Optical traps are useful for studying the effects of forces on single molecules. Feedback-based force clamps are often used to maintain a constant load, but the response time of the feedback limits bandwidth and can introduce instability. We developed a novel force clamp that operates without feedback, taking advantage of the anharmonic region of the trapping potential where the differential st...

The Saccharomyces cerevisiae Rad24 and Rad17 checkpoint proteins are part of an early response to DNA damage in a signal transduction pathway leading to cell cycle arrest. Rad24 interacts with the four small subunits of replication factor C (RFC) to form the RFC-Rad24 complex. Rad17 forms a complex with Mec3 and Ddc1 (Rad1731) and shows structural similarities with the replication clamp PCNA. T...

Introduction: Beta-carboline alkaloids of P. harmala are shown to have immune-modulatory effects in several studies. Extracts of this plant have significant anti-inflammatory effect via the inhibition of some inflammatory mediators including PGE2 and TNF-α. In postmortem studies, structural alterations to the cerebellum have been recognized, including Purkinje cell loss being re...

when we were both living in Trinity College, Cambridge. He finished as an undergraduate in 1935 and was a research scholar and, from 1936, a Junior Research Fellow; I came up as an undergraduate in 1935. In the summer of 1939, he went to the marine laboratory at Plymouth to do experiments on the giant nerve fibres of squid. He invited me to join him, which I did at the beginning of August; we l...