title: Investigating Macromolecular Rate Theory

authors: Prentice, Erica J.

subjects: MMRT

abstract: Curvature with temperature is a defining characteristic of enzyme catalysed rates.  Historically, curvature has been described by Arrhenius behaviour up to a temperature optimum (Tₒₚₜ), while decreases in rates above Tₒₚₜ have been attributed to protein denaturation.  However, various evidence indicates that denaturation is insufficient to explain the decreases in rates above Tₒₚₜ.  Macromolecular rate theory (MMRT) has been proposed as a description of the temperature dependent curvature of enzyme rates based on the expansion of established thermodynamic principals.  MMRT postulates that it is the unusually large change in heat capacity associated with enzyme catalysis (ΔCǂₚ) that results in curvature of rates with temperature.  This description is commensurate with the classical description of enzyme catalysis which involves the tighter binding of the transition state (TS) to the enzyme.  
Here, the molecular origins of the ΔCǂₚ associated with catalysis are explored through crystallography and molecular dynamics simulations.  Methods are developed which calculate a ΔCǂₚ commensurate with experimental values from in silico data.  Simulations reveal that global rigidification is responsible for reduced heat capacity at the TS, although some protein regions contribute more significantly to differences at the TS.  Exploration of the relationship between enzyme mass and catalytic efficiency implicates the vibrational modes captured in dynamics simulations as a reservoir for energy, some of which is available to drive catalysis.  This provides a theoretical framework for the large size of enzymes and extraordinary rate enhancements enzyme catalysts achieve.      
Curvature with temperature is also a feature of organism growth rates and the fluxes through ecosystems.  Here, an experimental validation of the applicability of MMRT to these multi-enzyme systems is presented based on the characterisation of an enzymatic pathway.  The inherent temperature dependence of an enzyme pathway is found to be an average of the temperature dependence of the constituent enzymes.  This relationship shows the factors influencing the rates of enzymes are relevant at the organism level, providing an intrinsic temperature response upon which regulatory responses act.  This proof gives an experimental justification of the application of MMRT to organism and ecosystem temperature data.

text: Investigating Macromolecular Rate Theory Curvature with temperature is a defining characteristic of enzyme catalysed rates.  Historically, curvature has been described by Arrhenius behaviour up to a temperature optimum (Tₒₚₜ), while decreases in rates above Tₒₚₜ have been attributed to protein denaturation.  However, various evidence indicates that denaturation is insufficient to explain the decreases in rates above Tₒₚₜ.  Macromolecular rate theory (MMRT) has been proposed as a description of the temperature dependent curvature of enzyme rates based on the expansion of established thermodynamic principals.  MMRT postulates that it is the unusually large change in heat capacity associated with enzyme catalysis (ΔCǂₚ) that results in curvature of rates with temperature.  This description is commensurate with the classical description of enzyme catalysis which involves the tighter binding of the transition state (TS) to the enzyme.  
Here, the molecular origins of the ΔCǂₚ associated with catalysis are explored through crystallography and molecular dynamics simulations.  Methods are developed which calculate a ΔCǂₚ commensurate with experimental values from in silico data.  Simulations reveal that global rigidification is responsible for reduced heat capacity at the TS, although some protein regions contribute more significantly to differences at the TS.  Exploration of the relationship between enzyme mass and catalytic efficiency implicates the vibrational modes captured in dynamics simulations as a reservoir for energy, some of which is available to drive catalysis.  This provides a theoretical framework for the large size of enzymes and extraordinary rate enhancements enzyme catalysts achieve.      
Curvature with temperature is also a feature of organism growth rates and the fluxes through ecosystems.  Here, an experimental validation of the applicability of MMRT to these multi-enzyme systems is presented based on the characterisation of an enzymatic pathway.  The inherent temperature dependence of an enzyme pathway is found to be an average of the temperature dependence of the constituent enzymes.  This relationship shows the factors influencing the rates of enzymes are relevant at the organism level, providing an intrinsic temperature response upon which regulatory responses act.  This proof gives an experimental justification of the application of MMRT to organism and ecosystem temperature data.

year: 2017

title: A reduced magnetohydrodynamic model of coronal heating in open magnetic regions driven by reflected low-frequency waves

authors: Oughton, Sean

subjects: MHD

abstract: A reduced magnetohydrodynamic (RMHD) description is employed to examine a suggestion made by W. H. Matthaeus and colleagues in 1999 that coronal heating might be sustained by a cascade of low-frequency MHD turbulence. Here RMHD simulations show that the low-frequency cascade to high transverse wavenumbers can be driven by an externally maintained flux of low-frequency propagating Alfvén waves, in combination with reflection caused by an inhomogeneous background medium. The simulations show that the suggestions made previously on the basis of a phenomenology are indeed realizable. In addition, the effect is seen to sensitively depend on the presence of reflection, as the background turbulence level needed to maintain the cascade can be sustained only when reflection is imposed. The steady level of turbulence is insensitive to the initial seed turbulence level (provided it is nonzero). Consequences of this model for realistic models of coronal heating in open field-line regions are discussed.

text: A reduced magnetohydrodynamic model of coronal heating in open magnetic regions driven by reflected low-frequency waves A reduced magnetohydrodynamic (RMHD) description is employed to examine a suggestion made by W. H. Matthaeus and colleagues in 1999 that coronal heating might be sustained by a cascade of low-frequency MHD turbulence. Here RMHD simulations show that the low-frequency cascade to high transverse wavenumbers can be driven by an externally maintained flux of low-frequency propagating Alfvén waves, in combination with reflection caused by an inhomogeneous background medium. The simulations show that the suggestions made previously on the basis of a phenomenology are indeed realizable. In addition, the effect is seen to sensitively depend on the presence of reflection, as the background turbulence level needed to maintain the cascade can be sustained only when reflection is imposed. The steady level of turbulence is insensitive to the initial seed turbulence level (provided it is nonzero). Consequences of this model for realistic models of coronal heating in open field-line regions are discussed.

