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- Title
- “This story was inside me this whole time, just waiting” : Coming to Blackgirl storying
- Creator
- Johnson, Lauren Elizabeth Reine
- Date
- 2021
- Collection
- Electronic Theses & Dissertations
- Description
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This dissertation project explores the various ways Blackgirls (Hill, 2016) from across a New Orleans came together in a collective space to engage in discussions of Blackgirlhood, wherein they shared and developed insights into their individual and collective understandings of self and community. Collective members’ multimodal storying, discussions, and reflections, are centered in this dissertation in response to an urgent need for more expansive presentations of Blackgirls. Informed by...
Show moreThis dissertation project explores the various ways Blackgirls (Hill, 2016) from across a New Orleans came together in a collective space to engage in discussions of Blackgirlhood, wherein they shared and developed insights into their individual and collective understandings of self and community. Collective members’ multimodal storying, discussions, and reflections, are centered in this dissertation in response to an urgent need for more expansive presentations of Blackgirls. Informed by theories, methodologies, and pedagogies, including: Black feminisms and Black Girlhood Studies (e.g., Collins, 2000; Dillard, 2016; Hill, 2016; hooks, 1996; Owens et al., 2017), Indigenous storywork (Archibald, 2008), sociocultural perspectives of literacies (e.g., Street, 1984), and culturally responsive/sustaining humanizing pedagogies (e.g., Ladson-Billings, 1995; Paris & Alim, 2017; Paris & Winn, 2014), this study also builds with the works and examples as put forth by other Blackgirls and Black women, such as Toni Cade Bambara’s (1996) “The Education of a Storyteller” to inquire into how centering Blackgirls and their narratives may move us towards what I conceptualize as “Blackgirl storying,” a medium that we used to critically name and honor our lives and the plurality of Blackgirlhood.
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- Title
- “THE NAME ISN’T GOING TO CHANGE EVERYTHING, BUT IT’S GOING TO MAKE IT BETTER” : GENDER INCLUSION IN TRADITIONALLY SINGLE-GENDER CHORAL ENSEMBLES
- Creator
- McKiernan, Jessica
- Date
- 2021
- Collection
- Electronic Theses & Dissertations
- Description
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The purpose of this dissertation was to tell the stories of conductors leading traditionally single-gender choral ensembles and how they considered practices and discourses surrounding gender and gender inclusion in ensembles traditionally defined by gender exclusion. In line with narrative inquiry, the research puzzles explored (1) how conductors’ intra- and interpersonal experiences with gender influenced the ways they saw and experienced gender, and (a) how those experiences influenced...
Show moreThe purpose of this dissertation was to tell the stories of conductors leading traditionally single-gender choral ensembles and how they considered practices and discourses surrounding gender and gender inclusion in ensembles traditionally defined by gender exclusion. In line with narrative inquiry, the research puzzles explored (1) how conductors’ intra- and interpersonal experiences with gender influenced the ways they saw and experienced gender, and (a) how those experiences influenced their choral pedagogy; (2) the discourses surrounding gender in traditionally single-gender choral ensembles, (a) how those discourses were created, and (b) who created the discourses; (3) practices the conductors employed to create environments honoring and valuing a variety of gender identities; and (4) the areas in which the conductors felt they succeeded in creating or struggled to create environments honoring and valuing a variety of gender identities. The research design was emergent. Megan and Chris (pseudonyms)–two directors of women’s and men’s choirs, respectively, at public universities–and the singers of those ensembles co-constructed narratives surrounding gender inclusion in their choirs. Through a series of individual interviews and small-group and large-group discussions with the conductors and singers, five major themes emerged. First, both singers and conductors found the ensembles to be important spaces for meaning-making, and they problematized many of the values and challenges of choral ensembles defined by gender. Second, the conductors and singers addressed a number of stereotypes and assumptions related to women’s, treble, men’s, and tenor-bass ensembles and interrogated assumptions about gender, particularly as it related to trans and gender-expansive singers. Third, they addressed gender inclusion as it related to policies and practices such as uniforms, rehearsal language, and program logistics. Fourth, they stressed the importance of open communication between students and conductors, allowing for student agency and input, facilitating difficult conversations within choral ensembles, and centering the voices of trans and gender-expansive singers. Finally, allyship was a central theme to the project as singers and conductors reflected on privilege, inclusion and exclusion, and ensuring that allyship is actionable and not performative. At the end of the project, the women’s choir singers and the conductor chose to move away from a gendered choral model. The conductor of the men’s choir saw moving away from a gendered choral model as an essential part of creating a gender-inclusive ensemble, while the singers saw the benefits of the gendered choral model outweighing the drawbacks. Based on the themes, a number of implications, considerations, and recommendations emerged as it related to choral policies and practices. Conductors and singers can implement more inclusive policies as it relates to language, literature selection and discussion, uniforms, voice classification, external image of the ensemble, and choral program hierarchies. Regardless of ensemble classification, conductors and singers need to acknowledge and problematize the impact of gender in choral ensembles. Future research related to gender must prioritize an intersectional approach and center the voices of trans and gender-expansive individuals.
