The fibre type composition of thoracic and lumbar paravertebral muscles in man.
Samples of longissimus and multifidi muscles at the thoracic and lumbar levels of the spine were examined histochemically on autopsy specimens from 21 adult male subjects (aged 22 to 46 years) and on biopsies from 17 adult patients during surgery for disorders of the lumbar intervertebral disc. In the superficial and deep thoracic muscles, 74% of fibres were of the Type I variety. In the lumbar region, Type I fibres amounted to 57% in the superficial, and to 63% in the deep muscles. The diameter of Type I fibres was significantly greater than that of Type II fibres.
We give a brief introduction to the study of the algebraic structures -- and their geometrical interpretations -- which arise in the BRST construction of a conformal string background. Starting from the chiral algebra $\cA$ of a string background, we consider a number of elementary but universal operations on the chiral algebra. From these operations we deduce a certain fundamental odd Poisson structure, known as a Gerstenhaber algebra, on the BRST cohomology of $\cA$. For the 2D string background, the correponding G-algebra can be partially described in term of a geometrical G-algebra of the affine plane $\bC^2$. This paper will appear in the proceedings of {\it Strings 95}.