955 resultados para Maxillary sinus lifting


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La enfermedad de disco lumbar de origen laboral se presenta como una patología frecuente a nivel mundial en la masa trabajadora de diferentes sectores económicos expuesta a factores de riesgo biomecánico, afectando negativamente a la persona como ser individual y social, y repercutiendo en las economías en diferentes niveles. Objetivo Establecer la prevalencia de los factores de riesgo biomecánico en los casos con diagnóstico de enfermedad de disco lumbar calificados como enfermedad de origen laboral por la Junta Regional de Calificación de Invalidez del Meta, en el período comprendido entre 2011 a 2014, explorando la asociación entre los factores sociodemográficos y laborales. Metodología: Estudio de corte transversal con información retrospectiva de historias clínicas de pacientes con enfermedad de disco lumbar calificados de origen laboral, entre el 2011 – 2014. Resultados: La prevalencia de los factores de riesgo biomecánico fue: flexión columna con 94.1%, caminando durante la mayor parte de la jornada laboral 51.7%, levantar y/o depositar manualmente objetos 53.4%, manipulación de carga mayor a 25 kg, 49.2% y vibración cuerpo entero más de 4 horas 16.9%. Estos factores fueron mayores en trabajadores de obras civiles y manipuladores de materiales con 20.3%, en actividades económicas de servicios con 33.1% y construcción 21.2%. Se encontró asociación estadísticamente significativa de la enfermedad de disco lumbar con el género y la exposición a vibración/impacto cuerpo entero. Conclusión: Los factores de riesgo biomecánico como la posición de la columna vertebral en flexión, el levantamiento y depósito de carga, la manipulación de peso mayor a 15 kgs, la postura de cuerpo caminando, la exposición a vibración a cuerpo entero, y el tiempo de exposición, son elementos fundamentales a tener en cuenta en el proceso de calificación de origen de la enfermedad discal lumbar.

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INTRODUCCION La hipotensión arterial por anestesia raquídea en embarazadas llevadas a cesárea es frecuente y deletérea para la madre y el feto, sin que a la fecha exista una herramienta clínicamente útil para predecirla. La variabilidad de la frecuencia cardiaca es una medida que estima la actividad del sistema nervioso autónomo y algunos estudio iniciales indican una posible utilidad como herramienta predictiva de hipotensión arterial en esta población. METODOLOGIA Se realizó un estudio observacional descriptivo para examinar el comportamiento de la variabilidad de la frecuencia cardiaca, medida como razón de Baja frecuencia/Alta frecuencia, con un punto de corte de 2.5 tomada con un reloj POLAR RS800CX, en una población de pacientes con embarazo a término llevadas a cesárea, en un hospital de tercer nivel en Bogotá- Colombia entre Febrero y Abril del 2015. RESULTADOS El estudio incluyó 82 pacientes. Se determinó que la razón Baja frecuencia/Alta frecuencia mayor a 2,5 era poco frecuente en nuestra población (15.85%), y su asociación no fue significativa. DISCUSION El presente estudio demostró que la asociación entre la presencia de hipotensión y un índice Baja frecuencia/Alta frecuencia con punto de corte de 2.5 no es significativo para nuestra población de mujeres con embarazo a término llevadas a cesárea con anestesia espinal. Según los resultados se sugieres un punto de corte de 1.6 como punto de partida para la realización de nuevos estudios que permitan validar este valor.

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Son múltiples y constantes los debates que se han dado en la comunidad jurídica nacional sobre permitir que los socios o accionistas de una sociedad respondan directamente con su patrimonio por las acreencias de la persona jurídica a través de la utilización de la "teoría del levantamiento del velo corporativo". Dada la importancia de este tema, expertos colombianos de primer nivel se reúnen en esta obra para exponer sus puntos de vista sobre la aplicación de esta institución en Colombia. Adicionalmente, este libro incluye el informe de ejecución del proyecto de investigación , adelantado por la línea de investigación en Derecho Comercial del Grupo de Derecho Privado de la Facultad de Jurisprudencia, el cual fue financiado por el Centro de Investigaciones, Estudios y Consultoría (CIEC) de la Universidad del Rosario.Dada la importancia de este tema, expertos colombianos de primer nivel se reúnen en esta obra para exponer sus puntos de vista sobre la aplicación de esta institución en Colombia.