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- Title
- “THE CHINESE ARE COMING” : A HISTORY OF CHINESE MIGRANTS IN NIGERIA
- Creator
- Liu, Shaonan
- Date
- 2018
- Collection
- Electronic Theses & Dissertations
- Description
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My dissertation examines the historical and contemporary migration of Chinese people to Nigeria as well as their interaction with the Nigerian state, workers, and consumers in late colonial and post-independence Nigeria. Beginning in the 2000s, Chinese migrants, together with Chinese products, have indeed greatly influenced the economy of Africa, and particularly Nigeria; but the significant Chinese presence in Nigeria is not a particularly recent phenomenon. As early as the 1960s, an...
Show moreMy dissertation examines the historical and contemporary migration of Chinese people to Nigeria as well as their interaction with the Nigerian state, workers, and consumers in late colonial and post-independence Nigeria. Beginning in the 2000s, Chinese migrants, together with Chinese products, have indeed greatly influenced the economy of Africa, and particularly Nigeria; but the significant Chinese presence in Nigeria is not a particularly recent phenomenon. As early as the 1960s, an influential yet understudied group of Chinese migrants began to dominate key manufacturing industries in Nigeria, including textiles, footwear, and enamelware, controlling more than 50 percent of the Nigerian and even the West African market in these three product types. These early Chinese immigrants had a profound influence not only on the economy, but also on the daily lives of ordinary Nigerians. What factors have pulled and pushed Chinese migrants to Nigeria? How have early and recent waves of Chinese migration influenced the local economy and people’s daily lives? How have the meanings of Chinese products to different groups of Nigerians changed over time, and how have these groups made cultural as well as economic sense of these products? How have Chinese transnational networks of information, capital, and goods interacted with African networks, institutions, communities, and individuals?Combining archival records, oral history interviews, and participant observation, I will examine the long-term and recent influence of Chinese activities on Nigerian societies and economies. I argue that the Chinese presence in Nigeria was a historical and evolving concept that changed over time, varied with place, and differed by targeted groups. Hong Kong Chinese industrialists who built factories, employed Nigerian workers, and manufactured products locally in the 1960s had a different influence from the mainland Chinese traders who imported made-in-China products and undermined local manufacturing industries from the 1990s onward. Therefore, by focusing on Chinese migrants in Nigeria and placing them in a wider historical context of Nigerian industrialization from the era of decolonization to the present, my dissertation challenges the Eurocentric narrative of Chinese migrants’ role as laborers and reveals how different groups of Chinese migrants—entrepreneurs, traders, and workers—were shaped by, and in turn shaped, the history of both Nigeria and China. However, this transnational influence was not unidirectional. I also argue that it was the changing policy of Nigerian governments, the evolving preference of Nigerian consumers, and decisions of Nigerian traders that attracted both the early wave of Chinese industrialists and the later wave of Chinese traders and products to come. It was also the broader historical context of Nigeria— decolonization, industrialization, civil war, and economic crisis—that determined the destiny of Chinese migrants in the country.
