los propósitos señalados, y a partir de una experiencia concreta, se propone la reflexión desde una matriz transdisciplinar sobre los alcances y limitaciones de la instancia de entrevista grupal como espacio de participación comunitaria y dispositivo de co-construcción de datos.Como resultado, se dispone de una mirada metodológica ampliada hacia dimensiones epistemológicas, que asisten a las reacciones que enfrentan tanto los acercamientos ingenuos que pretenden una suerte de desaparición del investigador para dar voz al “otro”, como los que asumen que el investigador interpreta las interpretaciones de los entrevistados desde una posición privilegiada y distante.

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

    Science.gov (United States)

    Griffith, Richard

    2017-01-02

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

  7. Deep coronal hole associated with quiescent filament

    Science.gov (United States)

    Kesumaningrum, Rasdewita; Herdiwidjaya, Dhani

    2014-03-01

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

  8. La neuroplasticidad aplicada al deporte

    OpenAIRE

    Fernández, Hernán

    2015-01-01

    Me decidí a realizar la siguiente ponencia, para analizar y reconocer la importancia que implica el trabajo cognitivo en el entrenamiento deportivo. El abordaje que efectuaré, está enfocado en el desarrollo del entrenamiento cognitivo, su fundamento y el desarrollo de la neuroplasticidad. Analizaré el concepto de neuroplasticidad y neurogénesis como base al sustento teórico de la neurociencia aplicada al deporte. También remarcaré diversas metodologías prácticas, con su fundamento teóri...

  9. La neuroplasticidad aplicada al deporte

    OpenAIRE

    Fernández, Hernán

    2015-01-01

    Me decidí a realizar la siguiente ponencia, para analizar y reconocer la importancia que implica el trabajo cognitivo en el entrenamiento deportivo. El abordaje que efectuaré, está enfocado en el desarrollo del entrenamiento cognitivo, su fundamento y el desarrollo de la neuroplasticidad. Analizaré el concepto de neuroplasticidad y neurogénesis como base al sustento teórico de la neurociencia aplicada al deporte. También remarcaré diversas metodologías prácticas, con su fundamento teóri...

  10. A percepção dos acadêmicos de enfermagem sobre o cuidado à mulher no trabalho de parto e nascimento: uma abordagem qualitativa La percepción de los académicos de enfermería frente al cuidado de la mujer en el trabajo de parto y nacimiento: un abordaje cualitativo The nursing student's perception about the women care in the labor and birth period: a qualitative approach

    Directory of Open Access Journals (Sweden)

    Thiago Bicchieri

    2006-08-01

    Full Text Available O presente estudo tem como objetivo identificar a percepção dos acadêmicos de enfermagem sobre o cuidado prestado à mulher no trabalho de parto e nascimento. Trata-se de um estudo descritivo com abordagem qualitativa. Foram entrevistados 30 acadêmicos de enfermagem pertencentes a uma escola de enfermagem de âmbito federal, situada no município do Rio de Janeiro. Os resultados demonstraram que os graduandos possuem uma visão crítica sobre o cuidado oferecido à mulher no centro obstétrico e o classificam como cuidado inadequado e extremamente tecnicista e, que as atividades ditas humanizadas e benéficas no trabalho de parto e nascimento estão distantes do preconizado pelo Ministério da Saúde. Considera que as mulheres precisam ser percebidas e ouvidas, valorizando uma assistência que reforce sua autonomia e respeite seus direitos enquanto mulher e cidadã.El presente estudio tiene como objetivo identificar la percepción de los académicos de enfermería sobre el cuidado prestado a la mujer en el trabajo de parto y nacimiento en la percepción de los académicos de enfermería. Se trata de un estudio descriptivo con abordaje cualitativo. Fueron entrevistados 30 académicos de enfermería pertenecientes a una escuela de enfermería de ámbito federal, situada en el municipio de Río de Janeiro. Los resultados demuestran que los universitarios poseen una visión crítica sobre el cuidado ofrecido a la mujer en el centro obstétrico y lo clasifica como cuidado inadecuado extremadamente tecnicista y que las actividades humanizadas y benéficas en el trabajo de parto y parto están distantes del preconizado por el Ministerio de la Salud. Por lo tanto, las mujeres necesitan ser percibidas, oídas, valorizando una asistencia que les traiga los mejores resultados, refuerce su autonomía y respete sus derechos en la condición de mujer y ciudadana.The present study has the objective to identify the care given to women in pre-childbirth and

  11. Blind Stereoscopy of the Coronal Magnetic Field

    CERN Document Server

    Aschwanden, Markus J; Malanushenko, Anna

    2015-01-01

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

  12. The Inconvenient Truth About Coronal Dimmings

    CERN Document Server

    McIntosh, Scott W

    2008-01-01

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

  13. EIT waves and coronal magnetic field diagnostics

    Institute of Scientific and Technical Information of China (English)

    CHEN PengFei

    2009-01-01

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

  14. Solar coronal plumes and the fast solar wind

    CERN Document Server

    Dwivedi, B N

    2015-01-01

    The spectral profiles of the coronal Ne viii line at 77 nm have different shapes in quiet-Sun regions and coronal holes (CHs). A single Gaussian fit of the line profile provides an adequate approximation in quiet-Sun areas, whereas a strong shoulder on the long-wavelength side is a systematic feature in CHs. Although this has been noticed since 1999, no physical reason for the peculiar shape could be given. In an attempt to identify the cause of this peculiarity, we address three problems that could not be conclusively resolved in a review article by a study team of the International Space Science Institute (ISSI; Wilhelm et al. 2011) : (1) The physical processes operating at the base and inside of plumes as well as their interaction with the solar wind (SW). (2) The possible contribution of plume plasma to the fast SW streams. (3) The signature of the first-ionization potential (FIP) effect between plumes and inter-plume regions (IPRs). Before the spectroscopic peculiarities in IPRs and plumes in polar coron...

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

    CERN Document Server

    Rose, Marvin; Crenshaw, Michael; Glidden, Ana

    2015-01-01

    Coronal-Line Forest Active Galactic Nuclei (CLiF AGN) are remarkable in the sense that they have a rich spectrum of dozens of coronal emission lines (e.g. [FeVII], [FeX] and [NeV]) in their spectra. Rose, Elvis & Tadhunter (2015) suggest that the inner obscuring torus wall is the most likely location of the coronal line region in CLiF AGN, and the unusual strength of the forbidden high ionization lines is due to a specific AGN-torus inclination angle. Here we test this suggestion using mid-IR colours (4.6$\\mu$m-22$\\mu$m) from the Wide-Field Infrared Survey Explorer (WISE) for the CLiF AGN. We use the Fischer et al. (2014) result that showed that as the AGN-torus inclination becomes more face on, the Spitzer 5.5$\\mu$m to 30$\\mu$m colours become bluer. We show that the [W2-W4] colours for the CLiF AGN ($\\langle$[W2-W4]$\\rangle$ = 5.92$\\pm$0.12) are intermediate between SDSS type 1 ($\\langle$[W2-W4]$\\rangle$ = 5.22$\\pm$0.01) and type 2 AGN ($\\langle$[W2-W4]$\\rangle$ = 6.35$\\pm$0.03). This implies that the AG...

  16. DESAFÍOS DIDÁCTICOS EN EL ABORDAJE DE CONTENIDOS AMBIENTALES EN LA ESCUELA MEDIA

    Directory of Open Access Journals (Sweden)

    Andrea Viviana Ajón

    2015-12-01

    Full Text Available Los contenidos ambientales en la enseñanza de la Geografía representan desde hace tiempo, un atajo de la disciplina para mostrar el espíritu renovador del temario en la escuela, a través del ingreso de nuevos conceptos y del abordaje de problemáticas de relevancia social. La inclusión de dichos contenidos en el aula expresó un giro didáctico –impulsado desde el currículum- en la medida que favoreció la revisión del peso de la geografía física en las clases, en los libros escolares y en la planificación anual del profesor. Propició el tratamiento de problemáticas en diferentes escalas, el reconocimiento de actores sociales y sus intereses, el papel del Estado y organizaciones civiles, despertando el genuino interés de los alumnos. Sin embargo, este proceso no estuvo ni está exento de preguntas, desafíos metodológicos y dificultades. Particularmente se registran tres debilidades: la abundancia de información proveniente de los medios masivos de comunicación e Internet que suele reemplazar la explicación de lo ambiental desde la geografía; la persistencia de la importancia asignada a la geografía física previo al análisis de un caso ambiental; ciertas limitaciones provenientes de la línea renovada para la enseñanza de temáticas ambientales en la escuela. Os conteúdos ambientais no ensino da geografia tem representado a algum tempo um atalho da disciplina para mostrar o espírito inovador do seu currículo na escola, através da entrada de novos conceitos e abordagem de com relevância social. A inclusão destes conteúdos na sala de aula expressou uma rotação educacional – impulsionado pelo currículo - na medida em que favoreceu a revisão do peso da geografia física nas aulas, nos livros didáticos e no planejamento anual do professor. Proporcionando o tratamento da problemática em diferentes escalas, com o reconhecimento dos atores sociais e seus interesses, e do o papel do Estado e das organizações civis

  17. Prácticas de alimentación de los padres y conductas alimentarias en niños:¿Existe información suficiente para el abordaje de los problemas de alimentación?

    OpenAIRE

    Castrillón, Isabel Cristina; Giraldo Roldán, Óscar Ignacio

    2014-01-01

    Los problemas en la alimentación infantil aumentan, a pesar de los esfuerzos de instituciones gubernamentales para vigilar indicadores de salud nutricional y de las campañas de educación que brindan información al respecto. Este artículo busca revisar información disponible sobre el manejo de problemas de alimentación infantil. La primera parte, muestra el estado de los problemas de alimentación infantil y enuncia las consecuencias de la falta de información para su abordaje. La segunda, anal...

  18. Evaluación de proyectos en las Instituciones de Educación Superior: su abordaje a través del Enfoque de Marco Lógico

    OpenAIRE

    González Carella, María Inés; Zanfrillo, Alicia Inés

    2006-01-01

    El presente trabajo presenta la aplicación del Enfoque de Marco Lógico como metodología de abordaje para la evaluación de proyectos en las Instituciones de Educación Superior. Dicho enfoque proporciona una metodología para la planificación de proyectos inscriptos en ayudas internacionales al desarrollo, aplicables también a otros contextos. La aplicación de este enfoque se realiza sobre el proyecto BIBLOS de Cooperación Internacional, entre la Universidad de Islas Baleares de España y la Facu...

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

    Science.gov (United States)

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

    1998-01-01

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

  20. Recent advances in coronal heating

    CERN Document Server

    De Moortel, Ineke

    2015-01-01

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

  1. Coronal Mass Ejections travel time

    Science.gov (United States)

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

    2017-10-01

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

  2. Abordaje médico forense de los cuerpos mutilados criminalmente

    OpenAIRE

    José Vicente Pachar Lucio

    2015-01-01

    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 literatur...

  3. Abordaje interdisciplinario de tres hermanas con Amelogénesis imperfecta: Reporte de Caso

    OpenAIRE

    Brenes A., Alejandra; Montero S., Olman

    2011-01-01

    Tres hermanas con edades de 7, 9 y 12 años fueron atendidas en la clínica del Posgrado de Odontopediatría de la Universidad de Costa Rica; ellas presentaban amelogénesis imperfecta tipo hipoplásico y mordida abierta anterior. La higiene bucodental en las tres, era muy deficiente, lo que obligó el abordaje con sesiones de fase higiénica que permitieran posteriormente, iniciar el tratamiento rehabilitador. Cada caso fue estudiado en forma independiente. Se hizo necesario proceder interdisciplin...

  4. FORWARD: A toolset for multiwavelength coronal magnetometry

    Directory of Open Access Journals (Sweden)

    Sarah eGibson

    2016-03-01

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

  5. FORWARD: A toolset for multiwavelength coronal magnetometry

    Science.gov (United States)

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

    2016-03-01

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

  6. Observational features of equatorial coronal hole jets

    Directory of Open Access Journals (Sweden)

    G. Zimbardo

    2010-03-01

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

  7. Space weather and coronal mass ejections

    CERN Document Server

    Howard, Tim

    2013-01-01

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

  8. Slipping magnetic reconnection in coronal loops.

    Science.gov (United States)

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

    2007-12-07

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

  9. Abordaje del binomio violencia-infancia: Reflexiones críticas Boarding of binomialviolence-childhood: Critical reflections

    Directory of Open Access Journals (Sweden)

    Matilde De la Iglesia

    2005-12-01

    Full Text Available El abordaje del binomio violencia-infancia implica una reflexión crítica acerca de la existencia de una disociación entre la ley y los imaginarios instituidos en lo referente al tema. Las circunstancias que introducen a niñas, niños y adolescentes en la institución judicial, conllevan diferentes niveles de violencia coexistentes. La familia, los sistemas político-institucionales y socio-culturales, entre otros, confluyen en sostener la eficacia de un orden de producción de subjetividades sustentado en una modalidad binaria de inclusión-exclusión, la cual se reproduce en acto al interior de las instituciones y del sistema de judicialización. Dichos imaginarios atraviesan las prácticas profesionales del psicólogo forense así como también, la práctica del investigador. Se requiere una mirada reflexiva al interior de esta última al contemplar que el propio investigador es simultáneamente actor social dentro del conjunto que se ha convertido en objeto de su investigación.The boarding of the binomial violence-childhood implies a critical reflection about the existence of a dissosciation between the law and the imaginary ones instituted in the referring thing to the subject.The circumstances that introduce girls, boys and adolescents in the judicial institution, entail different coexisting levels of violence. The family, the political-institutional and sociocultural systems, among others, comes together in maintaining the effectiveness of an order of production of subjectivities sustained in a binary modality of inclusion-exclusion, which reproduces in act to the interior of the institutions and the judicial system. Instituted imaginaries cross the professional practices of the forense psychologist as well as, the practice of the investigator. A reflective glance to the interior of this last one is required that the own investigator is simultaneously social actor within the set that has become object of its researcher.

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

    Science.gov (United States)

    Campero, Alvaro

    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 enfermos con cavernomas de la RTM fueron operados por el autor. De acuerdo a la ubicacion en la RTM, 4 cavernomas se ubicaron en el sector anterior, 2 cavernomas se localizaron en el sector medio y 1 cavernoma se ubico en el sector posterior. Para el sector anterior de la RTM se utilizo un abordaje transsilviano-transinsular; para el sector medio de la RTM se utilizo un abordaje transtemporal (lobectomia temporal anterior); y para el sector posterior de la RTM se utilizo un abordaje supracerebeloso-transtentorial. Conclusión: Dividir la RTM en 3 sectores nos permite adecuar el abordaje en función a la localización de la lesión. Así, el sector anterior es bien abordable a través de la fisura silviana; el sector medio a través de una vía transtemporal; y el sector posterior por un abordaje supracerebeloso. PMID:26600986

  11. Abordaje médico forense de los cuerpos mutilados criminalmente

    Directory of Open Access Journals (Sweden)

    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.

  12. Relating magnetic reconnection to coronal heating.

    Science.gov (United States)

    Longcope, D W; Tarr, L A

    2015-05-28

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

  13. Microwave Enhancement in Coronal Holes: Statistical Properties

    Indian Academy of Sciences (India)

    Ν. Gopalswamy; Κ. Shibasaki; Μ. Salem

    2000-09-01

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

  14. Observational Consequences of Coronal Heating Mechanisms

    Science.gov (United States)

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

    2014-01-01

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

  15. Multidimensional modeling of coronal rain dynamics

    CERN Document Server

    Fang, X; Keppens, R

    2013-01-01

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

  16. Coronal Magnetism and Forward Solarsoft Idl Package

    Science.gov (United States)

    Gibson, S. E.

    2014-12-01

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

  17. Descripción de variantes del acceso transeptoesfenoidal para el abordaje de la patología selar

    OpenAIRE

    Arias A,Roberto; Gómez G,Matías; Rojas O,Mónica

    2014-01-01

    El abordaje quirúrgico de la patología selar ha sufrido importantes cambios desde sus primeras descripciones. Inicialmente de manejo neuroquirúrgico, hoy en día el abordaje hipofisiario transeptoesfenoidal se ha transformado en una de las vías de acceso más utilizadas por el otorrinolaringólogo para lesiones a nivel de silla turca. Esta publicación describe un tipo de acceso transeptoesfenoidal utilizado por el otorrinolaringólogo en el Instituto de Neurocirugía Dr. Alfonso Asenjo (INCA) en e...

  18. Los abordajes terapéuticos propioceptivos efectivos en esguince del ligamento lateral externo de tobillo en deportistas.

    OpenAIRE

    Enachescu, Florentin Marius

    2014-01-01

    Pregunta de revisión: ¿Que abordajes terapéuticos propioceptivos son efectivos en la recuperación de un esguince de tobillo en deportistas? Objetivo: El objetivo principal de este trabajo es identificar los abordajes terapéuticos propioceptivos en un esguince del ligamento lateral externo de tobillo, aplicados en deportistas. Metodología: Consiste en una revisión bibliográfica de las principales fuentes y bases de datos biomédicas: Pubmed, Embase, PEDro, The Cochrane Library y Cinahl....

  19. Observational Properties of Coronal Mass Ejections

    Science.gov (United States)

    2006-01-01

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

  20. The relationship between the magnetic field and the coronal activities in the polar region

    Science.gov (United States)

    Shimojo, Masumi

    The image of the polar region of the sun is changing based on the observations taken by the three telescopes aboard the Hinode satellite. Based on the data of Solar Optical Telescope (SOT) aboard Hinode, Tsuneta et al. (2007) reported that there are many localized magnetic poles in the polar region, and the magnetic strength of the magnetic poles is over thousand Gauss. They called the strong magnetic pole in the polar region "kG-pathce". And, Cirtain, et al. (2007) and Savcheva, et al. (2007) presented that the occurrence rate of X-ray jets in the polar region is very high and 10 events/hour. Their result was obtained by the high resolution observations by X-ray Telescope (XRT) aboard Hinode. These results are very important for understanding the fast solar wind that blows from the polar region. On the other hand, in order to understand the activities in the polar region, it is very important to investigate the relationship between the magnetic environments and the coronal structures/activities. In the paper, for the purpose, we aligned the photospheric images (G-band, Stoke-IQUV of FeI), the chromospheric images (Ca II H line, Stokes-V of Na) and coronal images (X-ray) obtained by Hinode, and investigate the relationship. Basically, the co-alignment process was done based on the alignment information of the telescopes reported by Shimizu et al. (2007). And, we aligned the images using the curve of the solar limb, finally. As the result of the co-alignments, we found the following things. 1) On most kG-patches in the polar coronal hole, there is any coronal structure. 2) X-ray jets in the polar coronal hole are not always associated with the kG-patches. Some X-ray jets are associated with very weak magnetic field. And, the jets are strongly associated with the emerging/cancelling magnetic flux. The first one suggests that the coronal heating is not effective only in the magnetic field strong, such as the center of the sunspot. The second result indicates that the

  1. MULTIDIMENSIONAL MODELING OF CORONAL RAIN DYNAMICS

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-10

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

  2. Observational features of equatorial coronal hole jets

    CERN Document Server

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

    2010-01-01

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

  3. Coronal rain in magnetic bipolar weak fields

    Science.gov (United States)

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

    2017-07-01

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

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

    Science.gov (United States)

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

    1996-01-01

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

  5. Characteristics of Coronal Mass Ejections

    Science.gov (United States)

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

    2014-12-01

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

  6. Classification and Physical parameters EUV coronal jets with STEREO/SECCHI.

    Science.gov (United States)

    Nistico, Giuseppe; Bothmer, Volker; Patsourakos, Spiro; Zimbardo, Gaetano

    In this work we present observations of EUV coronal jets, detected with the SECCHI (Sun Earth Connection Coronal and Heliospheric Investigation) imaging suites of the two STEREO spacecraft. Starting from catalogues of polar and equatorial coronal hole jets (Nistico' et al., Solar Phys., 259, 87, 2009; Ann. Geophys. in press), identified from simultaneous EUV and white-light coronagraph observations, taken during the time period March 2007 to April 2008 when solar activity was at minimum, we perfom a detailed study of some events. A basic char-acterisation of the magnetic morphology and identification of the presence of helical structure were established with respect to recently proposed models for their origin and temporal evo-lution. A classification of the events with respect to previous jet studies shows that amongst the 79 events, identified into polar coronal holes, there were 37 Eiffel tower -type jet events commonly interpreted as a small-scale ( 35 arcsec) magnetic bipole reconnecting with the ambi-ent unipolar open coronal magnetic fields at its looptops, 12 lambda-type jet events commonly interpreted as reconnection with the ambient field happening at the bipoles footpoints. Five events were termed micro-CME type jet events because they resembled classical three-part structured coronal mass ejections (CMEs) but on much smaller scales. The remainig 25 cases could not be uniquely classified. Thirty-one of the total number of events exhibited a helical magnetic field structure, indicative for a torsional motion of the jet around its axis of propaga-tion. The jet events are found to be also present in equatorial coronal holes. We also present the 3-D reconstruction, temperature, velocity, and density measurements of a number of jets during their evolution.

  7. ON THE OBSERVATION AND SIMULATION OF SOLAR CORONAL TWIN JETS

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jiajia; Wang, Yuming; Zhang, Quanhao [CAS Key Laboratory of Geospace Environment, School of Earth and Space Sciences, University of Science and Technology of China, NO. 96, Jinzhai Road, Hefei, Anhui 230026 (China); Fang, Fang [Laboratory for Atmospheric and Space Physics, University of Colorado at Boulder, 1234 Innovation Drive, Boulder, CO 80303 (United States); McIntosh, Scott W.; Fan, Yuhong [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307 (United States)

    2016-02-01

    We present the first observation, analysis, and modeling of solar coronal twin jets, which occurred after a preceding jet. Detailed analysis on the kinetics of the preceding jet reveals its blowout-jet nature, which resembles the one studied in Liu et al. However, the erupting process and kinetics of the twin jets appear to be different from the preceding one. Lacking detailed information on the magnetic fields in the twin jet region, we instead use a numerical simulation using a three-dimensional (3D) MHD model as described in Fang et al., and find that in the simulation a pair of twin jets form due to reconnection between the ambient open fields and a highly twisted sigmoidal magnetic flux, which is the outcome of the further evolution of the magnetic fields following the preceding blowout jet. Based on the similarity between the synthesized and observed emission, we propose this mechanism as a possible explanation for the observed twin jets. Combining our observation and simulation, we suggest that with continuous energy transport from the subsurface convection zone into the corona, solar coronal twin jets could be generated in the same fashion addressed above.

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

    Directory of Open Access Journals (Sweden)

    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

  9. Braquioplastia: abordaje simple Braquioplastias: Uma abordagem simplificada Brachioplasty: a simple aproach

    Directory of Open Access Journals (Sweden)

    C. Roxo del Pino

    2009-09-01

    Full Text Available Los miembros superiores representan una unidad estético- funcional muy importante en la definición del contorno corporal. Con la popularización de las cirugía de remodelación del contorno corporal tras grandes pérdidas ponderales también se ha producido un incremento en la práctica de braquioplastias. El propósito de nuestra trabajo es el mostrar nuestra experiencia en braquioplastia enfocada hacia la simplificación del abordaje quirúrgico para lograr corregir la flacidez de la zona póstero-inferior de los brazos. Presentamos un estudio retrospectivo sobre 22 pacientes sometidas a braquioplastia mediante la técnica de abordaje quirúrgico propuesta, encaminada a reducir el excedente dermo-graso mediante maniobras bidigitales y colocando la cicatriz resultante en el surco braquial interno. El resultado obtenido fue satisfactorio y las complicaciones mínimas y locales, del tipo de dehiscencia, cicatriz hipertrófica, hematoma y linfocele. Ninguna complicación comprometió el resultado final. La simplicidad del procedimiento y los resultado satisfactorios, con baja morbilidad y buena posición de las cicatrices, hacen que el abordaje que practicamos sea una buena opción quirúrgica para el tratamiento de las deformidades de los miembros superiores.The uppers limbs represent a very important aestheticfunctionary unit in the body contouring definition. Because of the popularization of the body contour surgery after massive weight loss, there has been noted a raise in the number of brachioplasties in the last years. Our proposal is to show the author experience in brachioplasty, focusing a new approach for correction of flaccidity associated or not to lipodystrophy of the arms. This article represents a retrospective study of 22 patients submitted to brachioplasty with the approach proposed by the authors. It consists in the resection of the excess of fat and skin in the arms using bidigital maneuver aiming to leave the final scar in

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

    Science.gov (United States)

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

    2007-05-01

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

  11. Reparación de la insuficiencia mitral funcional mediante abordaje del aparato subvalvular. Resultados a medio plazo

    Directory of Open Access Journals (Sweden)

    Álvaro Pedraz-Prieto

    2017-07-01

    Conclusiones: El abordaje del aparato subvalvular en la reparación de la insuficiencia mitral funcional se presenta como una alternativa válida en el tratamiento de este tipo de insuficiencia, ofreciendo buenos resultados en lo que a evolución postoperatoria y tasa de recidiva a medio plazo se refiere.

  12. 31. Abordaje transaórtico de la tetralogía de fallot en el adulto

    Directory of Open Access Journals (Sweden)

    M.T. González López

    2012-04-01

    Conclusiones: El cierre de la CIV en la tetralogía de Fallot del adulto mediante abordaje transaórtico resulta sencillo, por las dimensiones de la raíz y el acabalgamiento sobre la misma. En casos de situs inversus, esta técnica facilita sobremanera la corrección final.

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

    Directory of Open Access Journals (Sweden)

    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.

