Heat activates the dormant spores of certain Bacillus spp., which is reflected in the "activation shoulder" in their survival curves. At the same time, heat also inactivates the already active and just activated spores, as well as those still dormant. A stochastic model based on progressively changing probabilities of activation and inactivation can describe this phenomenon. The model is presen...

In a previous paper (1) the inactivation of catalase by heat at different pH was studied. It was discovered that the heat inactivation depends upon the hydrogen ion concentration of the enzyme solution which affects both the velocity and the extent of the reaction. It was also found there that 65” was the critical temperature for the enzyme preparation since at this temperature the catalase was...

Xist RNA inactivates one mammalian X chromosome (the Xi) by associating with it in cis. The mechanism of this interaction is unresolved. Jeon and Lee (2011) now show that YY1 binds both Xist RNA and DNA, thereby providing a mechanism to anchor Xist to the Xi and facilitate X chromosome inactivation.

In recent years, considerable interest has been manifested in the thermal inactivation of animal viruses (Friedman and De Berry, 1959; LehmannGrube and Syverton, 1959; Youngner, 1957; Woese, 1960). Apart from the practical aspects, studies of the temperature sensitivity of virus particles offer a natural step in the analysis of their physicochemical properties (Gard and Maal0e, 1959) and, as su...