Significance of DNA base excision repair in the maintenance of mitochondrial function in Saccharomyces cerevisiae /

Mitochondria have an important role in cell metabolism, being the major site of ATP production via oxidative phosphorylation (OXPHOS). Accumulation of mtDNA mutations have been linked to the development of respiratory dysfunction, apoptosis, and aging. Base excision repair (BER) is the major and the only certain repair pathway existing in mitochondria that is in responsible for removing and repairing various base modifications as well as abasic sites (AP sites). In this research, Saccharomyces cerevisiae (S. cerevisiae) BER gene knockout strains, including 3 single DNA glycosylase gene knockout strains and Ap endonuclease (Apn 1 p) knockout strain were used to examine the importance of this DNA repair pathway to the maintenance of respiratory function. Here, I show that individual DNA glycosylases are nonessential in maintenance of normal function in yeast mitochondria, corroborating with previous research in mammalian experimental models. The yeast strain lacking Apn 1 p activity exhibits respiratory deficits, including inefficient and significantly low intracellular ATP level, which maybe due to partial uncoupling of OXPHOS. Growth of this yeast strain on respiratory medium is inhibited, but no evidence was found for increased ROS level in Apn 1 p mitochondria. This strain also shows an increased cell size, and this observation combined with an uncoupled OXPHOS may indicate a premature aging in the Apnlp knockout strain, but more evidence is needed to support this hypothesis. However, the BER is necessary for maintenance of mitochondrial function in respiring S.cerevisiae.

An exploratory study of nurses' perceptions of their action learning experience /

Each year, the College of Nurses of Ontario (CNO) requires all registered nurses and registered practical nurses in Ontario to complete a Reflective Practice learning activity. In doing so, nurses are expected to perform a self- assessment, identify a practice problem or issue, create and implement a personal learning plan, and evaluate the learning and outcomes accomplished. The process and components of CNO's Reflective Practice program are very similar to an Action Learning activity. The purpose of this qualitative research was to explore the perceptions of 1 1 nurses who completed at least 1 Action Learning activity. Data analysis of their comments provided insight into their perceptions of the Action Learning experience, perceptions of the negative and positive characteristics of various activities within the Action Learning process, and perceptions of barriers or challenges within this experience. The author concluded that participants perceived their Action Learning activities to be a positive experience because the process focused on practice problems and issues, enhanced thinking about practice problems, and achieved practice-relevant outcomes. However, the results indicated that self-directed learning and journal writing were difficult activities for some participants, and some experienced negative emotional responses during reflection. The research concluded that barriers to implementation of Action Learning include a lack of understanding of the process and a perceived lack of support from employers.