San Francisco Health Care Security Ordinance & its intersection with the Health Care Accountability Ordinance Joannie C. Chang Office of Labor Standards Enforcement City & County of San Francisco January 2009.
In geometry, a torus (plural tori) is a surface of revolution generated by revolving a circle in three-dimensional space about an axis coplanar with the circle.he flat torus is a torus with the metric inherited from its representation as the quotient, R 2 / L, where L is a discrete subgroup of R 2 isomorphic to Z 2. This gives the quotient the structure of a Riemannian manifold.
Sagittal keel. The Sagittal keel (torus) is a thickening of bone on part or all of the midline of the frontal bone, or parietal bones where they meet along the sagittal suture, or on both bones. Sagittal keels differ from sagittal crests, which are found in some earlier hominins (notably the genus Paranthropus) and in a range of other mammals.