An investigation of the functional role of GRAB in the context of Rab3, Rab8 and Rab11

Rab GTPases are the largest family of the Ras superfamily and are key regulators of membrane trafficking within the cell. There are over 60 members of the Rab family which localise to specific membrane compartments and interact with effector proteins to regulate membrane trafficking processes, such as vesicle formation, vesicle trafficking within the cell and fusion with an acceptor compartment. Multiple effector proteins have been identified for many Rabs, some of which can interact with more than one Rab to link their function at a specific membrane location or to link them together in a Rab activation cascade. Rabin8 is one such protein which is an effector for Rab11a and a Guanine nucleotide Exchange Factor (GEF) for Rab8a. Rabin8 participates in a conserved Rab activation cascade which is critical in the formation of primary cilia. Data presented in this thesis has shown that GRAB interacts with Rab3a, Rab8a, Rab11a and Rab11b in a nucleotide dependent manner. Furthermore, the minimal interacting regionbetween these proteins has been investigated. The functional outcome of GRAB knockdown has also been examined and data in this thesis highlights the phenotypic outcome.

The human impacts of flower farm development in the Ethiopian Rift Valley region

The flower industry has a reputation for heavy usage of toxic chemicals and polluting the environment, enormous consumption of water, and poor working condition and low wage level in various parts of the world. It is unfortunate that this industry is adamant to change and repeating the same mistakes in Ethiopia. Because of this, - there is a growing concern among the general public and the international community about sustainability of the Ethiopian flower industry. Consequently, working conditions in the flower industry, impacts of wage income on the livelihoods of employees, coping strategies of low wage flower farm workers, impacts of flower farms on the livelihoods of local people and environmental pollution and conflict, were analysed. Both qualitative and quantitative research methods were employed. Four quantitative data sets: labour practice, employees’ income and expenditure, displaced household, and flower grower views survey were collected between 2010 and 2012. Robust regression to identify the determinants of wage levels, and Multinomial logit to identify the determinants of coping strategies of flower farm workers and displaced households were employed. The findings show the working conditions in flower farms are characterized by low wages, job insecurity and frequent violation of employees’ rights, and poor safety measures. To ensure survival of their family, land dispossessed households adopt a wide range of strategies including reduction in food consumption, sharing oxen, renting land, share cropping, and shifting staple food crops. Most experienced scarcity of water resources, lack of grazing areas, death of herds and reduced numbers of livestock due to water source pollution. Despite the Ethiopian government investment in attracting and creating conducive environment for investors, not much was accomplished when it comes to enforcing labour laws and environmental policies. Flower farm expansion in Ethiopia, as it is now, can be viewed as part of the global land and water grab and is not all inclusive and sustainable. Several recommendations are made to improve working conditions, maximize the benefits of flower industry to the society, and to the country at large.