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- Title
- “SAVE ETHNIC STUDIES, SAVE OUR STORIES” : A QUALITATIVE INVESTIGATION EXPLORING ETHNIC STUDIES' GENEALOGIES, POLICIES, AND INDIANA TEACHERS' EXPERIENCES
- Creator
- Patrón-Vargas, Jasmin
- Date
- 2022
- Collection
- Electronic Theses & Dissertations
- Description
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Since 2010, more than a dozen states have introduced legislation supporting K-12 ethnic studies. This three-article dissertation considers the historical and contemporary development of ethnic studies programs. Drawing on decolonial thought and policy enactment theory, I investigate (1) the origins of Chicano studies programs, a subdiscipline of ethnic studies; (2) the mission and goals of contemporary K-12 ethnic studies; and (3) the perspectives of ethnic studies teachers in Indiana. Data...
Show moreSince 2010, more than a dozen states have introduced legislation supporting K-12 ethnic studies. This three-article dissertation considers the historical and contemporary development of ethnic studies programs. Drawing on decolonial thought and policy enactment theory, I investigate (1) the origins of Chicano studies programs, a subdiscipline of ethnic studies; (2) the mission and goals of contemporary K-12 ethnic studies; and (3) the perspectives of ethnic studies teachers in Indiana. Data sources include primary and secondary documents, including program proposals, brochures, legislative documents, curriculum materials, and semi-structured interviews. Findings demonstrate that (1) ethnic studies programs from the 1960s were created to decenter Eurocentric models of learning; (2) despite valuable efforts to engage ethnic studies, current policy and curriculum materials contain serious shortcomings; and (3) ethnic studies teachers’ perceptions of the Indiana Ethnic Studies Standards are shaped by their level of experience, racial identity, local context and sociopolitical climate. Collectively, these papers offer new insights about the development and implementation of ethnic studies in K-12 school settings.
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- Title
- “NEED TO TALK” : A LATENT CLASS ANALYSIS OF SEXUAL VICTIMIZATION DISCLOSURE TO A NATIONAL SEXUAL ASSAULT ONLINE HOTLINE
- Creator
- Feeney, Hannah
- Date
- 2019
- Collection
- Electronic Theses & Dissertations
- Description
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Sexual violence is a pervasive social problem in the United States that affects has long-term negative health consequences for children, adolescents, and adults. While some survivors choose to disclose their victimization to informal or formal resources, others choose to access a third, less studied source of support: online sexual assault crisis lines. Anonymous online hotlines allow survivors a confidential space to disclose sexual victimization and may be particularly beneficial for those...
Show moreSexual violence is a pervasive social problem in the United States that affects has long-term negative health consequences for children, adolescents, and adults. While some survivors choose to disclose their victimization to informal or formal resources, others choose to access a third, less studied source of support: online sexual assault crisis lines. Anonymous online hotlines allow survivors a confidential space to disclose sexual victimization and may be particularly beneficial for those who have not previously disclosed or are facing barriers to accessing other services. The current study utilized data from a national anonymous online hotline to answer two main research questions, guided by Liang and colleagues (2005) Model of Helpseeking and Change. First, are there latent classes of hotline sessions that differ based on victim and assault characteristics, and second, do these latent classes account for variation in disclosure behaviors among victims. Results revealed a four-class solution and relationships between class membership and disclosure behavior were identified. Findings suggest that anonymous online sexual assault hotlines are an instrumental resource that can both address survivors’ immediate needs and build bridges to sustainable, long-term support networks. Implications for practice are discussed.
