Cuerpo extraño en vía bronquial.Reporte de un caso

Mujer de 39 años de edad, que ingresó a la institución por presentar disnea leve, tos, sibilantes; además de notar que no contaba con una pieza dental provisional colocada pocos días atrás. Se logró localizar el cuerpo extraño con la ayuda de una tomografía de tórax y se extrajo mediante broncofibroscopía flexible.A 39-year-old woman was admitted to this institution because she had mild dyspnea, cough, wheezings, and noticed the absence of a dental prosthesis that was placed a few days before. The foreign body was localized by tomography, and the remotion was successful with flexible bronchoscopic

He II λ4686 in η Carinae: Collapse of the wind-wind collision region during periastron passage

The periodic spectroscopic events in η Carinae are now well established and occur near the periastron passage of two massive stars in a very eccentric orbit. Several mechanisms have been proposed to explain the variations of different spectral features, such as an eclipse by the wind-wind collision (WWC) boundary, a shell ejection from the primary star or accretion of its wind onto the secondary. All of them have problems explaining all the observed phenomena. To better understand the nature of the cyclic events, we performed a dense monitoring of η Carinae with five Southern telescopes during the 2009 low-excitation event, resulting in a set of data of unprecedented quality and sampling. The intrinsic luminosity of the He II λ4686 emission line (L 310 L) just before periastron reveals the presence of a very luminous transient source of extreme UV radiation emitted in the WWC region. Clumps in the primary's wind probably explain the flare-like behavior of both the X-ray and He II λ4686 light curves. After a short-lived minimum, He II λ4686 emission rises again to a new maximum, when X-rays are still absent or very weak. We interpret this as a collapse of the WWC onto the "surface" of the secondary star, switching off the hard X-ray source and diminishing the WWC shock cone. The recovery from this state is controlled by the momentum balance between the secondary's wind and the clumps in the primary's wind.Facultad de Ciencias Astronómicas y Geofísica

He II λ4686 in η Carinae: Collapse of the wind-wind collision region during periastron passage

The periodic spectroscopic events in η Carinae are now well established and occur near the periastron passage of two massive stars in a very eccentric orbit. Several mechanisms have been proposed to explain the variations of different spectral features, such as an eclipse by the wind-wind collision (WWC) boundary, a shell ejection from the primary star or accretion of its wind onto the secondary. All of them have problems explaining all the observed phenomena. To better understand the nature of the cyclic events, we performed a dense monitoring of η Carinae with five Southern telescopes during the 2009 low-excitation event, resulting in a set of data of unprecedented quality and sampling. The intrinsic luminosity of the He II λ4686 emission line (L 310 L) just before periastron reveals the presence of a very luminous transient source of extreme UV radiation emitted in the WWC region. Clumps in the primary's wind probably explain the flare-like behavior of both the X-ray and He II λ4686 light curves. After a short-lived minimum, He II λ4686 emission rises again to a new maximum, when X-rays are still absent or very weak. We interpret this as a collapse of the WWC onto the "surface" of the secondary star, switching off the hard X-ray source and diminishing the WWC shock cone. The recovery from this state is controlled by the momentum balance between the secondary's wind and the clumps in the primary's wind.Facultad de Ciencias Astronómicas y Geofísica

He II λ4686 in η Carinae: Collapse of the wind-wind collision region during periastron passage

The periodic spectroscopic events in η Carinae are now well established and occur near the periastron passage of two massive stars in a very eccentric orbit. Several mechanisms have been proposed to explain the variations of different spectral features, such as an eclipse by the wind-wind collision (WWC) boundary, a shell ejection from the primary star or accretion of its wind onto the secondary. All of them have problems explaining all the observed phenomena. To better understand the nature of the cyclic events, we performed a dense monitoring of η Carinae with five Southern telescopes during the 2009 low-excitation event, resulting in a set of data of unprecedented quality and sampling. The intrinsic luminosity of the He II λ4686 emission line (L 310 L) just before periastron reveals the presence of a very luminous transient source of extreme UV radiation emitted in the WWC region. Clumps in the primary's wind probably explain the flare-like behavior of both the X-ray and He II λ4686 light curves. After a short-lived minimum, He II λ4686 emission rises again to a new maximum, when X-rays are still absent or very weak. We interpret this as a collapse of the WWC onto the "surface" of the secondary star, switching off the hard X-ray source and diminishing the WWC shock cone. The recovery from this state is controlled by the momentum balance between the secondary's wind and the clumps in the primary's wind.Facultad de Ciencias Astronómicas y Geofísica

Local hydrological conditions influence tree diversity and composition across the Amazon basin

Tree diversity and composition in Amazonia are known to be strongly determined by the water supplied by precipitation. Nevertheless, within the same climatic regime, water availability is modulated by local topography and soil characteristics (hereafter referred to as local hydrological conditions), varying from saturated and poorly drained to well-drained and potentially dry areas. While these conditions may be expected to influence species distribution, the impacts of local hydrological conditions on tree diversity and composition remain poorly understood at the whole Amazon basin scale. Using a dataset of 443 1-ha non-flooded forest plots distributed across the basin, we investigate how local hydrological conditions influence 1) tree alpha diversity, 2) the community-weighted wood density mean (CWM-wd) – a proxy for hydraulic resistance and 3) tree species composition. We find that the effect of local hydrological conditions on tree diversity depends on climate, being more evident in wetter forests, where diversity increases towards locations with well-drained soils. CWM-wd increased towards better drained soils in Southern and Western Amazonia. Tree species composition changed along local soil hydrological gradients in Central-Eastern, Western and Southern Amazonia, and those changes were correlated with changes in the mean wood density of plots. Our results suggest that local hydrological gradients filter species, influencing the diversity and composition of Amazonian forests. Overall, this study shows that the effect of local hydrological conditions is pervasive, extending over wide Amazonian regions, and reinforces the importance of accounting for local topography and hydrology to better understand the likely response and resilience of forests to increased frequency of extreme climate events and rising temperatures

Local hydrological conditions influence tree diversity and composition across the Amazon basin.

Na Publicação: Carolina V. Castilho; Joice Ferreira

Enhancing regional capacity in chronic disease surveillance in the Americas Medidas para reforzar la vigilancia de las enfermedades crónicas en las Américas

Existe la necesidad de reforzar la capacidad regional para la vigilancia de las enfermedades crónicas en las Américas. Los objetivos de este artículo son 1) ofrecer nuestro apoyo decidido a favor de la vigilancia de las enfermedades crónicas, 2) presentar una revisión descriptiva y un resumen de las actividades de vigilancia y los problemas en torno a las mismas en las Américas, 3) confeccionar una lista de recursos y fuentes de consulta para obtener más información, y 4) ofrecer unas recomendaciones para reforzar la capacidad regional. Este artículo se basa en una revisión personal de informes, sitios de Internet y apuntes personales procedentes de diversos proyectos, reuniones y actividades relacionados con la vigilancia de las enfermedades crónicas en las Américas, y en un análisis a profundidad de los materiales recopilados. Se ha determinado que las agencias sanitarias internacionales, los gobiernos de diversos países, las organizaciones no gubernamentales y los profesionales de la sanidad pública han dedicado grandes esfuerzos a la construcción y al desarrollo de las capacidades de vigilancia de las enfermedades crónicas en la Región. Para seguir apoyando el aumento de dichas capacidades, se hace necesario establecer una red de redes (una metarred) cuya misión debería ser la vigilancia de la vigilancia. Siete aspectos importantes para el aumento de esta capacidad son la estrategia, la colaboración, la información, la educación, la novedad, la comunicación, y la evaluación