Yeast cells grown anaerobically have been shown to vary in their ultrastructure and absorption spectrum depending upon the composition of the growth medium. The changes observed in the anaerobically grown cells are governed by the availability of unsaturated fatty acids and ergosterol and a catabolite or glucose repression. All the cells contain nuclear and plasma membranes, but the extent of t...

I discuss a memorandum entitled " A True state of the Case and Controversy between Sir Isaak Newton & Dr Robert Hooke as the Priority of that Noble Hypothesis of Motion of ye Planets about ye Sun as their Centers " , where Robert Hooke summarized his seminal contributions to the physics of orbital motion and to the theory of universal gravitation. In a brief handwritten but undated memorandum e...

Let G(xr − xe) be the causal Green function for the wave equation in four spacetime dimensions, representing the signal received at the spacetime point xr due to an impulse emitted at the spacetime point xe. Such emission and reception processes are highly idealized, since no signal can be emitted or received at a single (mathematical) point in space and time. We present a simple model for exte...