title: Structure theory for second order 2D superintegrable systems with 1-parameter potentials

authors: Kalnins, Ernie G.

subjects: maths

abstract: The structure theory for the quadratic algebra generated by first and second order constants of the motion for 2D second order superintegrable systems with nondegenerate (3-parameter) and or 2-parameter potentials is well understood, but the results for the strictly 1-parameter case have been incomplete. Here we work out this structure theory and prove that the quadratic algebra generated by first and second order constants of the motion for systems with 4 second order constants of the motion must close at order three with the functional relationship between the 4 generators of order four. We also show that every 1-parameter superintegrable system is Stäckel equivalent to a system on a constant curvature space.

text: Structure theory for second order 2D superintegrable systems with 1-parameter potentials The structure theory for the quadratic algebra generated by first and second order constants of the motion for 2D second order superintegrable systems with nondegenerate (3-parameter) and or 2-parameter potentials is well understood, but the results for the strictly 1-parameter case have been incomplete. Here we work out this structure theory and prove that the quadratic algebra generated by first and second order constants of the motion for systems with 4 second order constants of the motion must close at order three with the functional relationship between the 4 generators of order four. We also show that every 1-parameter superintegrable system is Stäckel equivalent to a system on a constant curvature space.

year: 2009

title: Fungal biodiversity in extreme environments and wood degradation potential

authors: Jurgens, Joel Allan

subjects: fungi

abstract: This doctoral thesis reports results from a multidisciplinary investigation of fungi from extreme locations, focusing on one of the driest and thermally broad regions of the world, the Taklimakan Desert, with comparisons to polar region deserts. Additionally, the capability of select fungal isolates to decay lignocellulosic substrates and produce degradative related enzymes at various temperatures was demonstrated.  

The Taklimakan Desert is located in the western portion of the People's Republic of China, a region of extremes dominated by both limited precipitation, less than 25 mm of rain annually and tremendous temperature variation. The organisms that inhabit this region are required to function in conditions that preclude most forms of life. Fungi are particularly interesting organisms for consideration of life in extreme environments since they absorb nutrients from their surroundings with diffusion taking place through the cell wall and plasma membrane requiring free water.  The regions near the poles are another example of areas with extreme environmental conditions, with the north and south polar regions having similarities and differences to each other and to the Taklimakan Desert. All three regions experiences extreme cold but only the Taklimakan Desert has exceedingly warm temperatures. The Taklimakan Desert is diurnal and the polar regions have long periods of light and dark in summer and winter months, respectively. The annual precipitation in the specific polar sites is between 100-200 mm, 5-20 fold more than the Taklimakan Desert.

From soil, rock and wood collected in the Taklimakan Desert, 194 independent fungal isolates were generated and identified based on extracted DNA and analysis of the internal transcribed spacer (ITS) region of the rDNA. Dominant taxa were from closely related Thielavia, Embellisia and Alternaria genera. Total DNA extracted directly from environmental samples and subjected to molecular fingerprinting identified 51 consensus sequences almost entirely of taxa not represented by culturing, with the dominant taxa in the Penicillium and Colletotrichum genera.  
 
The sequence data from the Taklimakan Desert cultured fungi were phylogenetically investigated by means of neighbor-joining analysis and compared to fungal sequences derived from various substrates collected at sites in Antarctica and the Arctic with wood as the common substrate from which isolates were obtained among all three locations. Based on comparisons of consensus sequences to the polar fungi and fungal databases, 72 isolates appear to represent novel taxa that may be endemic to the Taklimakan Desert and warrant further investigation. 

Selected fungal isolates from the Taklimakan Desert, Arctic and Antarctic research were investigated to determine and compare their ability to degrade two types of lignocellulose substrates, Pinus resinosa and Populus tremuloides, the latter being a genera of tree identified in some locations of the Taklimakan Desert and the former as a model softwood example. Fungi from all regions were able to degrade these substrates to varying degrees though minimal weight loss was common. These isolates did not produce cellulase or lignin peroxidase concurrent to the temperatures prevalent in the regions from which they were collected, posing interesting possibilities for their wood degradation pathways.

text: Fungal biodiversity in extreme environments and wood degradation potential This doctoral thesis reports results from a multidisciplinary investigation of fungi from extreme locations, focusing on one of the driest and thermally broad regions of the world, the Taklimakan Desert, with comparisons to polar region deserts. Additionally, the capability of select fungal isolates to decay lignocellulosic substrates and produce degradative related enzymes at various temperatures was demonstrated.  

