title: The distribution and relative ecological roles of autotrophic and heterotrophic diazotrophs in the McMurdo Dry Valleys, Antarctica

authors: Coyne, Kathryn J.

subjects: Science & Technology

abstract: The McMurdo Dry Valleys (MDV) in Antarctica harbor a diverse assemblage of mat-forming diazotrophic cyanobacteria that play a key role in nitrogen cycling. Prior research showed that heterotrophic diazotrophs also make a substantial contribution to nitrogen fixation in MDV. The goals of this study were to survey autotrophic and heterotrophic diazotrophs across the MDV to investigate factors that regulate the distribution and relative ecological roles of each group. Results indicated that diazotrophs were present only in samples with mats, suggesting a metabolic coupling between autotrophic and heterotrophic diazotrophs. Analysis of 16S rRNA and nifH gene sequences also showed that diazotrophs were significantly correlated to the broader bacterial community, while co-occurrence network analysis revealed potential interspecific interactions. Consistent with previous studies, heterotrophic diazotrophs in MDV were diverse, but largely limited to lakes and their outlet streams, or other environments protected from desiccation. Despite the limited distribution, heterotrophic diazotrophs may make a substantial contribution to the nitrogen budget of MDV due to larger surface area and longer residence times of lakes. This work contributes to our understanding of key drivers of bacterial.

text: The distribution and relative ecological roles of autotrophic and heterotrophic diazotrophs in the McMurdo Dry Valleys, Antarctica The McMurdo Dry Valleys (MDV) in Antarctica harbor a diverse assemblage of mat-forming diazotrophic cyanobacteria that play a key role in nitrogen cycling. Prior research showed that heterotrophic diazotrophs also make a substantial contribution to nitrogen fixation in MDV. The goals of this study were to survey autotrophic and heterotrophic diazotrophs across the MDV to investigate factors that regulate the distribution and relative ecological roles of each group. Results indicated that diazotrophs were present only in samples with mats, suggesting a metabolic coupling between autotrophic and heterotrophic diazotrophs. Analysis of 16S rRNA and nifH gene sequences also showed that diazotrophs were significantly correlated to the broader bacterial community, while co-occurrence network analysis revealed potential interspecific interactions. Consistent with previous studies, heterotrophic diazotrophs in MDV were diverse, but largely limited to lakes and their outlet streams, or other environments protected from desiccation. Despite the limited distribution, heterotrophic diazotrophs may make a substantial contribution to the nitrogen budget of MDV due to larger surface area and longer residence times of lakes. This work contributes to our understanding of key drivers of bacterial.

year: 2020-03-01

title: Student and expert perceptions of the role of mathematics within physics

authors: Wilson, Marcus T.

subjects: physics

abstract: Students’ perceptions of the role of mathematics within physics were examined. I propose that the identification of physics as a science based ultimately on experiment is a threshold concept: transformation from a naïve view that physics is based upon mathematics to an expert view that physics is based on experiment is difficult for students. Seven students taking first-year university physics were interviewed in two focus groups; nine practising physicists from academia and industry (considered as experts) were interviewed as six individuals plus one focus group of three participants. Of particular interest was the ‘expert’ view emphasizing the conceptual nature of physics. This was a threshold in understanding that had not been crossed by students. Rather, students viewed mathematics and physics as being more strongly connected than did practising physicists; specifically that “maths explains physics”. Experts consider this view as holding back a student’s understanding of the subject and preventing them from becoming effective physicists. It is troublesome to students because they are less able to identify the relevant concepts before trying to tackle a problem with mathematics, making their approach less likely to be effective, however, both groups (physicists and students) identified physics as belonging to ‘the real world’ and that mathematics shows how physical entities can be combined or related, indicating student responses are not completely naïve. Opinions on how best to teach mathematical concepts in physics varied considerably across participants.