  14. Las neurociencias para el abordaje de la didáctica de las finanzas

    OpenAIRE

    Florentino Rico Calvano; Pedro Puentes Rozo

    2016-01-01

    El presente artículo de revisión se centra en determinar cuál es el discurso de las neurociencias para el abordaje de la didáctica de las finanzas, y cuáles son las estrategias y didácticas aplicadas a la enseñabilidad de las finanzas y su correspondencia con la práctica y los modelos pedagógicos. Se identificaron teorías didácticas que fundamentarán las prácticas educativas de los docentes en la enseñabilidad, evaluando, articulando y confrontando los fundamentos pedagógicos que poseen los d...

  15. Las neurociencias para el abordaje de la didáctica de las finanzas

    OpenAIRE

    Florentino Rico Calvano; Pedro Puentes Rozo

    2016-01-01

    El presente artículo de revisión se centra en determinar cuál es el discurso de las neurociencias para el abordaje de la didáctica de las finanzas, y cuáles son las estrategias y didácticas aplicadas a la enseñabilidad de las finanzas y su correspondencia con la práctica y los modelos pedagógicos. Se identificaron teorías didácticas que fundamentarán las prácticas educativas de los docentes en la enseñabilidad, evaluando, articulando y confrontando los fundamentos pedagógicos que poseen los d...

  16. DIVERSIDAD JUVENIL EN EL CONTEXTO EDUCATIVO: REFLEXIONES PARA UN ABORDAJE INTERCULTURAL

    Directory of Open Access Journals (Sweden)

    Carol Graciela Morales-Trejos

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  18. Entre la gestión del riesgo y el abordaje psicosocial

    Directory of Open Access Journals (Sweden)

    Matamoros Calvo, María Cristina

    2013-06-01

    Full Text Available El trabajo en la gestión para la reducción del riesgo por desastres, contempla diferentes elementos dentro de su estrategia, muchos de ellos de contenido técnico y otros de índole social; y para su ejecución y cumplimiento de los objetivos se requiere de esfuerzos interdisciplinarios, para poder hacer abordajes integrales. Por tanto, en este escrito se pretende hacer una reflexión en torno a la relación entre la gestión del riesgo y el aporte de la psicología como ciencia social, llamando desde ahí la atención sobre la importancia de considerar el factor psicosocial en las estrategias de reducción del riesgo. Para lo cual se hace un recorrido desde la concepción de la psicología, de la gestión del riesgo, para finalmente arribar a una mirada integradora como propuesta en el abordaje del riesgo, de las emergencias y los desastres The work in management to reduce the risk by disasters, includes different elements within the strategy, most of them of technical content and others of social nature. For the execution and compliance of the objectives, it is necessary to have interdisciplinary efforts to apply integral focus. In this context, this work tries to reflect around the relation between risks management and the contribution of psychology as a social science, emphasizing the importance of considering the psychosocial factor in the risk reduction strategies. For this, there is a walk from the conception of psychology to the risk management, to finally arrive at an integral gaze as a proposal to the risk approach for emergencies and disasters

  19. Ectopic folliculosebaceous units at the coronal sulcus.

    Science.gov (United States)

    Fernandez-Flores, Angel

    2014-12-01

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

  20. Coronal Jet Plasma Properties and Acceleration Mechanisms

    Science.gov (United States)

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

    2017-08-01

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

  1. Orbitotomía lateral mediante abordaje temporal Lateral orbitotomy using a temporal approach

    Directory of Open Access Journals (Sweden)

    H. Herencia Nieto

    2005-12-01

    Full Text Available La orbitotomía lateral sigue siendo en el momento actual la técnica quirúrgica de elección para la biopsia o extirpación de lesiones intraorbitarias laterales al nervio óptico, la biopsia del propio nervio óptico y la extirpación de la glándula lacrimal. Se han descrito múltiples incisiones cutáneas para llevar a cabo esta intervención; la más frecuentemente empleada por el momento es la incisión palpebral, que discurre a nivel de alguna arruga del párpado superior. Aunque los resultados obtenidos con esta incisión suelen ser aceptables, no está exenta de complicaciones, ni estéticas ni funcionales. Por esto, en los últimos años han ido apareciendo nuevas incisiones que intentan evitar estas complicaciones. Entre estas nuevas vías de abordaje a la pared lateral de la órbita se encuentra la incisión temporal. En los últimos 3 años, se ha intervenido en nuestro servicio a cuatro pacientes para llevar a cabo biopsia o extirpación de masas intraorbitarias mediante orbitotomía lateral, siempre a través de una incisión temporal. En todos los casos esta incisión permitió una amplia exposición del campo quirúrgico y la cómoda realización de la intervención, obteniéndose resultados estéticos y funcionales excelentes, y sin ninguna secuela ni complicación permanente. La complicación específica más frecuente de esta incisión es la paresia de la rama frontal del nervio facial. Una técnica de disección cuidadosa suele ser suficiente para evitarla. Todo esto hace que esta incisión, tal y como la describimos aquí, sea de elección para llevar a cabo la orbitotomía lateral, constituyendo en nuestro criterio una alternativa perfectamente válida y a tener en cuenta frente a las incisiones «clásicas», a las que llega a superar en muchos aspectos.The lateral orbitotomy it still the surgical technique of choice for biopsies or the removal of intraorbital lesions that are lateral to the optic nerve, for biopsies of

  2. Coronal heating in multiple magnetic threads

    CERN Document Server

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

    2015-01-01

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

  3. The Fundamental Structure of Coronal Loops

    Science.gov (United States)

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

    2012-01-01

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

  4. A unified theory of coronal heating

    Science.gov (United States)

    Ionson, J. A.

    1985-01-01

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

  5. A Contemporary View of Coronal Heating

    CERN Document Server

    Parnell, Clare E; 10.1098/rsta.2012.0113

    2012-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-03-10

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

  7. Magnetohydrodynamic Modeling of Coronal Evolution and Disruption

    Science.gov (United States)

    Linker, Jon

    2002-01-01

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

  8. Full Halo Coronal Mass Ejections: Arrival at the Earth

    CERN Document Server

    Shen, Chenglong; Pan, Zonghao; Miao, Bin; Ye, Pinzhong; Wang, S

    2014-01-01

    A geomagnetic storm is mainly caused by a front-side coronal mass ejection (CME) hitting the Earth and then interacting with the magnetosphere. However, not all front-side CMEs can hit the Earth. Thus, which CMEs hit the Earth and when they do so are important issues in the study and forecasting of space weather. In our previous work (Shen et al., 2013), the de-projected parameters of the full-halo coronal mass ejections (FHCMEs) that occurred from 2007 March 1 to 2012 May 31 were estimated, and there are 39 front-side events could be fitted by the GCS model. In this work, we continue to study whether and when these front-side FHCMEs (FFHCMEs) hit the Earth. It is found that 59\\% of these FFHCMEs hit the Earth, and for central events, whose deviation angles $\\epsilon$, which are the angles between the propagation direction and the Sun-Earth line, are smaller than 45 degrees, the fraction increases to 75\\%. After checking the deprojected angular widths of the CMEs, we found that all of the Earth-encountered CM...

  9. Transformaciones en el abordaje de la diabetes: análisis de las evidencias científicas publicadas por dos sociedades científicas (1980-2010

    Directory of Open Access Journals (Sweden)

    Mónica Serena Perner

    2013-01-01

    Full Text Available El objetivo de este trabajo es describir y analizar los cambios en la definición de la diabetes como enfermedad y la relación con las transformaciones en su abordaje terapéutico. Se realizó un análisis de contenido sobre los artículos, guías y consensos publicados por la Sociedad Argentina de Diabetes (SAD y la Asociación Latinoamericana de Diabetes (ALAD entre los años 1980 y 2010. Se desagregaron las diferentes clasificaciones, los valores considerados normales para definir a una persona como diabética y el tratamiento, analizando críticamente los cambios y modificaciones encontrados con el auxilio de categorías como medicalización, riesgo y estilos de vida. Como resultado del análisis hemos podido observar cómo el creciente proceso de medicalización, la dependencia con respecto al conocimiento científico de países centrales, los intereses de la industria farmacéutica y el lugar central del tratamiento farmacológico se inscriben en el abordaje de la diabetes y se hacen visibles a través de los cambios sucedidos en los últimos 30 años.

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

    CERN Document Server

    Pierrard, V; Lemaire, J F

    2012-01-01

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

  11. Large-scale Globally Propagating Coronal Waves

    Directory of Open Access Journals (Sweden)

    Alexander Warmuth

    2015-09-01

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

  12. Coronal bright points associated with minifilament eruptions

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-12-01

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

  13. Observing coronal nanoflares in active region moss

    CERN Document Server

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

    2013-01-01

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

  14. OBSERVING CORONAL NANOFLARES IN ACTIVE REGION MOSS

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-06-10

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

  15. Role of Magnetic Carpet in Coronal Heating

    Indian Academy of Sciences (India)

    S. R. Verma; Diksha Chaudhary

    2008-03-01

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

  16. Magnetic Topology of Coronal Hole Linkages

    Science.gov (United States)

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

    2010-01-01

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

  17. Adulto mayor: propuesta de abordaje de la neumonía adquirida en la comunidad

    Directory of Open Access Journals (Sweden)

    Miguel Ángel Serra Valdés

    2016-04-01

    Full Text Available Fundamento: la neumonía adquirida en la comunidad constituye la causa principal de hospitalización entre los ancianos. Su letalidad es elevada. En la actualidad existen diversos scores de riesgo y pronóstico, así como diferentes Guías Prácticas Clínicas.Objetivo: elaborar una propuesta para el abordaje de la neumonía adquirida en la comunidad en el anciano, aplicable tanto en la Atención Primaria de Salud, como en la hospitalización.Métodos: se realizó la búsqueda de información mediante términos de indexación sobre neumonía adquirida en la comunidad, en especial en el adulto mayor o anciano, así como guías existentes nacionales y de diferentes países, sociedades y consensos regionales a través de Clinical Evidence, The Cochrane Library, PUBMED, Google Académico, MEDLINE, LIS, Scielo, Medscape, LILACS, Latindex, HINARI, MEDIGRAPHIC-NEWS y otros. Se asumieron aquellas publicaciones que reunían las evidencias de mayor calidad de acuerdo con los criterios de Grading of Recommendations of Assessment Development and Evaluations. Resultados: se elaboró una propuesta de abordaje práctico en cualquier nivel de atención de nuestro sistema de salud y teniendo en cuenta el cuadro básico de medicamentos actual. Se consideró la epidemiología, factores de riesgo, estratificación del riesgo, tratamiento y letalidad. Conclusiones: la neumonía adquirida en la comunidad constituye un problema actual y un reto futuro. Esta propuesta puede ser utilizada por los profesionales que participan en la asistencia de esta afección en cualquier nivel de atención. Su aplicación pudiera mejorar la atención médica, disminuir la letalidad, los costos y mejorar la calidad de vida.

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

    CERN Document Server

    Chen, Feng

    2015-01-01

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

  19. Predicting Coronal Mass Ejections Using Machine Learning Methods

    CERN Document Server

    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...

  20. Nonlinear Force-free Coronal Magnetic Stereoscopy

    Science.gov (United States)

    Chifu, Iulia; Wiegelmann, Thomas; Inhester, Bernd

    2017-03-01

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

  1. Standing sausage modes in curved coronal slabs

    Science.gov (United States)

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

    2016-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Balmaceda, María Isabel

    2015-12-01

    Full Text Available 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 carreras universitarias proyectuales. Se plantean las consecuencias de estos enfoques en la formación de los futuros profesionales y se fundamenta por qué se deberían generalizar modalidades que se sustenten en un enfoque crítico frente a la tecnología.

  3. Onset of the Magnetic Explosion in Solar Polar Coronal X-Ray Jets

    Science.gov (United States)

    Moore, Ronald L.; Sterling, Alphonse C.; Panesar, Navdeep

    2017-08-01

    We examine the onset of the driving magnetic explosion in 15 random polar coronal X-ray jets. Each eruption is observed in a coronal X-ray movie from Hinode and in a coronal EUV movie from Solar Dynamics Observatory. Contrary to the Sterling et al (2015, Nature, 523, 437) scenario for minifilament eruptions that drive polar coronal jets, these observations indicate: (1) in most polar coronal jets (a) the runaway internal tether-cutting reconnection under the erupting minifilament flux rope starts after the spire-producing breakout reconnection starts, not before it, and (b) aleady at eruption onset, there is a current sheet between the explosive closed magnetic field and ambient open field; and (2) the minifilament-eruption magnetic explosion often starts with the breakout reconnection of the outside of the magnetic arcade that carries the minifilament in its core. On the other hand, the diversity of the observed sequences of occurrence of events in the jet eruptions gives further credence to the Sterlling et al (2015, Nature, 523, 437) idea that the magnetic explosions that make a polar X-ray jet work the same way as the much larger magnetic explosions that make and flare and CME. We point out that this idea, and recent observations indicating that magnetic flux cancelation is the fundamental process that builds the field in and around pre-jet minifilaments and triggers the jet-driving magnetic explosion, together imply that usually flux cancelation inside the arcade that explodes in a flare/CME eruption is the fundamental process that builds the explosive field and triggers the explosion.This work was funded by the Heliophysics Division of NASA's Science Mission Directorate through its Living With a Star Targeted Research and Technology Program, its Heliophsyics Guest Investigators Program, and the Hinode Project.

  4. La religión como objeto de análisis: sobre el concepto y tres vías de abordaje histórico

    Directory of Open Access Journals (Sweden)

    Patricia Alejandra Fogelman

    2015-01-01

    Full Text Available En este trabajo propongo pensar la “religión” y señalarla como área de estudios definiendo, en primera instancia, ese concepto en relación con otros como “religiosidad” y “religiosidad popular” usados frecuentemente en la historiografía. En segundo lugar, propongo formular tres vías –entre muchas otras vigentes- de abordaje sobre la religiosidad a modo de caminos programáticos posibles en el campo historiográfico (refiriéndome especialmente al caso argentino actual, pero no de manera excluyente. En ese sentido, los tres grandes ejes de esta propuesta a la que me refiero son el recurso de las imágenes, la creación y puesta en circulación de discursos religiosos, así como la consolidación de redes de relaciones sociales más o menos institucionalizadas en la órbita de la Iglesia constituyen, respectivamente, tres grandes vías de análisis centrales que merecen ser recorridas en la consolidación de un área de estudios históricos sobre la religiosidad. El ejercicio propuesto tiende a tratar de reconocer su matriz historiográfica en una mixtura entre la renovada historia social y la historia cultural.

  5. FASES PRIMERA Y SEGUNDA DEL MÉTODO DE ABORDAJES LINGÜÍSTICOS CONVERGENTES: UN APORTE PARA EL ESTUDIO DE PROBLEMÁTICAS SOCIALES DESDE EL ACD

    Directory of Open Access Journals (Sweden)

    Mariana C. Marchese

    2016-01-01

    Full Text Available Desde el paradigma interpretativista, mediante una metodología cualitativa e inductiva y en el marco del acd, se presenta el Método de Abordajes Lingüísticos Convergentes y se explica sus fases primera y segunda. Este método, orientado a estudiar problemáticas sociales a partir del discurso, profundiza el análisis de los textos (escritos y orales, y producidos en el marco de diferentes géneros como unidades sociodiscursivas. Primero, se ejemplifica cómo se obtienen categorías discursivas relevantes para el estudio de problemáticas sociales. Particularmente, se trabaja sobre la problemática habitacional de la ciudad de Buenos Aires. Luego, se expone cómo se incorpora la Teoría de Focalización de la Información, específicamente, el estudio de las categorías focales. Finalmente, se resalta que el método, al permitir examinar los sistemas de creencias de los sujetos sociales, posibilita el pasaje a la reflexión social.

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

    Directory of Open Access Journals (Sweden)

    Carolina Remorini

    2010-01-01

    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 ecoculturales e históricos.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Abordaje del esguince de tobillo para el médico general

    Directory of Open Access Journals (Sweden)

    Diego Fernando Rincón Cardozo

    2015-04-01

    Full Text Available El esguince de tobillo es una de las patologías musculo esqueléticas más frecuentes tanto para el deportista como para la población en general, presentándose en el 30 % de las lesiones deportivas causando pérdida considerable de tiempo por discapacidad, y un costo elevado en la atención médica. La lesión más frecuente se presenta en el ligamento lateral en el 85% de los casos, 10% comprometen la sindesmosis y 5% el ligamento deltoideo. El esguince de tobillo se clasifica en 3 grados dependiendo de las características clínicas y de los hallazgos del examen físico, con lo cual se puede definir el tipo de manejo y el pronóstico. Dado que es una patología frecuente que acarrea morbilidad y discapacidad en los casos donde no se identifica precozmente, es importante conocer el abordaje diagnóstico y de clasificación para mejorar las tasas de recuperación y los buenos resultados.

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

    Indian Academy of Sciences (India)

    Milan Minarovjech; Milan Rybansky; Vojtech Rusin

    2000-09-01

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

  10. The Coronal Global Evolutionary Model (CGEM)

    Science.gov (United States)

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

    2013-07-01

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

  11. Reconnection and Spire Drift in Coronal Jets

    Science.gov (United States)

    Moore, Ronald; Sterling, Alphonse; Falconer, David

    2015-04-01

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

  12. Magnetic Topology of Coronal Hole Linkages

    CERN Document Server

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

    2010-01-01

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

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

    CERN Document Server

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

    2016-01-01

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

  14. Solar coronal observations at high frequencies

    CERN Document Server

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

    2001-01-01

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

  15. Chemical Fractionation and Abundances in Coronal Plasma

    CERN Document Server

    Drake, J J

    2003-01-01

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

  16. Microflares as Possible Sources for Coronal Heating

    Indian Academy of Sciences (India)

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

    2008-03-01

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

  17. Damped transverse oscillations of interacting coronal loops

    CERN Document Server

    Soler, Roberto

    2015-01-01

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

  18. Selamento coronário em Endodontia

    OpenAIRE

    Oliveira, Rui Pedro Barra de Sá

    2016-01-01

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

  19. Coronal Mass Ejections of Solar Cycle 23

    Indian Academy of Sciences (India)

    Nat Gopalswamy

    2006-06-01

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

  20. Interchange Reconnection and Coronal Hole Dynamics

    Science.gov (United States)

    2010-05-01

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

  1. Coronal Plumes in the Fast Solar Wind

    Science.gov (United States)

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

    2011-01-01

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

  2. Topics on shock waves and coronal seismology

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-07-15

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

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

    Science.gov (United States)

    Nitta, Nariaki V.; Mulligan, Tamitha

    2017-09-01

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

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

    Science.gov (United States)

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

    2017-01-01

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

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

    CERN Document Server

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

    2016-01-01

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

  6. The Lower Chromosphere in a Coronal Hole

    Science.gov (United States)

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

    2007-07-01

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

  7. Coronal Heating Observed with Hi-C

    Science.gov (United States)

    Winebarger, Amy R.

    2013-01-01

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

  8. Characteristics of polar coronal hole jets

    CERN Document Server

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

    2013-01-01

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

  9. Dynamics of Coronal-Hole Boundaries

    CERN Document Server

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

    2016-01-01

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

  10. A Mechanism for Coronal Hole Jets

    CERN Document Server

    Mueller, D A N

    2008-01-01

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

  11. Coronal Structure of Low-Mass Stars

    CERN Document Server

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

    2012-01-01

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

  12. The formation of an equatorial coronal hole

    Science.gov (United States)

    Yang, Liheng; Jiang, Yunchun; Zhang, Jun

    2010-02-01

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

  13. Propagating magnetohydrodynamics waves in coronal loops.

    Science.gov (United States)

    De Moortel, I

    2006-02-15

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

  14. Microflaring in Low-Lying Core Fields and Extended Coronal Heating in the Quiet Sun

    Science.gov (United States)

    Porter, Jason G.; Falconer, D. A.; Moore, Ronald L.

    1999-01-01

    We have previously reported analyses of Yohkoh SXT data examining the relationship between the heating of extended coronal loops (both within and stemming from active regions) and microflaring in core fields lying along neutral lines near their footpoints (J. G. Porter, D. A. Falconer, and R. L. Moore 1998, in Solar Jets and Coronal Plumes, ed. T. Guyenne, ESA SP-421, and references therein). We found a surprisingly poor correlation of intensity variations in the extended loops with individual microflares in the compact heated areas at their feet, despite considerable circumstancial evidence linking the heating processes in these regions. Now, a study of Fe XII image sequences from SOHO EIT show that similar associations of core field structures with the footpoints of very extended coronal features can be found in the quiet Sun. The morphology is consistent with the finding of Wang et al. (1997, ApJ 484, L75) that polar plumes are rooted at sites of mixed polarity in the magnetic network. We find that the upstairs/downstairs intensity variations often follow the trend, identified in the active region observations, of a weak correspondence. Apparently much of the coronal heating in the extended loops is driven by a type of core field magnetic activity that is "cooler" than the events having the coronal signature of microflares, i.e., activity that results in little heating within the core fields themselves. This work was funded by the Solar Physics Branch of NASA's Office of Space Science through the SR&T Program and the SEC Guest Investigator Program.

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

    CERN Document Server

    Wang, Tongjiang

    2010-01-01

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

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

    Science.gov (United States)

    Ionson, J. A.

    1984-01-01

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

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

    Science.gov (United States)

    Kong, Xiangliang; Chen, Yao; Guo, Fan

    2016-03-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

  19. Magnetic reconnection in the interior of interplanetary coronal mass ejections.

    Science.gov (United States)

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

    2014-07-18

    Recent in situ observations of interplanetary coronal mass ejections (ICMEs) found signatures of reconnection exhausts in their interior or trailing edge. Whereas reconnection on the leading edge of an ICME would indicate an interaction with the coronal or interplanetary environment, this result suggests that the internal magnetic field reconnects with itself. In light of this data, we consider the stability properties of flux ropes first developed in the context of astrophysics, then further elaborated upon in the context of reversed field pinches (RFPs). It was shown that the lowest energy state of a flux rope corresponds to ∇ × B = λB with λ a constant, the so-called Taylor state. Variations from this state will result in the magnetic field trying to reorient itself into the Taylor state solution, subject to the constraints that the toroidal flux and magnetic helicity are invariant. In reversed field pinches, this relaxation is mediated by the reconnection of the magnetic field, resulting in a sawtooth crash. If we likewise treat the ICME as a flux rope, any deviation from the Taylor state will result in reconnection within the interior of the flux tube, in agreement with the observations by Gosling et al. Such a departure from the Taylor state takes place as the flux tube cross section expands in the latitudinal direction, as seen in magnetohydrodynamic (MHD) simulations of flux tubes propagating through the interplanetary medium. We show analytically that this elongation results in a state which is no longer in the minimum energy Taylor state. We then present magnetohydrodynamic simulations of an elongated flux tube which has evolved away from the Taylor state and show that reconnection at many surfaces produces a complex stochastic magnetic field as the system evolves back to a minimum energy state configuration.

  20. Segmentation of Coronal Holes Using Active Contours Without Edges

    CERN Document Server

    Boucheron, L E; McAteer, R T J

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-20

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

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

    CERN Document Server

    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...

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

    OpenAIRE

    Teresa Rodríguez Rodríguez

    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...

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

    OpenAIRE

    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...

  5. CRUCE DE PARADIGMAS Y COMPLEJIZACIÓN DE ABORDAJES EN PROCESOS DE INVESTIGACIÓN-ACCIÓN SOCIAL

    OpenAIRE

    Ortecho, Mariana

    2012-01-01

    El presente artículo reúne una serie de reflexiones sobre algunas posibilidades de conciliación paradigmática de nivel epistemológico entre los enfoques cuantitativo y cualitativo de indagación científica, aplicada a experiencias de investigación-acción comunitaria. Desde estas primeras consideraciones, se propone complejizar los abordajes en torno a las problemáticas sociales que suelen ser leídas en claves disciplinares desde perspectivas excluyentes, que pierden la posibilidad de aprehende...

  6. Abordaje farmacoterapéutico del paciente hospitalizado con desórdenes hiperglucémicos

    OpenAIRE

    Chaverri Fernández, José Miguel; Cordero García, Eugenia; Fallas Retana, Fallom; Montoya Calderón, Vivian; Zavaleta Monestel, Esteban

    2014-01-01

    Justificación y Objetivo: Los desórdenes glucémicos están asociados a una mayor morbimortalidad en el ámbito hospitalario. El conocer la realidad actual y describir los modelos de abordaje farmacoterapéutico de los desórdenes glucémicos facilita la implementación de guías clínicas que promuevan el correcto uso de medicamentos. Material y métodos: Se propuso con este fin realizar un estudio observacional retrospectivo, que incluyera a los pacientes hospitalizados en el Hospital Clínica Bíblica...

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

    OpenAIRE

    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...

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

    CERN Document Server

    Zheng, Ruisheng; Du, Guohui; Li, Chuanyang

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-03-10

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

  10. Observing coronal nanoflares in active region moss

    OpenAIRE

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

    2013-01-01

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

  11. Solar coronal observations at high frequencies

    OpenAIRE

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

    2001-01-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

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

    2016-10-01

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

  14. Comments on "The Coronal Heating Paradox" by M.J. Aschwanden, A. Winebarger, D. Tsiklauri and H. Peter [2007, Astrophys J., 659, 1673

    CERN Document Server

    Mahajan, Swadesh M

    2007-01-01

    We point out the priority of our paper (Mahajan et al. 2001, Phys. Plasmas, 8, 1340) over (Aschwanden et al. 2007, Astrophys J., 659, 1673) in introducing the term "Formation and primary heating of the solar corona" working out explicit models (theory as well as simulation) for coronal structure formation and heating. On analyzing the Aschwanden et al. (2007) scenario of coronal heating process (shifted to the chromospheric heating) we stress, that for efficient loop formation, the primary upflows of plasma in chromosphere/transition region should be relatively cold and fast (as opposed to hot). It is during trapping and accumulation in closed field structures, that the flows thermalize (due to the dissipation of the short scale flow energy) leading to a bright and hot coronal structure. The formation and primary heating of a closed coronal structure (loop at the end) are simultaneous and a process like the "filling of the empty coronal loop by hot upflows" is purely speculative and totally unlikely.