year: 2001

title: Mormonism and the white possessive: Moving critical indigenous studies theory into the religious realm

authors: Simon, Hemopereki

abstract: This essay responds to the pressing need to pursue topics related to Mormonism from a research perspective that is at once critical, culturally affirming, and grounded in Indigenous views. The goal here is to provide a theoretical framework for Critical Indigenous Studies perspectives to emerge in Mormon and Lamanite Studies. I therefore submit the following questions as a contribution to and critique of Lamanite Studies within the broader fields of Mormon, Cultural, and Religious Studies:
1. Which theoretical frame(s) from Critical Indigenous 
Studies is/are best suited to address Lamanite and Mormon issues? 
2. How might we reframe current Critical Indigenous 
Studies Theory to undertake research on Mormon and 
Western religious topics? 

To address these questions, the article first outlines its 
positionality as a basis for understanding Simon’s approach to the research. The bulk of the research here focuses on describing Lamanitism in terms of its relationship to racism and whiteness. The article therefore continues with a description of the figure of 
Hagoth in The Book of Mormon, with a particular emphasis on their relationship to Te Moana-Nui-ā-Kiwa. From there the article outlines Unger’s theorem of contextuality and considers how Lamanitism might be considered an “artificial context” from a Critical Indigenous Studies perspective. A discussion of the Doctrine of Discovery, Manifest Destiny, and Moana Jackson’s idea of the culture of colonization is followed by a description of the “Racial Contract” and its speculative extension to Indigenous adherents of the Mormon Church. The article then explicates important and interrelated tikanga values from Te Ao Māori such as tapu and mana. Lastly, the article identifies the “white possessive” as a key doctrine for Critical Indigenous Studies and undertakes a reworking of the doctrine for its application to the Mormon Church. More specifically, I transmute the notion “white patriarchal sovereignty” into “white patriarchal salvation” in order to tailor it to critical Indigenous discussions of the Church. 
In my conclusion I attempt to answer the question – What is to be done? I assert that the Church is in conflict with the cultural revival of Te Ao Māori and the idea of “original instructions.” The Church’s claim to salvific truth and thinking is contradicted by my very identity and culturally informed ontology. The ensuing discussion confirms that as a colonizing entity the Church operates parallel to the government as a co-invading force in Indigenous lands. The idea of a Lamanite people as Polynesians, which includes Māori is called into question. I provide a continuum model to explain Indigenous realities in relation to religiosity and decolonization and suggest some topics as case studies for further investigation. The true purpose of this article is to facilitate the integration of critical Indigenous with Mormon and/or Lamanite Studies to bring about much-needed dialogue, discussion, and debate on the place of indigeneity in The Church of Jesus Christ of Latter-Day Saints.

text: Mormonism and the white possessive: Moving critical indigenous studies theory into the religious realm This essay responds to the pressing need to pursue topics related to Mormonism from a research perspective that is at once critical, culturally affirming, and grounded in Indigenous views. The goal here is to provide a theoretical framework for Critical Indigenous Studies perspectives to emerge in Mormon and Lamanite Studies. I therefore submit the following questions as a contribution to and critique of Lamanite Studies within the broader fields of Mormon, Cultural, and Religious Studies:
1. Which theoretical frame(s) from Critical Indigenous 
Studies is/are best suited to address Lamanite and Mormon issues? 
2. How might we reframe current Critical Indigenous 
Studies Theory to undertake research on Mormon and 
Western religious topics? 

To address these questions, the article first outlines its 
positionality as a basis for understanding Simon’s approach to the research. The bulk of the research here focuses on describing Lamanitism in terms of its relationship to racism and whiteness. The article therefore continues with a description of the figure of 
Hagoth in The Book of Mormon, with a particular emphasis on their relationship to Te Moana-Nui-ā-Kiwa. From there the article outlines Unger’s theorem of contextuality and considers how Lamanitism might be considered an “artificial context” from a Critical Indigenous Studies perspective. A discussion of the Doctrine of Discovery, Manifest Destiny, and Moana Jackson’s idea of the culture of colonization is followed by a description of the “Racial Contract” and its speculative extension to Indigenous adherents of the Mormon Church. The article then explicates important and interrelated tikanga values from Te Ao Māori such as tapu and mana. Lastly, the article identifies the “white possessive” as a key doctrine for Critical Indigenous Studies and undertakes a reworking of the doctrine for its application to the Mormon Church. More specifically, I transmute the notion “white patriarchal sovereignty” into “white patriarchal salvation” in order to tailor it to critical Indigenous discussions of the Church. 
In my conclusion I attempt to answer the question – What is to be done? I assert that the Church is in conflict with the cultural revival of Te Ao Māori and the idea of “original instructions.” The Church’s claim to salvific truth and thinking is contradicted by my very identity and culturally informed ontology. The ensuing discussion confirms that as a colonizing entity the Church operates parallel to the government as a co-invading force in Indigenous lands. The idea of a Lamanite people as Polynesians, which includes Māori is called into question. I provide a continuum model to explain Indigenous realities in relation to religiosity and decolonization and suggest some topics as case studies for further investigation. The true purpose of this article is to facilitate the integration of critical Indigenous with Mormon and/or Lamanite Studies to bring about much-needed dialogue, discussion, and debate on the place of indigeneity in The Church of Jesus Christ of Latter-Day Saints.

year: 2022