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- Title
- “AM I RACIST OR ARE MY ACTIONS RACIST?” : EXPERIENCES OF FOUR MUSIC EDUCATORS WHO LEARN ABOUT CRITICAL RACE THEORY
- Creator
- Lewis, Amy Belinda
- Date
- 2021
- Collection
- Electronic Theses & Dissertations
- Description
-
In this study, I critically examined the experiences of four music teachers who learned about critical race theory (CRT) in a professional learning community (PLC) in an effort to enhance teachers’ understandings of race and racism in music education. The participants engaged in readings, online reflections, discussions, and interactive lectures based on the five central CRT tenets: counternarratives, ordinariness, Whiteness as property, intersectionality, and interest convergence. The...
Show moreIn this study, I critically examined the experiences of four music teachers who learned about critical race theory (CRT) in a professional learning community (PLC) in an effort to enhance teachers’ understandings of race and racism in music education. The participants engaged in readings, online reflections, discussions, and interactive lectures based on the five central CRT tenets: counternarratives, ordinariness, Whiteness as property, intersectionality, and interest convergence. The following research questions guided the study:1. How do the music teachers’ perceptions of CRT evolve within the professional learning community experience? 2. How might an understanding of CRT influence music teachers’ practices/pedagogical choices? 3. How might participation in the PLC transform their approach toward race and racism? What, if any, transformations took place? These questions highlight teacher growth and reflection––a tool necessary for liberation (Lorde, 2007). Additionally, understanding race and racism in music education provides an opportunity to address racism through philosophical shifts and pedagogical changes. For this study, I employed an instrumental embedded case study (Yin, 2009) with multiple units of analysis in order to capture a deeper understanding of the participants’ experience. I used transformative learning theory (Mezirow, 1991) as an analytical lens to examine and explore if and/or how the participants experienced transformation throughout the PLC. I centered my analysis on the disorienting dilemmas (situations that challenge participants’ world views) the participants experienced during the PLC. The findings from this study suggest that learning about CRT in the context of a PLC can create an opportunity for participants to experience a foundational shift in understanding race and racism, both as music educators and in their individual lives. As participants expanded their understanding of racism, they critiqued common practices in music education such as the dominance of Western European classical music. Through deep, critical reflection, they questioned if they or their practices were racist. During this experience, the participants identified how their understanding of racism expanded in a way that recognizes racist structures in addition to individual racist acts. This expansion can shift perspectives and change actions inside the classroom to center and create music teaching practices that challenge structural racism.
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- Title
- Ý decay and isomeric studies of proton rich nuclei near the endpoint of the rp-process
- Creator
- Becerril Reyes, Ana Delia
- Date
- 2012
- Collection
- Electronic Theses & Dissertations
- Description
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Neutron-deficient nuclei in the vicinity of the N = Z = 50 doubly-magic shell closure were produced at the National Superconducting Cyclotron Laboratory to study their structure and their relevance in the astrophysical rp-process. The 100Sn nucleus is the heaviest particle-stable N = Z nucleus, and it is also thought to be doubly magic. Additionally, 100Sn and its closest neighbors lie in the path of rp-process, therefore, the production and study of the decay properties of these nuclei are...