  15. Modified Homogeneous Data Set of Coronal Intensities

    Science.gov (United States)

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

    2014-07-01

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

  16. Energetics of Solar Coronal Mass Ejections

    CERN Document Server

    Subramanian, P; Subramanian, Prasad; Vourlidas, Angelos

    2007-01-01

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

  17. SAUSAGE OSCILLATIONS OF CORONAL PLASMA STRUCTURES

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-12-20

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

  18. Analytical investigations on the Coronation Gospels manuscript

    Science.gov (United States)

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

    2017-01-01

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

  19. A Moreton Wave and its Coronal Counterparts

    Science.gov (United States)

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

    2016-07-01

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

  20. Association of solar coronal loops to photospheric magnetic field

    Science.gov (United States)

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

    2017-08-01

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

  1. Segmentation of Coronal Holes Using Active Contours Without Edges

    Science.gov (United States)

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

    2016-10-01

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

  2. Segmentation of Coronal Holes Using Active Contours Without Edges

    Science.gov (United States)

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

    2016-09-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    Mohsen Karami

    2016-10-01

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

  5. Stellar Coronal Response to Differential Rotation and Flux Emergence

    CERN Document Server

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

    2016-01-01

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

  6. Observing Episodic Coronal Heating Events Rooted in Chromospheric Activity

    CERN Document Server

    McIntosh, Scott W

    2009-01-01

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

  7. Solar Wind Associated with Near Equatorial Coronal Hole

    Indian Academy of Sciences (India)

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

    2015-09-01

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

  8. Long Term Spectral Evolution of Tidal Disruption Candidates Selected by Strong Coronal Lines

    CERN Document Server

    Yang, Chenwei; Ferland, Gary; Yuan, Weimin; Zhou, Hongyan; Jiang, Peng

    2013-01-01

    We present results of follow-up optical spectroscopic observations of seven rare, extreme coronal line emitting galaxies reported by Wang et al. (2012) with Multi-Mirror Telescope (MMT). Large variations in coronal lines are found in four objects, making them strong candidates of tidal disruption events (TDE). For the four TDE candidates, all the coronal lines with ionization status higher than [Fe VII] disappear within 5-9 years. The [Fe VII] faded by a factor of about five in one object (J0952+2143) within 4 years, whereas emerged in other two without them previously. A strong increment in the [O III] flux is observed, shifting the line ratios towards the loci of active galactic nucleus on the BPT diagrams. Surprisingly, we detect a non-canonical [O III]5007/[O III]4959 2 in two objects, indicating a large column density of O$^{2+}$ and thus probably optical thick gas. This also requires a very large ionization parameter and relatively soft ionizing spectral energy distribution (e.g. blackbody with $T < ...

  9. Statistical Evidence for the Existence of Alfv\\'enic Turbulence in Solar Coronal Loops

    CERN Document Server

    Liu, Jiajia; De Moortel, Ineke; Threlfall, James; Bethge, Christian

    2014-01-01

    Recent observations have demonstrated that waves which are capable of carrying large amounts of energy are ubiquitous throughout the solar corona. However, the question of how this wave energy is dissipated (on which time and length scales) and released into the plasma remains largely unanswered. Both analytic and numerical models have previously shown that Alfv\\'enic turbulence may play a key role not only in the generation of the fast solar wind, but in the heating of coronal loops. In an effort to bridge the gap between theory and observations, we expand on a recent study [De Moortel et al., ApJL, 782:L34, 2014] by analyzing thirty-seven clearly isolated coronal loops using data from the Coronal Multi-channel Polarimeter (CoMP) instrument. We observe Alfv\\'enic perturbations with phase speeds which range from 250-750 km/s and periods from 140-270 s for the chosen loops. While excesses of high frequency wave-power are observed near the apex of some loops (tentatively supporting the onset of Alfv\\'enic turbu...

  10. Constraining Large-Scale Solar Magnetic Field Models with Optical Coronal Observations

    Science.gov (United States)

    Uritsky, V. M.; Davila, J. M.; Jones, S. I.

    2015-12-01

    Scientific success of the Solar Probe Plus (SPP) and Solar Orbiter (SO) missions will depend to a large extent on the accuracy of the available coronal magnetic field models describing the connectivity of plasma disturbances in the inner heliosphere with their source regions. We argue that ground based and satellite coronagraph images can provide robust geometric constraints for the next generation of improved coronal magnetic field extrapolation models. In contrast to the previously proposed loop segmentation codes designed for detecting compact closed-field structures above solar active regions, we focus on the large-scale geometry of the open-field coronal regions located at significant radial distances from the solar surface. Details on the new feature detection algorithms will be presented. By applying the developed image processing methodology to high-resolution Mauna Loa Solar Observatory images, we perform an optimized 3D B-line tracing for a full Carrington rotation using the magnetic field extrapolation code presented in a companion talk by S.Jones at al. Tracing results are shown to be in a good qualitative agreement with the large-scalie configuration of the optical corona. Subsequent phases of the project and the related data products for SSP and SO missions as wwll as the supporting global heliospheric simulations will be discussed.

  11. Las neurociencias para el abordaje de la didáctica de las finanzas

    Directory of Open Access Journals (Sweden)

    Florentino Rico Calvano

    2016-01-01

    Full Text Available El presente artículo de revisión se centra en determinar cuál es el discurso de las neurociencias para el abordaje de la didáctica de las finanzas, y cuáles son las estrategias y didácticas aplicadas a la enseñabilidad de las finanzas y su correspondencia con la práctica y los modelos pedagógicos. Se identificaron teorías didácticas que fundamentarán las prácticas educativas de los docentes en la enseñabilidad, evaluando, articulando y confrontando los fundamentos pedagógicos que poseen los docentes para el desarrollo humano teniendo en cuenta el contexto. Se resalta la importancia que tiene la incorporación de los conocimientos científicos y tecnológicos en la transformación de las futuras pedagogías y didácticas. Se destaca el aporte de las neurociencias para alcanzar la excelencia en la educación con el trabajo interdisciplinar que haga compatible la educación con el funcionamiento del cerebro, y la investigación en el aula como práctica normal de la actividad docente. Se incorporan nuevas y novedosas estrategias de aprendizaje considerando las orientaciones dadas por la teoría de Ned Herrmann. Se evalúan, ejecutan y planifican propuestas didácticas acordes a los tipos de inteligencia y a los resultados de la investigación en neurociencia que permitieron saber que el cerebro conjuga el pensar, el sentir y el actuar. Se tiene claro que los contextos implican ciertas estrategias didácticas que es necesario contextualizar con el conocimiento, enfatizando sobre la realidad con utilidad social y la contextualización de los saberes. Se aprecia cómo el aprendizaje cambia la estructura física del sistema, organiza y reorganiza el cerebro, dentro de la orientación ética de emancipación humana. Abstract This essay focuses on determine what is the discourse of neuroscience to approach the teaching of finance, teaching strategies and teachability applied to finance and correspondence with the practice and teaching

  12. The Breakout Model for Coronal Jets with Filaments

    Science.gov (United States)

    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.).

  13. Implications of Coronal Line Emission in NGC 4696

    CERN Document Server

    Chatzikos, M; Ferland, G J; Canning, R E A; Fabian, A C; Sanders, J S; van Hoof, P A M; Johnstone, R M; Lykins, M; Porter, R L

    2014-01-01

    We announce a new facility in the spectral code CLOUDY that enables tracking the evolution of a cooling parcel of gas with time. For gas cooling from temperatures relevant to galaxy clusters, earlier calculations estimated the [Fe XIV] {\\lambda}5303 / [Fe X] {\\lambda}6375 luminosity ratio, a critical diagnostic of a cooling plasma, to slightly less than unity. By contrast, our calculations predict a ratio ~3. We revisit recent optical coronal line observations along the X-ray cool arc around NGC 4696 by Canning et al. (2011), which detected [Fe X] {\\lambda}6375, but not [Fe XIV] {\\lambda}5303. We show that these observations are not consistent with predictions of cooling flow models. Differential extinction could in principle account for the observations, but it requires extinction levels (A_V > 3.625) incompatible with previous observations. The non-detection of [Fe XIV] implies a temperature ceiling of 2.1 million K. Assuming cylindrical geometry and transonic turbulent pressure support, we estimate the gas...

  14. A Data-driven Analytic Model for Proton Acceleration by Large-scale Solar Coronal Shocks

    Science.gov (United States)

    Kozarev, Kamen A.; Schwadron, Nathan A.

    2016-11-01

    We have recently studied the development of an eruptive filament-driven, large-scale off-limb coronal bright front (OCBF) in the low solar corona, using remote observations from the 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 that the results approach the expected DSA steady-state behavior. We then apply the model to the event of 2011 May 11 using the OCBF time-dependent parameters derived by Kozarev et al. We find that the compressive front likely produced energetic particles as low as 1.3 solar radii in the corona. Comparing the modeled and observed fluences near Earth, we also find that the bulk of the acceleration during this event must have occurred above 1.5 solar radii. With this study we have taken a first step in using direct observations of shocks and compressions in the innermost corona to predict the onsets and intensities of solar energetic particle events.

  15. Magnetic structure of Coronal Mass Ejections

    CERN Document Server

    Lyutikov, Maxim

    2012-01-01

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

  16. Periodicities in Solar Coronal Mass Ejections

    CERN Document Server

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

    2003-01-01

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

  17. Kinematical properties of coronal mass ejections

    CERN Document Server

    Temmer, Manuela

    2016-01-01

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

  18. Coronal Neutrino Emission in Hypercritical Accretion Flows

    CERN Document Server

    Kawabata, R; Kawanaka, N

    2007-01-01

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

  19. A magnetohydrodynamic theory of coronal loop transients

    Science.gov (United States)

    Yeh, T.

    1982-01-01

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

  20. Solar Eruptions: Coronal Mass Ejections and Flares

    Science.gov (United States)

    Gopalswamy, Nat

    2012-01-01

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

  1. Stealthy but Geoeffective Coronal Mass Ejections

    Science.gov (United States)

    Nitta, Nariaki; Mulligan, Tamitha

    2017-08-01

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

  2. Numerical Simulation of DC Coronal Heating

    Science.gov (United States)

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

    2016-05-01

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

  3. The Dynamics of Coronal-Hole Boundaries

    Science.gov (United States)

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

    2015-12-01

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

  4. PROMINENCE ACTIVATION BY CORONAL FAST MODE SHOCK

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-03-01

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

  5. Variabilidad en el abordaje de las heridas crónicas: ¿qué opinan las enfermeras?

    Directory of Open Access Journals (Sweden)

    José Antonio Esperón Güimil

    Full Text Available Objetivo: conocer las opiniones de las enfermeras sobre la variabilidad en el abordaje y manejo de las heridas crónicas, así como los factores que la causan. Métodos: cumplimentación voluntaria de un cuestionario por enfermeras de los tres niveles asistenciales. El cuestionario incluía ítems sociodemográficos, nivel asistencial, nivel de formación en heridas, implicación en investigación y si consideraban que existe variabilidad en el abordaje de las heridas crónicas. Resultados: porcentaje de respuesta del 14%. El 90% consideraba que existía variabilidad. Enumeraron 202 razones para explicar esa variabilidad, que se clasificaron en diez causas. Un porcentaje elevado considera que tiene formación específica en heridas; sin embargo, más de la mitad de los encuestados (65,5% señala que la variabilidad está relacionada con un déficit de formación. Otras causas reflejadas fueron el "estilo de práctica profesional" (41%, la "discontinuidad de cuidados" (24,5% y el "exceso/escasez de productos" (14%. El análisis inferencial no mostró ninguna relación significativa entre las variables estudiadas y la respuesta de la existencia o no de variabilidad. Conclusión: Aunque las guías de práctica clínica reflejan recomendaciones basadas en la evidencia en el abordaje de las heridas crónicas, el estudio muestra que un alto porcentaje de las encuestadas consideran que existe variabilidad en el tratamiento de aquellas. A pesar del nivel de formación que dicen tener un gran número de encuestadas, una de las principales causas de la existencia de variabilidad es el déficit de formación, además del estilo de práctica profesional, la discontinuidad de cuidados y el exceso-escasez de productos.

  6. A New Method for Coronal Magnetic Field Reconstruction

    Science.gov (United States)

    Yi, Sibaek; Choe, Gwang-Son; Cho, Kyung-Suk; Kim, Kap-Sung

    2017-08-01

    A precise way of coronal magnetic field reconstruction (extrapolation) is an indispensable tool for understanding of various solar activities. A variety of reconstruction codes have been developed so far and are available to researchers nowadays, but they more or less bear this and that shortcoming. In this paper, a new efficient method for coronal magnetic field reconstruction is presented. The method imposes only the normal components of magnetic field and current density at the bottom boundary to avoid the overspecification of the reconstruction problem, and employs vector potentials to guarantee the divergence-freeness. In our method, the normal component of current density is imposed, not by adjusting the tangential components of A, but by adjusting its normal component. This allows us to avoid a possible numerical instability that on and off arises in codes using A. In real reconstruction problems, the information for the lateral and top boundaries is absent. The arbitrariness of the boundary conditions imposed there as well as various preprocessing brings about the diversity of resulting solutions. We impose the source surface condition at the top boundary to accommodate flux imbalance, which always shows up in magnetograms. To enhance the convergence rate, we equip our code with a gradient-method type accelerator. Our code is tested on two analytical force-free solutions. When the solution is given only at the bottom boundary, our result surpasses competitors in most figures of merits devised by Schrijver et al. (2006). We have also applied our code to a real active region NOAA 11974, in which two M-class flares and a halo CME took place. The EUV observation shows a sudden appearance of an erupting loop before the first flare. Our numerical solutions show that two entwining flux tubes exist before the flare and their shackling is released after the CME with one of them opened up. We suggest that the erupting loop is created by magnetic reconnection between

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

    CERN Document Server

    Bourdin, Philippe-A; Peter, Hardi

    2014-01-01

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

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

    Science.gov (United States)

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

    2016-11-01

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

  9. X-ray Jet observations in coronal holes and evidence for MHD waves

    Science.gov (United States)

    Cirtain, J.; Davey, A.

    2008-05-01

    Hinode observations of polar coronal holes have revealed that X-ray jets have two distinct velocities, one near the Alfvén speed (~800 km s-1) and another near the sound speed (200 km s-1). This analysis has been reported in Cirtain et al. (2007). In addition to the evidence of Alfvén waves and evaporation flow, there are some subset of jets that appear to oscillate in the direction transverse to the jet axis. We will present studies of these oscillations using both XRT and EIS (Hinode) data, and NFI/SOT ( Hinode) data when available.

  10. Cirugía híbrida de la enfermedad del cayado aórtico: un abordaje sistemático

    Directory of Open Access Journals (Sweden)

    Pedro J. Aranda

    2009-09-01

    La presente revisión propone un abordaje sistemático de la enfermedad del cayado aórtico, dividiendo éste en «zonas de anclaje proximal». Se describen las distintas estrategias y los resultados iniciales de esta aún joven modalidad terapéutica.

  11. Electroweak Hall Effect of Neutrino and Coronal Heating

    CERN Document Server

    Ishikawa, Kenzo

    2015-01-01

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

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

    Science.gov (United States)

    De Moortel, Ineke; Nakariakov, Valery M

    2012-07-13

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

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

    CERN Document Server

    De Moortel, Ineke

    2012-01-01

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

  14. Formation of the current sheet in a coronal streamer

    CERN Document Server

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

    2011-01-01

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

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

    LENUS (Irish Health Repository)

    Counihan, K P

    2012-08-01

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

  16. Automated tracing of open-field coronal structures for an optimized large-scale magnetic field reconstruction

    Science.gov (United States)

    Uritsky, V. M.; Davila, J. M.; Jones, S. I.

    2014-12-01

    Solar Probe Plus and Solar Orbiter will provide detailed measurements in the inner heliosphere magnetically connected with the topologically complex and eruptive solar corona. Interpretation of these measurements will require accurate reconstruction of the large-scale coronal magnetic field. In a related presentation by S. Jones et al., we argue that such reconstruction can be performed using photospheric extrapolation methods constrained by white-light coronagraph images. Here, we present the image-processing component of this project dealing with an automated segmentation of fan-like coronal loop structures. In contrast to the existing segmentation codes designed for detecting small-scale closed loops in the vicinity of active regions, we focus on the large-scale geometry of the open-field coronal features observed at significant radial distances from the solar surface. The coronagraph images used for the loop segmentation are transformed into a polar coordinate system and undergo radial detrending and initial noise reduction. The preprocessed images are subject to an adaptive second order differentiation combining radial and azimuthal directions. An adjustable thresholding technique is applied to identify candidate coronagraph features associated with the large-scale coronal field. A blob detection algorithm is used to extract valid features and discard noisy data pixels. The obtained features are interpolated using higher-order polynomials which are used to derive empirical directional constraints for magnetic field extrapolation procedures based on photospheric magnetograms.

  17. Abordaje psicoterapeutico sistémico individual con jóvenes diagnosticados con trastorno de somatización

    OpenAIRE

    Silva Guzmán, María Angélica

    2010-01-01

    Esta investigación tiene por objetivo comprender los procesos de cambio y transformación de narrativas en el joven diagnosticado con trastorno de somatización a través de un abordaje de intervención sistémica individual. Se realizó una investigación de corte cualitativo, utilizando la modalidad de investigación intervención, con metodología de estudio de caso con diseño de casos múltiples con única unidad de análisis, trabajando en el análisis y evaluación de las herramientas terapéuticas inf...

  18. ¿Es razonable el abordaje laparoscópico en patología maligna colo-rectal?

    OpenAIRE

    Hernandez-Lizoain, J.L. (Jose Luis); Diez-Caballero, A. (Alberto); J. Baixauli; F. Martinez; F. Pardo; Cienfuegos, J.A. (Javier A.)

    1999-01-01

    Desde que se efectuó la primera resección de colon por vía laparoscópica en 1990, han sido publicados numerosos artículos, manifestándose diferentes opiniones, algunas de ellas francamente contrapuestas, en cuanto a validez o no de esta vía de abordaje quirúrgico, para el tratamiento del cáncer colo-rectal. El presente estudio de revisión pretende poner en claro cuál es la situación actual de la resección de colon por vía laparoscópica. Se analizan las ventajas e inconvenientes de dicho tr...

  19. ASPECTOS ONTOLÓGICOS Y EPISTEMOLÓGICOS EN LAS RELACIONES INTERNACIONALES: BREVES PROPUESTAS DE ABORDAJES TEÓRICOS

    Directory of Open Access Journals (Sweden)

    Alberto Lozano Vázquez

    2016-06-01

    Full Text Available El presente ensayo tiene por objetivo analizar los aspectos ontológicos y epistemológicos que han nutrido y formado la construcción teórica de las Relaciones Internacionales (RI. El argumento es una afirmación condicional y es sencilla: Si no se comprenden los fundamentos ontológicos y epistemológicos de las RI entonces no hay precisión en el abordaje teórico de los casos de estudio. Los casos de estudio pueden ser hechos, problemas o situaciones que ocurren en el mundo y la correcta aplicación de las teorías para su interpretación permite a los investigadores de esta disciplina encontrar mejores explicaciones y una mejor comprensión de éstos para, así, eventualmente, proponer soluciones asequibles a dichos problemas o situaciones. Se concluye que: 1 dependiendo del problema (variable dependiente se elige la teoría que mejor lo explique atribuyendo cierta causalidad (variable independiente, con las respectivas implicaciones ontológicas, epistemológicas y metodológicas; 2 que el carácter científico de la disciplina no es un asunto acabado; 3 que referirse a las teorías como paradigmas puede no ser tan útil como se cree; 4 que hay posibilidades dialógicas entre positivismo y post-positivismo para realizar preguntas de investigación en Relaciones Internacionales; y 5 que en la forma de ver el mundo está el abordaje teórico. La contribución consiste en orientar a los estudiosos de las RI en su elección teórica, dentro de varias opciones, para sus investigaciones científicosociales de carácter internacional.

  20. Abdominoplastia multifuncional en ancla: nuestra experiencia y nueva sistemática de abordaje en el paciente sin adelgazamiento

    Directory of Open Access Journals (Sweden)

    J. Muñoz i Vidal

    Full Text Available La dermolipectomía multifuncional en ancla es una técnica efectiva en el tratamiento del contorno corporal en pacientes que han sufrido grandes pérdidas de peso. En la actualidad, en el sistema público de salud español, no es infrecuente que el cirujano plástico deba abordar pacientes en los que no ha habido adelgazamiento alguno y que más allá del contorno corporal, requieren una reparación de la pared abdominal. Los procedimientos reconstructivos de la pared abdominal no están reñidos con un abordaje simultáneo del contorno corporal para una mejora funcional y de la calidad de vida del paciente. Exponemos nuestra experiencia con este conocido patrón de dermolipectomía en 32 casos, en los que mostramos el abordaje hecho en 3 pacientes con ausencia o fracaso en el adelgazamiento. El gran volumen intrabdominal, graso y visceral, de estos pacientes sin adelgazamiento, conlleva que puedan presentar complicaciones por alteración en la relación continente-contenido abdominal tras grandes dermolipectomías; las más frecuentes son dehiscencia de sutura, necrosis de los colgajos, alteraciones respiratorias o cierre a tensión que en último término puede desencadenar un síndrome compartimental intrabdominal. La adaptación y fisioterapia respiratoria preoperatoria del enfermo, el diseño de colgajos suprapúbicos que eviten el cierre a tensión en el punto de unión de las suturas, el no despegamiento de los colgajos y la estimación de la presión intrabdominal intraoperatoria, permiten ampliar la indicación de este patrón de dermolipectomía a pacientes en los que no ha habido adelgazamiento.

  1. Flare Prediction Using Photospheric and Coronal Image Data

    Science.gov (United States)

    Jonas, E.; Shankar, V.; Bobra, M.; Recht, B.

    2016-12-01

    We attempt to forecast M-and X-class solar flares using a machine-learning algorithm and five years of image data from both the Helioseismic and Magnetic Imager (HMI) and Atmospheric Imaging Assembly (AIA) instruments aboard the Solar Dynamics Observatory. HMI is the first instrument to continuously map the full-disk photospheric vector magnetic field from space (Schou et al., 2012). The AIA instrument maps the transition region and corona using various ultraviolet wavelengths (Lemen et al., 2012). HMI and AIA data are taken nearly simultaneously, providing an opportunity to study the entire solar atmosphere at a rapid cadence. Most flare forecasting efforts described in the literature use some parameterization of solar data - typically of the photospheric magnetic field within active regions. These numbers are considered to capture the information in any given image relevant to predicting solar flares. In our approach, we use HMI and AIA images of solar active regions and a deep convolutional kernel network to predict solar flares. This is effectively a series of shallow-but-wide random convolutional neural networks stacked and then trained with a large-scale block-weighted least squares solver. This algorithm automatically determines which patterns in the image data are most correlated with flaring activity and then uses these patterns to predict solar flares. Using the recently-developed KeystoneML machine learning framework, we construct a pipeline to process millions of images in a few hours on commodity cloud computing infrastructure. This is the first time vector magnetic field images have been combined with coronal imagery to forecast solar flares. This is also the first time such a large dataset of solar images, some 8.5 terabytes of images that together capture over 3000 active regions, has been used to forecast solar flares. We evaluate our method using various flare prediction windows defined in the literature (e.g. Ahmed et al., 2013) and a novel per

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

    Science.gov (United States)

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

    2017-10-01

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

  3. Standing Slow MHD Waves in Radiatively Cooling Coronal Loops

    CERN Document Server

    Al-Ghafri, Khalil Salim

    2015-01-01

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

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

    Science.gov (United States)

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

    2009-12-01

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

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

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

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

  6. Cyclical Variation of the Quiet Corona and Coronal Holes

    Indian Academy of Sciences (India)

    Takashi Sakurai

    2000-09-01

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

  7. Anticipating the Geoeffectiveness of Coronal Mass Ejections Project

    Data.gov (United States)

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

  8. Coronal Dynamics at Recent Total Solar Eclipses

    Science.gov (United States)

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

    2014-12-01

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

  9. Exploración del modelo coronal MHD de Uchida

    Science.gov (United States)

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

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

  10. Observing the formation of flare-driven coronal rain

    OpenAIRE

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

    2016-01-01

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

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

    Science.gov (United States)

    Klimchuk, James A.

    2011-01-01

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

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

    Science.gov (United States)

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

    2006-06-01

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

  13. MHD Modeling of Differential Rotation in Coronal Holes

    Science.gov (United States)

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

    2004-01-01

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

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

    National Research Council Canada - National Science Library

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

    2015-01-01

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

  15. The Contribution of Coronal Jets To The Solar Wind

    CERN Document Server

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

    2016-01-01

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

  16. Evolving Coronal Holes and Interplanetary Erupting Stream Disturbances

    Indian Academy of Sciences (India)

    Rajendra Shelke

    2006-06-01

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

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

    CERN Document Server

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

    2016-01-01

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

  18. Stellar Differential Rotation and Coronal Timescales

    CERN Document Server

    Gibb, G P S; Mackay, D H

    2014-01-01

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

  19. Radio-quiet Fast Coronal Mass Ejections

    Science.gov (United States)

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

    2004-12-01

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

  20. Multiscale Modeling of Solar Coronal Magnetic Reconnection

    Science.gov (United States)

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

    2010-01-01

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

  1. Potential Method of Predicting Coronal Mass Ejection

    Science.gov (United States)

    Imholt, Timothy

    2001-10-01

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

  2. Are Coronal Loops Isothermal or Multithermal? Yes!

    CERN Document Server

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

    2009-01-01

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

  3. Geometric Model of a Coronal Cavity

    Science.gov (United States)

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

    2010-01-01

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

  4. Surface Flux Emergence and Coronal Eruption

    Science.gov (United States)

    Fang, Fang

    2016-05-01

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

  5. Coronal activity from the ASAS eclipsing binaries

    CERN Document Server

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

    2008-01-01

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

  6. Geometric Model of a Coronal Cavity

    Science.gov (United States)

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

    2010-01-01

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

  7. Why are halo coronal mass ejections faster?

    Institute of Scientific and Technical Information of China (English)

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

    2010-01-01

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

  8. A Catalog of Coronal "EIT Wave" Transients

    Science.gov (United States)

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

    2009-01-01

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

  9. Energy Release in Driven Twisted Coronal Loops

    Science.gov (United States)

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

    2016-01-01

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

  10. On the Origin of Coronal Mass Ejections: How Does the Emergence of a Magnetic Flux Rope Reorganize the Solar Corona?

    Science.gov (United States)

    Roussev, I. I.; Galsgaard, K.; Lugaz, N.; Sokolov, I.

