Class: divisions along

Figure 1 IRT absolute frequency distribution for one session of a fixed interval schedule for control (top) and monkeys exposed to 500/zg/kg per day of lead (bottom). The divisions along the abscissa represent classes of time between successive responses, in 100 ms increments. The lead-treated monkeys in general had a much higher absolute frequency of IRTs and a distribution skewed towards shorter IRTs...

A logical division is made for the adsorption of nonelectrolytes according to whether they are in dilute or concentrated solution. In dilute solutions, the treatment is very similar to that for gas adsorption, whereas in concentrated binary mixtures the role of the solvent becomes more explicit. An important class of adsorbed materials, self-assembling monolayers, are briefly reviewed along with an overview of the essential features of polymer adsorption. The adsorption of electrolytes is treated briefly, mainly in terms of the exchange of components in an electrical double layer. 

Certain proteins endow cells with unique capabilities for movement. Cell division, muscle contraction, and cell motility represent some of the ways in which cells execute motion. The contractile and motile proteins underlying these motions share a common property they are filamentous or polymerize to form filaments. Examples include actin and myosin, the filamentous proteins forming the contractile systems of cells, and tubulin, the major component of microtubules (the filaments involved in the mitotic spindle of cell division as well as in flagella and cilia). Another class of proteins involved in movement includes dynein and kinesin, so-called motor proteins that drive the movement of vesicles, granules, and organelles along microtubules serving as established cytoskeletal tracks. ... 

The division of crystals into crystal systems and crystal classes is based on the symmetry of the crystal as a finite object, or the symmetry of a single unit cell. In a unit cell all of the corners are equivalent points, since by translation along the axes the entire pattern can be... 

Granule motion also occurs at the outer edge of the spindle. A special class occurs from the poles to the equator during late anaphase and telophase in endosperm divisions of several plants (Bajer and Mole-Bajer, 1956). More typical are cytoplasmic saltatory motions. These sudden, rapid (microns per second) translations of granules through several microns are polarized by the spindle in several cell types and then occur mainly radial to the asters and pole-to-pole along the edge of the spindle (reviewed by Rebhun, 1967,1971). 

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