Show moreNeutron-deficient nuclei in the vicinity of the N = Z = 50 doubly-magic shell closure were produced at the National Superconducting Cyclotron Laboratory to study their structure and their relevance in the astrophysical rp-process. The 100Sn nucleus is the heaviest particle-stable N = Z nucleus, and it is also thought to be doubly magic. Additionally, 100Sn and its closest neighbors lie in the path of rp-process, therefore, the production and study of the decay properties of these nuclei are of great interest for the experimental and theoretical nuclear physics and astrophysics community.Previous attempts to produce these nuclei were hampered by large amounts of contaminants produced with higher abundances than those of the nuclides of interst. The Radio Frequency Fragment Separator (RFFS) was designed and built at the NSCLin order to purify rare neutron-deficient secondary beams. The implementation of this device has made a number of beta-decay experiments feasible at the NSCL. The experiment described in this work (NSCL Experiment 07034) was the second one to utilize the RFFS to successfully determine beta-decay half-lives, beta-delay proton emission branching ratios and beta-delayed gamma spectroscopy.The nuclei of interest were produced at NSCL via fragmentation of a 112Sn primary beam accelerated to 120 MeV/nucleon, impinging on a 9Be target. The secondary beam was first selected by the A1900 Fragment Separator and purified further with the RFFS. The N = Z nuclei 100Sn, 98In and 96Cd were produced and their beta decaywas studied. The observed production cross sections of these nuclei are lower than predicted by factors of 10-30. Their beta-decay half-lives were found to be 0.55(+0.70 -0.31) s for 100Sn, 0.66(40)s for an isomeric state in 98In, and 47(13) ms for its ground state,and 1.03 (0.2)s for 96Cd. The experimental determination of the half-life of 96Cd was of special interest as it was the last rp-process waiting point to be measured. The effect of the half-life of 96Cd on the nuclear abundances produced by an rp-process and the origin of the light-p nucleus 96Ru were explored.Other exotic nuclei produced in Experiment 07034 include 101Sn, 100,99In, 98,97Cd, 96,95,94Ag, 94,93,92Pd, 92,91Rh and 90,91Ru. For the cases with sufficiently high statistics their beta-decay half-lives were determined and compared with previous measurements and theoretical predictions. Several isomeric states were found andtheir decay modes analysed. In particular, a new microsecond isomer decaying by a gamma cascade was observed in 96Ag for the first time and the level scheme of this nucleus is presented, together with the results of two shell-model calculations performed within the (p1/2g9/2) and (p3/2p1/2f5/2g9/2) model spaces, respectively. It was found that the shell model calculation with the larger model space reproduced level energies and isomeric decay half-lives reasonably well.
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- Title
- ¹⁴N(p, p') at 29.8, 36.6, and 40.0 MeV and the strength of the tensor force in nuclear reaction
- Creator
- Fox, Stanley Haim, 1942-
- Date
- 1972
- Collection
- Electronic Theses & Dissertations
- Title
- ¹³C nuclear magnetic resonance studies of 2-aryl-2-nonbornyl cations
- Creator
- Lam, Bing Lun
- Date
- 1973
- Collection
- Electronic Theses & Dissertations
- Title
- ¹H NMR spectroscopic studies of dinuclear transition metal carboxylate adducts of DNA oligonucleotides
- Creator
- Carrasco, Elizabeth Ursula Lozada
- Date
- 1998
- Collection
- Electronic Theses & Dissertations
- Title
- ³¹P-NMR spectroscopy of phosphocreatine recovery transients in rat skeletal muscle
- Creator
- Paganini, Anthony Toby
- Date
- 1998
- Collection
- Electronic Theses & Dissertations
- Title
- ³H]serotonin binding to cell fractions and dissociated cells of blastula, gastrula, prism and pluteus sea urchin (Arbacia punctulata) embryos
- Creator
- Brown, Kenneth Michael
- Date
- 1982
- Collection
- Electronic Theses & Dissertations
- Title
- ³H-ouabain binding and sodium-pump activity measured in myocytes isolated from guinea-pig heart
- Creator
- Stemmer, Paul
- Date
- 1986
- Collection
- Electronic Theses & Dissertations
- Title
- ²⁰Mg beta decay and the ¹⁵O(alpha, gamma)¹⁹Ne(p, gamma)²⁰Na reaction sequence in Type I x-ray bursts
- Creator
- Glassman, Brent
- Date
- 2020
- Collection
- Electronic Theses & Dissertations
- Description
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Constraining the ¹⁵O(alpha, gamma)¹⁹Ne(p, gamma)²⁰Na reaction rate is critically important for accurately simulating x-ray burst light curves, our only x-ray burst observable from Earth. Both the ¹⁵O(alpha, gamma)¹⁹Ne(p, gamma) and )¹⁹Ne(p, gamma)²⁰Na reaction rates have been studied using a multitude of experimental techniques, yet only upper limits had been determined at the outset of the present work. The ¹⁵O(alpha, gamma)¹⁹Ne(p, gamma) reaction in particular has been singled out as the...