    2010-12-01

    The physical causes leading to the occurrence of Coronal Mass Ejections (CMEs) on the Sun have been debated for almost four decades now. One of the leading mechanisms suggests that a CME may occur as the result of the emergence of a twisted magnetic flux rope from the convection zone into the solar corona. This process have been investigated by a number of researchers over the years, and it has been demonstrated that an eruption of the coronal magnetic field can in principle occur. The majority of these studies, however, involve some ad-hoc prescription of the electric field at the photosphere resembling flux emergence, and they neglect the ambient coronal magnetic field. In addition, most of these flux-emergence simulations are performed in a Cartesian domain, which extends only to a few dozen pressure scale-heights into the corona. Thus, it is difficult to assess the role of boundary driving and limited computational domain on the resulting evolution of the erupting coronal magnetic field. In this paper, we present a new model of CMEs that mitigates these two effects. To achieve this, we couple the "local" magnetic-flux-emergence (MFE) model of Archontis et al. (2004) with a global MHD model of the solar corona and solar wind. The model coupling is performed using the Space Weather Modeling Framework. In the coupled model, the MFE simulation provides time-dependent boundary conditions for all MHD quantities into the global model, where the physical coupling is done at the photospheric boundary. The physical evolution of the system is followed using the BATS-R-US "ideal" MHD code well beyond the complete emergence of the magnetic flux from the convection zone. We discuss the dynamics of the flux emergence process and the related response of the pre-existing coronal magnetic field in the context of CME production.

  11. Importancia del abordaje clínico de los problemas de aprendizaje frente a la tendencia a medicalizar a las infancias y adolescencias actuales.

    Directory of Open Access Journals (Sweden)

    Gabriela Dueñas

    2014-05-01

    Full Text Available Este trabajo pretende visibilizar la importancia del papel que -en la emergencia, consolidación y expansión del fenómeno de “la patologización y medicalización de las infancias y adolescencias”- parecen desempeñar hoy cierto tipo de criterios de abordaje de las problemáticas en el aprendizaje con las que nos interpelan en la actualidad tantos niños y adolescentes desde las aulas. Para esto, se hace referencia a prácticas psicopedagógi-cas de tipo re-educativas, a partir de las cuales se cuestionan las miradas cognitivo conductuales en las que se apoyan y se establecen diferencias con el tipo de intervenciones que -en su lugar- se propone desde un enfoque clínico psicopedagógico y de la psicología educacional, con el objeto de contribuir a que los discursos provenientes de este ámbito comiencen a ocupar un lugar central en la agenda que sobre estos temas se desarrollen, dado que -con frecuencia- se observan postergados y relegados al campo educativo como si nada tuvieran que ver con lo que hace a la especificidad de lo clínico y la incidencia que éstos tienen en los procesos de constitución de la subjetividad . This work pretends to visualize the importance of the role that in the emergency, consolidation and expansion of the phenomenon of pathological view and over medication of the present childhood and adolescence seem to perform today certain types of criteria on which to base the undertaking of learning problems we are today faced with by children and teenagers in the classroom. To get this aim, we refer to re educated psycho educational practises, from which the cognitive-conductual views are questioned where they supported on, and different interventionist typed are proposed from the clinical psycho pedagogical and psycho educational approach. With the aim of contribute to lectures from this area start to occupy a central place in the schedule developed on these subjects, considering that, frequently, they are

  12. Dificultades en el abordaje de las crisis psicóticas de los adolescentes.

    Directory of Open Access Journals (Sweden)

    Enrique Serrano Guerra

    1987-01-01

    Full Text Available En este trabajo se articulan una serie de reflexiones sobre las implicaciones que el tiempo, el espacio y el fenómeno puberal, tienen en la irrupción de las crisis psicóticas de los adolescentes. Se analizan las actitudes que pueden tomarse al abordar las mismas, así como el papel que juegan tanto los aspectos corporales, como los elementos de contención familiar. Por último se esboza un intento de explicación teórica de algunas de las manifestaciones clínicas frecuentes de estos adolescentes en crisis, frente al hecho de la escucha y la elaboración de la urgencia.

  13. Abordaje biológico de la caries profunda de dentina: el tratamiento por etapas

    Directory of Open Access Journals (Sweden)

    María Inés Garchitorena

    Full Text Available El objetivo de este trabajo es abordar el diagnóstico y el tratamiento de la lesión cariosa en la dentina profunda desde un enfoque biológico y conservador. Comprender la fisiología y la histopatología del complejo dentino pulpar, así como las condiciones que mantienen activa la lesión dentinaria son elementos determinantes que deben considerarse al momento de realizar tratamientos restauradores. Se realiza una revisión bibliografica orientada al estudio o análisis de la enfermedad caries en dentina, su diagnóstico y su tratamiento en situaciones clínicas que permitan una respuesta del complejo dentino pulpar. Se propone el tratamiento por etapas como alternativa a la remoción completa de la dentina cariada profunda. Se apuesta de esta manera a la capacidad reaccional pulpar con el objetivo de evitar exposiciones pulpares, brindando al paciente un tratamiento con enfoque preventivo e integral

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-12-10

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

  15. MAGNETIC FLUX SUPPLEMENT TO CORONAL BRIGHT POINTS

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-02-10

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

  16. Forecasting Coronal Mass Ejections from Vector Magnetograms

    Science.gov (United States)

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

    2002-01-01

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

  17. Nanodust dynamics during a coronal mass ejection

    Science.gov (United States)

    Czechowski, Andrzej; Kleimann, Jens

    2017-09-01

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

  18. Abordaje de un caso clínico tratado desde una perspectiva integradora

    OpenAIRE

    Montes-Berges, Beatriz; Moreno Ratia, Mª Victoria

    2011-01-01

    Este trabajo tiene como objetivo presentar la eficacia de una terapia de integración. Esto supone ir más allá de los límites de los enfoques de escuelas únicas, integrando técnicas y descubrimientos que aunque en principio pueden parecer, en determinadas ocasiones, incompatibles a nivel teórico, resultan enriquecedores en la práctica clínica. Desde esta perspectiva, se ha llevado a cabo el tratamiento de una usuaria adscrita al programa de Violencia de Género, dada la gran vari...

  19. Implicancia de las condiciones subjetivas en el abordaje del VIH : Primeras aproximaciones

    OpenAIRE

    Erbetta, Anahí E.

    2009-01-01

    El presente trabajo corresponde al avance del proyecto de investigación “Las incidencias de las condiciones subjetivas en la eficacia del tratamiento médico de pacientes con VIH/SIDA”. El mismo se encuadra en el Convenio Marco de la Facultad de Psicología con la Municipalidad de La Plata, el cual avala la inserción como becaria en el Centro Número 13 de Referencia Programa Municipal de Prevención de la Infección por VIH/SIDA. De acuerdo a la metodología propuesta, la investigación comporta en...

  20. Comparativa de Abordajes de Cursos Introductorios de Programación

    OpenAIRE

    2016-01-01

    El pensamiento computacional se basa en resolver problemas haciendo uso de conceptos de informática, desarrollar esta habilidad es la tarea principal de las asignaturas de introducción a la programación en las carreras universitarias. En general, aunque se han creado lenguajes cada vez más cercanos al lenguaje humano, la programación no resulta ser una materia intuitiva ni de fácil comprensión y, por lo tanto, suele tratarse de una asignatura con una alta tasa de deserción. En este contexto, ...

  1. Walter Benjamin y los pasajes de París: el abordaje metodológico

    OpenAIRE

    Daniel Hiernaux-Nicolas

    1999-01-01

    Walter Benjamin (1892-1940) ha sido uno de los investigadores más creativos de su generación, además de lo difícil que resulta ubicarlo en una línea, debido a la vastedad, intensidad y variedad de una obra que sólo llegó entera al público gracias a la recopilación de las Gesammelte Schriften, realizada por Rolf Tiedemann durante los años sesenta y setenta. Si bien en la actualidad existe una moda benjaminiana, falta mucho por analizar, entre otros aspectos, lo referente a los textos o citas d...

  2. Síntomas y complicaciones posfunduplicatura: abordaje diagnóstico y tratamiento

    OpenAIRE

    S. Sobrino-Cossío; J.C. Soto-Pérez; E. Coss-Adame; G. Mateos-Pérez; O. Teramoto Matsubara; J. Tawil; M. Vallejo-Soto; A. Sáez-Ríos; J.A. Vargas-Romero; A.M. Zárate-Guzmán; E.S. Galvis-García; M. Morales-Arámbula; O. Quiroz-Castro; A. Carrasco-Rojas; J.M. Remes-Troche

    2017-01-01

    En la actualidad la funduplicatura laparoscópica tipo Nissen se considera el tratamiento quirúrgico de elección para la enfermedad por reflujo gastroesofágico (ERGE) y su efectividad a largo plazo es mayor del 90%. Dentro de los factores predictores de buena respuesta clínica están la adecuada selección del paciente y la experiencia del cirujano. Sin embargo, la prevalencia de síntomas nuevos, persistentes y recurrentes posteriores al procedimiento antirreflujo puede ser de hasta un 30%. Las ...

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

    Directory of Open Access Journals (Sweden)

    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.

  4. Standing Slow MHD Waves in Radiatively Cooling Coronal Loops

    Indian Academy of Sciences (India)

    K. S. Al-Ghafri

    2015-06-01

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

  5. Standing Kink modes in three-dimensional coronal loops

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-04-01

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

  6. Solar Active Region Coronal Jets. II. Triggering and Evolution of Violent Jets

    Science.gov (United States)

    Sterling, Alphonse C.; Moore, Ronald L.; Falconer, David A.; Panesar, Navdeep K.; Martinez, Francisco

    2017-07-01

    We study a series of X-ray-bright, rapidly evolving active region coronal jets outside the leading sunspot of AR 12259, using Hinode/X-ray telescope, Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) and Helioseismic and Magnetic Imager (HMI), and Interface Region Imaging Spectrograph (IRIS) data. The detailed evolution of such rapidly evolving “violent” jets remained a mystery after our previous investigation of active region jets. The jets we investigate here erupt from three localized subregions, each containing a rapidly evolving (positive) minority-polarity magnetic-flux patch bathed in a (majority) negative-polarity magnetic-flux background. At least several of the jets begin with eruptions of what appear to be thin (thickness ≲ 2\\prime\\prime ) miniature-filament (minifilament) “strands” from a magnetic neutral line where magnetic flux cancelation is ongoing, consistent with the magnetic configuration presented for coronal-hole jets in Sterling et al. (2016). Some jets strands are difficult/impossible to detect, perhaps due to, e.g., their thinness, obscuration by surrounding bright or dark features, or the absence of erupting cool-material minifilaments in those jets. Tracing in detail the flux evolution in one of the subregions, we find bursts of strong jetting occurring only during times of strong flux cancelation. Averaged over seven jetting episodes, the cancelation rate was ˜ 1.5× {10}19 Mx hr-1. An average flux of ˜ 5× {10}18 Mx canceled prior to each episode, arguably building up ˜1028-1029 erg of free magnetic energy per jet. From these and previous observations, we infer that flux cancelation is the fundamental process responsible for the pre-eruption build up and triggering of at least many jets in active regions, quiet regions, and coronal holes.

  7. EL ABORDAJE DE LO INFINITO. Acerca de la necesidad de una definición de los proyectos estéticos en el Teatro de Títeres en Colombia.

    Directory of Open Access Journals (Sweden)

    María Teresa Vela Mendoza

    2008-09-01

    Full Text Available Resumen: En este artículo se proponen algunas estrategias para la construcción de una historia del teatro de títeres en Colombia durante los últimos treinta años. Se parte de las dificultades de su abordaje teniendo en cuenta dos hechos: la ausencia de crítica, la cual se reemplaza por la trascripción de los comentarios elaborados por los autores en las notas culturales de los periódicos; y la ausencia de reflexión por parte de los artistas acerca de su trabajo, tanto de su proceso creativo como de la manera de llevarlo a cabo.Ante esto se propone la construcción de la historia del teatro de títeres a partir de la categoría: proyecto estético, el cual depende de los procesos de formación y de la manera como se resuelven los problemas artísticos genéricos. Se propone el uso de la categoría desde los siguientes elementos:1. El planteamiento dramatúrgico referido al estilo y a los temas tratados.2. La forma. En relación con las técnicas, los géneros y las soluciones plásticas.3. Las formas organizativas ya se trate de grupos o de compañías.

  8. El dolor neuropático y su abordaje terapéutico

    OpenAIRE

    Serdio Mier, Alberto

    2015-01-01

    El dolor neuropático resulta de una lesión o enfermedad que afecta al sistema nervioso somatosensorial. Entre los múltiples mecanismos descritos que participan en la génesis y perpetuación del dolor neuropático se incluyen, entre otros, la generación de descargas ectópicas, la sensibilización periférica y central y, la alteración de las vías de modulación descendente. El manejo clínico del dolor neuropático sólo proporciona un alivio sintomático e incluye el uso de terapias tanto farmacológic...

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

    OpenAIRE

    Nancy Chavarría-Arana; Pablo Saborío-Chacón; Sara Fernández-Rojas

    2013-01-01

    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 año...

  10. Orbitotomía lateral mediante abordaje temporal Lateral orbitotomy using a temporal approach

    OpenAIRE

    H. Herencia Nieto; J.J. Verdaguer Martín; F. Riba García; J. Calvo de Mora Álvarez; A. del Amo Fernández de Velasco; R. Pujol Romanya; Navarro Cuéllar, C.

    2005-01-01

    La orbitotomía lateral sigue siendo en el momento actual la técnica quirúrgica de elección para la biopsia o extirpación de lesiones intraorbitarias laterales al nervio óptico, la biopsia del propio nervio óptico y la extirpación de la glándula lacrimal. Se han descrito múltiples incisiones cutáneas para llevar a cabo esta intervención; la más frecuentemente empleada por el momento es la incisión palpebral, que discurre a nivel de alguna arruga del párpado superior. Aunque los resultados obte...

  11. Sobrepeso y obesidad: una propuesta de abordaje desde la sociología

    Directory of Open Access Journals (Sweden)

    Marcelina Cruz Sánchez

    2013-01-01

    Full Text Available El sobrepeso y la obesidad son considerados un grave problema de salud pública, por su presencia en enfermedades crónicas como las cardiovasculares y la diabetes, que se observan cada vez más entre los pobres y más en las mujeres. Para combatir y revertir el problema se pide a la persona que modifique su estilo de vida, por ser el responsable de la epidemia de obesidad, pero se considera que esto niega la responsabilidad que tiene la estructura social. Como la obesidad y el sobrepeso rebasan la perspectiva biomédica, y son un problema de desigualdad social y de género, se propone un enfoque social para comprender sus raíces sociales, y al estilo de vida como cualidad colectiva más que individual.

  12. Abordaje de lesiones por pénfigo ampolloso en prolapso genital

    Directory of Open Access Journals (Sweden)

    Olga Barredo González

    Full Text Available Las enfermedades bullosas o ampollares comprenden un grupo heterogéneo de cuadros cuya lesión elemental común es la ampolla. Los pénfigos y los penfigoides pertenecen al grupo de las enfermedades bullosas de origen autoinmunitario. El prolapso genital es el descenso o desplazamiento de los órganos pélvicos, a través de la vagina y en dirección a la vulva, que se produce como consecuencia del fallo de sus elementos de suspensión y sustentación así como la inervación y musculatura del sistema urinario e intestinal. En este caso presentamos nuestra experiencia en el manejo y tratamiento tópico de lesiones por pénfigo ampolloso en prolapso visceropélvico total que dificultaban la cirugía.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. The Search for Stellar Coronal Mass Ejections

    Science.gov (United States)

    Villadsen, Jacqueline Rose

    2017-05-01

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

  17. The Search for Stellar Coronal Mass Ejections

    Science.gov (United States)

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

    2017-01-01

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

  18. Mechanisms of Plasma Acceleration in Coronal Jets

    Science.gov (United States)

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

    2016-12-01

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

  19. Characterizing the Properties of Coronal Magnetic Null Points

    Science.gov (United States)

    Barnes, Graham; DeRosa, Marc; Wagner, Eric

    2015-08-01

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

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

    Indian Academy of Sciences (India)

    Leonard Strachan

    2008-03-01

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

  1. Determination of coronal temperatures from electron density profiles

    CERN Document Server

    Lemaire, J F

    2011-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2010-01-01

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

  3. A data driven kinetic approach to coronal heating

    CERN Document Server

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

    2016-01-01

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

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

    CERN Document Server

    Nistico, G; Patsourakos, S; Zimbardo, G

    2009-01-01

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

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

    Indian Academy of Sciences (India)

    Nagendra Kumar; Pradeep Kumar; Shiv Singh; Anil Kumar

    2008-03-01

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

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

    Science.gov (United States)

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

    2012-01-01

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

  7. Examining the Properties of Jets in Coronal Holes

    Science.gov (United States)

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

    2012-01-01

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

  8. Transverse, Propagating Velocity Perturbations in Solar Coronal Loops

    CERN Document Server

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

    2015-01-01

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

  9. Using Coronal Hole Maps to Constrain MHD Models

    Science.gov (United States)

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

    2017-08-01

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

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

    Science.gov (United States)

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

    2012-01-01

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

  11. The Nature of CME-Flare Associated Coronal Dimming

    CERN Document Server

    Cheng, J X

    2016-01-01

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

  12. Flux Rope Formation Preceding Coronal Mass Ejection Onset

    CERN Document Server

    Green, L M

    2009-01-01

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

  13. Polarisation of microwave emission from reconnecting twisted coronal loops

    CERN Document Server

    Gordovskyy, Mykola; Kontar, Eduard

    2016-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2012-01-01

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

  15. SIMULATIONS OF SOLAR JETS CONFINED BY CORONAL LOOPS

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-03-20

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

  16. Abordaje integral de pacientes costarricenses afectados con la enfermedad de Huntington y sus familiares

    Directory of Open Access Journals (Sweden)

    Melissa Vasquez-Cerdas

    2011-09-01

    Full Text Available Objetivo: Realizar el diagnóstico molecular a personas afectadas con la enfermedad de Huntington y familiares con el 50% de riesgo, y brindarles asesoramiento genético, seguimiento y evaluación psicológica y clínica, con el fin de mejorar su calidad de vida y prevenir la ocurrencia y recurrencia de la enfermedad de Huntington. Métodos: Diagnóstico molecular a pacientes con diagnóstico clínico, familiares asintomáticos con 50% de riesgo y pacientes con diagnóstico confuso. Se les brindó asesoramiento genético y evaluación psicológica. Los pacientes positivos que no tenían un control regular fueron referidos al neurólogo. Resultados: El diagnóstico molecular se realizó a 64 personas (35 mujeres y 29 hombres. De estas, seis tenían diagnóstico clínico de Huntington, el cual se confirmó, y 6 tenían diagnóstico confuso; de estas últimas, cinco resultaron negativas para la enfermedad de Huntington, y una, positiva. Las restantes 52 personas correspondían a familiares en riesgo, y de estas, 17 resultaron ser portadoras. En total, 20 mujeres y 17 hombres fueron efectivamente evaluados en el nivel psicológico. Los análisis moleculares mostraron un perfil de repeticiones similar al de otras poblaciones. Conclusión: El diagnóstico molecular es de gran ayuda, pues algunas enfermedades pueden confundirse con la de Huntington. El diagnóstico presintomático cubre satisfactoriamente las siguientes expectativas de las personas: aliviar la incertidumbre, planear el cuidado de la salud y conocer si los hijos tienen riesgo. En general, no se ha encontrado grandes diferencias entre las personas evaluadas en el nivel psicológico, ya sea que porten un diagnóstico molecular positivo o negativo.

  17. Reflexiones para el abordaje de la salud, el cuerpo y el movimiento corporal en la escuela

    Directory of Open Access Journals (Sweden)

    Nancy Molina-Achury

    2013-12-01

    Full Text Available El Departamento del Movimiento Corporal Humano de la Universidad Nacional de Colombia, ha validado la necesidad de formalizar su presencia en el ámbito de la escuela en la forma de una práctica universitaria. Se parte del reconocimiento de que las experiencias de articulación escuela-salud han sido diversas y, aunque guardan referencias comunes en el campo discursivo, es común encontrar valoraciones por parte de los actores participantes que refieren una permanente tensión en la relación salud-educación. Esta tensión frecuentemente es sustentada en una lógica de imposición vertical de sentidos, procesos y acciones por parte del primero sobre el segundo. Este escrito pretende aportar elementos conceptuales y estratégicos para una visión crítica, al tiempo que plantea elementos para el diseño de propuestas de articulación, que ubican como centralidad la necesidad de configurar un objeto común que oriente el sentido de las acciones en torno al proceso de promoción de la autonomía. Para ello se propone el diseño de propuestas de trabajo que retomen reflexiones en torno a cuatro aspectos: el proceso de construcción de conocimiento y las posibilidades que ofrece la incorporación de elementos que hacen parte del llamado nuevo paradigma, la concepción de la salud como proceso histórico centrado en las relaciones sociales que impactan de manera integral a los sujetos y grupos, la visión del cuerpo y del movimiento corporal más allá de receptáculo de las condiciones de deterioro de la calidad de vida, y el lugar de la educación en la construcción de sujetos autónomos.

  18. Automatic measurement of orbital volume in unilateral coronal synostosis

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  19. Coronal seismology waves and oscillations in stellar coronae

    CERN Document Server

    Stepanov, Alexander; Nakariakov, Valery M

    2012-01-01

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

  20. Ensemble Forecasting of Coronal Mass Ejections Using the WSA-ENLIL with CONED Model

    Science.gov (United States)

    Emmons, D.; Acebal, A.; Pulkkinen, A.; Taktakishvili, A.; MacNeice, P.; Odstricil, D.

    2013-01-01

    The combination of the Wang-Sheeley-Arge (WSA) coronal model, ENLIL heliospherical model version 2.7, and CONED Model version 1.3 (WSA-ENLIL with CONED Model) was employed to form ensemble forecasts for 15 halo coronal mass ejections (halo CMEs). The input parameter distributions were formed from 100 sets of CME cone parameters derived from the CONED Model. The CONED Model used image processing along with the bootstrap approach to automatically calculate cone parameter distributions from SOHO/LASCO imagery based on techniques described by Pulkkinen et al. (2010). The input parameter distributions were used as input to WSA-ENLIL to calculate the temporal evolution of the CMEs, which were analyzed to determine the propagation times to the L1 Lagrangian point and the maximum Kp indices due to the impact of the CMEs on the Earth's magnetosphere. The Newell et al. (2007) Kp index formula was employed to calculate the maximum Kp indices based on the predicted solar wind parameters near Earth assuming two magnetic field orientations: a completely southward magnetic field and a uniformly distributed clock-angle in the Newell et al. (2007) Kp index formula. The forecasts for 5 of the 15 events had accuracy such that the actual propagation time was within the ensemble average plus or minus one standard deviation. Using the completely southward magnetic field assumption, 10 of the 15 events contained the actual maximum Kp index within the range of the ensemble forecast, compared to 9 of the 15 events when using a uniformly distributed clock angle.

  1. Deflections of Fast Coronal Mass Ejections and the Properties of Associated Solar Energetic Particle Events

    Science.gov (United States)

    Kahler, S. W.; Akiyama, S.; Gopalswamy, N.

    2012-01-01

    The onset times and peak intensities of solar energetic particle (SEP) events at Earth have long been thought to be influenced by the open magnetic fields of coronal holes (CHs). The original idea was that a CH lying between the solar SEP source region and the magnetic footpoint of the 1 AU observer would result in a delay in onset and/or a decrease in the peak intensity of that SEP event. Recently, Gopalswamy et al. showed that CHs near coronal mass ejection (CME) source regions can deflect fast CMEs from their expected trajectories in space, explaining the appearance of driverless shocks at 1 AU from CMEs ejected near solar central meridian (CM). This suggests that SEP events originating in CME-driven shocks may show variations attributable to CH deflections of the CME trajectories. Here, we use a CH magnetic force parameter to examine possible effects of CHs on the timing and intensities of 41 observed gradual E approx 20 MeV SEP events with CME source regions within 20 deg. of CM. We find no systematic CH effects on SEP event intensity profiles. Furthermore, we find no correlation between the CME leading-edge measured position angles and SEP event properties, suggesting that the widths of CME-driven shock sources of the SEPs are much larger than the CMEs. Independently of the SEP event properties, we do find evidence for significant CME deflections by CH fields in these events

  2. Role of Loss of Equilibrium and Magnetic Reconnection in Coronal Eruptions: Resistive and Hall MHD simulations

    Science.gov (United States)

    Yang, H.; Bhattacharjee, A.; Forbes, T. G.