text: Student and expert perceptions of the role of mathematics within physics Students’ perceptions of the role of mathematics within physics were examined. I propose that the identification of physics as a science based ultimately on experiment is a threshold concept: transformation from a naïve view that physics is based upon mathematics to an expert view that physics is based on experiment is difficult for students. Seven students taking first-year university physics were interviewed in two focus groups; nine practising physicists from academia and industry (considered as experts) were interviewed as six individuals plus one focus group of three participants. Of particular interest was the ‘expert’ view emphasizing the conceptual nature of physics. This was a threshold in understanding that had not been crossed by students. Rather, students viewed mathematics and physics as being more strongly connected than did practising physicists; specifically that “maths explains physics”. Experts consider this view as holding back a student’s understanding of the subject and preventing them from becoming effective physicists. It is troublesome to students because they are less able to identify the relevant concepts before trying to tackle a problem with mathematics, making their approach less likely to be effective, however, both groups (physicists and students) identified physics as belonging to ‘the real world’ and that mathematics shows how physical entities can be combined or related, indicating student responses are not completely naïve. Opinions on how best to teach mathematical concepts in physics varied considerably across participants.

year: 2014

title: A Mana Wahine inquiry into indigenous governance

authors: Toi, Sharon Marjorie

subjects: Mana Wahine

abstract: This thesis investigates the question “How can indigenous women reinvigorate their role in tribal governance structures when many such structures continue to reinforce gendered colonial constructs within which women are marginalised?”  It is noted that contemporary tribal governance structures are often considered a site within which indigenous peoples can express cultural identity, however, when indigenous women are clearly under-represented in positions of power within those structures, this thesis questions why this situation continues. 
First, the thesis seeks to address the broad historical context within which indigenous women were subjected to colonial constructs of legislation, paternalistic government policies and the mechanisms of a euro-western court system policy. It is against this backdrop that comparisons are drawn that take into account the historical relationships between Māori, First Nations, Aboriginal, and Native American women and their respective colonising governments which bear alarming similarities in terms of the subjugation of these populations of women through colonisation. The significance of this historical-comparative lens is to illustrate how the status of women became seriously eroded within indigenous societies from traditional through to modern times. Consequently, this thesis goes on to explore the contemporary socio-political status of indigenous women as a result of their colonised history. 
From this broad historical context, the thesis narrows its view to examine commonalities and differences in relation to Māori and Native American women's experiences of tribal governance as tribal leaders and women of cultural significance and influence. The thesis changes tack to reflect the specific research intent of my Fulbright scholar experience to the University of Arizona, Tucson Arizona. Narrowing the focus of the research allowed me to analyse in more detail, beneficial comparisons of what was working for women tribal leaders under the auspices of the largely successful Native Nations Institute, Indigenous Governance Programme, in comparison to Māori women in tribal governance in Aotearoa, New Zealand. Importantly, this research synergises indigenous women’s shared knowledge in the reinvigoration of traditional tribal governance structures. The objective being to establish a body of knowledge that gives strength to a collective indigenous women's experience of governance from which normative propositions of indigenous governance based on western concepts can be examined, challenged and potentially transformed.  
It is noted that indigenous women have been included as essential decision-makers and leaders in traditional tribal governance systems; however, contemporary indigenous governance models do little to reflect this. The impact is that for indigenous women, tribal institutions and structures can themselves embed and reflect western colonial and patriarchal ideologies. Through our colonial experiences, indigenous peoples have inherited an oppressive gender legacy entrenched in policy and legislation that is socially constructed and instructed. To survive, indigenous women have to engage, challenge, resist and mitigate gendered spaces. This research highlights the extent to which indigenous women’s ways of leading or governing continue to be circumscribed in the on-going process of colonisation. Colonialism was a gendered process, and consequently, this thesis draws upon indigenous Feminist, Kaupapa Maori and Mana Wahine (Māori women’s) theoretical frameworks to analyse the complex ways that intersecting discourses of colonialism, race, gender and power continue to marginalise indigenous women within tribal governance. Indigenous Feminist theory also provides a framework for contextualising how First Nations, Aboriginal and Native American/American Indian women speak to these issues.  Importantly, how indigenous women are engaging in decolonising methodologies that impact the colonised practices, ways and attitudes they have or are currently experiencing in tribal governance, are also revealed.
Lastly, this thesis contributes to legal scholarship by contextualising the specific challenges of tribal governance for indigenous women. It addresses this by situating women’s experiences and ways of ‘being and doing’ within the micro tribal governance context while taking account of the macro realities of tribal governance politically, socially and more importantly, culturally.