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El artículo forma parte de un monográfico dedicado al Foro Social de la Educación celebrado en Barcelona del 25 al 27 de febrero de 2005

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Recent radar and rain-gauge observations from the island of Dominica, which lies in the eastern Caribbean sea at 15 N, show a strong orographic enhancement of trade-wind precipitation. The mechanisms behind this enhancement are investigated using idealized large-eddy simulations with a realistic representation of the shallow trade-wind cumuli over the open ocean upstream of the island. The dominant mechanism is found to be the rapid growth of convection by the bulk lifting of the inhomogenous impinging flow. When rapidly lifted by the terrain, existing clouds and other moist parcels gain buoyancy relative to rising dry air because of their different adiabatic lapse rates. The resulting energetic, closely-packed convection forms precipitation readily and brings frequent heavy showers to the high terrain. Despite this strong precipitation enhancement, only a small fraction (1%) of the impinging moisture flux is lost over the island. However, an extensive rain shadow forms to the lee of Dominica due to the convective stabilization, forced descent, and wave breaking. A linear model is developed to explain the convective enhancement over the steep terrain.

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The “natural laboratory” of mountainous Dominica (15°N) in the trade wind belt is used to study the physics of tropical orographic precipitation in its purest form, unforced by weather disturbances or by the diurnal cycle of solar heating. A cross-island line of rain gauges and 5-min radar scans from Guadeloupe reveal a large annual precipitation at high elevation (7 m yr^{−1}) and a large orographic enhancement factor (2 to 8) caused primarily by repetitive convective triggering over the windward slope. The triggering is caused by terrain-forced lifting of the conditionally unstable trade wind cloud layer. Ambient humidity fluctuations associated with open-ocean convection may play a key role. The convection transports moisture upward and causes frequent brief showers on the hilltops. The drying ratio of the full air column from precipitation is less than 1% whereas the surface air dries by about 17% from the east coast to the mountain top. On the lee side, a plunging trade wind inversion and reduced instability destroys convective clouds and creates an oceanic rain shadow.

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The low-temperature reactivity of water (D2O) adsorbed on clean and oxygen pre-covered Cu(1 1 0) was studied using high resolution X-ray photoelectron spectroscopy (HRXPS) and low energy electron diffraction (LEED). On the clean surface partial dissociation to hydroxyl was observed already at 95 K. Upon annealing to 220 K hydrogen bonded water-hydroxyl chains are formed. Upon further annealing water desorbs leaving behind a layer of hydroxyl, most of which desorbs recombinatively eventually. With pre-adsorbed oxygen water reacts to hydroxyl lifting the added-row reconstruction even below 225 K. Upon annealing this adsorbate layer passes through essentially the same stages as without pre-adsorbed oxygen.

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The present study investigates the initiation of precipitating deep convection in an ensemble of convection-resolving mesoscale models. Results of eight different model runs from five non-hydrostatic models are compared for a case of the Convective and Orographically-induced Precipitation Study (COPS). An isolated convective cell initiated east of the Black Forest crest in southwest Germany, although convective available potential energy was only moderate and convective inhibition was high. Measurements revealed that, due to the absence of synoptic forcing, convection was initiated by local processes related to the orography. In particular, the lifting by low-level convergence in the planetary boundary layer is assumed to be the dominant process on that day. The models used different configurations as well as different initial and boundary conditions. By comparing the different model performance with each other and with measurements, the processes which need to be well represented to initiate convection at the right place and time are discussed. Besides an accurate specification of the thermodynamic and kinematic fields, the results highlight the role of boundary-layer convergence features for quantitative precipitation forecasts in mountainous terrain.