    2008-12-01

    It has long been suggested that eruptive phenomena such as coronal mass ejections, prominence eruptions, and large flares might be caused by a loss of equilibrium in a coronal flux rope (Van Tend and Kuperus, 1978). Forbes et al. (1994) developed an analytical two-dimensional model in which eruptions occur due to a catastrophic loss of equilibrium and relaxation to a lower-energy state containing a thin current sheet. Magnetic reconnection then intervenes dynamically, leading to the release of magnetic energy and expulsion of a plasmoid. We have carried out high-Lundquist-number simulations to test the loss-of equilibrium mechanism, and demonstrated that it does indeed occur in the quasi-ideal limit. We have studied the subsequent dynamical evolution of the system in resistive and Hall MHD models for single as well as multiple arcades. The typical parallel electric fields are super-Dreicer, which makes it necessary to include collisionless effects via a generalized Ohm's law. It is shown that the nature of the local dissipation mechanism has a significant effect on the global geometry and dynamics of the magnetic configuration. The presence of Hall currents is shown to alter the length of the current sheet and the jets emerging from the reconnection site, directed towards the chromosphere. Furthermore, Hall MHD effects break certain symmetries of resistive MHD dynamics, and we explore their observational consequences.

  3. Evaluation of standoff distance method to determine the coronal magnetic field using CME-driven shocks

    Science.gov (United States)

    Suresh, K.; Shanmugaraju, A.; Syed Ibrahim, M.

    2016-11-01

    We have analyzed the propagation characteristics of four limb coronal mass ejections (CMEs) with their shocks. These CMEs were observed in 18 frames up to 18 solar radii using LASCO white light images. Gopalswamy and Yashiro (Astrophys. J. 736:L17, 2011) introduced the standoff distance method (SOD) to find the magnetic field in the corona using CME-driven shock. In this paper, we have used this technique to determine the magnetic field strength and to study the propagation/shock formation condition of these CMEs at 18 different locations. Since the thickness of shock sheath (standoff distance or SOD) is not constant around CME, we estimate the shock parameters and their variation in large and small SOD regions of the shock. The Mach number ranges from 1.7 to 2.8 and Alfvén speed varies from 197 to 857 km s^{-1}. Finally, we estimate the magnetic field variation in the corona. The magnetic field strength ranges from 4.9 to 26.2 mG from 8.3 to 17.5 solar radii. The estimated magnetic field strength in this study is consistent with the literature value (7.6 to 45.8 mG from Gopalswamy and Yashiro (Astrophys. J. 736:L17, 2011), and 6 to 105 mG from Kim et al. (Astrophys. J. 746:118, 2012)) and it smoothly follows the general coronal magnetic field profile.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

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

    2017-06-01

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

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

    Directory of Open Access Journals (Sweden)

    R. Castro-Pérez

    2010-06-01

    benignas del hígado tratadas quirúrgicamente mediante el abordaje transvaginal asistido por minilaparoscopia. Pacientes y métodos: mujeres de 44 y 45 años de edad, respectivamente. La paciente 1 presentaba un pequeño tumor de 1,2 cm de Ø, en el lóbulo izquierdo del hígado. En su preoperatorio no se logró precisar su etiología y se decidió extirparlo quirúrgicamente. La paciente 2 presentaba un quiste simple del hígado muy sintomático de 8 cm de Ø situado en el subsegmento VI, se negó a realizarse el tratamiento esclerosante por vía percutánea, por lo que se recomendó el tratamiento quirúrgico. Se les ofreció a ambas realizar la intervención mediante cirugía laparoscópica o el abordaje transvaginal, aceptando este último. El neumoperitoneo se realizó con presión de 15 mmHg. Se colocaron 2 minipuertos en abdomen, uno en región umbilical de 5 mm Ø y el otro de 3 mm Ø en el sitio más próximo a la lesión. Con visión directa se colocó 1 trocar en la pared posterior del fondo del saco vaginal de 11 mm Ø para el paso de un endoscopio rígido. En la paciente 1 se utilizó este mismo orificio para, adyacente al trocar, introducir un disector largo. En la paciente 2 se introdujo un segundo trocar de 5 mm Ø para el paso de instrumentos de trabajo. Ambos especímenes fueron extraídos a través de la vagina en bolsas extractoras. Se registró el tiempo quirúrgico, necesidad de analgésicos y complicaciones postoperatorias. Resultados: los tiempos quirúrgicos fueron de 51 y 73 minutos, respectivamente. La paciente operada del quiste hepático requirió administración de analgésico postoperatorio. El alta hospitalaria fue dada antes de las 24 horas de la intervención. No se han presentado complicaciones postoperatorias relacionadas con el proceder después de un seguimiento mínimo de 6 meses. Conclusiones: con el empleo de instrumentos rígidos, fue posible realizar el tratamiento quirúrgico de dos lesiones benignas del hígado, de poca

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

    Directory of Open Access Journals (Sweden)

    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

  8. Examen de post-efecto para experiencias anómalo/ paranormales con un abordaje humanista

    Directory of Open Access Journals (Sweden)

    Alejandro Parra

    2014-07-01

    Full Text Available Se presentan los resultados de una investigación que tuvo como objetivos: explorar la utilidad de la terapia grupal para hacer frente a los efectos de las experiencias paranormales y explorar cómo la terapia humanista produce cambios positivos hacia las experiencias anómalo/paranormales. Se les pidió a la muestra (N= 20, rango 22-71 años, M= 45,65, DT= 12,52, 65 % mujeres y 35 % varones, responder un cuestionario autoadministrado de siete preguntas antes y al finalizar su participación en un grupo. La actividad incluyó tres fases: (1 Exposición, (2 Interpretación y (3 Cierre del grupo. Los participantes indicaron que el grupo ayudó a disminuir su malestar emocional (p = ,001, y lograr una comprensión a sus experiencias (p = ,008. Abstract This article shows the results of an investigation aimed to: explore the usefulness of group therapy to deal with the effects of paranormal experiences and explore how humanistic therapy produces positive changes to the anomalous/paranormal experiences. They were asked to sample (N = 20, range 22-71 years, M = 45.65, SD = 12.52, 65 % female and 35 % male, a self-administered questionnaire to answer seven questions before and after your participation in a group. The activity included three phases: (1 Exposure (2 Interpretation y (3 Close the group. Participants indicated that the group helped reduce their emotional distress (p = .001, and gain an understanding of their experiences (p = .008.

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

    Science.gov (United States)

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

    2017-07-01

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

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

    DEFF Research Database (Denmark)

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

    2017-01-01

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

  11. ¿QUÉ ES EL DINERO? UN ABORDAJE DESDE LA PSICOLOGÍA ECONÓMICA

    Directory of Open Access Journals (Sweden)

    Gustavo Guzmán Fernández

    2000-01-01

    Full Text Available Este artículo se desenvuelve alrededor de cuatro líneas argumentales en relación al dinero. Por un lado, parte de una breve introducción que toma en cuenta tanto su origen, como hijo legítimo del comercio, como la influencia que ha tenido en la expansión de antiguos imperios. En la segunda sección se presentan aspectos históricos y contextuales que han llevado a materializarlo de diferentes formas en los distintos núcleos humanos que abarcan desde pieles hasta conchas de caurí, pasando por cuentas de barro o barras de sal. La dimensión simbólica del dinero se ejemplifica en este apartado cuando se lo relaciona a la imagen del poder, su función como vehículo de información y propaganda o el significado místico-religioso que adquiere en diferentes culturas. En la tercera parte se hace una mayor profundización de la entidad simbólica del dinero desde la perspectiva del Interaccionismo Simbólico. La creencia que un símbolo es un hecho social compartido y que un fenómeno tiene significado en relación directa a su función práctica permite considerar este marco teórico como un constructo válido para estudiar el dinero. Por último, se plantea la existencia de dineros especiales. Avanzando más allá del cariz instrumental del dinero aportado por la economía, la visión de la antropología y la sociología nos demuestran que existen en el dinero aspectos culturales y sociales fuera de la esfera del mercado y que éstos pueden inclusive ser causas de «mutaciones», como es el caso del dinero virtual.

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

    Science.gov (United States)

    Matsumoto, Takuma

    2016-11-01

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

  13. The Relationship of Coronal Mass Ejections to Streamers

    CERN Document Server

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

    1999-01-01

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

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

    Science.gov (United States)

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

    1982-01-01

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

  15. Closed-Field Coronal Heating Driven by Wave Turbulence

    CERN Document Server

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

    2016-01-01

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

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

    NARCIS (Netherlands)

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

    1999-01-01

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

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

    Science.gov (United States)

    Kazachenko, M.

    2014-12-01

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

  18. Quantifying the Significance of Substructure in Coronal Loops

    Science.gov (United States)

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

    2014-12-01

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

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

    Science.gov (United States)

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

    2013-01-01

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

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

    Science.gov (United States)

    Guhathakurta, Madhulika

    1998-01-01

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

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

    CERN Document Server

    Matsumoto, Takuma

    2016-01-01

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

  2. Abordaje metodológico para la exploración de la experiencia emocional en sus distintas dimensiones

    Directory of Open Access Journals (Sweden)

    Claudia J. Arias

    2013-12-01

    Full Text Available La experiencia emocional es un constructo complejo y multidimensional. En este artículo se propone un abordaje comprensivo de triangulación metodológica. El mismo se basa el modelo de Experiencia emocional propuesto por Lawton, que incluye una serie de dimensiones que permiten explorar gran variedad de aspectos de este constructo a través de las escalas: 1 Intensidad del afecto, 2 Moderación del afecto positivo, 3 Búsqueda de sensaciones, 4 Control cognitivo, 5 Madurez emocional, 6  Disimulación afectiva, 7 Responsividad psicofisiológica, 8 Variabilidad afectiva, 9 Duración del afecto, 10 Rapidez de la respuesta afectiva. En lo relativo a la exploración cualitativa se proponen  indagar situaciones cotidianas en las que se aplican estrategias de Control Cognitivo, Simulación Emocional, la Selección de situaciones y la Búsqueda de sensaciones en el encuadre de una entrevista semi-estructurada diseñada para este estudio. Se incluyen los datos del proceso de validación en población de la ciudad de Mar del Plata, las características de la muestra seleccionada para el estudio y el procedimiento de administración de instrumentos aplicado. Respecto del análisis de datos, se describen las técnicas estadísticas (descriptivas e inferenciales y de análisis de contenido (técnicas inductivas aplicadas.

  3. Hydrodynamics of the plasma confined inside coronal loops: flare and microflare models

    Science.gov (United States)

    Betta, R.; Peres, G.; Reale, F.; Serio, S.

    The plasma contained in coronal loops behaves macroscopically like a fluid and its dynamics and evolution may be described by hydrodynamics provided mass, momentum and energy transport occurs only along magnetic field lines. In fact, coronal loops are very often observed not to change their geometry during a flare, and this suggests that the magnetic field structure may basically act to confine the plasma while chromospheric plasma evaporation and temperature increase cause the increase in brightness. In other words, though the source of the energy release in loops may be of magnetic origin, the subsequent loops response may be adequately described by hydrodynamics in those instances in which the global magnetic field does not change. We have developed such a hydrodynamic model (Peres et al. 1982), which takes into account the main physical effects such as gravity, viscosity, ionization, radiative losses and thermal conduction and which is capable of giving a correct description of the steep and dynamic transition region between the chromosphere and the corona (Betta et al. 1997). Here we show how a plasma confined inside coronal loops responds when it is subject to impulsive heating. We simulate flares by creating a sudden energy release in a localized position along the loop (although the plasma dynamics does not depend crucially on the position of energy release). The initial configuration consists of a loop in hydrostatic equilibrium and steady-state energy balance (i.e.,in which there is an average heating which balances radiation losses and thermal conduction). The hydrodynamic calculations show the formation of an evaporation front propagating from the chromosphere to the corona, while the temperature increases in the loop from the top towards the footpoints anchored in the photosphere and the transition region moves progressively downwards. When the heating is switched off the plasma cools slowly during the decay phase of the flare until a thermal

  4. Successive Homologous Coronal Mass Ejections Driven by Shearing and Converging Motions in Solar Active Region NOAA 12371

    Science.gov (United States)

    Vemareddy, P.

    2017-08-01

    We study the magnetic field evolution in AR 12371, related to its successive eruptive nature. During the disk transit of seven days, the active region (AR) launched four sequential fast coronal mass ejections (CMEs), which are associated with long duration M-class flares. Morphological study delineates a pre-eruptive coronal sigmoid structure above the polarity inversion line (PIL) similar to Moore et al.’s study. The velocity field derived from tracked magnetograms indicates persistent shear and converging motions of polarity regions about the PIL. While these shear motions continue, the crossed arms of two sigmoid elbows are being brought to interaction by converging motions at the middle of the PIL, initiating the tether-cutting reconnection of field lines and the onset of the CME explosion. The successive CMEs are explained by a cyclic process of magnetic energy storage and release referred to as “sigmoid-to-arcade-to-sigmoid” transformation driven by photospheric flux motions. Furthermore, the continued shear motions inject helicity flux with a dominant negative sign, which contributes to core field twist and its energy by building a twisted flux rope (FR). After a limiting value, the excess coronal helicity is expelled by bodily ejection of the FR, which is initiated by some instability as realized by intermittent CMEs. This AR is in contrast with the confined AR 12192 with a predominant negative sign and larger helicity flux, but much weaker (-0.02 turns) normalized coronal helicity content. While predominant signed helicity flux is a requirement for CME eruption, our study suggests that the magnetic flux normalized helicity flux is a necessary condition accommodating the role of background flux and appeals to a further study of a large sample of ARs.

  5. SISTEMA INMUNE Y GENÉTICA: UN ABORDAJE DIFERENTE A LA DIVERSIDAD DE ANTICUERPOS.

    Directory of Open Access Journals (Sweden)

    Matta Camacho Nubia Estela

    2011-12-01

    Full Text Available RESUMEN Es común encontrar en los libros de inmunología o de genética un capítulo con el título de “sistema inmune y genética”, sin embargo su asociación se centra en cómo la generación de anticuerpos rompió el paradigma “un gen, una proteína”, pues en el caso de la producción de anticuerpos, un gen produce millones de proteínas. El sistema inmune tiene muchos vínculos con la genética y la herencia; esta asociación se da porque cualquier sustancia o compuesto que produzca un organismo, es un antígeno potencial cuando es reconocido como extraño por el sistema inmune de otro organismo, sea este de la misma o de diferente especie. La producción de proteínas que potencialmente pueden ser antigénicas están ligadas al genotipo del individuo. La capacidad de responder y el tipo e intensidad de respuesta a los antígenos también ha sido demostrado que está correlacionado con el genotipo del individuo en cuestión, así como deficiencias en las respuestas inmunes pueden estar asociadas con mutaciones o polimorfismos genéticos que resultan en la susceptibilidad a enfermedades infecciosas. Este artículo se busca presentar ejemplos de la relación del sistema inmune y la genética, en la misma dirección de la conferencia ofrecida para la cátedra de Sede “Todo lo que usted quiere saber de genética y nunca se atrevió a preguntar”. Palabras claves: HLA, respuesta inmune, grupos sanguíneos, antígenos. ABSTRACT It is common to find in immunology or genetic books a chapter entitled “immune system and genetics”; this association focuses on how the generation of antibodies broke the paradigm “one gene, one protein”, since in this case one gene generates millions of proteins. However, the immune system has many more links to genetics and heredity. For example, any substance or compound that an organism produces is a potential antigen, when it is recognized as foreign by the immune system of another

  6. On the enhanced coronal mass ejection detection rate since the solar cycle 23 polar field reversal

    CERN Document Server

    Petrie, Gordon

    2015-01-01

    Coronal mass ejections (CMEs) with angular width $> 30^{\\circ}$ have been observed to occur at a higher rate during solar cycle 24 compared to cycle 23, per sunspot number. This result is supported by data from three independent databases constructed using Large Angle and Spectrometric Coronagraph Experiment (LASCO) coronagraph images, two employing automated detection techniques and one compiled manually by human observers. According to the two databases that cover a larger field of view, the enhanced CME rate actually began shortly after the cycle 23 polar field reversal, in 2004, when the polar fields returned with a 40\\% reduction in strength and interplanetary radial magnetic field became $\\approx 30\\%$ weaker. This result is consistent with the link between anomalous CME expansion and heliospheric total pressure decrease recently reported by Gopalswamy et al.

  7. Sizes and locations of coronal mass ejections - SMM observations from 1980 and 1984-1989

    Science.gov (United States)

    Hundhausen, A. J.

    1993-01-01

    A statistical description of the sizes and locations of 1209 mass ejections observed with the SMM coronagraph/polarimeter in 1980 and 1984-1989 is presented. The average width of the coronal mass ejections detected with this instrument was close to 40 deg in angle for the entire period of SMM observations. No evidence was found for a significant change in mass ejection widths as reported by Howard et al. (1986). There is clear evidence for changes in the latitude distribution of mass ejections over this epoch. Mass ejections occurred over a much wider range of latitudes at the times of high solar activity (1980 and 1989) than at times of low activity (1985-1986).

  8. Self-similar expansion of solar coronal mass ejections: Implications for Lorentz self-force driving

    Energy Technology Data Exchange (ETDEWEB)

    Subramanian, Prasad; Arunbabu, K. P.; Mauriya, Adwiteey [Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pashan, Pune 411008 (India); Vourlidas, Angelos, E-mail: p.subramanian@iiserpune.ac.in [Space Science Division, Naval Research Laboratory, 4555 Overlook Avenue, SW Washington, DC 20375 (United States)

    2014-08-01

    We examine the propagation of several coronal mass ejections (CMEs) with well-observed flux rope signatures in the field of view of the SECCHI coronagraphs on board the STEREO satellites using the graduated cylindrical shell fitting method of Thernisien et al. We find that the manner in which they propagate is approximately self-similar; i.e., the ratio (κ) of the flux rope minor radius to its major radius remains approximately constant with time. We use this observation of self-similarity to draw conclusions regarding the local pitch angle (γ) of the flux rope magnetic field and the misalignment angle (χ) between the current density J and the magnetic field B. Our results suggest that the magnetic field and current configurations inside flux ropes deviate substantially from a force-free state in typical coronagraph fields of view, validating the idea of CMEs being driven by Lorentz self-forces.

  9. Modeling solar coronal bright point oscillations with multiple nanoflare heated loops

    CERN Document Server

    Chandrashekhar, K

    2015-01-01

    Intensity oscillations of coronal bright points (BPs) have been studied for past several years. It has been known for a while that these BPs are closed magnetic loop like structures. However, initiation of such intensity oscillations is still an enigma. There have been many suggestions to explain these oscillations, but modeling of such BPs have not been explored so far. Using a multithreaded nanoflare heated loop model we study the behavior of such BPs in this work. We compute typical loop lengths of BPs using potential field line extrapolation of available data (Chandrashekhar et al. 2013), and set this as the length of our simulated loops. We produce intensity like observables through forward modeling and analyze the intensity time series using wavelet analysis, as was done by previous observers. The result reveals similar intensity oscillation periods reported in past observations. It is suggested these oscillations are actually shock wave propagations along the loop. We also show that if one considers di...

  10. Magnetic Field in the Gravitationally Stratified Coronal Loops

    Indian Academy of Sciences (India)

    B. N. Dwivedi; A. K. Srivastava

    2015-03-01

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

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

    Science.gov (United States)

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

    2010-01-01

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

  12. New techniques for the characterisation of dynamical phenomena in solar coronal images

    Science.gov (United States)

    Robbrecht, E.

    2007-02-01

    ^23-10^25 J. They are often observed n association with low coronal activity, such as flares and filament eruptions. During the first years of CME observation, it was believed that a flare was a necessary condition for CME occurrence. The widely accepted picture today is that flares and CMEs are both different manifestations of magnetic field restructuring through reconnection (flare) and the expulsion of mass (CME). Up till now, the SOHO mission has been the best mission for CME studies because of the increased resolution, cadence, sensitivity and dynamic range of the LASCO instruments, but also because of the large array of ground-based instruments (Howard 2006). The complexity of the CME-picture grew likewise. The next mission with a coronagraph is the NASA STEREO mission (Solar Terrestrial Relations Observatory), launched on 26 Oct. 2006. In chapter 4 we test the possibility of automatically detecting CMEs in LASCO data. We describe the algorithm CACTus (Computer Aided CME Tracking) and test its validity on a short period of 6 days. In chapter 5 we present our newly constructed CME catalog based on our automated detection scheme. It is the first automatically generated catalog which runs over a complete solar cycle (cycle 23). It required no human interaction, which implies it is totally objective. It includes all transients obeying the observational definition of CME as a "new, discrete, bright, white-light feature in the coronagraph field-of-view moving radially outward" (Hundhausen et al. 1984). As a result, our catalog contains much more events, mostly narrow, than are included in the classical CDAW CME catalog (Yashiro et al. 2004) which is assembled manually. We discuss the CME rate over the solar cycle and present important new statistics on the CACTus CME parameters (size, latitude, speed). CME research has gained an increased interest due to their strong space weather impact. Space weather is defined by the European Space Agency (ESA) 1 as the "conditions on the

  13. The Foggy EUV Corona and Coronal Heating by MHD Waves From Explosive Reconnection Events

    Science.gov (United States)

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

    2008-05-01

    In 0.5 arcsec/pixel TRACE coronal EUV images, the corona rooted in active regions that are at the limb and are not flaring is seen to consist of (1) a complex array of discrete loops and plumes embedded in (2) a diffuse ambient component that shows no fine structure and gradually fades with height. For each of two not-flaring active regions, Cirtain et al (2006, Sol. Phys., 239, 295) found that the diffuse component is (1) approximately isothermal and hydrostatic and (2) emits well over half of the total EUV luminosity of the active-region corona. Here, from a TRACE Fe XII coronal image of another not-flaring active region, the large sunspot active region AR 10652 when it was at the west limb on 30 July 2004, we separate the diffuse component from the discrete-loop component by spatial filtering, and find that the diffuse component has about 60% of the total luminosity. If under much higher spatial resolution than that of TRACE (e.g., the 0.1 arcsec/pixel resolution of the Hi-C sounding- rocket experiment proposed by J. W. Cirtain et al), most of the diffuse component remains diffuse rather being resolved into very narrow loops and plumes, this will raise the possibility that the EUV corona in active regions consists of two basically different but comparably luminous components: one being the set of discrete bright loops and plumes and the other being a truly diffuse component filling the space between the discrete loops and plumes. This dichotomy would imply that there are two different but comparably powerful coronal heating mechanisms operating in active regions, one for the distinct loops and plumes and another for the diffuse component. We present a scenario in which (1) each discrete bright loop or plume is a flux tube that was recently reconnected in a burst of reconnection, and (2) the diffuse component is heated by MHD waves that are generated by these reconnection events and by other fine-scale explosive reconnection events, most of which occur in and

  14. ALS Association

    Science.gov (United States)

    ... ALS and their families in areas affected by Hurricane Harvey. Learn More The ALS Association Disaster Relief Fund ... ALS and their families in areas affected by Hurricane Harvey. Learn More Our Mission To discover treatments and ...

  15. Electron-microscopical Studies on the Sclerosed Dentin Second Report : Comparative observations on the intertubular deposits in the coronal dentin, dental calculus and salivary stone

    OpenAIRE

    赤羽, 章司; 枝, 重夫; 川上, 敏行; 中村, 千仁; 河住, 信

    1982-01-01

    For the purpose of serchirg the origin of the intratubular deposits in the coronal sclerosed dentin, the deposits were compared with dental calculus and salivary stone by a scanning electron microscope and electron probe microanalysers with energy and wavelength dispersive x-ray spectroscopies including the contour map method. Results were as follows: 1. The layer of minute crystals covered on the attrition surface contained the elements of Na, Mg, Al, P, S, Cl, Ca, Mn, Fe, Zn, Br. 2. The rho...

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

    CERN Document Server

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

    2015-01-01

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

  17. Reproducibility of the interpretation of coronal 3D ultrasound view of the uterus to evaluate the position of Essure(®) 3 months after hysteroscopic procedure.

    Science.gov (United States)

    Capmas, P; Letendre, I; Levaillant, J-M; Fuchs, F; Panel, P; Chambon, G; Villefranque, V; Levy-Zauberman, Y; Fernandez, H

    2017-07-01

    Three-dimensional sonography is a good alternative method to assess the position of microinserts. Adequate position after three months allows for the interruption of other contraception. Objective is to evaluate inter-observer reproducibility of the interpretation of coronal transvaginal 3D ultrasound view of the uterus to evaluate the position of Essure(®). Inter-observer reproducibility study. Fifty women underwent successful bilateral placement of microinserts (Essure(®)) by hysteroscopy in the Department of Gynaecology of a teaching hospital and were included in the study. At three month, 3D ultrasound coronal views of the fifty uterus (accounting for one hundred microinserts) were assessed by five different observers and microinsert position was classified according to the classification described by Legendre et al. Inter-observer reproducibility in reading the 3D coronal view of the uterus was evaluated. The k-value was disparate, from 0.26 to 0.82. Inter-observer reproducibility then ranged from fair to almost perfect, depending on a prior knowledge of the position classification. Transvaginal 3D coronal view of the uterus is sufficient to assess the positioning of the microinserts when the practionner or the surgeon is familiar with the classification method. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  18. Analisis del balance coronal y último nivel artrodesado en escoliosis idiopática lenke 5: parámetros radiográficos específicos

    Directory of Open Access Journals (Sweden)

    Nicolás Siderakis

    2013-12-01

    Full Text Available OBJETIVO: Determinar las modificaciones postoperatorias que se producen en el balance coronal de los pacientes con escoliosis idiopática del adolescente (EIA con curvas de Lenke tipo 5, realizando un análisis pre y postoperatorio de los siguientes parámetros radiológicos: último nivel vertebral artrodesado, inclinación de L4, traslación de vértebra apical, obliquidade lumbosacra, ángulo de Cobb y balance coronal previo. MÉTODOS: Se evaluaron 20 pacientes con diagnóstico de EIA con curvas de Lenke tipo 5, con un seguimiento promedio de 36 meses (R: 24 a 48. La edad promedio al momento de la cirugía fue de 15,3 años (R: 13 a 20 años, siendo la distribución por sexo de 16 mujeres y 4 hombres. RESULTADOS: En nuestra serie hemos detectado una correlación directa entre el AVTL y el LSTOA con el balance coronal postoperatorio, tanto en el grupo de los pacientes que mejoraron (14 pacientes, como en aquellos en los que el balance coronal empeoró (6 pacientes. CONCLUSIÓN: De la serie evaluada, fueron el AVTL y el LSTOA, los parámetros radiográficos específicos.

