RESUMEN
PURPOSE: To report an adult case of cervical lung herniation involving the azygous lobe and to review the literature. METHODS: A trauma patient was incidentally found to have a cervical lung herniation involving the azygous lobe. We reviewed the literature on cervical lung herniation, described techniques used to diagnose and evaluate cervical lung herniations and summarized management options. RESULTS: Cervical lung herniation results in a defect in Sibson's fascia allowing the apical lung to protrude above the thoracic inlet. In the adult population, these are commonly seen after trauma or surgical intervention, but congenital forms have also been described in the pediatric population. Apical herniation of the lung can cause symptoms due to mass effect on the esophagus or trachea. We report an adult case of cervical lung herniation involving the azygous lobe. CONCLUSION: Cervical lung herniation is a relatively rare entity compared to lung herniation through the rib cage. Knowledge of this entity is essential to properly evaluate trauma patients and to diagnose patients who have symptoms of cough, dysphagia or a bulging neck mass.
RESUMEN
The analogues of Arimoto's definition of conditional Rényi entropy and Rényi mutual information are explored for abstract alphabets. These quantities, although dependent on the reference measure, have some useful properties similar to those known in the discrete setting. In addition to laying out some such basic properties and the relations to Rényi divergences, the relationships between the families of mutual informations defined by Sibson, Augustin-Csiszár, and Lapidoth-Pfister, as well as the corresponding capacities, are explored.
RESUMEN
Interpolation techniques provide a method to convert point data of a geographic phenomenon into a continuous field estimate of that phenomenon, and have become a fundamental geocomputational technique of spatial and geographical analysts. Natural neighbour interpolation is one method of interpolation that has several useful properties: it is an exact interpolator, it creates a smooth surface free of any discontinuities, it is a local method, is spatially adaptive, requires no statistical assumptions, can be applied to small datasets, and is parameter free. However, as with any interpolation method, there will be uncertainty in how well the interpolated field values reflect actual phenomenon values. Using a method based on natural neighbour distance based rates of error calculated for data points via cross-validation, a cross-validation error-distance field can be produced to associate uncertainty with the interpolation. Virtual geography experiments demonstrate that given an appropriate number of data points and spatial-autocorrelation of the phenomenon being interpolated, the natural neighbour interpolation and cross-validation error-distance fields provide reliable estimates of value and error within the convex hull of the data points. While this method does not replace the need for analysts to use sound judgement in their interpolations, for those researchers for whom natural neighbour interpolation is the best interpolation option the method presented provides a way to assess the uncertainty associated with natural neighbour interpolations.