Show moreConstraining the ¹⁵O(alpha, gamma)¹⁹Ne(p, gamma)²⁰Na reaction rate is critically important for accurately simulating x-ray burst light curves, our only x-ray burst observable from Earth. Both the ¹⁵O(alpha, gamma)¹⁹Ne(p, gamma) and )¹⁹Ne(p, gamma)²⁰Na reaction rates have been studied using a multitude of experimental techniques, yet only upper limits had been determined at the outset of the present work. The ¹⁵O(alpha, gamma)¹⁹Ne(p, gamma) reaction in particular has been singled out as the most important reaction rate of all currently unknown rates to measure. Utilizing the beta decay of ²⁰Mg to populate ²⁰Na excited states, we further constrain the ¹⁹Ne(p,gamma)²⁰Na reaction rate by searching for gamma decays from the most important resonance at E_x=2647 keV. Additionally, by populating ²⁰Na excited states high above the proton threshold, we populate the most important ¹⁹Ne resonance for measuring the ¹⁵O(alpha, gamma)¹⁹Ne(p, gamma) reaction rate at E_x=4.03 MeV. Herein, the results of this study are reported including: The full ²⁰Mg beta-delayed gamma ray spectrum and decay scheme; the upper limit on the beta decay feeding of the ²⁰Na 2647 keV state; the Doppler broadening analysis of nine gamma ray peaks from six excited states in ¹⁹Ne; the intensity of ²⁰Mg(beta,p,gamma) to the 4.03 MeV state in ¹⁹Ne; the measurement of the ²⁰Na excitation energy at 7.44 {+0.25_{-0.22 MeV feeding the 4.03 MeV state in ¹⁹Ne; and the measurement of the center of mass proton energy for the feeding of the important 4.03 MeV state in ¹⁹Ne at 1.23 {+0.25_{-0.22 MeV.
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- Title
- ¡Palenque! : Cross Cultural Exchange among Indigenous and African Peoples in 17th Century Veracruz, Mexico
- Creator
- Ramirez, Christian Valentin
- Date
- 2021
- Collection
- Electronic Theses & Dissertations
- Description
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With the arrival of 16th century Spanish migrants to the Americas came new geopolitical identities, racial and cultural hierarchies, and the transformation of social relationships between and among Indigenous communities in Mesoamerica. The Spanish were accompanied by both free and enslaved Africans who transformed the social, cultural, and racial structures of what would later become New Spain. In the context of this historical reality, this dissertation will explore two Afro-Indigenous...
Show moreWith the arrival of 16th century Spanish migrants to the Americas came new geopolitical identities, racial and cultural hierarchies, and the transformation of social relationships between and among Indigenous communities in Mesoamerica. The Spanish were accompanied by both free and enslaved Africans who transformed the social, cultural, and racial structures of what would later become New Spain. In the context of this historical reality, this dissertation will explore two Afro-Indigenous palenques, or self-liberated settlements, by the names of San Lorenzo de los Negros (Yanga) and Nuestra Señora de Guadalupe de los Morenos de Amapa (Mandinga), using a case study approach that combines analysis of primary archival data and secondary literary sources. By exploring self-liberated communities, I will reconstruct a narrative about Afro-Indigenous alliances and their multiple forms of collective resistance against their colonial conditions. The goal is to historicize the African presence as they coalesced with the Indigenous world in New Spain. Additionally, my goal is to demonstrate how European modernity was a key operating ideology in the assignment of their racial/ethnic identities.This dissertation examines the following: 1) investigates and trace the historical processes that made colonial Veracruz a location of cross-cultural exchange; 2) to examines how two distinct colonized groups adapted themselves to their new social relations initiated by Spanish colonialism in order to form their respective palenques; 3) explore how the Spanish racialization project reorganized the racial/ethnic identities of its’ subjects for colonial stability. Overall, this dissertation addresses the literary gap in Sociology and Chicano/Latino Studies concerning the social processes that created the need for palenques during the colonial Mexican era.
