Validation of a numerical simulation using experimental data is a necessary prerequisite for verification of proper use of numerical method. This article deals with a comparison of velocities as predicted by an idealized model of human upper airways during stationary inspiration for three different breathing regimes. For the purpose of this study, a model which includes a realistic geometry of the mouth cavity and glottis coupled with and idealized geometry of the trachea and bronchial tree up to the fourth generation on branching was made. Calculations were compared with experimental data acquired by Phase-Doppler Particle Anemometry (P/DPA) on the identical geometry. Velocity data were compared at three points in the trachea. Specific air flow characteristics are documented and discussed based on results of the numerical simulation of the velocity field. and Obsahuje seznam literatury
An unidentified myxosporean parasite (CKX) is described from the kidney of approximately 80% of spawning coho salmon Oncorhynchus kisutch (Walbaum) in British Columbia, Canada and Washington, United States of America. Morphological features were described using light and electron microscopy. Sequencing of polymerase chain reaction (PCR) amplified 18S ribosomal RNA gene and in situ hybridisation were used to further characterise CKX. The parasite occurred with a focal distribution within tubule epithelial cells, the tubule lumen and the interstitium as primary cells containing from one to at least 16 secondary cells. Luminal stages were degenerate and sporogony was not observed. In situ hybridisation using a digoxygenin-labelled DNA probe confirmed CKX to be the source of DNA used in PCR analyses. CKX 18S rDNA sequences were most similar (97%) to those of Sphaerospora oncorhynchi. Phylogenetic analysis revealed similarities among the 18S rDNA sequences of CKX, S. oncorhynchi and Myxidium lieberkuehni. CKX is hypothesised to be the abortive extrasporogonic development of a Sphaerospora sp. or Myxidium sp. occurring in immune-incompetent spawning and senescent salmon.