The construction of the Hidroituango- the largest dam in Colombia- has produced serious environmental and social impact on the population surrounding the project. That is why inhabitants affected by the dam founded the Rios Vivos Antioquia Movement (RVAM) to fight against this construction and defend the human rights of the community. This research analyses the strategies used by the movement in its opposition to the project, the support of external actors in the development of those strategies and the outcomes at the local and national level. To frame the empirical data, a review of the theoretical approach about social movements and human rights defenders is presented. In addition, the research explored tactics used by RVAM to persuade, socialise and pressure in human rights violations campaigns, according to Keck and Sikkink frames and the contentious politic defined by Tilly and Tarrow. To analyse the movement’s strategies, this thesis used data from RVAM's website and is based on interviews with leaders of the movement and external actors that have supported them. This analysis concluded that although the social and environmental strategies developed by the movement have not succeeded in stopping the construction of the dam, these actions have resulted in the strengthening of social struggle in the area and the empowerment of women. These strategies exerted pressure on the government to set up collective protection measures for human rights defenders in risk in the whole country. Furthermore, the accompaniment of external actors helped to develop networks with other organisations and increased the international advocacy for the movement. Resumen: La construcción de Hidroituango, la represa más grande de Colombia, ha producido un grave impacto ambiental y social en la población que rodea el proyecto. Es por eso que los habitantes afectados por la hidroeléctrica fundaron el Movimiento Ríos Vivos Antioquia (MRVA) para luchar contra el proyecto y defender los derechos humanos de la comunidad. Esta investigación analiza las estrategias utilizadas por el movimiento en su oposición al proyecto, el apoyo de actores externos en el desarrollo de esas estrategias y los resultados a nivel local y nacional. Este trabajo presenta una revisión del enfoque teórico sobre los movimientos sociales y los defensores de los derechos humanos. Además, la investigación exploró las tácticas utilizadas por MRVA para persuadir, socializar y presionar en campañas de violaciones de derechos humanos, de acuerdo con los marcos de Keck y Sikkink y la política contenciosa definida por Tilly y Tarrow. Para analizar las estrategias del movimiento, esta tesis utilizó datos del sitio web de MRVA y se basó en entrevistas con líderes del movimiento y actores externos que los han apoyado. Este análisis concluyó que aunque las estrategias sociales y ambientales desarrolladas por el movimiento no han logrado detener la construcción de la represa, estas acciones han resultado en el fortalecimiento de la lucha social y en el empoderamiento de las mujeres. Además, presionaron al gobierno para que estableciera medidas de protección colectiva para los defensores de derechos humanos en riesgo en todo el país. Asimismo, el acompañamiento de actores externos ayudó a desarrollar redes con otras organizaciones y aumentó la defensa internacional del movimiento.

The central system for generating genetic diversity and protecting the genomic integrity of replicating cells, from bacteria to humans, involves the homologous recombination (HR) machinery. It involves the process of exchange of molecules between DNA strands using the homology sequences. Because these machineries are highly efficient and precise it has become a useful analytical tool for the bacterial geneticists, thus, the engineering recombinant DNA molecules by homologous recombination, method called recombineering, is functional for sequence deletions, substitutions, or insertions. Under some conditions, the phage-mediated recombination system can be provided in E. coli by the ? phage Red enzymes, Red? and Red?. It involves a processive 5’ to 3’ exonuclease or a member of helicase family, namely Red?, which generates single stranded DNA (ssDNA) regions that are substrates for the single strand annealing protein (SSAP), i. e. Red?, which promotes joining of the DNA molecules by joining the recently replicated complementary sequences. The motivation of this study is to contribute to the understanding of the physical and functional coupling of the two enzymes Red? and Red?, as well as understanding the influence of including the DNA into the reaction, which acts as the substrate. Consequently, the experiments were designed and performed incorporating in vitro techniques not only for finding protein-protein interactions, such as co-immunoprecipitations and size exclusion chromatography, but also for analyzing the exonuclease activity of Red?. Also, the interaction of DNA with Red enzymes by means of the mobility shift assays was evaluated. In parallel, in vivo tests were made with the objective of defining the stoichiometry of the intracellular concentrations of both proteins during the co-expression in E. coli. In order to reveal more about the physical coupling of Red system’s components the preliminary data of a fluorescence correlation spectroscopy assay is described with the aim of determining whether the presence of Red? has an effect on Red?’s dwell-time on its substrate.