A kinetic theory of glasses is developed using equilibrium theory as a foundation. After establishing basic criteria for glass formation and the capability of the equilibrium entropy theory to describe the equilibrium aspects of glass formation, a minimal model for the glass kinetics is proposed. Our kinetic model is based on a trapping description of particle motion in which escapes from deep wells provide the rate-determining steps for motion. The formula derived for the zero frequency viscosity η (0,T) is log η (0,T) = B − AF(T)kT where F is the free energy and T the temperature. Contrast this to the Vogel-Fulcher law log η (0,T) = B + A/(T − Tc). A notable feature of our description is that even though the location of the equilibrium second-order transition in temperature-pressure space is given by the break in the entropy or volume curves the viscosity and its derivative are continuous through the transition. The new expression for η (0,T) has no singularity at a critical temperature Tc as in the Vogel-Fulcher law and the behavior reduces to the Arrhenius form in the glass region. Our formula for η (0,T) is discussed in the context of the concepts of strong and fragile glasses, and the experimentally observed connection of specific heat to relaxation response in a homologous series of polydimethylsiloxane is explained. The frequency and temperature dependencies of the complex viscosity η (ω< T), the diffusion coefficient D(ω< T), and the dielectric response ε (ω< T) are also obtained for our kinetic model and found to be consistent with stretched exponential behavior.

The distribution of maize mitochondrial transcripts in polysomal RNA fractions obtained from root tissue, shoot tissue, or isolated intact mitochondria was analyzed. The distribution of cox3 transcripts that differ in 5' untranslated RNA sequence was similar in total polysomal and total mitochondrial RNA fractions, suggesting that 5' heterogeneity does not affect recruitment of transcripts into the polysomal RNA. The distribution of spliced and unspliced cox2 transcripts was also analyzed in polysomes from total tissue or isolated mitochondria, and both precursor and mature mRNAs were present in the high-molecular-weight RNA fraction. These results suggest that ribosomal association with mitochondrial transcripts is not selective.