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An investigation is presented of a quasi-stationary convective system (QSCS) which occurred over the UK Southwest Peninsula on 21 July 2010. This system was remarkably similar in its location and structure to one which caused devastating flash flooding in the coastal village of Boscastle, Cornwall on 16 August 2004. However, in the 2010 case rainfall accumulations were around four times smaller and no flooding was recorded. The more extreme nature of the Boscastle case is shown to be related to three factors: (1) higher rain rates, associated with a warmer and moister tropospheric column and deeper convective clouds; (2) a more stationary system, due to slower evolution of the large-scale flow; and (3) distribution of the heaviest precipitation over fewer river catchments. Overall, however, the synoptic setting of the two events was broadly similar, suggesting that such conditions favour the development of QSCSs over the Southwest Peninsula. A numerical simulation of the July 2010 event was performed using a 1.5-km grid length configuration of the Met Office Unified Model. This reveals that convection was repeatedly initiated through lifting of low-level air parcels along a quasi-stationary coastal convergence line. Sensitivity tests are used to show that this convergence line was a sea breeze front which temporarily stalled along the coastline due to the retarding influence of an offshore-directed background wind component. Several deficiencies are noted in the 1.5-km model’s representation of the storm system, including delayed convective initiation; however, significant improvements are observed when the grid length is reduced to 500 m. These result in part from an improved representation of the convergence line, which enhances the associated low-level ascent allowing air parcels to more readily reach their level of free convection. The implications of this finding for forecasting convective precipitation are discussed.

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Many factors, both mesoscale and larger scale, often come together in order for a particular convective initiation to take place. The authors describe a modeling study of a case from the Convective Storms Initiation Project (CSIP) in which a single thunderstorm formed behind a front in the southern United Kingdom. The key features of the case were a tongue of low-level high θw air associated with a forward-sloping split front (overrunning lower θw air above), a convergence line, and a “lid” of high static stability air, which the shower was initially constrained below but later broke through. In this paper, the authors analyze the initiation of the storm, which can be traced back to a region of high ground (Dartmoor) at around 0700 UTC, in more detail using model sensitivity studies with the Met Office Unified Model (MetUM). It is established that the convergence line was initially caused by roughness effects but had a significant thermal component later. Dartmoor had a key role in the development of the thunderstorm. A period of asymmetric flow over the high ground, with stronger low-level descent in the lee, led to a hole in a layer of low-level clouds downstream. The surface solar heating through this hole, in combination with the tongue of low-level high θw air associated with the front, caused the shower to initiate with sufficient lifting to enable it later to break through the lid.

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How does the work of designers impact on the safety of operatives at the construction site? Safety research and policy emphasize the importance of designing for safe construction, yet the interface between design and construction is poorly understood: accidents have multiple causes making it hard to establish causal links between design choices and safety outcomes. An in-depth case study of a major station project examines how professionals on the construction site perceive and manage the safety challenges of a building design. Analyses reveal understandings that, on the project studied, design has an impact on safety because of: (1) the timing of design work, where the volume of late design changes increased the difficulty of planning safe procedures, e.g. for working at height, lifting heavy items, refurbishing and demolishing old buildings; and (2) inputs from design stakeholders with insufficient practical knowledge of construction and operation required unplanned work-arounds, e.g. to coordinate different sub-systems, provide maintenance access, and manage loads during construction. These findings suggest that safety suffers where projects are under-designed, and that alongside regulation, there is a need for robust management attention to the contractual structures, incentives, processes and tools that enable clients and designers to understand material practices of construction and operation.

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In the UK, architectural design is regulated through a system of design control for the public interest, which aims to secure and promote ‘quality’ in the built environment. Design control is primarily implemented by locally employed planning professionals with political oversight, and independent design review panels, staffed predominantly by design professionals. Design control has a lengthy and complex history, with the concept of ‘design’ offering a range of challenges for a regulatory system of governance. A simultaneously creative and emotive discipline, architectural design is a difficult issue to regulate objectively or consistently, often leading to policy that is regarded highly discretionary and flexible. This makes regulatory outcomes difficult to predict, as approaches undertaken by the ‘agents of control’ can vary according to the individual. The role of the design controller is therefore central, tasked with the responsibility of interpreting design policy and guidance, appraising design quality and passing professional judgment. However, little is really known about what influences the way design controllers approach their task, providing a ‘veil’ over design control, shrouding the basis of their decisions. This research engaged directly with the attitudes and perceptions of design controllers in the UK, lifting this ‘veil’. Using in-depth interviews and Q-Methodology, the thesis explores this hidden element of control, revealing a number of key differences in how controllers approach and implement policy and guidance, conceptualise design quality, and rationalise their evaluations and judgments. The research develops a conceptual framework for agency in design control – this consists of six variables (Regulation; Discretion; Skills; Design Quality; Aesthetics; and Evaluation) and it is suggested that this could act as a ‘heuristic’ instrument for UK controllers, prompting more reflexivity in relation to evaluating their own position, approaches, and attitudes, leading to better practice and increased transparency of control decisions.