Introgression is the permanent incorporation of genes from the genome of one population into that of another through hybridisation and backcrossing. With the advent of genetically modified crops,... Show moreIntrogression is the permanent incorporation of genes from the genome of one population into that of another through hybridisation and backcrossing. With the advent of genetically modified crops, the potential that transgenes might introgress from cultivated to wild plants has become a point of scientific scrutiny. This thesis presents a methodology by which the risk of introgression can be quantified in terms of empirically determined quantities. A proposed measure of risk is the hazard rate. The hazard rate of introgression is the probability per time unit that introgression occurs given that it has not previously occurred. Particular attention is drawn to demographic stochasticity, genetical mechanisms and both random and deterministic time-inhomogeneities. A sample chapter also outlines the application of the models with empirical data. Show less
In this PhD thesis, I have described the novel time-resolved sum-frequency generation (TR-SFG) spectroscopic technique that I developed during the course of my PhD research and used it study the... Show moreIn this PhD thesis, I have described the novel time-resolved sum-frequency generation (TR-SFG) spectroscopic technique that I developed during the course of my PhD research and used it study the ultrafast vibrational, structural and orientational dynamics of water molecules at model biological membranes - key towards understanding the dynamic hydrogen-bonded structure of water interfacial with model biological membranes. The TR-SFG technique developed, follows a pump-probe experimental scheme whereby an intense IR laser pulse excites molecular vibrations and the Sum Frequency Generation (SFG) pulse is used to probe the dynamics of surface molecules as they relax back to the ground state, as a function of the time delay between the excitation and probe pulses. The rate and mechanism of vibrational relaxation (lifetime dynamics) helps in understanding the effects of local molecular structure and hydrogen bonding around these surface molecules. Show less