Coexistence of two anatomical bronchial variances

Coexistence of two anatomical bronchial variances.

1 of 3 DESCRIPTION A 70-year-old man with mediastinal lymphadenopathy was referred to our centre for endobronchial ultrasound with transbronchial needle aspiration. During the bronchoscopic examination, two separate anatomical bronchial variances were observed: a supernumerary ‘true’ tracheal bronchus branching off from the distal right lateral wall of the trachea ( fi gure 1A ) and a displaced...

Two-Sample Testing for Equality of Variances

To test for equality of variances given two independent random samples from univariate normal populations, popular choices would be the two-sample F test and Levene’s test. The latter is a nonparametric test while the former is parametric: it is the likelihood ratio test, and also a Wald test. Another Wald test of interest is based on the difference in the sample variances. We give a nonparamet...

Variances of Population Projections: Comparison of Two Approaches

A Nonparametric Two-Sample Wald Test of Equality of Variances

We develop a test for equality of variances given two independent random samples of observations. The test can be expected to perform well when both sample sizes are at least moderate and the sample variances are asymptotically equivalent to the maximum likelihood estimators of the population variances. The test is motivated by and is here assessed for the case when both populations sampled are...

The right bronchial artery. Anatomical considerations and surgical approach.

In spite of the fact that bronchial arteries have been known for a long time, their real function in pulmonary physiology is still under discussion. The participation of these arteries in many pathological conditions of the lungs was the subject of numerous clinical (Cockett and Vass, 1950; Cudkowicz and Armstrong, 1951 ; Cudkowicz, 1952; Liebow, Hales, and Lindskog, 1949; Liebow, Hales, Harris...