title: Propagation and dissipation of Alfvén waves in stellar atmospheres permeated by isothermal winds

authors: Verdini, A.

subjects: magnetohydrodynamics

abstract: We investigate the nonlinear evolution of Alfvén waves in a radially stratified isothermal atmosphere with wind, from the atmospheric base out to the Alfvénic point. Nonlinear interactions, triggered by wave reflection due to the atmospheric gradients, are assumed to occur mainly in directions perpendicular to the mean radial magnetic field. The nonlinear coupling between waves propagating in opposite directions is modeled by a phenomenological term, containing an integral turbulent length scale, which acts as a dissipative coefficient for waves of a given frequency. Although the wind acceleration profile is not determined self-consistently one may estimate the dissipation rate inside the layer and follow the evolution of an initial frequency spectrum. Reflection of low frequency waves drives dissipation across the whole spectrum, and steeper gradients, i.e. lower coronal temperatures, enhance the dissipation rate. Moreover, when reasonable wave amplitudes are considered, waves of all frequencies damp at the same rate and the spectrum is not modified substantially during propagation. Therefore the sub-Alfvénic coronal layer acts differently when waves interact nonlinearly, no longer behaving as a frequency dependent filter once reflection-generated nonlinear interactions are included, at least within the classes of models discussed here.

text: Propagation and dissipation of Alfvén waves in stellar atmospheres permeated by isothermal winds We investigate the nonlinear evolution of Alfvén waves in a radially stratified isothermal atmosphere with wind, from the atmospheric base out to the Alfvénic point. Nonlinear interactions, triggered by wave reflection due to the atmospheric gradients, are assumed to occur mainly in directions perpendicular to the mean radial magnetic field. The nonlinear coupling between waves propagating in opposite directions is modeled by a phenomenological term, containing an integral turbulent length scale, which acts as a dissipative coefficient for waves of a given frequency. Although the wind acceleration profile is not determined self-consistently one may estimate the dissipation rate inside the layer and follow the evolution of an initial frequency spectrum. Reflection of low frequency waves drives dissipation across the whole spectrum, and steeper gradients, i.e. lower coronal temperatures, enhance the dissipation rate. Moreover, when reasonable wave amplitudes are considered, waves of all frequencies damp at the same rate and the spectrum is not modified substantially during propagation. Therefore the sub-Alfvénic coronal layer acts differently when waves interact nonlinearly, no longer behaving as a frequency dependent filter once reflection-generated nonlinear interactions are included, at least within the classes of models discussed here.

year: 2005

title: The Voices of First Nations and Métis Educators: nahtōhta (listen), kiskēyita (learn) and nistōhta (understand)

authors: Laliberte, Cornelia Dawn

subjects: First Nations

abstract: This thesis begins by considering some of the learning practices of First Nations people prior to colonization. It discusses the influences that the colonial education system has had on disproportionate numbers of First Nations and Métis students over time, both through policy and practices. It considers both their ongoing expectations of and resistance to a system that is perpetuating ongoing disadvantage. It proposes both an Indigenous lens and a critical lens through which to critique the historical discourses, policies and pedagogies that have continued to emerge.  
A collaborative story then exemplifies the experiences of two Métis and two First Nations educators in Saskatchewan as they move from their homes and families into formal education and then strive through the tertiary system to become teachers and school leaders themselves. As these educators position and reposition themselves within their own experiences in education, a more transformative path forward is revealed. Intertwined throughout is a critical story of the importance of social justice if we are to ensure that more Métis and First Nations children can achieve at school and take their rightful place as citizens of their own country and the wider world. Advice from the late Simon Kytwayhat, a respected Cree Elder, "nahtōhta (listen), kiskēyita (learn) and nistōhta (understand)” is a central learning for Indigenous people themselves and for non-Indigenous people.

text: The Voices of First Nations and Métis Educators: nahtōhta (listen), kiskēyita (learn) and nistōhta (understand) This thesis begins by considering some of the learning practices of First Nations people prior to colonization. It discusses the influences that the colonial education system has had on disproportionate numbers of First Nations and Métis students over time, both through policy and practices. It considers both their ongoing expectations of and resistance to a system that is perpetuating ongoing disadvantage. It proposes both an Indigenous lens and a critical lens through which to critique the historical discourses, policies and pedagogies that have continued to emerge.  
A collaborative story then exemplifies the experiences of two Métis and two First Nations educators in Saskatchewan as they move from their homes and families into formal education and then strive through the tertiary system to become teachers and school leaders themselves. As these educators position and reposition themselves within their own experiences in education, a more transformative path forward is revealed. Intertwined throughout is a critical story of the importance of social justice if we are to ensure that more Métis and First Nations children can achieve at school and take their rightful place as citizens of their own country and the wider world. Advice from the late Simon Kytwayhat, a respected Cree Elder, "nahtōhta (listen), kiskēyita (learn) and nistōhta (understand)” is a central learning for Indigenous people themselves and for non-Indigenous people.

year: 2016

title: Blue-lip'd cannibal ladies: The allure of the exotic in the illicit Resolution Journal of Gunner John Marra

authors: Ryan, Tom

subjects: John Marra

abstract: Discusses the history and content of the “Journal of the Resolution’s Voyage”, an unauthorized and illicitly published account of Cook’s second voyage of exploration in the Antipodes, by Gunner John Marra of the Resolution’s crew.

text: Blue-lip'd cannibal ladies: The allure of the exotic in the illicit Resolution Journal of Gunner John Marra Discusses the history and content of the “Journal of the Resolution’s Voyage”, an unauthorized and illicitly published account of Cook’s second voyage of exploration in the Antipodes, by Gunner John Marra of the Resolution’s crew.

year: 2001