Nasopharyngeal bursitis: from embryology to clinical presentation

Nasopharyngeal bursitis is a relatively rare syndrome characterized by a collection of symptoms that multidisciplinary specialists should be aware of. Here we present an audit of cases presenting to a rhinology clinic over a two-year period, as well as an overview of the relevant embryology and different clinical presentations of nasopharyngeal bursitis. For 2008–2009, six patients were diagnosed to have nasopharyngeal bursitis, including four males and two females, of mean age 54 years. Two distinct pathologic types were observed, comprising three patients with classical Tornwaldt’s cyst and three with crust-type bursitis. This audit highlights the importance of recognition of the crust-type of nasopharyngeal bursitis and its anatomic and clinical features. A combined endonasal and transoral endoscopic approach is a minimally invasive procedure and an effective method of treating both types of the disease. Our findings are discussed in relation to the embryology of the disorder, with a clinical emphasis on crust- type nasopharyngeal bursitis

On the formulation of snow thermal conductivity in large-scale sea ice models

An assessment of the performance of a state-of-the-art large-scale coupled sea ice - ocean model, including a new snow multilayer thermodynamic scheme, is performed. Four 29-years-long simulations are compared against each other and against sea ice thickness and extent observations. Each simulation uses a separate parameterization for snow thermo-physical properties. The first simulation uses a constant thermal conductivity and prescribed density profiles. The second and third parameterizations use typical power-law relationships linking thermal conductivity directly to density (prescribed as in the first simulation). The fourth parameterization is newly developed and consists of a set of two linear equations relating the snow thermal conductivity and density to the mean seasonal wind speed. Results show that simulation 1 leads to a significant overestimation of the sea ice thickness due to overestimated thermal conductivity, particularly in the Northern Hemisphere. Parameterizations 2 and 4 lead to a realistic simulation of the Arctic sea ice mean state. Simulation 3 results in the underestimation of the sea ice basal growth in both hemispheres, but is partly compensated by lateral growth and snow ice formation in the Southern Hemisphere. Finally, parameterization 4 improves the simulated snow depth distributions by including snow packing by wind, and shows potential for being used in future works. The intercomparison of all simulations suggests that the sea ice model is more sensitive to the snow representation in the Arctic than it is in the Southern Ocean, where the sea ice thickness is not driven by temperature profiles in the snow

Description of the Earth system model of intermediate complexity LOVECLIM version 1.2

The main characteristics of the new version 1.2 of the three-dimensional Earth system model of intermediate complexity LOVECLIM are briefly described. LOVECLIM 1.2 includes representations of the atmosphere, the ocean and sea ice, the land surface (including vegetation), the ice sheets, the icebergs and the carbon cycle. The atmospheric component is ECBilt2, a T21, 3-level quasi-geostrophic model. The ocean component is CLIO3, which consists of an ocean general circulation model coupled to a comprehensive thermodynamic-dynamic sea-ice model. Its horizontal resolution is of 3° by 3°, and there are 20 levels in the ocean. ECBilt-CLIO is coupled to VECODE, a vegetation model that simulates the dynamics of two main terrestrial plant functional types, trees and grasses, as well as desert. VECODE also simulates the evolution of the carbon cycle over land while the ocean carbon cycle is represented by LOCH, a comprehensive model that takes into account both the solubility and biological pumps. The ice sheet component AGISM is made up of a three-dimensional thermomechanical model of the ice sheet flow, a visco-elastic bedrock model and a model of the mass balance at the ice-atmosphere and ice-ocean interfaces. For both the Greenland and Antarctic ice sheets, calculations are made on a 10 km by 10 km resolution grid with 31 sigma levels. LOVECLIM1.2 reproduces well the major characteristics of the observed climate both for present-day conditions and for key past periods such as the last millennium, the mid-Holocene and the Last Glacial Maximum. However, despite some improvements compared to earlier versions, some biases are still present in the model. The most serious ones are mainly located at low latitudes with an overestimation of the temperature there, a too symmetric distribution of precipitation between the two hemispheres, and an overestimation of precipitation and vegetation cover in the subtropics. In addition, the atmospheric circulation is too weak. The model also tends to underestimate the surface temperature changes (mainly at low latitudes) and to overestimate the ocean heat uptake observed over the last decade