title: Eurythermalism of a deep-sea symbiosis system from an enzymological aspect

authors: Lee, Charles Kai-Wu

subjects: Equilibrium Model

abstract: The recently proposed and experimentally validated Equilibrium Model provides the most detailed description of temperature's effect on enzyme catalytic activity to date.  By introducing an equilibrium between Eact, the active form of enzyme, and Einact, a reversibly inactivated form of enzyme, the Equilibrium Model explains apparent enzyme activity loss at high temperatures that cannot be accounted for by irreversible thermal denaturation.  The Equilibrium Model describes enzyme behavior in the presence of substrates and under assay conditions; thus its associated parameters, deltaHeq and Teq, may have physiological significance.
The Equilibrium Model parameters have been determined for twenty-one enzymes of diverse origins.  The results demonstrated the wide applicability of the Equilibrium Model to enzymes of different types and temperature affinity.  The study has also established deltaHeq as the first quantitative measure of enzyme eurythermalism and demonstrated the relationship between Teq and optimal growth temperature of organisms.  The Equilibrium Model is therefore a useful tool for studying enzyme temperature adaptation and its role in adaptations to thermophily and eurythermalism.  Moreover, it potentially enables a description of the originating environment from the properties of the enzymes.
The Equilibrium Model has been employed to characterize enzymes isolated from bacterial episymbionts of Alvinella pompejana.  A. pompejana inhabits one of the most extreme environments known to science and has been proposed as an extremely eurythermal organism.  A metagenomic study of the A. pompejana episymbionts has unveiled new information related to the adaptive and metabolic properties of the bacterial consortium; the availability of metagenomic sequences has also enabled targeted retrieval and heterologous expression of A. pompejana episymbiont genes.  By inspecting enzymes derived from the unique episymbiotic microbial consortium intimately associated with A. pompejana, the study has shed light on temperature adaptations in this unique symbiotic relationship.  The findings suggested that eurythermal enzymes are one of the mechanisms used by the microbial consortium to achieve its adaptations.
By combining metagenomic and enzymological studies, the research described in this thesis has lead to insights on the eurythermalism of a complex microbial system from an enzymological aspect.  The findings have enhanced our knowledge on how life adapts to extreme environments, and the validation of the Equilibrium Model as a tool for studying enzyme temperature adaptation paves the way for future studies.

text: Eurythermalism of a deep-sea symbiosis system from an enzymological aspect The recently proposed and experimentally validated Equilibrium Model provides the most detailed description of temperature's effect on enzyme catalytic activity to date.  By introducing an equilibrium between Eact, the active form of enzyme, and Einact, a reversibly inactivated form of enzyme, the Equilibrium Model explains apparent enzyme activity loss at high temperatures that cannot be accounted for by irreversible thermal denaturation.  The Equilibrium Model describes enzyme behavior in the presence of substrates and under assay conditions; thus its associated parameters, deltaHeq and Teq, may have physiological significance.
The Equilibrium Model parameters have been determined for twenty-one enzymes of diverse origins.  The results demonstrated the wide applicability of the Equilibrium Model to enzymes of different types and temperature affinity.  The study has also established deltaHeq as the first quantitative measure of enzyme eurythermalism and demonstrated the relationship between Teq and optimal growth temperature of organisms.  The Equilibrium Model is therefore a useful tool for studying enzyme temperature adaptation and its role in adaptations to thermophily and eurythermalism.  Moreover, it potentially enables a description of the originating environment from the properties of the enzymes.
The Equilibrium Model has been employed to characterize enzymes isolated from bacterial episymbionts of Alvinella pompejana.  A. pompejana inhabits one of the most extreme environments known to science and has been proposed as an extremely eurythermal organism.  A metagenomic study of the A. pompejana episymbionts has unveiled new information related to the adaptive and metabolic properties of the bacterial consortium; the availability of metagenomic sequences has also enabled targeted retrieval and heterologous expression of A. pompejana episymbiont genes.  By inspecting enzymes derived from the unique episymbiotic microbial consortium intimately associated with A. pompejana, the study has shed light on temperature adaptations in this unique symbiotic relationship.  The findings suggested that eurythermal enzymes are one of the mechanisms used by the microbial consortium to achieve its adaptations.
By combining metagenomic and enzymological studies, the research described in this thesis has lead to insights on the eurythermalism of a complex microbial system from an enzymological aspect.  The findings have enhanced our knowledge on how life adapts to extreme environments, and the validation of the Equilibrium Model as a tool for studying enzyme temperature adaptation paves the way for future studies.

year: 2007

title: Farming, droughts and Covid-19: The creation and maintenance of community in a time of hardship and forced social restrictions

authors: Cheetham, Erin Mae

subjects: Farming

abstract: In the summer of 2019-2020 the Hawkes Bay farming community of RD9 was faced with extreme drought conditions. To further compound the droughts effects on the RD9 community, they were also made to abide by the strict social restrictions required to limit the transmission of Covid-19 throughout the community from March to May of 2020. As farmers are already required to live in physical isolation due to their profession, the Covid-19 isolation period compounded the pre-existing tensions between the farmers of RD9 and the wider New Zealand community and New Zealand government. In this thesis I argue that more needs to be done in order to help New Zealand farmers with the environmental, social and economic issues that farmers face at an increasing level. From the increasing frequency of droughts, the constant government restructures impacting on the agricultural sector at both at the ground level and industrial level, and consistent and persistent social and physical isolation experienced in rural living, New Zealand farmers are having to deal with many events that are out of their control. As such, I argue that it is crucial to consider how to help farmers maintain a sense of wellbeing, connection and belonging during a period of hardship in periods of hardships such as the situations that unfolded in 2020.