text: A Mana Wahine inquiry into indigenous governance This thesis investigates the question “How can indigenous women reinvigorate their role in tribal governance structures when many such structures continue to reinforce gendered colonial constructs within which women are marginalised?”  It is noted that contemporary tribal governance structures are often considered a site within which indigenous peoples can express cultural identity, however, when indigenous women are clearly under-represented in positions of power within those structures, this thesis questions why this situation continues. 
First, the thesis seeks to address the broad historical context within which indigenous women were subjected to colonial constructs of legislation, paternalistic government policies and the mechanisms of a euro-western court system policy. It is against this backdrop that comparisons are drawn that take into account the historical relationships between Māori, First Nations, Aboriginal, and Native American women and their respective colonising governments which bear alarming similarities in terms of the subjugation of these populations of women through colonisation. The significance of this historical-comparative lens is to illustrate how the status of women became seriously eroded within indigenous societies from traditional through to modern times. Consequently, this thesis goes on to explore the contemporary socio-political status of indigenous women as a result of their colonised history. 
From this broad historical context, the thesis narrows its view to examine commonalities and differences in relation to Māori and Native American women's experiences of tribal governance as tribal leaders and women of cultural significance and influence. The thesis changes tack to reflect the specific research intent of my Fulbright scholar experience to the University of Arizona, Tucson Arizona. Narrowing the focus of the research allowed me to analyse in more detail, beneficial comparisons of what was working for women tribal leaders under the auspices of the largely successful Native Nations Institute, Indigenous Governance Programme, in comparison to Māori women in tribal governance in Aotearoa, New Zealand. Importantly, this research synergises indigenous women’s shared knowledge in the reinvigoration of traditional tribal governance structures. The objective being to establish a body of knowledge that gives strength to a collective indigenous women's experience of governance from which normative propositions of indigenous governance based on western concepts can be examined, challenged and potentially transformed.  
It is noted that indigenous women have been included as essential decision-makers and leaders in traditional tribal governance systems; however, contemporary indigenous governance models do little to reflect this. The impact is that for indigenous women, tribal institutions and structures can themselves embed and reflect western colonial and patriarchal ideologies. Through our colonial experiences, indigenous peoples have inherited an oppressive gender legacy entrenched in policy and legislation that is socially constructed and instructed. To survive, indigenous women have to engage, challenge, resist and mitigate gendered spaces. This research highlights the extent to which indigenous women’s ways of leading or governing continue to be circumscribed in the on-going process of colonisation. Colonialism was a gendered process, and consequently, this thesis draws upon indigenous Feminist, Kaupapa Maori and Mana Wahine (Māori women’s) theoretical frameworks to analyse the complex ways that intersecting discourses of colonialism, race, gender and power continue to marginalise indigenous women within tribal governance. Indigenous Feminist theory also provides a framework for contextualising how First Nations, Aboriginal and Native American/American Indian women speak to these issues.  Importantly, how indigenous women are engaging in decolonising methodologies that impact the colonised practices, ways and attitudes they have or are currently experiencing in tribal governance, are also revealed.
Lastly, this thesis contributes to legal scholarship by contextualising the specific challenges of tribal governance for indigenous women. It addresses this by situating women’s experiences and ways of ‘being and doing’ within the micro tribal governance context while taking account of the macro realities of tribal governance politically, socially and more importantly, culturally.

year: 2019