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- Title
- ¡A MUCHO ORGULLO! SOY VOTANTE
- Date
- 1960/1989
- Collection
- Midwest Chicano Latino Activism Collection (MICHILAC)
- Description
-
Red background on upper half, and blue background on lower half with bold white lettering. LCAA in lower left corner.
- Title
- a synthetic medium for microbiological assay of riboflavin, pantothenic acid, biotin, nicotinic acid, pyridoxine and folic acid
- Creator
- Hyma, Andrew M.
- Date
- 1945
- Collection
- Electronic Theses & Dissertations
- Title
- [FeFe]-hydrogenase substrate transport mechanisms and investigation of algal hydrogen metabolism
- Creator
- Cornish, Adam
- Date
- 2012
- Collection
- Electronic Theses & Dissertations
- Description
-
The global population has recently exceeded 7 billion people and the demand for energy continues to expand as the number of industrialized countries grows. Currently, the energy economy is dominated by the utilization of polluting and non-renewable fossil fuels. Both the collection and use of petroleum-based fuels is destructive to the environment and is not sustainable over a long time-scale, which justifies the investigation into the development of renewable, alternative fuels. Of the...
Show moreThe global population has recently exceeded 7 billion people and the demand for energy continues to expand as the number of industrialized countries grows. Currently, the energy economy is dominated by the utilization of polluting and non-renewable fossil fuels. Both the collection and use of petroleum-based fuels is destructive to the environment and is not sustainable over a long time-scale, which justifies the investigation into the development of renewable, alternative fuels. Of the various fuels that have been proposed, molecular hydrogen (H2) in particular holds great promise as a clean-burning fuel capable of supplementing the current energy economy, especially as the combustion of H2 generates only water vapor as by-product. H2 can be generated via a number of chemical processes, but current H2 technologies either require fossil fuels as inputs or are energy-inefficient. The biological production of H2, however, has garnered a great deal of interest because microorganisms are able to drive H2 synthesis using energy derived from both light and dark fermentative metabolisms. This manner of production does not depend on mining non-renewable resources and microbes can be cultured at the industrial scale without competing with arable land needed for agriculture. H2 evolution in these microorganisms is dependent on nitrogenases and/or hydrogenases, enzymes which utilize unique metal centers for catalysis. Hydrogenases have been of particular interest for industrial-scale H2 production because these enzymes are found in a diverse array of organisms and require only protons and electrons as substrates. In particular, [FeFe]-hydrogenases have very high turnover numbers and catalysis can be coupled to photosynthesis. Unfortunately, these enzymes are inactivated by molecular oxygen (O2), and a number of studies have therefore attempted to engineer O2-tolerant hydrogenases. However, engineering enzymes to introduce optimal qualities has been impeded by an incomplete understanding of the overall reaction mechanism. Substrate (protons, electrons, and 2) transport is essential to hydrogenase activity, yet relatively little information is available regarding the intraprotein transport of substrate in [FeFe]-hydrogenase. I focused my investigation on identifying and testing pathways important for substrate transport between the enzyme surface and the active site in the Clostridium pasteurianum [FeFe]-hydrogenase. I have elucidated a key pathway for proton transport and confirmed that two iron-sulfur clusters are essential in an electron transfer relay, contributing to the overall characterization of [FeFe]-hydrogenase activity. Green algae utilize [FeFe]-hydrogenases to catalyze H2 production using reducing equivalents derived from photosynthesis and these enzymes are an integral component of anaerobic metabolism in these microalgae. I explored the H2 production capabilities of a multicellular green alga, Volvox carteri, and characterized two hydrogenases likely responsible for this activity. In addition, a unique hydrogenase gene cluster discovered within the Volvox carteri genome provided interesting hints into the origin of [FeFe]-hydrogenase in green algae.
