In vivo study, using cadaveric dog cervical spine, was performed in which the middle segment of the vertebral body was removed producing anterior instability. Eleven various methods of stabilization ...utilizing polymethylmethacrylate and other fixation devices were employed, and their static strength in hyperextension was tested and compared. A portion of the same dog's cervical spine in each case was used as a control. The results indicate that all fixation methods failed to regain the normal structural strength in extension. Cement with wire or chain methods of fixation were superior to other methods in this study. Fixation rigidity approaching rigidity of the normal spine appeared to be a significant factor determining the strength of the reconstructed cervical spine. Combined anterior and posterior fixation did not provide further strength, although it did increase the rigidity of the fixation.
The canoe: a living tradition Howell, Colin; Jennings, John
The Beaver,
06/2003, Volume:
83, Issue:
3
Magazine Article
There is much more to this book than its stunning array of visual materials, however. The essays contained here will appeal to readers of various sorts and of differing inclinations. John Jennings's ...opening two chapters provide a lucid exposition of Canada's "white birch" wilderness that allowed for a "canoe developed to such perfection that, after European contact, it continued, unaltered except in size, to be the central element in the development of what is now Canada." In a coherent and broad-reaching overview, Jennings identifies three distinct North American frontier histories: the frontier of the horse, characterized by an absence of water and "mutual incomprehension" and confrontation between Europeans and native peoples; the settler frontier of the axe and plow; and the canoe frontier. Of these the canoe frontier was unique, because it "did not covet the land, only its bounty." The French and later the Scots came to look upon native peoples as "partners in a very lucrative trade," rather than as nomadic opponents of settled agriculture. Eventually the canoe frontier was eclipsed by the development of railways in the nineteenth century and later by the coming of the airplane to the north in the 1930s.
We generalize the results of AS, finding large classes of totally geodesic Seifert surfaces in hyperbolic knot and link complements, each the lift of a rigid 2-orbifold embedded in some hyperbolic ...3-orbifold. In addition, we provide a uniqueness theorem and demonstrate that many knots cannot possess totally geodesic Seifert surfaces by giving bounds on the width invariant in the presence of such a surface. Finally, we utilize these examples to demonstrate that the Six Theorem is sharp for knot complements in the 3-sphere.
Communications Hennessy, Bernard C.; Jennings, M. Kent; Zeigler, L. Harmon ...
The American political science review,
09/1966, Volume:
60, Issue:
3
Journal Article
