I found this article on breathing in a big anthology of brass playing articles at my work, then found it and read it again online. It has a lot of quotes and information from Arnold Jacobs and David Cugell, then director of the pulmonary function laboratory at Northwestern Memorial Hospital in Chicago, Illinois. It cuts through a lot of the bad and confusing pedagogy on breathing( not that it's all wrong, there just seems to be a wealth of questionable and contradictory info and advice). I hope it is an interesting read to the forum-readers, I certainly learned a fair bit.

Alex S