title: The effect of metal ions on the activity and thermostability of the extracellular proteinase from a thermophilic Bacillus, strain EA.1.

authors: Coolbear, Tim

subjects: enzyme

abstract: The proteinase from the extremely thermophilic Bacillus strain EA.1 exhibits maximum stability at a pH of approx. 6.5. In the presence of calcium ions the half-life at 95 degrees C of the enzyme at this pH was 17 min, and loss of activity followed first-order decay kinetics. The role of metal ions in the activity and stability of the enzyme was studied using the holoenzyme, the metal-depleted apoenzyme, and a zinc-enriched apoenzyme preparation. Zinc and calcium ions were the preferred bivalent cations for the active site and stabilization site(s) respectively. Stabilization by metal ions was not in itself a highly stringent process, but ions other than calcium which stabilized the enzyme generally had a concomitant inhibitory effect on activity. Inhibition and stabilization of the enzyme by cations were concentration-dependent effects and certain ions activated the apoenzyme but not the holoenzyme. Manganese(II) ions conferred some stability and also activated the enzyme, but in the latter case were not as effective as zinc ions. The results are discussed with reference to the ionic radii, co-ordination number and preferred ligand donors of the ions. Mercury(II) ions severely compromised enzyme activity and stability, and the effects of thiol-reactive agents suggest that thiol groups also have a role in enzyme integrity.

text: The effect of metal ions on the activity and thermostability of the extracellular proteinase from a thermophilic Bacillus, strain EA.1. The proteinase from the extremely thermophilic Bacillus strain EA.1 exhibits maximum stability at a pH of approx. 6.5. In the presence of calcium ions the half-life at 95 degrees C of the enzyme at this pH was 17 min, and loss of activity followed first-order decay kinetics. The role of metal ions in the activity and stability of the enzyme was studied using the holoenzyme, the metal-depleted apoenzyme, and a zinc-enriched apoenzyme preparation. Zinc and calcium ions were the preferred bivalent cations for the active site and stabilization site(s) respectively. Stabilization by metal ions was not in itself a highly stringent process, but ions other than calcium which stabilized the enzyme generally had a concomitant inhibitory effect on activity. Inhibition and stabilization of the enzyme by cations were concentration-dependent effects and certain ions activated the apoenzyme but not the holoenzyme. Manganese(II) ions conferred some stability and also activated the enzyme, but in the latter case were not as effective as zinc ions. The results are discussed with reference to the ionic radii, co-ordination number and preferred ligand donors of the ions. Mercury(II) ions severely compromised enzyme activity and stability, and the effects of thiol-reactive agents suggest that thiol groups also have a role in enzyme integrity.

year: 1992

title: Talking Ourselves: Stories of identities and linguistic possibilities of bilingual teachers working in English-medium early childhood services in the Auckland region

authors: Harvey, Nola Elizabeth

subjects: bilingual teachers

abstract: This thesis examines the ways in which five bilingual teachers use their two languages in English-medium early childhood services in the Auckland region. Questions regarding the possible mediation of bilingual identities for teachers and children created a further interrogation of teachers' 'lived experiences' of bilingual activity. The research, informed by critical multiculturalism, used a qualitative methodology and Narrative Inquiry that employed a spiral discourse or 'conversation' approach for data collection. The collaborative insights from participants and researcher became the foundation for further analysis. Findings revealed that bilingual teachers in the absence of government policy, worked powerfully to construct a critical bilingual praxis to counter deficit discourses of bilingualism in Aotearoa/New Zealand. Teachers' 'lived experiences' illustrated their deep knowledge of bilingualism and the use of two languages as critical linguistic and cultural resources for teaching and learning. As trusted agents for the educational and home language communities, 'doing self as bilingual teacher' worked cogeneratively to mediate bilingual identities for themselves and for children.