  19. Canino mandibular incluido: presentación de un caso atípico de abordaje quirúrgico por vía lingual

    OpenAIRE

    Rius Pastor, J.; Conde Mir, Ma Núria; Berini Aytés, Leonardo; Gay Escoda, Cosme; Jaume Riera, C.

    1996-01-01

    Se presenta el caso de un paciente varón que tenía el canino temporal inferior derecho no exfoliado a los 15 años de edad; a la exploración se descubrió que existía el canino permanente totalmente incluído, con la particularidad de que estaba asociado a un quiste folicular y que la posible causa de inclusión era la presencia de un premolar supernumerario también retenido; otra rareza a destacar es que se hizo un abordaje quirúrgico mixto, vestibular para el premolar supernumerario y lingual p...

  20. Estrategias para el abordaje de la neurofobia: aprendizaje basado en la experiencia : El modelo de Kolb y el enfoque fenomenológico

    OpenAIRE

    Pedersoli, Luis Carlos; Pedersoli Castellani, Luis Martín

    2011-01-01

    El abordaje de la “neurofobia” entendida según Jozefowicz como “el miedo a las neurociencias en general y a la clínica neurológica en particular por parte de médicos y estudiantes que conduce a la parálisis del pensamiento y de la acción” resulta una tarea compleja. La consideración de los estilos de aprendizaje predominantes en cada persona a través del modelo de Kolb y la forma de presentar la experiencia clínica mediante el enfoque fenomenológico, constituyen aproximaciones para el tratami...

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

    OpenAIRE

    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...

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

    OpenAIRE

    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 ...

  3. Efectividad de los abordajes de fisioterapia en niños con trastorno del espectro autista : una revisión sistemática

    OpenAIRE

    Ruiz Juárez, Itxaso

    2015-01-01

    RESUMEN: Diseño del estudio: Revisión sistemática acerca de la literatura científica disponible en las bases de datos sobre los diferentes tipos de abordajes terapéuticos en el tratamiento de niños con Trastorno del Espectro Autista (TEA). Objetivos: La intención de esta revisión ofrecer información mediante una búsqueda en la literatura actual sobre los métodos de tratamiento en fisioterapia para abarcar las necesidades de los niños con TEA, indicando si alguna de las terapias es más efe...

  4. Cirugía híbrida de la enfermedad del cayado aórtico: un abordaje sistemático

    OpenAIRE

    Aranda, Pedro J.; Muñoz, José Joaquín; Vivancos, Ricardo; González, Mayte; Loma, Julio Gutiérrez de

    2009-01-01

    La cirugía endovascular se impone en el tratamiento de un número sustancial de casos de enfermedad de aorta descendente. No obstante, la afectación del arco aórtico ha supuesto una frontera natural de este tratamiento hasta el reciente desarrollo de la llamada «cirugía híbrida», en la que, además de tratar el cayado con endoprótesis, se asocian derivaciones quirúrgicas de troncos supraaórticos. Potencialmente, este tipo de abordajes evitaría intervenciones más agresivas en una población cada ...

  5. Nuevas retóricas para viejas prácticas. Repensando la idea de diversidad y su uso en la comprensión y abordaje de la discapacidad Nuevas retóricas para viejas prácticas. Repensando la idea de diversidad y su uso en la comprensión y abordaje de la discapacidad

    Directory of Open Access Journals (Sweden)

    M.E. Almeida

    2010-03-01

    Full Text Available El presente ensayo recupera las reflexiones y producciones del equipo interdisciplinario de investigadores y docentes de la Facultad de Trabajo Social (FTS de la Universidad Nacional de Entre Ríos (UNER, Argentina1. Nos proponemos por un lado revisar críticamente la noción de diversidad y las prácticas que en ella se fundan y por otra abordar la perspectiva de la producción social de la discapacidad desde el paradigma de la complejidad. Intentaremos deconstruir el concepto de diversidad, no para cambiarlo simplemente por otro que nos incomode menos, sino para sumergirnos en la maraña de sentidos en que la diversidad se inscribe como descriptor de un cierto orden de cosas. Entendemos que la noción de diversidad, en tanto descriptiva de un cierto cúmulo de tipos posibles es muy útil en el campo de lo biológico, pero sin duda es necesario discutir algunas implicancias de su traslado lineal al campo de lo social. Finalmente, proponemos pensar y pasar de la perspectiva de atención a/en la diversidad al abordaje en la complejidad recuperando la idea de experiencias de complejidad, en referencia a experiencias que ya no se organizan y legitiman en torno al señalamiento e identificación de tal o cual complejo (como un otro específico y/o su complejidad, sino experiencias capaces de reconocerla como condición intrínseca a toda experiencia pedagógica, social, política, cultural.This essay recovers ideas and productions of the interdisciplinary team of researchers and professors from the Faculty of Social Work at the National University of Entre Rios, Argentine. We propose a critical review of the practices and the notion of diversity are based from, by means of using the perspective of the social production of disability and the paradigm of complexity. We try to deconstruct the concept of diversity, not just to change it for more comfortable ideas, but to dive into the confusion of meanings that diversity is as a descriptor of a certain

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

    Science.gov (United States)

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

    2009-10-01

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

  7. Standing sausage modes in coronal loops with plasma flow

    Science.gov (United States)

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

    2014-08-01

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

  8. Coronal Abundance Anomalies in Solar-Like Stars

    Science.gov (United States)

    Laming, John

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

  9. Problemas Relacionados al Alcohol: Bases Neurobiológicas del consumo de alcohol y Modelos Animales desarrollados para el abordaje de estas problemáticas

    Directory of Open Access Journals (Sweden)

    Roberto S. Miranda Morales

    2009-09-01

    Full Text Available The present review is focused on animal models for the study of alcohol use, abuse and dependence. These models have helped to understand several features of alcohol consumption, ranging from genetic influences to environmental factors such us early experiences with the drug. Additionally, animal models have been useful tools to assess the efficacy of pharmacological treatments as well as alcohol associated phenomena, such as craving, tolerance and reinstatement. First we introduce a short description of the neurobiological basis of alcohol reinforcement, focused on the opiate system. Then we cover several animal models, from genetic models, and models focused on the study of alcohol related disorders to animal models that emphasize the importance of early experiences with the drug in the development of alcohol use and alcohol related disorders.

  10. Conocimiento y Prácticas del personal docente con relación al abordaje del proceso de duelo en adolescentes.

    Directory of Open Access Journals (Sweden)

    Viriam Leiva Díaz

    2012-10-01

    Full Text Available The following article presents the partial results on the knowledge and practices of teachers in addressing the grieving teen's Julio Acosta Garcia Higher Institute of San Ramon. This research was performed using a quantitative approach, descriptive. For data collection a questionnaire was used, which allowed to characterize and understand the issues mentioned around the theme of the grieving process in adolescents. The information is grouped according to the systematic study of variables for later analysis. Among the most important findings, it is mentioned that the teachers have little knowledge about the processes of mourning in the period of adolescence, and few personal resources to advice and deal in duels early and timely process management grieving teens. We conclude that it is important that the teachers know what changes that occur during adolescence in the physical, social and psychological, as these can trigger the grieving process that require proper care to avoid the negative implications this may lead also how to intervene in major crisis, as well as some guidelines that will lead to a satisfactory resolution of mourning in this way to properly care for adolescents experiencing this kind of situation.

  11. La lingüística cognitiva: una aproximación al abordaje del lenguaje como fenómeno cognitivo integrado

    Directory of Open Access Journals (Sweden)

    Javier Aníbal Moreno Mojica

    2016-01-01

    Full Text Available La lingüística cognitiva es un movimiento lingüístico que concibe el lenguaje como una capacidad integrativa dentro de las tareas cognitivas propias del hombre, lo que devela que el lenguaje está basado en procesos de cognición complejos tales como la percepción, conceptualización, categorización, inferencia, entre otros, los que de una u otra forma permiten una aprehensión, funcionamiento, estructuración y adecuación de la realidad y el mundo. No obstante, debido a sus postulaciones en contraposición de paradigmas lingüísticos tradicionales, ha sido señalada más de teoría unificada que de una corriente como tal, llegando a desconocerse no solo sus orígenes, preguntas fundamentales, principios teóricos y tareas propias, sino sus aportes a la ciencia lingüística en lo que atañe a la concepción y comprensión de la facultad del lenguaje humano. A través de este artículo se presenta una aproximación a la lingüística cognitiva en cuanto a su desarrollo histórico, constructos teóricos fundamentales y tendencias particulares en lo propio a la relación lenguaje-cognición-realidad.

  12. Coronal Structures as Tracers of Sub-Surface Processes

    Indian Academy of Sciences (India)

    Alexei A. PevtSOV; Richard C. Canfield

    2000-09-01

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

  13. Turbulent coronal heating and the distribution of nanoflares

    CERN Document Server

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

    1997-01-01

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

  14. Coronal Streamers and Their Associated Solar Wind Streams

    Science.gov (United States)

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

    2012-12-01

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

  15. Polar Coronal Holes During Solar Cycles 22 and 23

    Institute of Scientific and Technical Information of China (English)

    Jun Zhang; J. Woch; S. Solanki

    2005-01-01

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

  16. Global Alfven Waves in Solar Physics: Coronal Heating

    Science.gov (United States)

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

    1990-11-01

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

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

    CERN Document Server

    Testa, Paola; Drake, Jeremy

    2015-01-01

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

  18. Doente coronário agudo, um retrato global

    OpenAIRE

    Ivo, Rita Maria Mendes Duarte Gomes

    2012-01-01

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

  19. Nonlinear Dynamics of the Parker Scenario for Coronal Heating

    CERN Document Server

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

    2007-01-01

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

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

    CERN Document Server

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Science.gov (United States)

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

    2010-12-01

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

  3. Coronal heating by the partial relaxation of twisted loops

    CERN Document Server

    Bareford, Michael; Browning, Philippa

    2012-01-01

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

  4. Spatial damping of propagating sausage waves in coronal cylinders

    CERN Document Server

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

    2015-01-01

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

  5. Coronal Mass Ejections and Non-recurrent Forbush Decreases

    Science.gov (United States)

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

    2014-10-01

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

  6. Energetic characterisation and statistics of solar coronal brightenings

    CERN Document Server

    Joulin, Vincent; Solomon, Jacques; Guennou, Chloé

    2016-01-01

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

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

    Science.gov (United States)

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

    2007-05-01

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

  8. Inferring the Coronal Density Irregularity from EUV Spectra

    CERN Document Server

    Hahn, Michael

    2016-01-01

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

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

    Science.gov (United States)

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

    1995-01-01

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

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

    Science.gov (United States)

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

    2016-10-01

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

  11. EUV and Coronagraphic Observations of Coronal Mass Ejections

    Indian Academy of Sciences (India)

    Durgesh Tripathi

    2006-06-01

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

  12. Energetic characterisation and statistics of solar coronal brightenings

    Science.gov (United States)

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

    2016-07-01

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

  13. Swift X-ray monitoring of stellar coronal variability

    Science.gov (United States)

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

    2017-08-01

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

  14. A Closer Look at the Alpha Persei Coronal Conundrum

    Science.gov (United States)

    Ayres, Thomas R.

    2017-03-01

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

  15. Diagnostics of Coronal Heating in Active-region Loops

    Science.gov (United States)

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

    2017-01-01

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

  16. Stellar Coronal Response to Differential Rotation and Flux Emergence

    OpenAIRE

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

    2016-01-01

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

  17. Un análisis crítico de las perspectivas de diálogo en la literatura sobre comunicación para el desarrollo y cambio social: abordajes y desafíos

    Directory of Open Access Journals (Sweden)

    Adriana Ángel Botero

    2011-01-01

    Full Text Available El objetivo de este estudio fue explorar la literatura producida en el campo de la comunicación para el desarrollo y el cambio social (cdsc, con el fin de: a. comprender la manera como diversos investigadores y profesionales de la comunicación han utilizado la noción de diálogo para definir, entender y apoyar los procesos de desarrollo y cambio social; b. explorar las implicaciones teóricas y prácticas de la utilización de distintos enfoques de diálogo. Después de analizar más de doscientos textos, concluimos que en el campo de la cdsc la noción de diálogo ha sido abordada, primordialmente, de tres maneras: diálogo como modelo de comunicación, diálogo como evento de comunicación interpersonal y diálogo como proceso de deliberación pública. En otras palabras, la cdsc ha definido el concepto en relación con tres escenarios: las teorías de los medios masivos de comunicación, la comunicación interpersonal y los procesos de deliberación pública. Una vez explicados dichos escenarios, presentamos los riesgos, consecuencias e implicaciones de cada uno de estos abordajes. Finalmente, exponemos algunos de los desafíos y retos que tiene la cdsc en relación con la aplicación de prácticas dialógicas. Además de ofrecer una mirada sistemática al uso de la noción de diálogo en este campo, nuestro estudio también revela limitaciones importantes en cada uno de dichos escenarios.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    CERN Document Server

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

    2016-01-01

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

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

    CERN Document Server

    Guarrasi, M; Orlando, S; Mignone, A; Klimchuk, J A

    2014-01-01

    The expansion of coronal loops in the transition region may considerably influence the diagnostics of the plasma emission measure. The cross sectional area of the loops is expected to depend on the temperature and pressure, and might be sensitive to the heating rate. The approach here is to study the area response to slow changes in the coronal heating rate, and check the current interpretation in terms of steady heating models. We study the area response with a time-dependent 2D MHD loop model, including the description of the expanding magnetic field, coronal heating and losses by thermal conduction and radiation from optically thin plasma. We run a simulation for a loop 50 Mm long and quasi-statically heated to about 4 MK. We find that the area can change substantially with the quasi-steady heating rate, e.g. by ~40% at 0.5 MK as the loop temperature varies between 1 and 4 MK, and, therefore, affects the interpretation of DEM(T) curves.

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

    CERN Document Server

    Li, Bo; Yu, Hui

    2012-01-01

    The origin of the heliospheric magnetic flux on the Sun, and hence the origin of the solar wind, is a topic of hot debate.While the prevailing view is that the solar wind originates from outside coronal streamer helmets, there also exists the suggestion that the open magnetic field spans a far wider region.Without the definitive measurement of the coronal magnetic field, it is difficult to resolve the conflict between the two scenarios without doubt.We present two 2-dimensional, Alfv\\'enic-turbulence-based models of the solar corona and solar wind, one with and the other without a closed magnetic field region in the inner corona.The purpose of the latter model is to test whether it is possible to realize a picture suggested by polarimetric measurements of the corona using the FeXIII 10747\\AA\\ line, where open magnetic field lines seem to penetrate the streamer base.The boundary conditions at the coronal base are able to account for important observational constraints, especially those on the magnetic flux dis...

  2. Disappearance of a coronal hole induced by a filament activation

    CERN Document Server

    Lin, Ma; Xiao-Li, Yan; Zhi-Ke, Xue

    2014-01-01

    We present a rare observation of direct magnetic interaction between an activating filament and a coronal hole (CH). The filament was a quiescent one located at the northwest of the CH. It underwent a nonradial activation, during which filament material constantly fell and intruded into the CH. As a result, the CH was clearly destroyed by the intrusion. Brightenings appeared at the boundaries and in the interior of the CH, meanwhile, its west boundaries began to retreat and the area gradually shrank. It is noted that the CH went on shrinking after the end of the intrusion and finally disappeared entirely. Following the filament activation, three coronal dimmings (D1-D3) were formed, among which D1 and D2 persisted throughout the complete disappearance of the CH. The derived coronal magnetic configuration shows that the filament was located below an extended loop system which obviously linked D1 to D2. By comparison with this result of extrapolation, our observations imply that the interaction between the fila...

  3. Bashful ballerina unveiled: Multipole analysis of the coronal magnetic field

    Science.gov (United States)

    Virtanen, I.; Mursula, K.

    2012-12-01

    Heliospheric current sheet (HCS) is the continuum of the coronal magnetic equator, dividing the heliospheric magnetic field (HMF) into two sectors (polarities). Because of its wavy structure, the HCS is often called the ballerina skirt. Several studies have proven that the HCS is southward shifted during about three years in the solar declining phase. This persistent phenomenon, called the bashful ballerina, has been verified by geomagnetic indices since 1930s, by OMNI data base since 1960s, by the WSO PFSS model since mid-1970s and by the Ulysses probe measurements during the fast latitude scans in 1994-1995 and 2007. We study here the Wilcox Solar Observatory measurements of the photospheric magnetic field and the PFSS extrapolation of the coronal magnetic field. We show that the quadrupole moment of the photospheric magnetic field, which is important for the HCS asymmetry (bashful ballerina), mainly arises from the difference between northern and southern polar field strengths. According to the WSO data the minimum time quadrupole is mainly due to the difference between the highest northern and southern latitude bins. Related studies imply that the southward shift of the HCS is related to the delayed development of southern coronal holes. We also discuss the suggested connection of the HCS asymmetry to sunspot hemispheric asymmetry.

  4. More of the Inconvenient Truth About Coronal Dimmings

    CERN Document Server

    McIntosh, Scott W; Leamon, Robert J

    2009-01-01

    We continue the investigation of a CME-driven coronal dimming from December 14 2006 using unique high resolution imaging of the chromosphere and corona from the Hinode spacecraft. Over the course of the dimming event we observe the dynamic increase of non-thermal line broadening of multiple emission lines as the CME is released and the corona opens; reaching levels seen in coronal holes. As the corona begins to close, refill and brighten, we see a reduction of the non-thermal broadening towards the pre-eruption level. The dynamic evolution of non-thermal broadening is consistent with the expected change of Alfven wave amplitudes in the magnetically open rarefied dimming region, compared to the dense closed corona prior to the CME. The presented data reinforce the belief that coronal dimmings must be temporary sources of the fast solar wind. It is unclear if such a rapid transition in the thermodynamics of the corona to a solar wind state has an effect on the CME itself.

  5. The Temperature-Dependent Nature of Coronal Dimmings

    CERN Document Server

    Robbrecht, Eva

    2010-01-01

    The opening-up of the magnetic field during solar eruptive events is often accompanied by a dimming of the local coronal emission. From observations of filament eruptions recorded with the Extreme-Ultraviolet Imager on STEREO during 2008-2009, it is evident that these dimmings are much more pronounced in 19.5 nm than in the lower-temperature line 17.1 nm, as viewed either on the disk or above the limb. We conclude that most of the cooler coronal plasma is not ejected but remains gravitationally bound when the loops open up. This result is consistent with Doppler measurements by Imada and coworkers, who found that the upflow speeds in a transient coronal hole increased dramatically above a temperature of 1 MK; it is also consistent with the quasistatic behavior of polar plumes, as compared with the hotter interplume regions that are the main source of the fast solar wind. When the open flux reconnects and closes down again, the trapped plasma is initially heated to such high temperatures that it is no longer v...

  6. Current systems of coronal loops in 3D MHD simulations

    CERN Document Server

    Warnecke, Jörn; Bingert, Sven; Peter, Hardi

    2016-01-01

    We study the magnetic field and current structure associated with a coronal loop. Through this we investigate to what extent the assumptions of a force-free magnetic field break down. We analyse a three-dimensional MHD model of the solar corona in an emerging active region with the focus on the structure of the forming coronal loops. The lower boundary of this simulation is taken from a model of an emerging active region. As a consequence of the emerging magnetic flux a coronal loop formes self-consistently. We investigate the current density along magnetic field lines inside (and outside) this loop and study the magnetic and plasma properties in and around this loop. The loop is defined as the bundle of field lines that coincides with enhanced emission in extreme UV. We find that the total current along the emerging loop changes its sign from being antiparallel to parallel to the magnetic field. Around the loop the currents form a complex non-force-free helical structure. This is directly related to a bipola...

  7. The Density of Coronal Plasma in Active Stellar Coronae

    CERN Document Server

    Testa, P; Peres, G; Testa, Paola; Drake, Jeremy J.; Peres, Giovanni

    2004-01-01

    We have analyzed high-resolution X-ray spectra of a sample of 22 active stars observed with the High Energy Transmission Grating Spectrometer on {\\em Chandra} in order to investigate their coronal plasma density. Densities where investigated using the lines of the He-like ions O VII, Mg XI, and Si XIII. While Si XIII lines in all stars of the sample are compatible with the low-density limit, Mg XI lines betray the presence of high plasma densities ($> 10^{12}$ cm$^{-3}$) for most of the sources with higher X-ray luminosity ($> 10^{30}$ erg/s); stars with higher $L_X$ and $L_X/L_{bol}$ tend to have higher densities at high temperatures. Ratios of O VII lines yield much lower densities of a few $10^{10}$ cm$^{-3}$, indicating that the ``hot'' and ``cool'' plasma resides in physically different structures. Our findings imply remarkably compact coronal structures, especially for the hotter plasma emitting the Mg XI lines characterized by coronal surface filling factor, $f_{MgXI}$, ranging from $10^{-4}$ to $10^{-...

  8. Spatial damping of propagating sausage waves in coronal cylinders

    Science.gov (United States)

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

    2015-09-01

    Context. Sausage modes are important in coronal seismology. Spatially damped propagating sausage waves were recently observed in the solar atmosphere. Aims: We examine how wave leakage influences the spatial damping of sausage waves propagating along coronal structures modeled by a cylindrical density enhancement embedded in a uniform magnetic field. Methods: Working in the framework of cold magnetohydrodynamics, we solve the dispersion relation (DR) governing sausage waves for complex-valued, longitudinal wavenumber k at given real angular frequencies ω. For validation purposes, we also provide analytical approximations to the DR in the low-frequency limit and in the vicinity of ωc, the critical angular frequency separating trapped from leaky waves. Results: In contrast to the standing case, propagating sausage waves are allowed for ω much lower than ωc. However, while able to direct their energy upward, these low-frequency waves are subject to substantial spatial attenuation. The spatial damping length shows little dependence on the density contrast between the cylinder and its surroundings, and depends only weakly on frequency. This spatial damping length is of the order of the cylinder radius for ω ≲ 1.5vAi/a, where a and vAi are the cylinder radius and the Alfvén speed in the cylinder, respectively. Conclusions: If a coronal cylinder is perturbed by symmetric boundary drivers (e.g., granular motions) with a broadband spectrum, wave leakage efficiently filters out the low-frequency components.

  9. Fast-sausage oscillations in coronal loops with smooth boundary

    Science.gov (United States)

    Lopin, I.; Nagorny, I.

    2014-12-01

    Aims: The effect of the transition layer (shell) in nonuniform coronal loops with a continuous radial density profile on the properties of fast-sausage modes are studied analytically and numerically. Methods: We modeled the coronal waveguide as a structured tube consisting of a cord and a transition region (shell) embedded within a magnetic uniform environment. The derived general dispersion relation was investigated analytically and numerically in the context of frequency, cut-off wave number, and the damping rate of fast-sausage oscillations for various values of loop parameters. Results: The frequency of the global fast-sausage mode in the loops with a diffuse (or smooth) boundary is determined mainly by the external Alfvén speed and longitudinal wave number. The damping rate of such a mode can be relatively low. The model of coronal loop with diffuse boundary can support a comparatively low-frequency, global fast-sausage mode of detectable quality without involving extremely low values of the density contrast. The effect of thin transition layer (corresponds to the loops with steep boundary) is negligible and produces small reductions of oscillation frequency and relative damping rate in comparison with the case of step-function density profile. Seismological application of obtained results gives the estimated Alfvén speed outside the flaring loop about 3.25 Mm/s.

  10. An estimate of solar wind velocity profiles in an coronal hole and a coronal streamer area (6-40 solar radius)

    Science.gov (United States)

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

    1995-01-01

    Using the total electron content data obtained by the Ulysses Solar Corona Experiment during the superior solar conjunction in summer 1991, we selected two data sets, one associated with a coronal hole and the other one with coronal streamer crossings. By doing this data splitting, we find two entirely different density profiles varying as r(exp -2.7) and r(exp -2.3) for the coronal hole and coronal streamers, respectively. Assuming mass flux conservation from the inner corona to one AU, an estimate for the velocity profiles or acceleration in these two different regions can be determined. The more negative exponent of the coronal hole density profile indicates a more extended heating and acceleration region or more flaring, or both. Various possible explanations will be discussed.

  11. Conocimientos y actitudes de los estudiantes de enfermería para el abordaje de las personas VIH/SIDA seropositivas

    Directory of Open Access Journals (Sweden)

    Nohelia Pérez,

    2014-12-01

    Full Text Available Objetivo: determinar los conocimientos y actitudes de los estudiantes de enfermería para el abordaje de las personas Virus de Inmunodeficiencia Humana/Síndrome de Inmunodeficiencia Adquirida seropositivas, durante el primer trimestre académico de 2014. Materiales y Métodos: El tipo de estudio fue no experimental, descriptivo, de abordaje cuantitativo y de corte transversal, con una muestra de 80 estudiantes pertenecientes a un programa de enfermería. Resultados: en cuanto a la caracterización demográfica se encontró que el género femenino ocupo el 63% de la muestra, el rango de edad predominante fue de 19 a 22 años ocupando el 55%; lo resultados también muestran que el conocimiento técnico tuvo mayor porcentaje de aciertos con 51%, seguido del conocimiento básico y el conocimiento general. El conocimiento básico tiene menor dispersión. Conclusiones: Los resultados de la investigación demostraron que las subvariables como la edad, el sexo, el estrato socioeconómico, no tienen ningún grado de influencia en el conocimiento y actitud del estudiante de enfermería en el manejo de personas Virus de Inmunodeficiencia Humana/Síndrome de Inmunodeficiencia Adquirida seropositivas; además un alto porcentaje de los estudiantes del programa de enfermería poseen un buen nivel de conocimientos sobre el tema.