The Taklimakan Desert is located in the western portion of the People's Republic of China, a region of extremes dominated by both limited precipitation, less than 25 mm of rain annually and tremendous temperature variation. The organisms that inhabit this region are required to function in conditions that preclude most forms of life. Fungi are particularly interesting organisms for consideration of life in extreme environments since they absorb nutrients from their surroundings with diffusion taking place through the cell wall and plasma membrane requiring free water.  The regions near the poles are another example of areas with extreme environmental conditions, with the north and south polar regions having similarities and differences to each other and to the Taklimakan Desert. All three regions experiences extreme cold but only the Taklimakan Desert has exceedingly warm temperatures. The Taklimakan Desert is diurnal and the polar regions have long periods of light and dark in summer and winter months, respectively. The annual precipitation in the specific polar sites is between 100-200 mm, 5-20 fold more than the Taklimakan Desert.

From soil, rock and wood collected in the Taklimakan Desert, 194 independent fungal isolates were generated and identified based on extracted DNA and analysis of the internal transcribed spacer (ITS) region of the rDNA. Dominant taxa were from closely related Thielavia, Embellisia and Alternaria genera. Total DNA extracted directly from environmental samples and subjected to molecular fingerprinting identified 51 consensus sequences almost entirely of taxa not represented by culturing, with the dominant taxa in the Penicillium and Colletotrichum genera.  
 
The sequence data from the Taklimakan Desert cultured fungi were phylogenetically investigated by means of neighbor-joining analysis and compared to fungal sequences derived from various substrates collected at sites in Antarctica and the Arctic with wood as the common substrate from which isolates were obtained among all three locations. Based on comparisons of consensus sequences to the polar fungi and fungal databases, 72 isolates appear to represent novel taxa that may be endemic to the Taklimakan Desert and warrant further investigation. 

Selected fungal isolates from the Taklimakan Desert, Arctic and Antarctic research were investigated to determine and compare their ability to degrade two types of lignocellulose substrates, Pinus resinosa and Populus tremuloides, the latter being a genera of tree identified in some locations of the Taklimakan Desert and the former as a model softwood example. Fungi from all regions were able to degrade these substrates to varying degrees though minimal weight loss was common. These isolates did not produce cellulase or lignin peroxidase concurrent to the temperatures prevalent in the regions from which they were collected, posing interesting possibilities for their wood degradation pathways.

year: 2010

title: He moana pukepuke e ekengia e te waka: Navigating a changing climate: A waka voyaging perspective

authors: McDonald, Rangihurihia Ann

subjects: Pacific voyaging

abstract: Human-induced climate change is threatening the ocean, natural ecosystems, and the global human population. Some groups, including Māori in Aotearoa, and Indigenous communities globally, will be disproportionately affected by the negative consequences of climate change. The current national and international governmental climate change responses underrepresent Indigenous peoples, issues, and knowledge. This thesis aims to contribute to the body of literature that documents Māori understandings, perspectives, and worldviews in relation to climate change. This work was guided by two inter-related questions. Firstly, what are the impacts of climate change on waka voyaging? Secondly, how can we draw on mātauranga (Māori knowledge) to respond to human-induced climate change?

Specifically, the research addresses gaps in the scholarly literature that has yet to consider the unique contributions of waka voyaging practitioners to the climate change conversation. This work seeks to better understand the wide-ranging effects of human-induced climate change on Māori communities, knowledge, and culture, through an investigation of the impacts on waka voyaging. Furthermore, it considers how mātauranga whakatere waka (Māori understandings of Pacific voyaging knowledge) can contribute to climate change responses today and into the future. 

Guided by a Pūrākau and Kaupapa Māori research approach, I undertook a large-scale literature review and conducted seven in-depth semi-structured one-to-one interviews with Māori voyagers trained in traditional Pacific non-instrument ocean navigation. I analysed the data using a theoretical thematic analysis. 