text: Talking Ourselves: Stories of identities and linguistic possibilities of bilingual teachers working in English-medium early childhood services in the Auckland region This thesis examines the ways in which five bilingual teachers use their two languages in English-medium early childhood services in the Auckland region. Questions regarding the possible mediation of bilingual identities for teachers and children created a further interrogation of teachers' 'lived experiences' of bilingual activity. The research, informed by critical multiculturalism, used a qualitative methodology and Narrative Inquiry that employed a spiral discourse or 'conversation' approach for data collection. The collaborative insights from participants and researcher became the foundation for further analysis. Findings revealed that bilingual teachers in the absence of government policy, worked powerfully to construct a critical bilingual praxis to counter deficit discourses of bilingualism in Aotearoa/New Zealand. Teachers' 'lived experiences' illustrated their deep knowledge of bilingualism and the use of two languages as critical linguistic and cultural resources for teaching and learning. As trusted agents for the educational and home language communities, 'doing self as bilingual teacher' worked cogeneratively to mediate bilingual identities for themselves and for children.

year: 2011

title: Hei oranga mo ngā wāhine hapū (o Hauraki) i roto i te whare ora

authors: Palmer, Stephanie

subjects: Psychological wellbeing

abstract: This thesis had four-main objectives. In the first instance, it aimed to improve understanding of psychosocial variables which may mediate the quality of Māori childbirth experience, namely: social support, coping strategies, cognitive appraisal, ethnic identity and psychological wellbeing. Secondly, it aimed to examine the relationship between these variables and the quality of childbirth experience. Thirdly, this thesis aimed to develop and pilot-test an instrument for the measurement of waiora among Māori. And fourthly, this thesis aimed to test whether waiora was a predictor of participants' childbirth experience. 
Thirty-one self-identified Māori women took part in the research. All participants gave birth at Thames Hospital in Hauraki during 1994. Attention is drawn to various ethical and methodological issues which have importance in the development of kaupapa Māori and Māori centred health research paradigms, such as, the role of koha, the validity of kanohi-ki-te-kanohi recruitment strategies and the need for collaborative decision-making processes. 
Prenatal waiora, ethnic identity, cognitive appraisal, coping strategies and social support predicted both quantitative and qualitative indicators of perinatal outcome. Obstetric technology was a very strong predictor of maternal postpartum perceptions and feelings of satisfaction or wellbeing. A preliminary model of the relationship between prenatal and perinatal predictors of Māori childbirth experience is presented. 
This research identifies the need to develop knowledge on psychosocial mediators of Māori childbirth experience. It is likely, however, that the quality of Māori childbirth experience will benefit from strategies which foster feelings of waiora and ethnic identity. The likelihood of a relationship between waiora and te ao Māori childbirth resources may hold particular interest for Māori. A range of strategies to improve the reliability and validity of Hōmai te Waiora ki Ahau as a tool for the measurement of waiora have been identified. As an outcome measure, this tool may have value in a range of contexts.

text: Hei oranga mo ngā wāhine hapū (o Hauraki) i roto i te whare ora This thesis had four-main objectives. In the first instance, it aimed to improve understanding of psychosocial variables which may mediate the quality of Māori childbirth experience, namely: social support, coping strategies, cognitive appraisal, ethnic identity and psychological wellbeing. Secondly, it aimed to examine the relationship between these variables and the quality of childbirth experience. Thirdly, this thesis aimed to develop and pilot-test an instrument for the measurement of waiora among Māori. And fourthly, this thesis aimed to test whether waiora was a predictor of participants' childbirth experience. 
Thirty-one self-identified Māori women took part in the research. All participants gave birth at Thames Hospital in Hauraki during 1994. Attention is drawn to various ethical and methodological issues which have importance in the development of kaupapa Māori and Māori centred health research paradigms, such as, the role of koha, the validity of kanohi-ki-te-kanohi recruitment strategies and the need for collaborative decision-making processes. 
Prenatal waiora, ethnic identity, cognitive appraisal, coping strategies and social support predicted both quantitative and qualitative indicators of perinatal outcome. Obstetric technology was a very strong predictor of maternal postpartum perceptions and feelings of satisfaction or wellbeing. A preliminary model of the relationship between prenatal and perinatal predictors of Māori childbirth experience is presented. 
This research identifies the need to develop knowledge on psychosocial mediators of Māori childbirth experience. It is likely, however, that the quality of Māori childbirth experience will benefit from strategies which foster feelings of waiora and ethnic identity. The likelihood of a relationship between waiora and te ao Māori childbirth resources may hold particular interest for Māori. A range of strategies to improve the reliability and validity of Hōmai te Waiora ki Ahau as a tool for the measurement of waiora have been identified. As an outcome measure, this tool may have value in a range of contexts.

year: 2002