Samenvatting 215 x to start a PhD there at the first place. Things have not developed as planned since, and at the end, I am still undecided whether he has been a constructive or distracting influence on my PhD. So, I am not sure whether he should have my acknowledgements here. But he certainly has my love. Following the thread that has lead me to pursuing a PhD, I ultimately find my parents, Rozina and Christophoros, who have always encouraged me to learn more. It is to them that I dedicate this dissertation.