Key findings suggest that waka voyaging is highly sensitive to changes in weather and climate.  Historical climatic and environmental change, as well as human-induced ecological change, have both promoted and discouraged Pacific voyaging in the past. In Aotearoa, the decline of voyaging after Polynesian settlement led to the dormancy of a significant body of ancestral knowledge, which Māori are continuing to recover. Key impacts of human-induced climate change include the exacerbation of adverse weather for voyaging, limiting the annual window of opportunity to voyage and spatial ranges of voyages. Another key impact is the decline of marine species used in non-instrument navigation due to a range of human activities, including human-induced climate change.  

Ultimately, this research finds that human-induced climate change was caused by a widespread human disconnection and subsequent domination of the environment. Research participants, Indigenous peoples, scholars, and civil society, advocate for a reconnection and global paradigm shift. Findings of this study indicate that mātauranga Māori provides a valuable framework for such a paradigm shift guided by the principles of whanaungatanga (connectedness, relationship, kinship) and kaitiakitanga (reciprocal acts of guardianship). 

Amidst rapid human-induced climate change, waka voyaging communities in Aotearoa and the Pacific are among the many Indigenous peoples globally, taking climate action, educating youth, raising awareness, advocating for ocean health, protecting natural environments, and maintaining traditional knowledge and practices on waka hourua (double-hulled voyaging canoes) which are themselves sustainable methods of ocean transportation.  

This thesis highlights the need for more research centring mātauranga Māori, recommends genuine partnerships between the government and Māori, and the resourcing of Māori communities themselves to be self-determining around climate change.

text: He moana pukepuke e ekengia e te waka: Navigating a changing climate: A waka voyaging perspective Human-induced climate change is threatening the ocean, natural ecosystems, and the global human population. Some groups, including Māori in Aotearoa, and Indigenous communities globally, will be disproportionately affected by the negative consequences of climate change. The current national and international governmental climate change responses underrepresent Indigenous peoples, issues, and knowledge. This thesis aims to contribute to the body of literature that documents Māori understandings, perspectives, and worldviews in relation to climate change. This work was guided by two inter-related questions. Firstly, what are the impacts of climate change on waka voyaging? Secondly, how can we draw on mātauranga (Māori knowledge) to respond to human-induced climate change?

Specifically, the research addresses gaps in the scholarly literature that has yet to consider the unique contributions of waka voyaging practitioners to the climate change conversation. This work seeks to better understand the wide-ranging effects of human-induced climate change on Māori communities, knowledge, and culture, through an investigation of the impacts on waka voyaging. Furthermore, it considers how mātauranga whakatere waka (Māori understandings of Pacific voyaging knowledge) can contribute to climate change responses today and into the future. 

Guided by a Pūrākau and Kaupapa Māori research approach, I undertook a large-scale literature review and conducted seven in-depth semi-structured one-to-one interviews with Māori voyagers trained in traditional Pacific non-instrument ocean navigation. I analysed the data using a theoretical thematic analysis. 

Key findings suggest that waka voyaging is highly sensitive to changes in weather and climate.  Historical climatic and environmental change, as well as human-induced ecological change, have both promoted and discouraged Pacific voyaging in the past. In Aotearoa, the decline of voyaging after Polynesian settlement led to the dormancy of a significant body of ancestral knowledge, which Māori are continuing to recover. Key impacts of human-induced climate change include the exacerbation of adverse weather for voyaging, limiting the annual window of opportunity to voyage and spatial ranges of voyages. Another key impact is the decline of marine species used in non-instrument navigation due to a range of human activities, including human-induced climate change.  

Ultimately, this research finds that human-induced climate change was caused by a widespread human disconnection and subsequent domination of the environment. Research participants, Indigenous peoples, scholars, and civil society, advocate for a reconnection and global paradigm shift. Findings of this study indicate that mātauranga Māori provides a valuable framework for such a paradigm shift guided by the principles of whanaungatanga (connectedness, relationship, kinship) and kaitiakitanga (reciprocal acts of guardianship). 

Amidst rapid human-induced climate change, waka voyaging communities in Aotearoa and the Pacific are among the many Indigenous peoples globally, taking climate action, educating youth, raising awareness, advocating for ocean health, protecting natural environments, and maintaining traditional knowledge and practices on waka hourua (double-hulled voyaging canoes) which are themselves sustainable methods of ocean transportation.  

This thesis highlights the need for more research centring mātauranga Māori, recommends genuine partnerships between the government and Māori, and the resourcing of Māori communities themselves to be self-determining around climate change.

year: 2022