139 research outputs found

    3D-imaging of foraminifera by X-ray microtomography

    Get PDF
    Abstrac

    Cefalea post- punción dural

    Get PDF
    Post-dural puncture headache (HPDP) is a widely known pathology, which occurs as the main complication after performing a diagnostic and treatment procedure which is spinal puncture, this is characterized by the leakage of cerebrospinal fluid with subsequent decrease in intracranial pressure, it is distinguished by a series of manifestations among them the most important intense headache, dull, non-pulsating type, generally of fronto-occipital location, which worsens the first 15 minutes after rising and improves in 15 minutes after change to supine position, the diagnosis is clinical but when it is not clear it can be confirmed with imaging tests, treatment should be done as soon as possible and divided into conservative and interventional, the choice will depend on the symptoms. This article will summarize pathophysiology, incidence, risk factors, clinical presentation, prevention, diagnosis and treatments.La cefalea post-punción dural (CPPD) es una patología de amplio conocimiento, la cual se produce como principal complicación posterior a realizar un procedimiento de diagnóstico y tratamiento el cual es la punción espinal. Este se caracteriza por la fuga de líquido cefalorraquídeo con posterior disminución de la presión intracraneal. Se distingue por una serie de manifestaciones entre ellas la más importante cefalea intensa, tipo sordo, no pulsante, generalmente de localización fronto-occipital, que empeora los primeros 15 minutos después de levantarse y mejora en 15 minutos después de cambiar a posición decúbito supino. El diagnóstico es clínico, pero cuando no se está seguro se puede confirmar con pruebas de imágenes. El tratamiento debe realizarse lo antes posible y se divide en conservador e intervencionista, cuya elección dependerá de la sintomatología. En este artículo se resumirá la fisiopatología, incidencia, factores de riesgos, presentación clínica, prevención, diagnóstico y tratamientos de esta condición

    Tectono-stratigraphic response of the Sandino Forearc Basin (N-Costa Rica and W-Nicaragua) to episodes of rough crust and oblique subduction

    Get PDF
    The southern Central American active margin is a world-class site where past and present subduction processes have been extensively studied. Tectonic erosion/accretion and oblique/orthogonal subduction are thought to alternate in space and time along the Middle American Trench. These processes may cause various responses in the upper plate, such as uplift/subsidence, deformation, and volcanic arc migration/ shut-off. We present an updated stratigraphic framework of the Late Cretaceous– Cenozoic Sandino Forearc Basin (SFB) which provides evidence of sedimentary response to tectonic events. Since its inception, the basin was predominantly filled with deep-water volcaniclastic deposits. In contrast, shallow-water deposits appeared episodically in the basin record and are considered as tectonic event markers. The SFB stretches for about 300 km and varies in thickness from 5 km (southern part) to about 16 km (northern part). The drastic, along-basin, thickness variation appears to be the result of (1) differential tectonic evolutions and (2) differential rates of sediment supply. (1) The northern SFB did not experience major tectonic events. In contrast, the reduced thickness of the southern SFB (5 km) is the result of at least four uplift phases related to the collision/accretion of bathymetric reliefs on the incoming plate: (i) the accretion of a buoyant oceanic plateau (Nicoya Complex) during the middle Campanian; (ii) the collision of an oceanic plateau (?) during the late Danian–Selandian; (iii) the collision/accretion of seamounts during the late Eocene–early Oligocene; (iv) the collision of seamounts and ridges during the Pliocene–Holocene. (2) The northwestward thickening of the SFB may have been enhanced by high sediment supply in the Fonseca Gulf area which reflects sourcing from wide, high relief drainage basins. In contrast, sedimentary input has possibly been lower along the southern SFB, due to the proximity of the narrow, lowland isthmus of southern Central America. Moreover, two phases of strongly oblique subduction affected the margin, producing strike-slip faulting in the forearc basin: (1) prior to the Farallon Plate breakup, an Oligocene transpressional phase caused deformation and uplift of the basin depocenter, triggering shallowing-upward of the Nicaraguan Isthmus in the central and northern SFB; (2) a Pleistocene–Holocene transtensional phase drives the NW-directed motion of a forearc sliver and reactivation of the graben-bounding faults of the late Neogene Nicaraguan Depression. We discuss arguments in favour of a Pliocene development of the Nicaraguan Depression and propose that the Nicaraguan Isthmus, which is the apparent rift shoulder of the depression, represents a structure inherited from the Oligocene transpressional phase
    corecore