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- Title
- [Delta]2079-tetrahydrocannabinol suppresses human monocyte activation and monocyte-mediated astrocyte inflammation : implications for HIV-associated neuroinflammation
- Creator
- Rizzo, Michael Denton
- Date
- 2019
- Collection
- Electronic Theses & Dissertations
- Description
-
A hallmark of human immunodeficiency virus (HIV) infection is chronic immune activation and is believed to be one of the major contributors to neuroinflammation and HIV-associated neurocognitive disorder (HAND). Circulating activated monocytes, including those that are CD16⁺, have been implicated in HIV-associated neuroinflammation. These activated monocytes become infected with HIV in the periphery, cross the blood-brain barrier (BBB) and release inflammatory factors, HIV virions and viral...
Show moreA hallmark of human immunodeficiency virus (HIV) infection is chronic immune activation and is believed to be one of the major contributors to neuroinflammation and HIV-associated neurocognitive disorder (HAND). Circulating activated monocytes, including those that are CD16⁺, have been implicated in HIV-associated neuroinflammation. These activated monocytes become infected with HIV in the periphery, cross the blood-brain barrier (BBB) and release inflammatory factors, HIV virions and viral proteins. These factors lead to HIV infection and activation of brain-resident cells, including microglia and astrocytes, driving a pro-inflammatory environment in the brain. Ultimately, these processes contribute to neuronal dysfunction and death, ultimately resulting in cognitive decline in up to 50% of the HIV-infected population. Cannabis is widely used by the HIV-infected population at an estimated prevalence of 23-56% in the United States. [Delta]2079-Tetrahydrocannabinol (THC) and cannabidiol (CBD), two major constituents of cannabis, are known to have immune suppressive and anti-inflammatory properties. The overall objective of this project was to determine whether the cannabinoids, THC and CBD, could suppress monocyte activation and monocyte-mediated astrocyte inflammation, which are key processes implicated in chronic neuroinflammation and HAND. Herein, it is shown that HIV-infected donors using cannabis displayed a lower level of circulating activated (CD16⁺) monocytes and plasma IP-10 compared to non-using HIV-infected donors. Furthermore, in vitro studies revealed that THC but not CBD suppressed monocyte expression of CD16 and secretion of IP-10, suggesting that THC is the major cannabinoid in cannabis promoting the anti-inflammatory effects. To determine whether activated monocytes could promote inflammatory functions of brain-resident glial cells, we developed a human co-culture system utilizing primary monocytes and cell-line/primary fetal astrocytes with viral-related stimulators (IFNa a0333nd a TLR7 agonist - R837). Monocytes, together with IFNa a0333nd/or R837, promoted astrocyte secretion of MCP-1, IL-6 and IP-10. Furthermore, monocyte-derived IL-1v0333 was critical for astrocyte secretion of pro-inflammatory factors, as neutralization of IL-1v0333 strongly hampered the astrocyte response, while direct addition of recombinant IL-1v0333 to astrocyte monocultures mimicked the actions of monocytes. In vitro THC treatment of the R837-stimulated co-culture resulted in decreased astrocyte production of MCP-1 and IL-6, while CBD increased IL-6 production and had no effect on MCP-1 production. With the use of separate monocyte and astrocyte monocultures, THC and CBD were shown to directly target both cell types. Interestingly, THC and CBD were both shown to decrease the percent of astrocytes producing IL-6 and MCP-1, which for THC, is concordant with the co-culture observation. However, the CBD-mediated decrease in IL-6 and MCP-1 production in the astrocyte monoculture differed from the observations in the CBD-treated co-culture. Our findings were explained when THC and CBD were shown to suppress and augment monocyte production of IL-1v0333, respectively. Furthermore, the CBD-mediated augmentation of monocyte-derived IL-1v0333 was able to override the direct CBD suppression on the astrocytes. Collectively, THC but not CBD, impairs monocyte activation and monocyte-driven astrocyte inflammatory responses. In the context of HAND, cannabis use, in particular THC, may decelerate monocyte processes that are implicated in neuroinflammation and cognitive dysfunction.
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- Title
- Zymogen granule membrane phosphorylation and glycoprotein topology in the exocrine pancreas
- Creator
- Lewis, Douglas S.
- Date
- 1977
- Collection
- Electronic Theses & Dissertations