  12. The Foggy EUV Corona and Coronal Heating by MHD Waves from Explosive Reconnection Events

    Science.gov (United States)

    Moore, Ron L.; Cirtain, Jonathan W.; Falconer, David A.

    2008-01-01

    In 0.5 arcsec/pixel TRACE coronal EUV images, the corona rooted in active regions that are at the limb and are not flaring is seen to consist of (1) a complex array of discrete loops and plumes embedded in (2) a diffuse ambient component that shows no fine structure and gradually fades with height. For each of two not-flaring active regions, found that the diffuse component is (1) approximately isothermal and hydrostatic and (2) emits well over half of the total EUV luminosity of the active-region corona. Here, from a TRACE Fe XII coronal image of another not-flaring active region, the large sunspot active region AR 10652 when it was at the west limb on 30 July 2004, we separate the diffuse component from the discrete loop component by spatial filtering, and find that the diffuse component has about 60% of the total luminosity. If under much higher spatial resolution than that of TRACE (e. g., the 0.1 arcsec/pixel resolution of the Hi-C sounding-rocket experiment proposed by J. W. Cirtain et al), most of the diffuse component remains diffuse rather being resolved into very narrow loops and plumes, this will raise the possibility that the EUV corona in active regions consists of two basically different but comparably luminous components: one being the set of discrete bright loops and plumes and the other being a truly diffuse component filling the space between the discrete loops and plumes. This dichotomy would imply that there are two different but comparably powerful coronal heating mechanisms operating in active regions, one for the distinct loops and plumes and another for the diffuse component. We present a scenario in which (1) each discrete bright loop or plume is a flux tube that was recently reconnected in a burst of reconnection, and (2) the diffuse component is heated by MHD waves that are generated by these reconnection events and by other fine-scale explosive reconnection events, most of which occur in and below the base of the corona where they are

  13. Abordaje subcraneal discusión y revisión histórica de la técnica quirúrgica Anterior subcranial approach: Discussion and historical review of the surgical technique

    OpenAIRE

    I. Zubillaga Rodríguez; G. Sánchez Aniceto; J.J. Montalvo Moreno; R. Díaz Lobato

    2009-01-01

    Introducción. La cirugía de la base craneal es en la actualidad una realidad que se ha ido consolidando en las últimas décadas. El vertiginoso avance tecnológico desarrollado ha actuado como motor en la evolución de las técnicas quirúrgicas que abordan dicha región anatómica. Su impulso definitivo se ha cimentado en el concepto básico de equipo multidisciplinario. Material y métodos. Se describe el abordaje subcraneal como alternativa a los tradicionales abordajes a la base craneal anterior. ...

  14. TRANSITION-REGION/CORONAL SIGNATURES AND MAGNETIC SETTING OF SUNSPOT PENUMBRAL JETS: HINODE (SOT/FG), Hi-C, AND SDO/AIA OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Tiwari, Sanjiv K.; Moore, Ronald L.; Winebarger, Amy R. [NASA Marshall Space Flight Center, Mail Code ZP 13, Huntsville, AL 35812 (United States); Alpert, Shane E., E-mail: sanjiv.k.tiwari@nasa.gov [Department of Physics and Astronomy, Rice University, Houston, TX 77005 (United States)

    2016-01-10

    Penumbral microjets (PJs) are transient narrow bright features in the chromosphere of sunspot penumbrae, first characterized by Katsukawa et al. using the Ca ii H-line filter on Hinode's Solar Optical Telescope (SOT). It was proposed that the PJs form as a result of reconnection between two magnetic components of penumbrae (spines and interspines), and that they could contribute to the transition region (TR) and coronal heating above sunspot penumbrae. We propose a modified picture of formation of PJs based on recent results on the internal structure of sunspot penumbral filaments. Using data of a sunspot from Hinode/SOT, High Resolution Coronal Imager, and different passbands of the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory, we examine whether PJs have signatures in the TR and corona. We find hardly any discernible signature of normal PJs in any AIA passbands, except for a few of them showing up in the 1600 Å images. However, we discovered exceptionally stronger jets with similar lifetimes but bigger sizes (up to 600 km wide) occurring repeatedly in a few locations in the penumbra, where evidence of patches of opposite-polarity fields in the tails of some penumbral filaments is seen in Stokes-V images. These tail PJs do display signatures in the TR. Whether they have any coronal-temperature plasma is unclear. We infer that none of the PJs, including the tail PJs, directly heat the corona in active regions significantly, but any penumbral jet might drive some coronal heating indirectly via the generation of Alfvén waves and/or braiding of the coronal field.

  15. Imaging solar coronal magnetic structures in 3D

    Science.gov (United States)

    Cartledge, N. P.

    The study of solar coronal structures and, in particular prominences, is a key part of understanding the highly complex physical mechanisms occurring in the Sun's atmosphere. Solar prominences are important in their own right and some of the most puzzling questions in solar theory have arisen through their study. For example, how do they form and how is their mass continuously replenished? How can the magnetic field provide their continuous support against gravity over time periods of several months? How can such cool, dense material exist in thermal equilibrium in the surrounding coronal environment? Why do they erupt? A study of their structure and that of the surrounding medium is important in determining the nature of the coronal plasma and magnetic field. Also, prominences are closely associated with other key phenomena such as coronal mass ejections and eruptive solar flares which occur as a prominence loses equilibrium and rises from the solar surface. Our current understanding of these fascinating structures is extremely limited and we know very little about their basic global structure. In fact, recent prominence observations have caused our basic paradigms to be challenged (Priest, 1996) and so we must set up new models in order to gain even a fundamental understanding. Prominences are highly nonlinear, three-dimensional structures. Large feet (or barbs) reach out from the main body of a prominence and reach down to the photosphere where the dense material continuously drains away. These provide a real clue to the three-dimensional nature of the coronal field and its relation to the photospheric field. It is important, therefore, to make stereographic observations of prominences in order to gain a basic understanding of their essentially three-dimensional nature and attempt to formulate new paradigms for their structure and evolution. There is no doubt that the study of prominences in three dimensions is a crucial exercise if we are to develop a better

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

    Science.gov (United States)

    Savcheva, A. S.; van Ballegooijen, A. A.; DeLuca, E. E.

    2012-01-01

    We present the first field topology analysis based on nonlinear force-free field (NLFFF) models of a long-lasting coronal sigmoid observed in 2007 February with the X-Ray Telescope on Hinode. The NLFFF models are built with the flux rope insertion method and give the three-dimensional coronal magnetic field as constrained by observed coronal loop structures and photospheric magnetograms. Based on these models, we have computed horizontal maps of the current and the squashing factor Q for 25 different heights in the corona for all six days of the evolution of the region. We use the squashing factor to quantify the degree of change of the field line linkage and to identify prominent quasi-separatrix layers (QSLs). We discuss the major properties of these QSL maps and devise a way to pick out important QSLs since our calculation cannot reach high values of Q. The complexity in the QSL maps reflects the high degree of fragmentation of the photospheric field. We find main QSLs and current concentrations that outline the flux rope cavity and that become characteristically S-shaped during the evolution of the sigmoid. We note that, although intermittent bald patches exist along the length of the sigmoid during its whole evolution, the flux rope remains stable for several days. However, shortly after the topology of the field exhibits hyperbolic flux tubes (HFT) on February 7 and February 12 the sigmoid loses equilibrium and produces two B-class flares and associated coronal mass ejections (CMEs). The location of the most elevated part of the HFT in our model coincides with the inferred locations of the two flares. Therefore, we suggest that the presence of an HFT in a coronal magnetic configuration may be an indication that the system is ready to erupt. We offer a scenario in which magnetic reconnection at the HFT drives the system toward the marginally stable state. Once this state is reached, loss of equilibrium occurs via the torus instability, producing a CME.

  17. Tendencias historiográficas sobre el Feudalismo tardío y su abordaje en el Nivel Medio. Reproducción y dominación material

    Directory of Open Access Journals (Sweden)

    Kozul, Pedro

    2014-06-01

    Full Text Available Resumen Resulta trascendental vislumbrar un ensayo sobre las corrientes historiográficas por las cuales los manuales secundarios abordan la transición al capitalismo, en suplencia del Antiguo Régimen, como síntesis de la imperativa lineación clásica de matriz occidental e instancia superadora del oscuro Medioevo. Dicha tesitura constituyó un marco de dominación clasista, logrando imponer una concepción histórica. Los paradigmas signados a través de ella, modificaron el foco en que el historiador concentró su análisis sobre la Modernidad y su abordaje en la escuela secundaria. Este conductismo decimonónico, materializado en las Ciencias Sociales con la premisa de Orden y Progreso, imprimió su sello afirmando una visión urbana y pacífica que debía actualizarse, por una visión interna e insurreccional de la transición, para así dejar atrás las explicaciones liberales que habían concebido al capitalismo como un fenómeno exterior al Antiguo Régimen. Abstract It is transcendental to conduct a study on the historiographical trends by which the middle schools’ handbooks approach the transition to capitalism, in substitution of the Ancient Regime, as a synthesis of the arbitrary classical synchronization from occidental matrix and the surpassing status with regard to the Medieval Dark Ages. Such position constituted a classist domination framework, imposing a historical conception. The paradigms marked by this notion, have modified the ways in which historians focus on the analysis of Modernity and its approach to middle school. This nineteenth century behaviorism, materialized in the social sciences with the premise of order and progress, imprinted a model by stating a pacific urban vision that should be updated to an internal insurrectional vision of the transition in order to leave behind the liberal explanations that had conceived capitalism as being an external phenomenon of the Ancient Regime.

  18. Coronal structure analysis based on the potential field source surface modeling and total solar eclipse observation

    Science.gov (United States)

    Muhamad, Johan; Mumtahana, Farahhati; Sutastio, Heri; Imaduddin, Irfan; Putri, Gerhana P.

    2016-11-01

    We constructed global coronal magnetic fields of the Sun during the Total Solar Eclipse (TSE) 9 March 2016 by using Potential Field Source Surface (PFSS) model. Synoptic photospheric magnetogram data from Helioseismic and Magnetic Imager (HMI) onboard Solar Dynamics Observatory (SDO) was used as a boundary condition to extrapolate the coronal magnetic fields of the Sun. This extrapolated structure was analyzed by comparing the alignment of the fields from the model with coronal structure from the observation. We also used observational data of coronal structure during the total solar eclipse to know how well the model agree with the observation. As a result, we could identify several coronal streamers which were produced by the large closed loops in the lower regime of the corona. This result verified that the PFSS extrapolation can be used as a tool to model the inner corona with several constraints. We also discussed how the coronal structure can be used to deduce the phase of the solar cycle.

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

    CERN Document Server

    Jones, Shaela I; Uritsky, Vadim M

    2015-01-01

    The coronal magnetic field directly or indirectly affects a majority of the phenomena studied in space physics. It provides energy for coronal heating, controls the release of coronal mass ejections (CMEs), and drives heliospheric and magnetospheric activity, yet the coronal magnetic field itself has proven difficult to measure. This difficulty has prompted a decades-long effort to develop accurate, timely, models of the field - an effort that continues today. We have developed a method for improving global coronal magnetic field models by incorporating the type of morphological constraints which could be derived from coronal images. Here we report promising initial tests of this approach on two theoretical problems, and discuss opportunities for application.

  20. Direct observations of magnetic flux rope formation during a solar coronal mass ejection

    OpenAIRE

    Song, Hongqiang; Zhang, Jie; Chen, Yao; Cheng, Xin

    2014-01-01

    Coronal mass ejections (CMEs) are the most spectacular eruptive phenomena in the solar atmosphere. It is generally accepted that CMEs are results of eruptions of magnetic flux ropes (MFRs). However, a heated debate is on whether MFRs pre-exist before the eruptions or they are formed during the eruptions. Several coronal signatures, \\textit{e.g.}, filaments, coronal cavities, sigmoid structures and hot channels (or hot blobs), are proposed as MFRs and observed before the eruption, which suppor...

  1. First use of synoptic vector magnetograms for global nonlinear force free coronal magnetic field models

    OpenAIRE

    Tadesse, Tilaye; Wiegelmann, T.; Gosain, S.; Macneice, P.; Pevtsov, Alexei A.

    2013-01-01

    The magnetic field permeating the solar atmosphere is generally thought to provide the energy for much of the activity seen in the solar corona, such as flares, coronal mass ejections (CMEs), etc. To overcome the unavailability of coronal magnetic field measurements, photospheric magnetic field vector data can be used to reconstruct the coronal field. Currently there are several modelling techniques being used to calculate three-dimension of the field lines into the solar atmosphere. For the ...

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

    Directory of Open Access Journals (Sweden)

    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

  3. Charge States of Solar Cosmic Rays and Constraints on Acceleration Times and Coronal Transport

    CERN Document Server

    Ruffolo, D

    1997-01-01

    We examine effects on the charge states of energetic ions associated with gradual solar flares due to shock heating and stripping at high ion velocities. Recent measurements of the mean charges of various elements after the flares of 1992 Oct 30 and 1992 Nov 2 allow one to place limits on the product of the electron density times the acceleration or coronal residence time. In particular, any residence in coronal loops must be for < 0.03 s, which rules out models of coronal transport in loops, such as the bird cage model. The results do not contradict models of shock acceleration of energetic ions from coronal plasma at various solar longitudes.

  4. The Heliocentric Distance Where the Deflections and Rotations of Solar Coronal Mass Ejections Occur

    CERN Document Server

    Kay, C

    2015-01-01

    Understanding the trajectory of a coronal mass ejection (CME), including any deflection from a radial path, and the orientation of its magnetic field is essential for space weather predictions. Kay et al. (2015b) developed a model, Forecasting a CME's Altered Trajectory (ForeCAT), of CME deflections and rotation due to magnetic forces, not including the effects of reconnection. ForeCAT is able to reproduce the deflection of observed CMEs (Kay et al. 2015a). The deflecting CMEs tend to show a rapid increase of their angular momentum close to the Sun, followed by little to no increase at farther distances. Here we quantify the distance at which the CME deflection is "determined," which we define as the distance after which the background solar wind has negligible influence on the total deflection. We consider a wide range in CME masses and radial speeds and determine that the deflection and rotation of these CMEs can be well-described by assuming they propagate with constant angular momentum beyond 10 Rs. The a...

  5. Coronal Seismology of Flare-Excited Standing Slow-Mode Waves Observed by SDO/AIA

    Science.gov (United States)

    Wang, Tongjiang; Ofman, Leon; Davila, Joseph M.

    2016-05-01

    Flare-excited longitudinal intensity oscillations in hot flaring loops have been recently detected by SDO/AIA in 94 and 131 Å bandpasses. Based on the interpretation in terms of a slow-mode wave, quantitative evidence of thermal conduction suppression in hot (>9 MK) loops has been obtained for the first time from measurements of the polytropic index and phase shift between the temperature and density perturbations (Wang et al. 2015, ApJL, 811, L13). This result has significant implications in two aspects. One is that the thermal conduction suppression suggests the need of greatly enhanced compressive viscosity to interpret the observed strong wave damping. The other is that the conduction suppression provides a reasonable mechanism for explaining the long-duration events where the thermal plasma is sustained well beyond the duration of impulsive hard X-ray bursts in many flares, for a time much longer than expected by the classical Spitzer conductive cooling. In this study, we model the observed standing slow-mode wave in Wang et al. (2015) using a 1D nonlinear MHD code. With the seismology-derived transport coefficients for thermal conduction and compressive viscosity, we successfully simulate the oscillation period and damping time of the observed waves. Based on the parametric study of the effect of thermal conduction suppression and viscosity enhancement on the observables, we discuss the inversion scheme for determining the energy transport coefficients by coronal seismology.

  6. Ubiquitous High Speed Transition Region and Coronal Upflows in the Quiet Sun

    CERN Document Server

    Mcintosh, Scott W

    2009-01-01

    We study the line profiles of a range of transition region (TR) emission lines observed in typical quiet Sun regions. In magnetic network regions, the Si IV 1402\\AA{}, C IV 1548\\AA{}, N V 1238\\AA{}, O VI 1031\\AA{}, and Ne VIII 770\\AA{} spectral lines show significant asymmetry in the blue wing of the emission line profiles. We interpret these high-velocity upflows in the lower and upper TR as the quiet Sun equivalent of the recently discovered upflows in the low corona above plage regions (Hara et al., 2008). The latter have been shown to be directly associated with high-velocity chromospheric spicules that are (partially) heated to coronal temperatures and play a significant role in supplying the active region corona with hot plasma (DePontieu et al., 2009}. We show that a similar process likely dominates the quiet Sun network. We provide a new interpretation of the observed quiet Sun TR emission in terms of the relentless mass transport between the chromosphere and corona - a mixture of emission from dynami...

  7. THERMAL NON-EQUILIBRIUM REVISITED: A HEATING MODEL FOR CORONAL LOOPS

    Energy Technology Data Exchange (ETDEWEB)

    Lionello, Roberto; Linker, Jon A.; Mikic, Zoran [Predictive Science, Inc., 9990 Mesa Rim Rd., Ste. 170, San Diego, CA 92121-2910 (United States); Winebarger, Amy R. [NASA Marshall Space Flight Center, ZP 13, Huntsville, AL 35812 (United States); Mok, Yung, E-mail: lionel@predsci.com, E-mail: linkerj@predsci.com, E-mail: mikicz@predsci.com, E-mail: amy.r.winebarger@nasa.gov, E-mail: ymok@uci.edu [Department of Physics and Astronomy, University of California, 4129 Reines Hall, Irvine, CA 92697 (United States)

    2013-08-20

    The location and frequency of events that heat the million-degree corona are still a matter of debate. One potential heating scenario is that the energy release is effectively steady and highly localized at the footpoints of coronal structures. Such an energy deposition drives thermal non-equilibrium solutions in the hydrodynamic equations in longer loops. This heating scenario was considered and discarded by Klimchuk et al. on the basis of their one-dimensional simulations as incapable of reproducing observational characteristics of loops. In this paper, we use three-dimensional simulations to generate synthetic emission images, from which we select and analyze six loops. The main differences between our model and that of Klimchuk et al. concern (1) dimensionality, (2) resolution, (3) geometrical properties of the loops, (4) heating function, and (5) radiative function. We find evidence, in this small set of simulated loops, that the evolution of the light curves, the variation of temperature along the loops, the density profile, and the absence of small-scale structures are compatible with the characteristics of observed loops. We conclude that quasi-steady footpoint heating that drives thermal non-equilibrium solutions cannot yet be ruled out as a viable heating scenario for EUV loops.

  8. Diagnosing Coronal Heating in a Survey of Active Regions using the Time Lag Method

    Science.gov (United States)

    Viall, Nicholeen; Klimchuk, James A.

    2017-08-01

    In this paper we examine 15 different active regions observed with the Solar Dynamics Observatory and analyze their nanoflare properties using the time lag method. The time lag method is a diagnostic of whether the plasma is maintained at a steady temperature, or if it is dynamic, undergoing heating and cooling cycles. An important aspect of our technique is that it analyses both observationally distinct coronal loops as well as the much more prevalent diffuse emission surrounding them. Warren et al. (2012) first studied these same 15 active regions, which are all quiescent and exhibit a broad range of characteristics, including age, total unsigned magnetic flux, area, hot emission, and emission measure distribution. We find that widespread cooling is a generic property of both loop and diffuse emission from all 15 active regions. However, the range of temperatures through which the plasma cools varies between active regions and within each active region, and only occasionally is there full cooling from above 7 MK to well below 1 MK. We find that the degree of cooling is not well correlated with slopes of the emission measure distribution measured by Warren et al. (2012). We show that these apparently contradictory observations can be reconciled with the presence of a distribution of nanoflare energies and frequencies along the line of sight, with the average delay between successive nanoflare events on a single flux tube being comparable to the plasma cooling timescale. Warren, H. P., Winebarger, A. R., & Brooks, D. H. 2012, ApJ, 759, 141

  9. Adherencia al tratamiento en personas con hipertensión arterial

    OpenAIRE

    Herrera Guerra, Eugenia

    2012-01-01

    Objetivo: describir y analizar la adherencia a tratamientos farmacológicos y no farmacológicos en personas con hipertensión arterial, inscritas en el programa de control de una empresa social del Estado (ese) de baja complejidad en Montería.Metodología: diseño descriptivo transversal, con abordaje cuantitativo, con una muestra aleatoria de 177 personas que asistieron al servicio de consulta externa a control de la hipertensión arterial, mediante el instrumento “Factores que influyen en la adh...

  10. Hidrofobia medieval: miedos y peligros vinculados al agua en la literatura castellana del XV

    OpenAIRE

    2015-01-01

    El estudio del miedo ofrece una perspectiva muy sugerente para el abordaje de la Historia de las mentalidades. Pese a que, como objeto de estudio, el miedo ha incrementado su presencia en trabajos recientes, los investigadores se han centrado en ámbitos sustancialmente diferentes al aquí tratado. El agua, fuente de energía, vía de comunicación y recurso imprescindible para toda vida, ha sido vista también con suspicacia y su contacto con ella afrontado con especial prevención, de manera absol...

  11. Condiciones sociales en torno al suicidio en la región occidental de El Salvador.

    OpenAIRE

    Serreño Menéndez, Ángel Fredi

    2011-01-01

    Definición de suicidio -- Antigüedad clásica: Algunos abordajes acerca de la moralidad del suicidio -- El suicidio en la Edad Media: Satanás y las sanciones de la Iglesia -- El Renacimiento y la popularización del suicidio -- Ser o no ser, ésa es la cuestión”: Un debate filosófico -- Suicidio en el siglo XVII: Con una legitimación del suicidio -- Iluminismo: Apología y hostilidad al suicidio -- El suicidio en el siglo XIX: la culpabilización del suicidio -- El suicidio en el siglo XX: Nuevas ...

  12. Condiciones sociales en torno al suicidio en la región occidental de El Salvador.

    OpenAIRE

    Serreño Menéndez, Ángel Fredi

    2011-01-01

    Definición de suicidio -- Antigüedad clásica: Algunos abordajes acerca de la moralidad del suicidio -- El suicidio en la Edad Media: Satanás y las sanciones de la Iglesia -- El Renacimiento y la popularización del suicidio -- Ser o no ser, ésa es la cuestión”: Un debate filosófico -- Suicidio en el siglo XVII: Con una legitimación del suicidio -- Iluminismo: Apología y hostilidad al suicidio -- El suicidio en el siglo XIX: la culpabilización del suicidio -- El suicidio en el siglo XX: Nuevas ...

  13. Transition-Region/Coronal Signatures of Penumbral Microjets: Hi-C, SDO/AIA and Hinode (SOT/FG) Observations

    Science.gov (United States)

    Tiwari, Sanjiv K.; Alpert, Shane E.; Moore, Ronald L.; Winebarger, Amy R.

    2014-01-01

    Penumbral microjets are bright, transient features seen in the chromosphere of sunspot penumbrae. Katsuaka et al. (2007) noted their ubiquity and characterized them using the Ca II H-line filter on Hinode's Solar Optical Telescope (SOT). The jets are 1000{4000 km in length, 300{400 km in width, and last less than one minute. It was proposed that these penumbral microjets could contribute to the transition-region and coronal heating above sunspots. We examine whether these microjets appear in the transition-region (TR) and/or corona or are related{ temporally and spatially{ to similar brightenings in the TR and/or corona. First, we identify penumbral microjets with the SOT's Ca II H-line filter. The chosen sunspot is observed on July 11, 2012 from 18:50:00 UT to 20:00:00 UT at approx. 14 inches, -30 inches. We then examine the sunspot in the same field of view and at the same time in other wavelengths. We use the High Resolution Coronal Imager Telescope (Hi-C) at 193A and the 1600A, 304A, 171A, 193A, and 94A passbands of the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamic Observatory. We include examples of these jets and where they should appear in the other passbands, but find no signifcant association, except for a few jets with longer lifetimes and bigger sizes seen at locations in the penumbra with repeated stronger brightenings. We conclude that the normal microjets are not heated to transition-region/coronal temperatures, but the larger jets are.

  14. 351. Toracotomía bilateral (técnica de clamshell para abordaje de patología compleja de aorta torácica y arco en un solo tiempo

    Directory of Open Access Journals (Sweden)

    S. Villar

    2012-04-01

    Conclusiones: En nuestra experiencia, el abordaje tipo clamshell es útil en tratamiento de patología extensa y compleja de arco aórtico y aorta torácica. Destaca la necesidad de ventilación mecánica prolongada, complicación derivada del tipo de procedimiento.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    Bo Li; Xing Li; Hui Yu

    2012-01-01

    The origin of the heliospheric magnetic flux on the Sun,and hence the origin of the solar wind,is a topic of hot debate.While the prevailing view is that the solar wind originates from outside the coronal streamer helmets,there also exists the suggestion that the open magnetic field spans a far wider region.Without the definitive measurement of the coronal magnetic field,it is difficult to unambiguously resolve the conflict between the two scenarios.We present two 2-dimensional,Alfvénic-turbulence-based models of the solar corona and solar wind,one with and the other without a closed magnetic field region in the inner corona.The purpose of the latter model is to test whether it is possible to realize a picture suggested by polarimetric measurements of the corona using the Fe ⅩⅢ 10747(A) line,where open magnetic field lines seem to penetrate the streamer base.The boundary conditions at the coronal base are able to account for important observational constraints,especially those on the magnetic flux distribution.Interestingly,the two models provide similar polarized brightness (pB) distributions in the field of view (FOV) of SOHO/LASCO C2 and C3 coronagraphs.In particular,a dome-shaped feature is present in the C2 FOV even for the model without a closed magnetic field.Moreover,both models fit the Ulysses data scaled to 1 AU equally well.We suggest that:1) The pB observations cannot be safely taken as a proxy for the magnetic field topology,as is often implicitly assumed.2) The Ulysses measurements,especially the one showing a nearly uniform distribution with heliocentric latitude of the radial magnetic field,do not rule out the ubiquity of open magnetic fields on the Sun.

