This work is dedicated to my husband Oscar Cuadros Linares, to my father Raul Soriano Filinich, and to my mother, Dora Vargas Núñez de Soriano. Foremost, I wish to give my heartfelt thanks to a very special person, my husband Oscar Cuadros. Thanks for his unconditional love, his unflagging encouragement, patience, and continued support that made the culmination of this thesis possible. I greatly value his insightful comments, the stimulating discussions, that helped me to keep things in perspective, the sleepless nights we were working together before deadlines and for all the fun we have had on this journey. I would like to express my special appreciation and my sincere gratitude to my advisor Prof. Maria Cristina Ferreira de Oliveira. Thanks (i) for the continuous support and patience during all my Ph.D. study and research, especially in the most critical periods, (ii) for her helpful and priceless advice, and (iii) for her insightful comments. Also, I would like to thank Prof. Bernd Hamann for receiving me as a visiting research scholar at the University of California, Davis. Thanks for his guidance, for supporting my research ideas, and for his insightful discussions about the research in the last months. Both of them, Prof. Cristina and Prof. Bernd, were and remain my best role models for a scientist and mentor. ¡Muchas gracias! I would like to extend my sincerest gratitude to the people who mean a lot to me, my parents Raul Soriano Filinich and Dora Vargas Núñez de Soriano. Thanks for their unconditional love, their emotional support, for all of the sacrifices that you have made on my behalf. Also, I express my thanks to my sister Laura, my little heart Fabio and my grandaunt Marlene Núñez (Pipito). I would also like to dedicate this thesis to the memory of my grandmother Mamá Nelly Núñez. It was hard to say goodbye from afar. Even though the Alzheimer's demons attacked her, she treasured the memory of her granddaughter Aurea. Many times she talked with me about her granddaughter(me) with so much love, and joy because she(I) would visit her, not knowing that it was me. My mind and my heart treasure the great memories we had. Rest in peace. I would like to thank all my friends from Brazil, Spain, United States and Peru, especially the Reginas girls, the Pipocas girls, and the Chelas guys, who always support me, give me good advice and make my life colorful. Finally, I acknowledge the financial support provided by the State of São Paulo Research Foundation (FAPESP) grants 12/24537-0 and 15/12831-0. "It will hurt. It will take time. It will require dedication. It will require willpower. You will need to make healthy decisions. It requires sacrifice. You will need to push your body to its max. There will be temptation. But, I promise you, when you reach your goal, it's worth it. " (Unknown)