I wish to thank my parents, Dilza and Moisés, for their constant support, patience, and advice, but most of all, for their love and attention.My eternal thanks to my sister Clara for being the best sister and the best friend, who always is there for me and makes my days happier.Finally, I wish to appreciate the best person in the world, Gustavo, for his love, kindness, and encouragement. I will be forever grateful for his endless support during all my years as a student, for inspiring me every day, and for being my partner in life.