text: Farming, droughts and Covid-19: The creation and maintenance of community in a time of hardship and forced social restrictions In the summer of 2019-2020 the Hawkes Bay farming community of RD9 was faced with extreme drought conditions. To further compound the droughts effects on the RD9 community, they were also made to abide by the strict social restrictions required to limit the transmission of Covid-19 throughout the community from March to May of 2020. As farmers are already required to live in physical isolation due to their profession, the Covid-19 isolation period compounded the pre-existing tensions between the farmers of RD9 and the wider New Zealand community and New Zealand government. In this thesis I argue that more needs to be done in order to help New Zealand farmers with the environmental, social and economic issues that farmers face at an increasing level. From the increasing frequency of droughts, the constant government restructures impacting on the agricultural sector at both at the ground level and industrial level, and consistent and persistent social and physical isolation experienced in rural living, New Zealand farmers are having to deal with many events that are out of their control. As such, I argue that it is crucial to consider how to help farmers maintain a sense of wellbeing, connection and belonging during a period of hardship in periods of hardships such as the situations that unfolded in 2020.

year: 2021

title: Ngā whakaaro o ngā ākonga: perspectives and experiences of Māori students in outdoor education in Aotearoa New Zealand

authors: Washbourn, Phil

subjects: Outdoor education

abstract: This study aims to develop an understanding of the perspectives and experiences of Māori students in a secondary school outdoor education programme in Aotearoa New Zealand. Lynch (2012) indicated that “there is a clear need, and wide scope, for research into: cultural elements of outdoor education programmes; cultural effects on participants; culturally appropriate research approaches and programme effects on, and experiences of, people who identify as Māori” (p.49). Outdoor education in Aotearoa New Zealand has been heavily influenced by ‘Eurocentric’ values and practices that contrast with those of Te Ao Māori. In line with a number of calls to re-envision the field, the perspectives and experiences of Māori and the incorporation of Te Ao Māori pedagogies are vital to the reconstruction of an integrated and inclusive Aotearoa New Zealand expression of Outdoor Education for the 21st century.
This study, guided by culturally responsive research methodology, used focus groups to investigate the opinions, thoughts and expectations of Māori students of outdoor education. Thematic analysis was used to analyse the focus group data, and four major themes were identified: the importance of shared experience and relationships to positive experiences of outdoor education; the distinctive practices of outdoor education make learning enjoyable and engaging; the importance to students of making connections with Te Ao Māori through experience, stories of places and history; and the complexity of engaging Māori in participation in outdoor education, including factors such as affordability, the influence of friends and whānau and prioritising educational pathways. A range of practices and approaches from Te Ao Māori are considered and presented, based on the contribution of the student participants, including pedagogical principles from Te Ao Māori such as wānanga, whanaungatanga and tauira. Suggestions for practice include developing connections within the community and experiencing Te Ao Māori learning contexts such as waka ama, noho marae and mahinga kai.

text: Ngā whakaaro o ngā ākonga: perspectives and experiences of Māori students in outdoor education in Aotearoa New Zealand This study aims to develop an understanding of the perspectives and experiences of Māori students in a secondary school outdoor education programme in Aotearoa New Zealand. Lynch (2012) indicated that “there is a clear need, and wide scope, for research into: cultural elements of outdoor education programmes; cultural effects on participants; culturally appropriate research approaches and programme effects on, and experiences of, people who identify as Māori” (p.49). Outdoor education in Aotearoa New Zealand has been heavily influenced by ‘Eurocentric’ values and practices that contrast with those of Te Ao Māori. In line with a number of calls to re-envision the field, the perspectives and experiences of Māori and the incorporation of Te Ao Māori pedagogies are vital to the reconstruction of an integrated and inclusive Aotearoa New Zealand expression of Outdoor Education for the 21st century.
This study, guided by culturally responsive research methodology, used focus groups to investigate the opinions, thoughts and expectations of Māori students of outdoor education. Thematic analysis was used to analyse the focus group data, and four major themes were identified: the importance of shared experience and relationships to positive experiences of outdoor education; the distinctive practices of outdoor education make learning enjoyable and engaging; the importance to students of making connections with Te Ao Māori through experience, stories of places and history; and the complexity of engaging Māori in participation in outdoor education, including factors such as affordability, the influence of friends and whānau and prioritising educational pathways. A range of practices and approaches from Te Ao Māori are considered and presented, based on the contribution of the student participants, including pedagogical principles from Te Ao Māori such as wānanga, whanaungatanga and tauira. Suggestions for practice include developing connections within the community and experiencing Te Ao Māori learning contexts such as waka ama, noho marae and mahinga kai.

year: 2018