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

    Science.gov (United States)

    Krista, Larisza; Gallagher, P.

    2011-05-01

    As solar activity is the foremost important aspect of space weather, the forecasting of flare and CME related transient geomagnetic storms has become a primary initiative. Minor magnetic storms caused by coronal holes (CHs) have also proven to be important due to their long-lasting and recurrent geomagnetic effects. In order to forecast CH related geomagnetic storms, the author developed the Coronal Hole Automated Recognition and Monitoring (CHARM) algorithm to replace the user-dependent CH detection methods commonly used. CHARM uses an intensity thresholding method to identify low intensity regions in EUV or X-ray images. Since CHs are regions of "open” magnetic field and predominant polarity, magnetograms were used to differentiate CHs from other low intensity regions. The Coronal Hole Evolution (CHEVOL) algorithm was developed and used in conjunction with CHARM to study the boundary evolution of CHs. It is widely accepted that the short-term changes in CH boundaries are due to the interchange reconnection between the CH open field lines and small loops. We determined the magnetic reconnection rate and the diffusion coefficient at CH boundaries in order to test the interchange reconnection model. The author also developed the Minor Storm (MIST) package to link CHs to high-speed solar wind (HSSW) periods detected at Earth. Using the algorithm the relationship between CHs, the corresponding HSSW properties, and geomagnetic indices were studied between 2000-2009. The results showed a strong correlation between the velocity and HSSW proton plasma temperature, which indicates that the heating and acceleration of the solar wind plasma in CHs are closely related, and perhaps caused by the same mechanism. The research presented here includes analysis of CHs on small and large spatial/temporal scales, allowing us to further our understanding of CHs as a whole.

  18. Coronal Loops: Observations and Modeling of Confined Plasma

    Directory of Open Access Journals (Sweden)

    Fabio Reale

    2014-07-01

    Full Text Available Coronal loops are the building blocks of the X-ray bright solar corona. They owe their brightness to the dense confined plasma, and this review focuses on loops mostly as structures confining plasma. After a brief historical overview, the review is divided into two separate but not independent parts: the first illustrates the observational framework, the second reviews the theoretical knowledge. Quiescent loops and their confined plasma are considered and, therefore, topics such as loop oscillations and flaring loops (except for non-solar ones, which provide information on stellar loops are not specifically addressed here. The observational section discusses the classification, populations, and the morphology of coronal loops, its relationship with the magnetic field, and the loop stranded structure. The section continues with the thermal properties and diagnostics of the loop plasma, according to the classification into hot, warm, and cool loops. Then, temporal analyses of loops and the observations of plasma dynamics, hot and cool flows, and waves are illustrated. In the modeling section, some basics of loop physics are provided, supplying fundamental scaling laws and timescales, a useful tool for consultation. The concept of loop modeling is introduced and models are divided into those treating loops as monolithic and static, and those resolving loops into thin and dynamic strands. More specific discussions address modeling the loop fine structure and the plasma flowing along the loops. Special attention is devoted to the question of loop heating, with separate discussion of wave (AC and impulsive (DC heating. Large-scale models including atmosphere boxes and the magnetic field are also discussed. Finally, a brief discussion about stellar coronal loops is followed by highlights and open questions.

  19. Geoeffectiveness of Coronal Mass Ejections in the SOHO Era

    DEFF Research Database (Denmark)

    Dumbovic, M.; Devos, A.; Vrsnak, B.;

    2014-01-01

    The main objective of the study is to determine the probability distributions of the geomagnetic Dst index as a function of the coronal mass ejection (CME) and solar flare parameters for the purpose of establishing a probabilistic forecast tool for the geomagnetic storm intensity. Several CME...... and flare parameters as well as the effect of successive-CME occurrence in changing the probability for a certain range of Dst index values, were examined. The results confirm some of already known relationships between remotely-observed properties of solar eruptive events and geomagnetic storms, namely...

  20. 3D reconstruction methods of coronal structures by radio observations

    Science.gov (United States)

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

    1992-01-01

    The ability to carry out the three dimensional (3D) reconstruction of structures in the solar corona would represent a major advance in the study of the physical properties in active regions and in flares. Methods which allow a geometric reconstruction of quasistationary coronal structures (for example active region loops) or dynamic structures (for example flaring loops) are described: stereoscopy of multi-day imaging observations by the VLA (Very Large Array); tomography of optically thin emission (in radio or soft x-rays); multifrequency band imaging by the VLA; and tracing of magnetic field lines by propagating electron beams.

  1. Magnetic fields, plasmas, and coronal holes - The inner solar system

    Science.gov (United States)

    Burlaga, L. F.

    1979-01-01

    Recent results concerning streams and magnetic fields in the inner solar system are reviewed. Observations have shown that MHD streams are bounded by thin shear layers within 1 AU, probably because they originate in coronal holes which have sharp boundaries. The properties of Alfvenic fluctuations in streams cannot be fully explained on the basis of the hypothesis that they are plane, transverse Alfven waves. A more complete and accurate description might be that they represent nonplanar general Alfven waves weakly coupled to a compressive mode and moving through a medium containing tangential discontinuities and other convected inhomogeneities.

  2. Huge Coronal Structure and Heating Constraints Determined from Serts Observations

    Science.gov (United States)

    Falconer, D. A.; Davila, J. M.

    2001-01-01

    Intensities of the extreme-ultraviolet (EUV) spectral lines were measured as a function of radius off the solar limb by two flights of the Goddard's Solar Extreme-Ultraviolet Rocket Telescope and Spectrograph (SERTS) for three quiet-Sun regions. Density scale heights were determined for the different spectral lines. Limits on the filling factor were determined. In the one case where an upper limit was determined it was much less than unity. coronal heating above 1.15 solar radii is required for all three regions studied. For reasonable filling factors, local heating is needed.

  3. Arquitectura en tejidos degradados de alta vulnerabilidad: "del caos al orden, de la simplicidad a la complejidad, de la dispersión a la estructuración, de la improbabilidad a la probabilidad y de la ignorancia al conocimiento"

    OpenAIRE

    Moyano Molina, Ana M.

    2016-01-01

    El abordaje científico, en tiempo real de actuación, de intervenciones sistemáticas en tejidos degradados de alta vulnerabilidad , materializa la heterogeneidad semántica de los registros de la experiencia colectiva, atendiendo una realidad que se despliega sobre un espacio multidimensional donde todo está relacionado con todo, en diferentes grados de intensidad, magnitud y frecuencia: el mundo real tiende realmente al desorden, al caos más que al cosmos. Crear espacios híbridos inclusivos, d...

  4. Arquitectura en tejidos degradados de alta vulnerabilidad: "del caos al orden, de la simplicidad a la complejidad, de la dispersión a la estructuración, de la improbabilidad a la probabilidad y de la ignorancia al conocimiento"

    OpenAIRE

    Moyano Molina, Ana M.

    2016-01-01

    El abordaje científico, en tiempo real de actuación, de intervenciones sistemáticas en tejidos degradados de alta vulnerabilidad , materializa la heterogeneidad semántica de los registros de la experiencia colectiva, atendiendo una realidad que se despliega sobre un espacio multidimensional donde todo está relacionado con todo, en diferentes grados de intensidad, magnitud y frecuencia: el mundo real tiende realmente al desorden, al caos más que al cosmos. Crear espacios híbridos inclusivos, d...

  5. Linfangioma quístico axilar gigante del adulto: características de presentación y abordaje quirúrgico

    Directory of Open Access Journals (Sweden)

    A. Navarro-Mancía

    2015-09-01

    Full Text Available Presentamos el abordaje clínico de un caso que se une a los 5 únicos publicados de condición clínica similar encontrados después de una revisión sistemática en la red de información médica en publicaciones disponibles. Se trata de un paciente adulto que presentaba una tumoración quística en la región axilar sin evidencia conocida de causalidad, con crecimiento gradual hasta alcanzar un gran volumen, y asintomática. El diagnóstico final fue de linfangioma quístico axilar gigante. Ante esta entidad clínica, de rara incidencia en la población adulta, es necesaria una cuidadosa planificación de tratamiento a fin de obtener un resultado satisfactorio. Es por ello que lo más relevante del abordaje quirúrgico en nuestro caso fue la necesidad de una disección meticulosa hasta lograr la identificación precisa de los vasos linfáticos aferentes de llenado, su sección y ligadura, para reducir el riesgo de recidiva. Todo lo anterior también se aplica para las tumoraciones de origen linfático congénitas, que son considerablemente más frecuentes en esta región anatómica en comparación con las que se dan en el paciente adulto.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. Chromospheric and Coronal Activity in the 500 Myr old Open Cluster M37: Evidence for Coronal Stripping?

    Science.gov (United States)

    Núñez, Alejandro; Agüeros, Marcel A.; Covey, Kevin R.; López-Morales, Mercedes

    2017-01-01

    We present the results of a spectroscopic survey to characterize chromospheric activity, as measured by {{H}}α emission, in low-mass members of the 500 Myr old open cluster M37. Combining our new measurements of {{H}}α luminosities ({L}{{H}α }) with previously cataloged stellar properties, we identify saturated and unsaturated regimes in the dependence of the {L}{{H}α }-to-bolometric luminosity ratio, {L}{{H}α }/{L}{bol}, on the Rossby number R o . All rotators with R o smaller than 0.03 ± 0.01 converge to an activity level of {L}{{H}α }/{L}{bol}=(1.27+/- 0.02)× {10}-4. This saturation threshold ({R}o,{sat}=0.03+/- 0.01) is statistically smaller than that found in most studies of the rotation–activity relation. In the unsaturated regime, slower rotators have lower levels of chromospheric activity, with {L}{{H}α }/{L}{bol}(R o ) following a power-law of index β =-0.51+/- 0.02, slightly shallower than that found for a combined ≈650 Myr old sample of Hyades and Praesepe stars. By comparing this unsaturated behavior to that previously found for coronal activity in M37 (as measured via the X-ray luminosity, {L}{{X}}), we confirm that chromospheric activity decays at a much slower rate than coronal activity with increasing R o . While a comparison of {L}{{H}α } and {L}{{X}} for M37 members with measurements of both reveals a nearly 1:1 relation, removing the mass-dependencies by comparing instead {L}{{H}α }/{L}{bol} and {L}{{X}}/{L}{bol} does not provide clear evidence for such a relation. Finally, we find that {R}o,{sat} is smaller for our chromospheric than for our coronal indicator of activity ({R}o,{sat}=0.03+/- 0.01 versus 0.09 ± 0.01). We interpret this as possible evidence for coronal stripping.

  8. Converging Supergranular Flows and the Formation of Coronal Plumes

    Science.gov (United States)

    Wang, Y.-M.; Warren, H. P.; Muglach, K.

    2016-01-01

    Earlier studies have suggested that coronal plumes are energized by magnetic reconnection between unipolar flux concentrations and nearby bipoles, even though magnetograms sometimes show very little minority-polarity flux near the footpoints of plumes. Here we use high-resolution extreme-ultraviolet (EUV) images and magnetograms from the Solar Dynamics Observatory (SDO) to clarify the relationship between plume emission and the underlying photospheric field. We find that plumes form where unipolar network elements inside coronal holes converge to form dense clumps, and fade as the clumps disperse again. The converging flows also carry internetwork fields of both polarities. Although the minority-polarity flux is sometimes barely visible in the magnetograms, the corresponding EUV images almost invariably show loop-like features in the core of the plumes, with the fine structure changing on timescales of minutes or less. We conclude that the SDO observations are consistent with a model in which plume emission originates from interchange reconnection in converging flows, with the plume lifetime being determined by the approximately 1-day evolutionary timescale of the supergranular network. Furthermore, the presence of large EUV bright points and/or ephemeral regions is not a necessary precondition for the formation of plumes, which can be energized even by the weak, mixed-polarity internetwork fields swept up by converging flows.

  9. Impulsively Driven Waves And Flows In Coronal Active Regions

    Science.gov (United States)

    Ofman, Leon; Wang, T.; Davila, J. M.; Liu, W.

    2012-05-01

    Recent SDO/AIA and Hinode EIS observations indicate that both (super) fast and slow magnetosonic waves are present in active region (AR) magnetic structures. Evidence for fast (100-300 km/s) impulsive flows is found in spectroscopic and imaging observations of AR loops. The super-fast waves were observed in magnetic funnels of ARs. The observations suggest that waves and flow are produced by impulsive events, such as (micro) flares. We have performed three-dimensional magnetohydrodynamic (3D MHD) simulations of impulsively generated flows and waves in coronal loops of a model bi-polar active region (AR). The model AR is initiated with a dipole magnetic field and gravitationally stratified density, with impulsively driven flow at the coronal base of the AR in localized magnetic field structures. We model the excitation of the flows in hot (6MK) and cold (1MK) active region plasma, and find slow and fast magnetosonic waves produced by these events. We also find that high-density (compared to surrounding corona) loops are produced as a result of the upflows. We investigate the parametric dependence between the properties of the impulsive flows and the waves. The results of the 3D MHD modeling study supports the conjecture that slow magnetosonic waves are often produced by impulsive upflows along the magnetic field, and fast magnetosonic waves can result from impulsive transverse field line perturbations associated with reconnection events. The waves and flows can be used for diagnostic of AR structure and dynamics.

  10. The 3D structure of Coronal Mass Ejections

    Science.gov (United States)

    Patsourakos, Spiros

    2016-07-01

    Coronal Mass Ejections (CMEs) represent one of the most powerful energy release phenomena in the entire solar system and are a major driver of space weather. Prior to 2006, our observational access to CMEs was limited to single viewpoint remote sensing observations in the inner/outer corona, and in-situ observations further away, e.g. at 1 AU. Taking all these factors together, turned out to be a major obstacle in our understanding and characterizing of the 3D structure and evolution of CMEs. The situation improved dramatically with the availability of multi-viewpoint imaging observations of CMEs, all way through from the Sun to 1 AU, from the STEREO mission since 2006, combined with observations from other missions (SOHO, Hinode, SDO, IRIS). With this talk we will discuss several key recent results in CME science resulting from the analysis of multi-viewpoint observations. This includes: (1) shape and structure; (2) kinematics and energetics; (3) trajectories, deflections and rotations; (4) arrival times and velocities at 1 AU; (5) magnetic field structure; (6) relationships with coronal and interplanetary shocks and solar energetic particles. The implications of these results in terms of CME theories and models will be also addressed. We will conclude with a discussion of important open issues in our understanding of CMEs and how these could be addressed with upcoming (Solar Orbiter, Solar Probe Plus) and under-study missions (e.g., L5).

  11. Swift X-ray monitoring of M dwarf coronal variability

    Science.gov (United States)

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

    2017-01-01

    We present new Swift observations of two M dwarfs with known exoplanets: GJ 15A and GJ 674. GJ 15A b is around 5.3 Earth masses with an 11.4 day orbital period, while GJ 674 is around 11.1 Earth masses with a 4.7 day orbital period. GJ 15A was observed several times in late 2014 and then monitored at approximately weekly intervals for several months in early 2016, for a total exposure of 18 ks. GJ 674 was monitored at approximately weekly intervals for most of 2016, for a total exposure of 40 ks. We provide light curves and hardness ratios for both sources, and also compare to earlier archival X-ray data. Both sources show significant X-ray variability, including between consecutive observations. We quantify the energy distribution for coronal flaring, and compare to optical results for M dwarfs from Kepler. Finally, we discuss the implications of M dwarf coronal activity for exoplanets orbiting within the nominal habitable zone.

  12. AN MHD AVALANCHE IN A MULTI-THREADED CORONAL LOOP

    Energy Technology Data Exchange (ETDEWEB)

    Hood, A. W.; Cargill, P. J.; Tam, K. V. [School of Mathematics and Statistics, University of St Andrews, St Andrews, Fife, KY16 9SS (United Kingdom); Browning, P. K., E-mail: awh@st-andrews.ac.uk [School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester, M13 9PL (United Kingdom)

    2016-01-20

    For the first time, we demonstrate how an MHD avalanche might occur in a multithreaded coronal loop. Considering 23 non-potential magnetic threads within a loop, we use 3D MHD simulations to show that only one thread needs to be unstable in order to start an avalanche even when the others are below marginal stability. This has significant implications for coronal heating in that it provides for energy dissipation with a trigger mechanism. The instability of the unstable thread follows the evolution determined in many earlier investigations. However, once one stable thread is disrupted, it coalesces with a neighboring thread and this process disrupts other nearby threads. Coalescence with these disrupted threads then occurs leading to the disruption of yet more threads as the avalanche develops. Magnetic energy is released in discrete bursts as the surrounding stable threads are disrupted. The volume integrated heating, as a function of time, shows short spikes suggesting that the temporal form of the heating is more like that of nanoflares than of constant heating.

  13. Physical properties of erupting plasma associated with coronal mass ejections

    Science.gov (United States)

    Lee, J.; Raymond, J. C.; Reeves, K. K.; Moon, Y.; Kim, K.

    2013-12-01

    We investigate the physical properties (temperature, density, and mass) of erupting plasma observed in X-rays and EUV, which are all associated with coronal mass ejections observed by SOHO/LASCO. The erupting plasmas are observed as absorption or emission features in the low corona. The absorption feature provides a lower limit to the cold mass while the emission feature provides an upper limit to the mass of observed plasma in X-ray and EUV. We compare the mass constraints for each temperature response and find that the mass estimates in EUV and XRT are smaller than the total mass in the coronagraph. Several events were observed by a few passbands in the X-rays, which allows us to determine the temperature of the eruptive plasma using a filter ratio method. The temperature of one event is estimated at about 8.6 MK near the top of the erupting plasma. This measurement is possibly an average temperature for higher temperature plasma because the XRT is more sensitive at higher temperatures. In addition, a few events show that the absorption features of a prominence or a loop change to emission features with the beginning of their eruptions in all EUV wavelengths of SDO/AIA, which indicates the heating of the plasma. By estimating the physical properties of the erupting plasmas, we discuss the heating of the plasmas associated with coronal mass ejections in the low corona.

  14. Observing the formation of flare-driven coronal rain

    CERN Document Server

    Scullion, E; Antolin, P; Wedemeyer, S; Vissers, G; Kontar, E P; Gallagher, P

    2016-01-01

    Flare-driven coronal rain can manifest from rapidly cooled plasma condensations near coronal loop-tops in thermally unstable post-flare arcades. We detect 5 phases that characterise the post-flare decay: heating, evaporation, conductive cooling dominance for ~120 s, radiative / enthalpy cooling dominance for ~4700 s and finally catastrophic cooling occurring within 35-124 s leading to rain strands with s periodicity of 55-70 s. We find an excellent agreement between the observations and model predictions of the dominant cooling timescales and the onset of catastrophic cooling. At the rain formation site we detect co-moving, multi-thermal rain clumps that undergo catastrophic cooling from ~1 MK to ~22000 K. During catastrophic cooling the plasma cools at a maximum rate of 22700 K s-1 in multiple loop-top sources. We calculated the density of the EUV plasma from the DEM of the multi-thermal source employing regularised inversion. Assuming a pressure balance, we estimate the density of the chromospheric componen...

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

    LENUS (Irish Health Repository)

    Tormey, W P

    2012-01-10

    BACKGROUND: The elevated risk of triggering a myocardial infarction by smoking cannabis is limited to the first 2 h after smoking. AIM: To examine the possible role of cannabis in cardiac deaths. CASES AND RESULTS: From 3,193 coroners\\' cases over 2 years, there were 13 cases where the clinical information was compatible with a primary cardiac cause of death. An inquest was held in three cases. Myocardial infarction was the primary cause of death in 54%. Other causes were sudden adult death syndrome, sudden death in epilepsy, and poisoning by alcohol and diazepam. Cannabis was mentioned once only on a death certificate, but not as a cause of death. Blood delta9-tetrahydrocannabinol-carboxylic acid was recorded in one case and in no case was plasma tetrahydrocannabinol (THC) measured. CONCLUSIONS: To attribute sudden cardiac death to cannabis, plasma THC should be measured in the toxicology screen in coroners\\' cases where urine cannabinoids are positive. A positive urine cannabinoids immunoassay alone is insufficient evidence in the linkage of acute cardiac death and cannabis.

  16. CONVERGING SUPERGRANULAR FLOWS AND THE FORMATION OF CORONAL PLUMES

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y.-M.; Warren, H. P. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Muglach, K., E-mail: yi.wang@nrl.navy.mil, E-mail: harry.warren@nrl.navy.mil, E-mail: karin.muglach@nasa.gov [Code 674, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2016-02-20

    Earlier studies have suggested that coronal plumes are energized by magnetic reconnection between unipolar flux concentrations and nearby bipoles, even though magnetograms sometimes show very little minority-polarity flux near the footpoints of plumes. Here we use high-resolution extreme-ultraviolet (EUV) images and magnetograms from the Solar Dynamics Observatory (SDO) to clarify the relationship between plume emission and the underlying photospheric field. We find that plumes form where unipolar network elements inside coronal holes converge to form dense clumps, and fade as the clumps disperse again. The converging flows also carry internetwork fields of both polarities. Although the minority-polarity flux is sometimes barely visible in the magnetograms, the corresponding EUV images almost invariably show loop-like features in the core of the plumes, with the fine structure changing on timescales of minutes or less. We conclude that the SDO observations are consistent with a model in which plume emission originates from interchange reconnection in converging flows, with the plume lifetime being determined by the ∼1 day evolutionary timescale of the supergranular network. Furthermore, the presence of large EUV bright points and/or ephemeral regions is not a necessary precondition for the formation of plumes, which can be energized even by the weak, mixed-polarity internetwork fields swept up by converging flows.

  17. Soft X-ray emission in flaring coronal loops

    CERN Document Server

    Pinto, R F; Brun, A S

    2014-01-01

    Solar flares are associated with intense soft X-ray emission generated by the hot flaring plasma in coronal magnetic loops. Kink unstable twisted flux-ropes provide a source of magnetic energy which can be released impulsively and account for the heating of the plasma in flares. We investigate the temporal, spectral and spatial evolution of the properties of the thermal X-ray emission produced in such kink-unstable magnetic flux-ropes using a series of MHD simulations. We deduce emission diagnostics and their temporal evolution and discuss the results of the simulations with respect to observations. The numerical setup used consists of a highly twisted loop embedded in a region of uniform and untwisted background coronal magnetic field. We let the kink instability develop, compute the evolution of the plasma properties in the loop (density, temperature) and deduce the X-ray emission properties of the plasma during the whole flaring episode. During the initial phase of the instability plasma heating is mostly ...

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

    CERN Document Server

    Feng, S W; Song, H Q; Wang, B; Kong, X L

    2016-01-01

    Solar coronal radio bursts are enhanced radio emission excited by energetic electrons accelerated during solar eruptions, studies on which are important for investigating the origin and physical mechanism of energetic particles and further diagnosing coronal parameters. Earlier studies suffered from a lack of simultaneous high-quality imaging data of the radio burst and the eruptive structure in the inner corona. Here we present a study on a complex solar radio eruption consisting of a type II and three reversely-drifting type III bursts, using simultaneous EUV and radio imaging data. It is found that the type II burst is closely associated with a propagating and evolving CME-driven EUV shock structure, originated initially at the northern shock flank and later transferred to the top part of the shock. This source transfer is co-incident with the presence of shock decay and enhancing signatures observed at the corresponding side of the EUV front. The electron energy accelerated by the shock at the flank is es...

  19. In What Magnetic Environment Are Coronal Loop Plasmas Located?

    Science.gov (United States)

    Lim, Daye; Choe, Gwang-Son

    2017-08-01

    As for coronal loops, there is a conventional wisdom that the plasma is confined inside magnetic flux tubes. However, a plasma pressure profile, which decreases from the center of a flux rope to its periphery, can be ideal MHD interchange unstable if field line ends are freely movable. In the solar corona, the strong line-tying condition impedes the interchange of the positions of elementary flux tubes, but ubiquitous magnetic reconnection processes can change plasma distribution in such a way that the system moves to a more stable state with a lower energy. In this study, we investigate the plasma redistribution in the merging process of many small flux ropes possibly representing loop strands, by an MHD simulation. We have found that the redistributed plasma is more concentrated between flux ropes rather than near the center of individual flux ropes. When flux ropes initially have different amounts of twists, the plasma tends to accumulate in less twisted regions. As larger and larger flux ropes are formed by successive merging processes, the ratio of poloidal flux to toroidal flux in a merged flux rope becomes smaller and smaller, i.e., field lines are less and less twisted. Our study may explain why the observed coronal loops appear very little twisted and quite well ordered in spite of continuous entangling motions in the photosphere and below.

  20. Global Energetics in Solar Flares and Coronal Mass Ejections

    Science.gov (United States)

    Aschwanden, Markus J.

    2017-08-01

    We present a statistical study of the energetics of coronal mass ejections (CME) and compare it with the magnetic, thermal, and nonthermal energy dissipated in flares. The physical parameters of CME speeds, mass, and kinetic energies are determined with two different independent methods, i.e., the traditional white-light scattering method using LASCO/SOHO data, and the EUV dimming method using AIA/SDO data. We analyze all 860 GOES M- and X-class flare events observed during the first 7 years (2010-2016) of the SDO mission. The new ingredients of our CME modeling includes: (1) CME geometry in terms of a self-similar adiabatic expansion, (2) DEM analysis of CME mass over entire coronal temperature range, (3) deceleration of CME due to gravity force which controls the kinetic and potentail CME energy as a function of time, (4) the critical speed that controls eruptive and confined CMEs, (5) the relationship between the center-of-mass motion during EUV dimming and the leading edge motion observed in white-light coronagraphs. Novel results are: (1) Physical parameters obtained from both the EUV dimming and white-light method can be reconciled; (2) the equi-partition of CME kinetic and thermal flare energy; (3) the Rosner-Tucker-Vaiana scaling law. We find that the two methods in EUV and white-light wavelengths are highly complementary and yield more complete models than each method alone.