A mi familia, ingenieros agrónomos por tradición e investigadores por vocación i Acknowledgements I have always preferred short acknowledgements, but I don't think I will be capable of summarizing in just a few lines everyone who has contributed to this Ph.D. thesis and who I would like to thank.To my supervisors, Prof. Antonio G. Torres and Dr. André J. A. Aarnink. To Antonio, for trusting me always, for teaching me the exciting world of research and introducing me to this motivating research topic. To André, for welcoming me in Wageningen UR for the first time, and since then, for your wise advices and suggestions, for your constant support, care and help. Thank you both for the final sprint! Special thanks to Dr. Nico W. M. Ogink, coordinator of the project "Dust reduction program in poultry production" financed by the Dutch Ministry of Agriculture, Nature and Food Quality under which this research was performed. For your sharp and critical revisions of the manuscript and initial proposals. For your kindness and friendship.To Txomin Hermosilla for your invaluable help and patience. This thesis is also part of you.To Huong Lai for sharing with me tough field work during sampling campaign, and to Marta Montero, for helping me in the endless analysis of samples in the electron microscope and for your careful work at the lab.Thanks to Albert Winkel and Jan van Harn for your work during (and after) the ionization experiment, as well as to the staff at the applied research centre "Het Spelderholt", in Lelystad, The Netherlands. Thanks are also due to Theo van Hattum and to the measurement team for their help during sampling.To Eef Lovink for your top-quality technical support.To Geert Kupers and Jean Slangen for your help at Biotechnion lab of Wageningen UR.To Dr. Julio Mosquera for your meticulous organizing and planning, for your smile and willingness to help. Thank you! To Dr. Salvador Calvet for your interest and always clever suggestions related to my work. A la Dra. Debra Westall, por tu tiempo y útiles recomendaciones para el texto y la presentación en inglés.A Manolo Millán y Alma García por los toques finales en la maquetación y diseño de este trabajo.A todas las personas del grupo de "Medio ambiente y energía" del Animal SciencesGroup ( A Vero, mi apoyo incondicional. Y a Marta, mi otro apoyo incondicional.A mis amigos y familia, por apoyarme y aguantarme (a mí y a mi trabajo).A mi hermana Alicia y a Emil, a Manolo (mi amor) y a mis padres (mis maestros en la ciencia y grandes admiradores): el agradecimiento más grande.Lo hemos logrado ¡gracias a vosotros! v AbstractLivestock housing, especially poultry and pigs, are major sources of particulate matter (PM). High ambient concentrations of PM can threaten human and animal health and welfare, as well as the environment. The best approach to reduce PM emissions from livestock houses seems to be to prevent it from being generated. Controlling PM at source not only reduces emissions but also improves inside air quality. Furthermore, data on particle morphology...

The degree of control and the costs of hypercholesterolaemia in both primary and secondary prevention vary enormously, depending on the criterion used by the group or scientific society.

80% and positive evaluation (between 8 and 9) by students in official surveys.

LinkedIn professional social network was used as a common platform for exposure, discussion and analysis of information. Its use can facilitate collaborative learning of students, stimulate their motivation and enhance their professional career project. The study was conducted in three subjects of the Master in Animal Production at the Universitat Politècnica de València during 2014-2015 academic year. The specific objectives were: i) to create a virtual learning community, ii) to facilitate student's active participation, iii) to enhance teacher-student and student-student interactions, iv) to promote critical thinking, and v) to encourage the use of this professional network that favors student's professional career plan. Four actions based on the development and maintenance of a LinkedIn group and the ellaboration of a heading of critical thinking were established. The achievement of the objectives was assessed by the instrinsic network's activity, as well as by quantitative and qualitative evaluations and a survey of self perception. All students created and used their profile regularly. Discussion topics were proposed, assessing student's participation during the study. The difficulty of evaluating the development of critical thinking was demonstrated.